Development and demonstration of flueric sounding rocket motor ignition
NASA Technical Reports Server (NTRS)
Marchese, V. P.
1974-01-01
An analytical and experimental program is described which established a flueric rocket motor ignition system concept incorporating a pneumatic match with a simple hand pump as the only energy source. An evaluation was made of this concept to determine the margins of the operating range and capabilities of every component of the system. This evaluation included a determination of power supply requirements, ignitor geometry and alinement, ignitor/propellant interfacing and materials and the effects of ambient temperatures and pressure. It was demonstrated that an operator using a simple hand pump for 30 seconds could ignite BKNO3 at a standoff distance of 100 m (330 ft) with the only connection to the ignitor being a piece of plastic pneumatic tubing.
Erlotinib-Conjugated Iron Oxide Nanoparticles as a Smart Cancer-Targeted Theranostic Probe for MRI.
Ali, Ahmed Atef Ahmed; Hsu, Fei-Ting; Hsieh, Chia-Ling; Shiau, Chia-Yang; Chiang, Chiao-Hsi; Wei, Zung-Hang; Chen, Cheng-Yu; Huang, Hsu-Shan
2016-11-11
We designed and synthesized novel theranostic nanoparticles that showed the considerable potential for clinical use in targeted therapy, and non-invasive real-time monitoring of tumors by MRI. Our nanoparticles were ultra-small with superparamagnetic iron oxide cores, conjugated to erlotinib (FeDC-E NPs). Such smart targeted nanoparticles have the preference to release the drug intracellularly rather than into the bloodstream, and specifically recognize and kill cancer cells that overexpress EGFR while being non-toxic to EGFR-negative cells. MRI, transmission electron microscopy and Prussian blue staining results indicated that cellular uptake and intracellular accumulation of FeDC-E NPs in the EGFR overexpressing cells was significantly higher than those of the non-erlotinib-conjugated nanoparticles. FeDC-E NPs inhibited the EGFR-ERK-NF-κB signaling pathways, and subsequently suppressed the migration and invasion capabilities of the highly invasive and migrative CL1-5-F4 cancer cells. In vivo tumor xenograft experiments using BALB/c nude mice showed that FeDC-E NPs could effectively inhibit the growth of tumors. T 2 -weighted MRI images of the mice showed significant decrease in the normalized signal within the tumor post-treatment with FeDC-E NPs compared to the non-targeted control iron oxide nanoparticles. This is the first study to use erlotinib as a small-molecule targeting agent for nanoparticles.
Erlotinib-Conjugated Iron Oxide Nanoparticles as a Smart Cancer-Targeted Theranostic Probe for MRI
NASA Astrophysics Data System (ADS)
Ali, Ahmed Atef Ahmed; Hsu, Fei-Ting; Hsieh, Chia-Ling; Shiau, Chia-Yang; Chiang, Chiao-Hsi; Wei, Zung-Hang; Chen, Cheng-Yu; Huang, Hsu-Shan
2016-11-01
We designed and synthesized novel theranostic nanoparticles that showed the considerable potential for clinical use in targeted therapy, and non-invasive real-time monitoring of tumors by MRI. Our nanoparticles were ultra-small with superparamagnetic iron oxide cores, conjugated to erlotinib (FeDC-E NPs). Such smart targeted nanoparticles have the preference to release the drug intracellularly rather than into the bloodstream, and specifically recognize and kill cancer cells that overexpress EGFR while being non-toxic to EGFR-negative cells. MRI, transmission electron microscopy and Prussian blue staining results indicated that cellular uptake and intracellular accumulation of FeDC-E NPs in the EGFR overexpressing cells was significantly higher than those of the non-erlotinib-conjugated nanoparticles. FeDC-E NPs inhibited the EGFR-ERK-NF-κB signaling pathways, and subsequently suppressed the migration and invasion capabilities of the highly invasive and migrative CL1-5-F4 cancer cells. In vivo tumor xenograft experiments using BALB/c nude mice showed that FeDC-E NPs could effectively inhibit the growth of tumors. T2-weighted MRI images of the mice showed significant decrease in the normalized signal within the tumor post-treatment with FeDC-E NPs compared to the non-targeted control iron oxide nanoparticles. This is the first study to use erlotinib as a small-molecule targeting agent for nanoparticles.
Ablation driven by hot electrons generated during the ignitor laser pulse in shock ignition
DOE Office of Scientific and Technical Information (OSTI.GOV)
Piriz, A. R.; Rodriguez Prieto, G.; Tahir, N. A.
2012-12-15
An analytical model for the ablation driven by hot electrons is presented. The hot electrons are assumed to be generated during the high intensity laser spike used to produce the ignitor shock wave in the shock ignition driven inertial fusion concept, and to carry on the absorbed laser energy in its totality. Efficient energy coupling requires to keep the critical surface sufficiently close to the ablation front and this goal can be achieved for high laser intensities provided that the laser wavelength is short enough. Scaling laws for the ablation pressure and the other relevant magnitudes of the ablation cloudmore » are found in terms of the laser and target parameters. The effect of the preformed plasma assembled by the compression pulse, previous to the ignitor, is also discussed. It is found that a minimum ratio between the compression and the ignitor pulses would be necessary for the adequate matching of the corresponding scale lengths.« less
Hydrogen disposal investigation for the Space Shuttle launch complex at Vandenberg Air Force Base
NASA Technical Reports Server (NTRS)
Breit, Terry J.; Elliott, George
1987-01-01
The concern of an overpressure condition on the aft end of the Space Shuttle caused by ignition of unburned hydrogen being trapped in the Space Shuttle Main Engine exhaust duct at the Vandenberg AFB launch complex has been investigated for fifteen months. Approximately twenty-five concepts have been reviewed, with four concepts being thoroughly investigated. The four concepts investigated were hydrogen burnoff ignitors (ignitors located throughout the exhaust duct to continuously ignite any unburned hydrogen), jet mixing (utilizing large volumes of high pressure air to ensure complete combustion of the hydrogen), steam inert (utilizing flashing hot water to inert the duct with steam) and open duct concept (design an open duct or above grade J-deflector to avoid trapping hydrogen gas). Extensive studies, analyses and testing were performed at six test sites with technical support from twenty-two major organizations. In December 1986, the Air Force selected the steam inert concept to be utilized at the Vandenberg launch complex and authorized the design effort.
The Interaction of Intense Laser Pulses with Preformed Plasmas for Fast Ignitor Studies
NASA Astrophysics Data System (ADS)
MacKinnon, A. J.
1998-11-01
The understanding of the interaction of intense picosecond laser pulses with preformed plasmas is essential for the fast ignitor concept. One of the major issues for this scheme concerns the propagation of ultra intense laser pulses through near critical density plasmas. Measurements of self-channelling of picosecond pulses due to relativistic and ponderomotive expulsion effects have recently been obtained in preformed plasmas at laser irradiances between 5-9x10^18 Wcm-2 footnote M. Borghesi et al, Phys. Rev Lett 78, 879 (1997).. The channel expansion after the laser pulse has been measured and an expansion velocity up to 1x10^9cms-1. was observed, implying ion energies around 1MeV. In addition, it was observed via Faraday rotation of an optical probe that the self focused channel is surrounded by a multi-megagauss magnetic field as predicted by 3D PIC simulations footnote A. Pukhov and J. Meyer-ter-Vehn, Phys. Rev Lett 76, 3975 (1996); M. Borghesi et al, Phys. Rev. Lett. 80, 5137 (1998).. The existence of this magnetic field is important for magnetic self-channelling of the relativistic electrons to high plasma densities. Good agreement was observed between the measurements and the 3D PIC simulations. The experimental results and PIC simulations will be presented and their relevance to the fast ignitor concept will be discussed.
Early, James W.; Lester, Charles S.
2004-01-13
Sequenced pulses of light from an excitation laser with at least two resonator cavities with separate output couplers are directed through a light modulator and a first polarzing analyzer. A portion of the light not rejected by the first polarizing analyzer is transported through a first optical fiber into a first ignitor laser rod in an ignitor laser. Another portion of the light is rejected by the first polarizing analyzer and directed through a halfwave plate into a second polarization analyzer. A first portion of the output of the second polarization analyzer passes through the second polarization analyzer to a second, oscillator, laser rod in the ignitor laser. A second portion of the output of the second polarization analyzer is redirected by the second polarization analyzer to a second optical fiber which delays the beam before the beam is combined with output of the first ignitor laser rod. Output of the second laser rod in the ignitor laser is directed into the first ignitor laser rod which was energized by light passing through the first polarizing analyzer. Combined output of the first ignitor laser rod and output of the second optical fiber is focused into a combustible fuel where the first short duration, high peak power pulse from the ignitor laser ignites the fuel and the second long duration, low peak power pulse directly from the excitation laser sustains the combustion.
Catalytic ignitor for regenerative propellant gun
NASA Technical Reports Server (NTRS)
Voecks, Gerald E. (Inventor); Ferraro, Ned W. (Inventor)
1994-01-01
An ignitor initiates combustion of liquid propellant in a gun by utilizing a heated catalyst onto which the liquid propellant is sprayed in a manner which mitigates the occurrence of undesirable combustion chamber oscillations. The heater heats the catalyst sufficiently to provide the activation necessary to initiate combustion of the liquid propellant sprayed thereonto. Two embodiments of the ignitor and three alternative mountings thereof within the combustion chamber are disclosed. The ignitor may also be utilized to dispose of contaminated, excess, or waste liquid propellant in a safe, controlled, simple, and reliable manner.
NASA Technical Reports Server (NTRS)
Taylor, Eric S. (Inventor); Myers, W. Neill (Inventor); Martin, Michael A. (Inventor)
2005-01-01
An ignitor for use with the MC-1 rocket engine has a cartridge bounded by two end caps with rupture disc assemblies connected thereto. A piston assembly within the cartridge moves from one end of the cartridge during the ignition process. The inlet of the ignitor communicates with a supply taken from the discharge of the fuel pump. When the pump is initially started, the pressure differential bursts the first rupture disc to begin the movement of the piston assembly toward the discharge end. The pressurization of the cartridge causes the second rupture disc to rupture and hypergolic fluid contained within the cartridge is discharged out the ignitor outlet.
Ignition improvement by injector arrangement in a multi-fuel combustor for micro gas turbine
NASA Astrophysics Data System (ADS)
Antoshkiv, O.; Poojitganont, T.; Jeansirisomboon, S.; Berg, H. P.
2018-01-01
The novel combustor design also has an impact on the ignitor arrangement. The conventional ignitor system cannot guarantee optimal ignition performance in the usual radial position. The difficult ignitability of gaseous fuels was the main challenge for the ignitor system improvement. One way to improve the ignition performance significantly is a torch ignitor system in which the gaseous fuel is directly mixed with a large amount of the combustor air. To reach this goal, the ignition process was investigated in detail. The micro gas turbine (MGT) ignition was optimised considering three main procedures: torch ignitor operation, burner ignition and flame propagation between the neighbour injectors. A successful final result of the chain of ignition procedures depends on multiple aspects of the combustor design. Performed development work shows an important step towards designing modern high-efficiency low-emission combustors.
Ignitor with stable low-energy thermite igniting system
Kelly, Michael D.; Munger, Alan C.
1991-02-05
A stable compact low-energy igniting system in an ignitor utilizes two components, an initiating charge and an output charge. The initiating charge is a thermite in ultra-fine powder form compacted to 50-70% of theoretical maximum density and disposed in a cavity of a header of the ignitor adjacent to an electrical ignition device, or bridgewire, mounted in the header cavity. The initiating charge is ignitable by operation of the ignition device in a hot-wire mode. The output charge is a thermite in high-density consoladated form compacted to 90-99% of theoretical maximum density and disposed adjacent to the initiating charge on an opposite end thereof from the electrical ignition device and ignitable by the initiating charge. A sleeve is provided for mounting the output charge to the ignitor header with the initiating charge confined therebetween in the cavity.
Catalytic Ignitor for Regenerative Propellant Gun
NASA Technical Reports Server (NTRS)
Voecks, Gerald E. (Inventor); Ferraro, Ned W. (Inventor)
1997-01-01
An ignitor initiates combustion of liquid propellant in a gun by utilizing a heated catalyst onto which the liquid propellant is sprayed in a manner which mitigates the occurrence of undesirable combustion chamber oscillations. The heater heats the catalyst sufficiently to provide the activation necessary to initiate combustion of the liquid propellant sprayed thereonto. Two embodiments of the igniter and three alternative mountings thereof within the combustion chamber are disclosed. The ignitor may also be utilized to dispose of contaminated, excess, or waste liquid propellant in a safe, controlled, simple, and reliable manner.
NASA Astrophysics Data System (ADS)
Ma, Xiaoxia; Cheng, Shengxian; Hu, Yan; Ye, Yinghua; Shen, Ruiqi
2018-03-01
The integration of composite energetic films (CEFs) with various types of initiators can effectively adjust their performance and represents potential applications in microscale energy-demanding systems. In this study, the Al/Bi2O3/graphene oxide (GO) CEFs were successfully integrated into copper micro-ignitors by electrophoretic deposition, a low-cost and time-saving method. The effects of the Al/Bi2O3/GO CEFs with different GO contents on exothermic performance and ignition properties of micro-ignitors were then systematically investigated in terms of heat release, activation energy, ignition duration, the maximum height of the ignition product, and ignition delay time. The results showed that the addition of GO promoted more heat releases and higher activation energies of Al/Bi2O3/GO CEFs. The addition of ≤3.5 wt. % GO prolonged the ignition duration from 450 μs to 950 μs and increased the maximum height of the ignition product from about 40 mm to 60 mm. However, the micro-ignitors with more than 3.5 wt. % GO cannot be ignited, which suggested that GO played a contradictory role in the ignition properties of micro-ignitors and the controlled GO content was a prerequisite for improved ignition performance. The ignition delay time gradually extended from 10.7 μs to 27.6 μs with increases in the GO contents of Al/Bi2O3 CEFs, revealing that an increase in the weight ratio of GO leads to lower ignition sensitivity of micro-ignitors.
Early, James W.; Lester, Charles S.
2002-01-01
In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. The beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion of it being recombined with the first portion after a delay before injection into the ignitor laser. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones.
Early, James W.; Lester, Charles S.
2003-01-01
In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In a third embodiment, alternating short and long pulses of light from the excitation light source are directed into the ignitor laser. Each of the embodiments of the invention can be multiplexed so as to provide laser light energy sequentially to more than one ignitor laser.
Early, James W.; Lester, Charles S.
2002-01-01
In the apparatus of the invention, a first excitation laser or other excitation light source is used in tandem with an ignitor laser to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using a single remote excitation light source for one or more small lasers located proximate to one or more fuel combustion zones. In the embodiment of the invention claimed herein, the beam from the excitation light source is split with a portion of it going to the ignitor laser and a second portion of it being combined with either the first portion after a delay before injection into the ignitor laser.
Installation of the Ignitor Machine at the Caorso Site
NASA Astrophysics Data System (ADS)
Migliori, S.; Pierattini, S.; Bombarda, F.; Faelli, G.; Zucchetti, M.; Coppi, B.
2008-11-01
The actual cost of building a new experiment can be considerably contained if infrastructures are already available on its envisioned site. The facilities of the Caorso site (near Piacenza, Italy) that, at present, houses a spent nuclear power station, have been analyzed in view of their utilization for the operation of the Ignitor machine. The main feature of the site is its robust connection to the electrical national power grid that can take the disturbance caused by Ignitor discharges with the highest magnetic fields and plasma currents, avoiding the need for rotating flywheels generators. Other assets include a vast building that can be modified to house the machine core and the associated diagnostic systems. A layout of the Ignitor plant, including the tritium laboratory and other service areas, the distribution of the components of the electrical power supply system and of the He gas cooling sytem are presented. Relevant safety issues have been analyzed, based on the in depth activation analysis of the machine components carried out by means of the FISPAC code. Waste management and environment impact issues, including risk to the population assessments, have also been addressed.
Perspectives for the high field approach in fusion research and advances within the Ignitor Program
NASA Astrophysics Data System (ADS)
Coppi, B.; Airoldi, A.; Albanese, R.; Ambrosino, G.; Belforte, G.; Boggio-Sella, E.; Cardinali, A.; Cenacchi, G.; Conti, F.; Costa, E.; D'Amico, A.; Detragiache, P.; De Tommasi, G.; DeVellis, A.; Faelli, G.; Ferraris, P.; Frattolillo, A.; Giammanco, F.; Grasso, G.; Lazzaretti, M.; Mantovani, S.; Merriman, L.; Migliori, S.; Napoli, R.; Perona, A.; Pierattini, S.; Pironti, A.; Ramogida, G.; Rubinacci, G.; Sassi, M.; Sestero, A.; Spillantini, S.; Tavani, M.; Tumino, A.; Villone, F.; Zucchi, L.
2015-05-01
The Ignitor Program maintains the objective of approaching D-T ignition conditions by incorporating systematical advances made with relevant high field magnet technology and with experiments on high density well confined plasmas in the present machine design. An additional objective is that of charting the development of the high field line of experiments that goes from the Alcator machine to the ignitor device. The rationale for this class of experiments, aimed at producing poloidal fields with the highest possible values (compatible with proven safety factors of known plasma instabilities) is given. On the basis of the favourable properties of high density plasmas produced systematically by this line of machines, the envisioned future for the line, based on novel high field superconducting magnets, includes the possibility of investigating more advanced fusion burn conditions than those of the D-T plasmas for which Ignitor is designed. Considering that a detailed machine design has been carried out (Coppi et al 2013 Nucl. Fusion 53 104013), the advances made in different areas of the physics and technology that are relevant to the Ignitor project are reported. These are included within the following sections of the present paper: main components issues, assembly and welding procedures; robotics criteria; non-linear feedback control; simulations with three-dimensional structures and disruption studies; ICRH and dedicated diagnostics systems; anomalous transport processes including self-organization for fusion burning regimes and the zero-dimensional model; tridimensional structures of the thermonuclear instability and control provisions; superconducting components of the present machine; envisioned experiments with high field superconducting magnets.
Theoretical Issues for Plasma Regimes to be Explored by the Ignitor Experiment
NASA Astrophysics Data System (ADS)
Cardinali, A.; Coppi, B.; Sonnino, G.
2014-10-01
At present, the Ignitor experiment is the only one designed and planned to approach and explore ignition regimes under controlled DT burning conditions. The machine parameters have been established on the basis of existing knowledge of the confinement properties of high density plasmas. A variety of improved confinement regimes are expected to be accessible by means of the available ICRH heating power in addition to the prevalent programmable Ohmic heating power and relying on the injection of high velocity pellets for density profile control. The relevance of the various known confinement regimes to the objectives of Ignitor is discussed. Among other theoretical efforts, a non-linear thermal energy balance equation is investigated to study the onset of thermonuclear instability in the plasmas expected to be produced in Ignitor. The equation for the temperature profile in the equilibrium state is solved with the resulting profiles in agreement with those obtained by a full transport code and commonly adopted scalings for them. The evolution of the thermonuclear instability that relies on the solution of the time dependent energy balance equation is obtained. Sponsored in part by the U.S. DOE.
Inertial Upper Stage Thermal Test Program
1989-04-12
EPDM , a tnermal insuiative rubber material covering the SRM ignitor housing, were made in both convective and radiative heater environments under...N2 to ensure an inert environment for these tests. 11 EPDM RUBBER FIBERGLAS PHENOLIC Fig. 2. IUS SRM-2 ignitor. 12 RADIA TOR EMI SHIELD-,," MOVABLE...testing. EPDM Grafoil seal, Viton Thermal-protection materials , IBSTRACT (Continue on reve4 if necessary and identify by block number) An extensive ther
Diagnostics Development for the Ignition Experiment Ignitor
NASA Astrophysics Data System (ADS)
Pizzicaroli, G.; Bombarda, F.; Licciulli, A.; Fersini, M.; Diso, D.; Kroegler, H.
2008-11-01
The Ignitor experiment is designed to reach ignition conditions. The short, but intense neutron flux will pose challenging conditions for diagnostics, such as magnetic sensors or bolometers, in direct proximity, or in direct view, of the plasma. An R&D program is in progress to manufacture mineral insulated magnetic coils with a reduced sensitivity to radiation effects. A double layer, MgO insulated Ni coil has been produced and tested. The wire is wound on an alumina core and the coil is housed in an alumina box for high refractoriness and minimum vacuum degassing. A lanthanide glass ceramic has been used as sealant for the box. At the same time, alternative methods to provide critical plasma position information during the high performance discharges in Ignitor are being explored. For example, the radiation emitted at the plasma edge by Mo^+14 can be monitored by means of a soft X- ray spectrometer equipped with a GEM detector, which allows high counting rates (> 1 MHz) and provides good energy resolution and flexibility of design. A 10x10 cm^2 multichannel prototype with its associated fast read-out system is being assembled. A layout of the complete spectrometer compatible with the Ignitor port design has been carried out, and the bolometer system design has been updated.
Bickes Jr., Robert W.; Renlund, Anita M.; Stanton, Philip L.
1994-11-01
A detonator for high explosives initiated by mechanical impact includes a cylindrical barrel, a layer of flyer material mechanically covering the barrel at one end, and a semiconductor bridge ignitor including a pair of electrically conductive pads connected by a semiconductor bridge. The bridge is in operational contact with the layer, whereby ignition of said bridge forces a portion of the layer through the barrel to detonate the explosive. Input means are provided for igniting the semiconductor bridge ignitor.
Bickes, Jr., Robert W.; Renlund, Anita M.; Stanton, Philip L.
1994-01-01
A detonator for high explosives initiated by mechanical impact includes a cylindrical barrel, a layer of flyer material mechanically covering the barrel at one end, and a semiconductor bridge ignitor including a pair of electrically conductive pads connected by a semiconductor bridge. The bridge is in operational contact with the layer, whereby ignition of said bridge forces a portion of the layer through the barrel to detonate the explosive. Input means are provided for igniting the semiconductor bridge ignitor.
The February 21, 1993 tornadoes of East Tennessee
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fricke, K.E.; Kornegay, F.C.
1993-08-11
A series of tornadoes struck the east Tennessee area on Sunday afternoon, February 21, 1993 around Knoxville, Lenoir City, and Oak Ridge causing millions of dollars worth of damage to both homes and businesses in the area, killing one, injuring a number of persons, and leaving a large area without power for many hours or even days due to damage to the local TVA transmission line network. One tornado touched down in the Department of Energy Oak Ridge Reservation near the Oak Ridge Y-12 Plant, continued through the Union Valley business district located just east of the plant, through themore » adjacent University of Tennessee Arboretum and then continued into the communities of Claxton and Powell. The path length of the tornado was approximately 13 miles. Damage to the Y-12 Plant was minimal, but the Union Valley business district was seriously damaged, including the Fusion Energy Design Center (FEDC) which houses a number of DOE related projects. The preliminary cost estimate of the damage to DOE facilities (both at Y-12 and at the FEDC) was around $520,000. This paper describes the local meteorological data, the tornado that struck near the Y-12 plant, the resulting damage both to the DOE facilities and to the surrounding communities, the plant emergency response and recovery activities, and the current hazard analyses being undertaken at the plant.« less
High-voltage crowbar circuit with cascade-triggered series ignitrons
Baker, William R. [Orinda, CA
1980-11-04
A series string of ignitrons for switching a large current at high voltage to ground. Switching is initiated by means of a negative trigger pulse applied to the cathode of the lowest voltage level ignitron next to ground to draw ground current through diodes in the ignitor circuit. The trigger pulse is applied thereby to the next higher ignitron cathode and sequentially to the remainder of the ignitrons in the string through diodes in respective ignitor circuits. Full line voltage is held off of nonconducting diodes and ignitrons by means of varistors.
High-voltage crowbar circuit with cascade-triggered series ignitrons
Baker, W.R.
A series string of ignitrons for switching a large current at high voltage to ground is discussed. Switching is initiated by means of a negative trigger pulse applied to the cathode of the lowest voltage level ignitron next to ground to draw ground current through diodes in the ignitor circuit. The trigger pulse is applied thereby to the next higher ignitron cathode and sequentially to the remainder of the ignitrons in the string through diodes in respective ignitor circuits. Full line voltage is held off of nonconducting diodes and ignitrons by means of varistors.
High-voltage crowbar circuit with cascade-triggered series ignitrons
Baker, W.R.
1980-11-04
A series string of ignitrons for switching a large current at high voltage to ground. Switching is initiated by means of a negative trigger pulse applied to the cathode of the lowest voltage level ignitron next to ground to draw ground current through diodes in the ignitor circuit. The trigger pulse is applied thereby to the next higher ignitron cathode and sequentially to the remainder of the ignitrons in the string through diodes in respective ignitor circuits. Full line voltage is held off of nonconducting diodes and ignitrons by means of varistors. 1 fig.
1999-07-20
Moments before launch, sparks from the external ignitors are visible below the engines of Space Shuttle Columbia. The ignitors burn off a hydrogen concentration outside the orbiter near the main engines. A cloud effect behind the Shuttle's solid rocket booster and access arm to the left is created by spray from the water deluge system. The launch of STS-93 was scrubbed at the T-7 second mark in the countdown due to an indication of a high concentration of hydrogen in an aft engine compartment. The reading was proven to be a false alarm. The launch is rescheduled for July 22 at 12:28 a.m
Enhanced propagation for relativistic laser pulses in inhomogeneous plasmas using hollow channels.
Fuchs, J; d'Humières, E; Sentoku, Y; Antici, P; Atzeni, S; Bandulet, H; Depierreux, S; Labaune, C; Schiavi, A
2010-11-26
The influence of long (several millimeters) and hollow channels, bored in inhomogeneous ionized plasma by using a long pulse laser beam, on the propagation of short, ultraintense laser pulses has been studied. Compared to the case without a channel, propagation in channels significantly improves beam transmission and maintains a beam quality close to propagation in vacuum. In addition, the growth of the forward-Raman instability is strongly reduced. These results are beneficial for the direct scheme of the fast ignitor concept of inertial confinement fusion as we demonstrate, in fast-ignition-relevant conditions, that with such channels laser energy can be carried through increasingly dense plasmas close to the fuel core with minimal losses.
Aircraft engine sump-fire studies
NASA Technical Reports Server (NTRS)
Loomis, W. R.
1976-01-01
Results of ongoing experimental studies are reported in which a 125-millimeter-diameter-advanced-bearing test rig simulating an engine sump is being used to find the critical range of conditions for fires to occur. Design, material, and operating concepts and techniques are being studied with the objective of minimizing the problem. It has been found that the vapor temperature near a spark ignitor is most important in determining ignition potential. At temperatures producing oil vapor pressures below or much above the calculated flammability limits, fires have not been ignited. But fires have been routinely started within the theoretical flammability range. This indicates that generalizing the sump-fire problem may make it amenable to analysis, with the potential for realistic solutions.
Design of an Integrated Plasma Control System and Extension of XSCTools to Ignitor
NASA Astrophysics Data System (ADS)
Albanese, R.; Ambrosino, G.; Artaserse, G.; Pironti, A.; Rubinacci, G.; Villone, F.; Ramogida, G.
2010-11-01
The performance of the integrated system for vertical stability, shape and plasma current control for the Ignitor machine has been assessed by means of the CREATELlinearized model of plasma responseootnotetextR. Albanese, F. Villone, Nucl. Fusion 38, 723 (1998) against a set of disturbances for the reference 11 MA limiter configuration and the 9 MA Double Null configuration. A new design, based on the methodology of the eXtreme Shape Controller (XSC) at JET, has been tested : by using all the shape control circuits with the exception of those used to control the vertical stability is possible to control up to four independent linear combinations of the 36 plasma-wall gaps. The results point out a substantial improvement in shape recovery, especially in the presence of a disturbance in li. The new shape controller can also automatically generate, via feedback control, new plasma shapes in the proximity of a given equilibrium configuration. The XSC ToolsootnotetextG. Ambrosino, R. Albanese et al., Fus. Eng.& Des. 74, 521 (2005) have been adapted and extended to develop linearized Ignitor models including 2D eddy currents and to solve inverse linearized plasma equilibria.
Plasma Wall interaction in the IGNITOR machine
NASA Astrophysics Data System (ADS)
Ferro, C.
1998-11-01
One of the critical issues in ignited machines is the management of the heat and particle exhaust without degradation of the plasma quality (pollution and confinement time) and without damage of the material facing the plasma. The IGNITOR machine has been conceived as a ``limiter" device, i.e., with the plasma leaning nearly on the entire surface of the first wall. Peak heat loads can easily be maintained at values lower than 1.35 MW/m^2 even considering displacements of the plasma column^1. This ``limiter" choice is based on the operational performances of high density, high field machines which suggests that intrinsic physics processes in the edge of the plasma are effective in spreading heat loads and maintaining the plasma pollution at a low level. The possibility of these operating scenarios has been demonstrated recently by different machines both in limiter and divertor configurations. The basis for the different physical processes that are expected to influence the IGNITOR edge parameters ^2 are discussed and a comparison with the latest experimental results is given. ^1 C. Ferro, G. Franzoni, R. Zanino, ENEA Internal Report RT/ERG/FUS/94/14. ^2 C. Ferro, R. Zanino, J. Nucl. Mater. 543, 176 (1990).
Analysis of Ignitor Discharges with Double X-point Magnetic Configurations
NASA Astrophysics Data System (ADS)
Airoldi, A.; Cenacchi, G.; Coppi, B.
2008-11-01
The Ignitor experiment was proposed and designed to achieve ignited and sub-ignited conditions in well confined deuterium-tritium plasmas. Thanks to its unique features (high magnetic field up to 13 T, high plasma current up to 11 MA, and high plasma density up to 5 x10^20 m-3), Ignitor is the only device capable of exploring plasma regimes that are relevant to a net power producing D-T reactor and are not accessible to other existing or planned machines. Double X-point scenarios with magnetic field up to 13 T and plasma current up to 9 MA are analyzed. In these configurations, the access to a high confinement state is assumed when the available plasma heating power, supported by the injected auxiliary power, is larger than the L-H threshold value, according to recent suggested scalings The H-regime is modeled by a global reduction of the thermal transport coefficients used for the L-regime. Situations in the presence and in the absence of sawtooth oscillations have been investigated. Quasi-stationary conditions can be attained when a process producing re- distribution of pressure and current profiles is active. B.Coppi, A.Airoldi, F.Bombarda, et al.,Nucl. Fusion 41, 1253 (2001) D.C. McDonald, A.J. Meakins, et al., PPCF 48, A439 (2006).
NASA Astrophysics Data System (ADS)
Barty, C. P. J.; Key, M.; Britten, J.; Beach, R.; Beer, G.; Brown, C.; Bryan, S.; Caird, J.; Carlson, T.; Crane, J.; Dawson, J.; Erlandson, A. C.; Fittinghoff, D.; Hermann, M.; Hoaglan, C.; Iyer, A.; Jones, L., II; Jovanovic, I.; Komashko, A.; Landen, O.; Liao, Z.; Molander, W.; Mitchell, S.; Moses, E.; Nielsen, N.; Nguyen, H.-H.; Nissen, J.; Payne, S.; Pennington, D.; Risinger, L.; Rushford, M.; Skulina, K.; Spaeth, M.; Stuart, B.; Tietbohl, G.; Wattellier, B.
2004-12-01
The technical challenges and motivations for high-energy, short-pulse generation with NIF and possibly other large-scale Nd : glass lasers are reviewed. High-energy short-pulse generation (multi-kilojoule, picosecond pulses) will be possible via the adaptation of chirped pulse amplification laser techniques on NIF. Development of metre-scale, high-efficiency, high-damage-threshold final optics is a key technical challenge. In addition, deployment of high energy petawatt (HEPW) pulses on NIF is constrained by existing laser infrastructure and requires new, compact compressor designs and short-pulse, fibre-based, seed-laser systems. The key motivations for HEPW pulses on NIF is briefly outlined and includes high-energy, x-ray radiography, proton beam radiography, proton isochoric heating and tests of the fast ignitor concept for inertial confinement fusion.
Shock ignition of thermonuclear fuel with high areal density.
Betti, R; Zhou, C D; Anderson, K S; Perkins, L J; Theobald, W; Solodov, A A
2007-04-13
A novel method by C. Zhou and R. Betti [Bull. Am. Phys. Soc. 50, 140 (2005)] to assemble and ignite thermonuclear fuel is presented. Massive cryogenic shells are first imploded by direct laser light with a low implosion velocity and on a low adiabat leading to fuel assemblies with large areal densities. The assembled fuel is ignited from a central hot spot heated by the collision of a spherically convergent ignitor shock and the return shock. The resulting fuel assembly features a hot-spot pressure greater than the surrounding dense fuel pressure. Such a nonisobaric assembly requires a lower energy threshold for ignition than the conventional isobaric one. The ignitor shock can be launched by a spike in the laser power or by particle beams. The thermonuclear gain can be significantly larger than in conventional isobaric ignition for equal driver energy.
NASA Technical Reports Server (NTRS)
Wintucky, E. G.; Gruber, R. P.
1978-01-01
An investigation of the high voltage pulse ignition characteristics of the 8 cm mercury ion thruster neutralizer cathode identified a low rate of voltage rise and long pulse duration as desirable factors for reliable cathode starting. Cathode starting breakdown voltages were measured over a range of mercury flow rates and tip heater powers for pulses with five different rates of voltage rise. Breakdown voltage requirements for the fastest rising pulse (2.5 to 3.0 kV/micro sec) were substantially higher (2 kV or more) than for the slowest rising pulse (0.3 to 0.5 kV/micro sec) for the same starting conditions. Also described is an improved, low impedance pulse ignitor circuit which reduces power losses and eliminates problems with control and packaging associated with earlier designs.
1997-06-09
A 40 K Fastrac II duration test performed at Marshall Test Stand 116. The purpose of this test was to gauge the length of time between contact of TEA (Triethylenealuminum) and LOX (liquid oxygen) as an ignitor for the Fastrac engine.
Developments for the ICRH System of the Ignitor Machine
NASA Astrophysics Data System (ADS)
Sassi, M.; Mantovani, S.; Coppi, B.
2014-10-01
The ICRH system that is suitable for the high-density plasmas to be produced by the Ignitor machine has been designed and components of it have been tested. This system will operate over the range 80-120 MHz, consistently with magnetic fields in the range 9-13 T. The maximum delivered power is in the interval 8 MW (at 80 MHz) to 6 MW (at 120 MHz) distributed over 4 ports. A full size prototype of the VTL between the port flange and the antenna straps, with the external support and precise guiding system has been constructed. The innovative quick latching system located at the end of the coaxial cable has been successfully tested, providing perfect interference with the spring Be-Cu electrical contacts. Vacuum levels of 10-6, compatible with the limit of material degassing, and electrical tests up to 12 kV without discharges have been obtained. Sponsored in part by the US DOE.
NASA Technical Reports Server (NTRS)
1997-01-01
A 40 K Fastrac II duration test performed at Marshall Test Stand 116. The purpose of this test was to gauge the length of time between contact of TEA (Triethylenealuminum) and LOX (liquid oxygen) as an ignitor for the Fastrac engine.
Barbee, Jr., Troy W.; Simpson, Randall L.; Gash, Alexander E.; Satcher, Jr., Joe H.
2012-12-11
Sol-gel chemistry is used to prepare igniters comprising energetic multilayer structures coated with energetic materials. These igniters can be tailored to be stable to environmental aging, i.e., where the igniters are exposed to extremes of both hot and cold temperatures (-30 C to 150 C) and both low (0%) and high relative humidity (100%).
Barbee, Jr., Troy W.; Simpson, Randall L [Livermore, CA; Gash, Alexander E [Brentwood, CA; Satcher, Jr., Joe H.
2011-05-31
Sol-gel chemistry is used to prepare igniters comprising energetic multilayer structures coated with energetic booster materials. These igniters can be tailored to be stable to environmental aging, i.e., where the igniters are exposed to extremes of both hot and cold temperatures (-30 C to 150 C) and both low (0%) and high relative humidity (100%).
Improved Confinement Regimes and the Ignitor Experiment
NASA Astrophysics Data System (ADS)
Bombarda, F.; Coppi, B.; Detragiache, P.
2013-10-01
The Ignitor experiment is the only one designed and planned to reach ignition under controlled DT burning conditions. The machine prameters have been established on the basis of existing knowledge of the confinement properties of high density plasmas. The optimal plasma evolution in order to reach ignition by means of Ohmic heating only, without the contribution of transport barriers has been identified. Improved confinement regimes are expected to be accessible by means of the available ICRH additional heating power and the injection of pellets for density profile control. Moreover, ECRH of the outer edge of the (toroidal) plasma column has been proposed using very high frequency sources developed in Russia. Ignition can then be reached at slightly reduced machine parameters. Significant exploration of the behavior of burning, sub-ignited plasmas can be carried out in less demanding operational conditions than those needed for ignition with plasmas accessing the I or H-regimes. These conditions will be discussed together with the provisions made in order to maintain the required (for ignition) degree of plasma purity. Sponsored in part by the U.S. DOE.
Leonov, S V; Pinchuk, P V; Rasnyuk, S V
The objective of the present study was to obtain the ballistic characteristics of the igniting primer (electrical ignitor) for the 18×45T cartridges of the 'Osa' pistol produced by different manufacturers. The experiments included a series of shots fired from the 'Osa' pistol with the use of cartridges having an energy of 85 Joules ('Novye oruzheinye tekhnologii', Ltd., Sergiev Posad) and 88 Joules ('A+A', Ltd, Tula). The shooting distance varied from the point blank range to 5, 10, 20, 30, 40, and 50 cm. The targets were either the femoral soft tissue of the cut-off human lower extremity, white cotton fabric, and the 1-5 cm high gelatin cylinder 25 cm in diameter. The experiments have demonstrated that the igniting primer (electrical ignitor) for the cartridges manufactured by the 'Novye oruzheinye tekhnologii', Ltd., Sergiev Posad, served as an additional factor of the shot responsible for the penetrating power of the ammunition at a distance of 50 cm. The data on the composition of metals used for the manufacturing of the igniting primers under consideration are presented.
Australian DefenceScience. Volume 15, Number 3, Spring
2007-01-01
ignition, high pressure sealing, ignitor and propellent design, and ballistics instrumentation . Validation of simulation models of internal ballistics...supplementing visual information obtained by sources such as radiography and scanning electron microscopy, revealing details about features that are not...otherwise visible. Hence, it can assist with the inspection of vital component parts that are subject to high stresses, like aircraft engine turbine
Major Disruptions and Other Issues Driving the Design of the Ignitor Plasma Chamber
NASA Astrophysics Data System (ADS)
Ramogida, G.; Frosi, P.; Coppi, B.
2012-10-01
The Plasma Chamber of the Ignitor machine is designed according to the information available about electromagnetic loads coming from the experimental knowledge and the increasingly accurate numerical models of the eddy and halo currents resulting from the worst disruption events in existing machines. The developed models deal with static, dynamic and modal analysis. The loads during nominal operations and also those arising from plasma disruptions, by far the most important ones, have been taken into account, as well as the design problems arising from the Mo tiles in the inboard edge of the vacuum vessel, the Faraday shields covering the 6 ports devoted to the ICRH system and, finally, the reaction forces coming from the regions of constraints with the C-Clamps (the retaining structure that support the plasma chamber both statically and dynamically). The plasma chamber has to perform several additional functions, such as to keep the vacuum, be bakeable, and support the set of plates that carry the Mo tiles facing the plasma column. According to the present design the chamber is made of Inconel and has a thickness varying from 26 to 52 mm.
Plasma Chamber Restraints in Ignitor and Relevant Disruption Analysis
NASA Astrophysics Data System (ADS)
Gasparotto, M.; Cucchiaro, A.; Capriccioli, A.; Celentano, G.; Rita, C.; Roccella, M.; Macco, B.; Micheli, I.; Ferrari, G.; Orlandi, S.; Coppi, B.
2000-10-01
The plasmas chamber (PC) of Ignitor is made of 12 D-shaped toroidal sectors of Inconel 625 welded together by automatic remote equipment. The thickness of the inboard wall is 17 mm while the middle and outboard walls are 26 mm thick. The PC is supported through the ports by the C-Clamp structure of the toroidal magnet. The main function of the PC supports is to resist the vertical and radial electromagnetic loads and to allow for free movement under thermal loads while providing electrical insulation from the C-Clamps and cryostat. The largest estimated loads are due to a Vertical Displacement Event (VDE) disruption that is followed by a thermal quench and then by the current quench. The vertical supports involve a connection of each radial port to the C-Clamp structure by a link system that withstands the calculated loads. The radial supports resist, with high stiffness, the centripetal and centrifugal forces. The end flange of each radial port is connected to the C-Clamp structure by a clamping sleeve device. The clamping sleeves are hydraulically operated to provide locking during discharge. The clamping sleeves of the radial support system have been validated by an appropriate series of tests.
Eternal triangle: the interaction of light source, electrical control gear, and optics
NASA Astrophysics Data System (ADS)
S'heeren, Griet
1998-04-01
In this particular 'affair' the participants are less than human but have individual personalities they bring to their relationship with each other. High pressure metal halide lamps such as BriteArc lamps have the highest luminance and radiance of all continuously operating practical light source. Since these lamps have short arcs and are available in power ratings from about 30W to 30kW they have found applications with various optical systems. Besides the lamps, such systems include an electrical control device and an optical system. To fulfil the user's requirements for a specific application, it is not only important to choose the right lamp, but crucial to achieve a harmonious marriage between the light source, electrical control device and the optics. To run a high pressure discharge lamp an ignitor/ballast system is essential This stabilizes the lamp parameters. The chemical components inside the lamp determine the lamp voltage and the gear determines, via the current, the lamp power. These are directly related in the luminance and color temperature of the emitted light. Therefore lamp performance and effective life are dependent on the ignitor, control gear and lamp combination. Since the lamp emits radiation in all directions, collection of the light from a lamp can be improved by using reflectors to deliver the light into a lens system. Since lamps with short arc gaps approach a point source they appear ideal for optical system applications. The shape of the reflector and the focusing of the lamp determine which part of the light is collected out of the light-arc. In the case of an LCD projector, the final light output also depends on the transmission characteristics of the LCD panels. Their nonlinearity causes the color of the emitted light to be different from the lamp color. All these parameters have to be optimized to obtain the highest performance. This leads to the conclusion that a carefully matched combination of lamp, ignitor/ballast and optics should guarantee the best system performance. This paper sets out to provide some guidelines on attempting to achieve a harmonious relationship between the three partners in this particular eternal triangle.
Computational study of arc discharges: Spark plug and railplug ignitors
NASA Astrophysics Data System (ADS)
Ekici, Ozgur
A theoretical study of electrical arc discharges that focuses on the discharge processes in spark plug and railplug ignitors is presented. The aim of the study is to gain a better understanding of the dynamics of electrical discharges, more specifically the transfer of electrical energy into the gas and the effect of this energy transfer on the flow physics. Different levels of computational models are presented to investigate the types of arc discharges seen in spark plugs and railplugs (i.e., stationary and moving arc discharges). Better understanding of discharge physics is important for a number of applications. For example, improved fuel economy under the constraint of stricter emissions standards and improved plug durability are important objectives of current internal combustion engine designs. These goals can be achieved by improving the existing systems (spark plug) and introducing more sophisticated ignition systems (railplug). In spite of the fact spark plug and railplug ignitors are the focus of this work, the methods presented in this work can be extended to study the discharges found in other applications such as plasma torches, laser sparks, and circuit breakers. The system of equations describing the physical processes in an air plasma is solved using computational fluid dynamics codes to simulate thermal and flow fields. The evolution of the shock front, temperature, pressure, density, and flow of a plasma kernel were investigated for both stationary and moving arcs. Arc propagation between the electrodes under the effects of gas dynamics and electromagnetic processes was studied for moving arcs. The air plasma is regarded as a continuum, single substance material in local thermal equilibrium. Thermophysical properties of high temperature air are used to take into consideration the important processes such as dissociation and ionization. The different mechanisms and the relative importance of several assumptions in gas discharges and thermal plasma modeling were investigated. Considering the complex nature of the studied problem, the computational models aid in analyzing the analytical theory and serve as relatively inexpensive tools when compared to experiments in design process.
2013-01-01
Background Continuity of care is essential for good quality diabetes management. We recently found that 46% of patients defaulted from care (had no contact with the clinic for 18 months after a follow-up appointment was ordered) in a Canadian multidisciplinary tertiary care diabetes clinic. The primary aim was to compare characteristics, diabetes processes of care, and outcomes from referral to within 1 year after leaving clinic or to the end of the follow-up period among those patients who defaulted, were discharged or were retained in the clinic. Methods Retrospective cohort study of 193 patients referred to the Foustanellas Endocrine and Diabetes Center (FEDC) for type 2 diabetes from January 1, 2005 to June 30, 2005. The FEDC is the primary academic referral centre for the Ottawa Region and provides multidisciplinary diabetes management. Defaulters (mean age 58.5 ± 12.5 year, 60% M) were compared to patients who were retained in the clinic (mean age 61.4 ± 10.47 years, 49% M) and those who were formally discharged (mean age 61.5 ± 13.2 years, 53.3% M). The chart audit population was then individually linked on an individual patient basis for laboratory testing, physician visits billed through OHIP, hospitalizations and emergency room visits using Ontario health card numbers to health administrative data from the Ministry of Health and Long-Term Care at the Institute for Clinical and Evaluative Sciences (ICES). Results Retained and defaulted patients had significantly longer duration of diabetes, more microvascular complications, were more likely to be on insulin and less likely to have a HbA1c < 7.0% than patients discharged from clinic. A significantly lower proportion of patients who defaulted from tertiary care received recommended monitoring for their diabetes (HbA1c measurements, lipid measurements, and periodic eye examinations), despite no difference in median number of visits to a primary care provider (PCP). Emergency room visits were numerically higher in the defaulters group. Conclusions Patients defaulting from a tertiary care diabetes hospital do not receive the recommended monitoring for their diabetes management despite attending PCP appointments. Efforts should be made to minimize defaulting in this group of individuals. PMID:23938105
Construction of a Full-size Component of the ICRH System
NASA Astrophysics Data System (ADS)
Mantovani, S.; Sassi, M.; Coppi, B.
2012-10-01
The ICRH system is an important component of the Ignitor project and all efforts have been made to ensure that its design takes into account the construction experience gained in the most advanced laboratories. The system is designed to operate over a frequency range 80-120 MHz, which is consistent with the use of magnetic fields in the range 9-13 T. The maximum delivered power ranges from 8 MW (at 80 MHz) to 6 MW (at 120 MHz) distributed over 4 ports. Since the transition from a detailed design to the actual construction is not without surprises we have constructed a full size prototype of the VTL between the port flange and the antenna straps, with the external support and precise guiding system. The innovative quick latching system located at the end of the coaxial cable was successfully tested, providing perfect interference with the spring Be-Cu electrical contacts. Special care was given to the finishing of the inox surfaces, and to the TIG welds. Vacuum levels of 10-6, compatible with the limit of material degassing, and electrical tests up to 12 kV without discharges have been obtained. A revision of the other key components of the Ignitor machine has been undertaken, taking into account the experience gained in the fabrication of the corresponding prototypes.
Optimal Equilibria and Plasma Parameter Evolutions for the Ignitor Experiment*
NASA Astrophysics Data System (ADS)
Airoldi, A.; Cenacchi, G.; Coppi, B.
2011-10-01
In view of the operation of the Ignitor machine in both the H and the I-regime, optimal equilibrium configurations that can sustain plasma currents Ip up to 10 MA with a double X-point have been identified. In fact, the emergence of the I-regime in double X-point configurations has not been observed experimentally yet. The characteristics of the magnetic equilibrium configurations that can be produced play a crucial role in the performance of the machine. Therefore, particular care has been devoted to the study of plasma equilibria relevant to the main phases of the discharge evolution. A series of simulations to be utilized for the control of the relevant (sub-ignited) plasma parameters has been carried out using the JETTO transport code considering different values of the plasma current and, correspondingly, of the magnetic field. Special attention has been devoted to non-igniting experiments with Ip = 5 MA and BT = 8 T, where BT is the toroidal magnetic field, as they can be performed with much better duty cycles and longer duration than experiments aimed at reaching the most extreme plasma parameters and ignition in particular. The results of the relevant analyses with a discussion of the adopted transport coefficients is presented. * Sponsored in part by ENEA and the U.S. DOE.
Aircraft Engine Sump Fire Mitigation, Phase 2
NASA Technical Reports Server (NTRS)
Rosenlieb, J. W.
1978-01-01
The effect of changes in the input parameters (air leakage flow rate and temperature and lubricating oil inlet flow rate and temperature) over a specified range on the flammability conditions within an aircraft engine bearing sump was investigated. An analytical study was performed to determine the effect of various parameters on the generation rate of oil vapor from oil droplets in a hot air stream flowing in a cylindrical tube. The ignition of the vapor-air mixture by an ignition source was considered. The experimental investigation demonstrated that fires would be ignited by a spark ignitor over the full range of air and oil flow rates and air temperatures evaluated. However, no fires could be ignited when the oil inlet temperature was maintained below 41.7 K (290 F). The severity of the fires ignited were found to be directly proportional to the hot air flow rate. Reasonably good correlation was found between the mixture temperature in the sump at the ignitor location and the flammability limits as defined by flammability theory; thus a fairly reliable experimental method of determining flammable conditions within a sump was demonstrated. The computerized mathematical model shows that oil droplet size and air temperature have the greatest influence on the generation rate of oil vapor.
Aircraft Cargo Compartment Fire Test Simulation Program
NASA Technical Reports Server (NTRS)
Blumke, R. E.
1977-01-01
The objective of the test was to assess fire containment and fire extinguishment in the cargo by reducing the ventilation through the cargo compartment. Parameters which were measured included ignition time, burnthrough time, and physical damage to the cargo liner, composition of selected combustible gases, temperature-time histories, heat flux, and detector response. The ignitor load was made of a typical cargo consisting of filled cardboard cartons occupying 50% of the compartment volume.
Development and testing of hermetic, laser-ignited pyrotechnic and explosive components
NASA Technical Reports Server (NTRS)
Kramer, Daniel P.; Beckman, Thomas M.; Spangler, Ed M.; Munger, Alan C.; Woods, C. M.
1993-01-01
During the last decade there has been increasing interest in the use of lasers in place of electrical systems to ignite various pyrotechnic and explosive materials. The principal driving force for this work was the requirement for safer energetic components which would be insensitive to electrostatic and electromagnetic radiation. In the last few years this research has accelerated since the basic concepts have proven viable. At the present time it is appropriate to shift the research emphasis in laser initiation from the scientific arena--whether it can be done--to the engineering realm--how it can be put into actual practice in the field. Laser initiation research and development at EG&G Mound was in three principal areas: (1) laser/energetic material interactions; (2) development of novel processing techniques for fabricating hermetic (helium leak rate of less than 1 x 10(exp -8) cu cm/s) laser components; and (3) evaluation and testing of laser-ignited components. Research in these three areas has resulted in the development of high quality, hermetic, laser initiated components. Examples are presented which demonstrate the practicality of fabricating hermetic, laser initiated explosive or pyrotechnic components that can be used in the next generation of ignitors, actuators, and detonators.
Hill, R.W.; Skinner, D.F. Jr.; Thorsness, C.B.
1983-05-26
A silane propane burner for an underground coal gasification process which is used to ignite the coal and to controllably retract the injection point by cutting the injection pipe. A narrow tube with a burner tip is positioned in the injection pipe through which an oxidant (oxygen or air) is flowed. A charge of silane followed by a supply of fuel, such as propane, is flowed through the tube. The silane spontaneously ignites on contact with oxygen and burns the propane fuel.
Hill, Richard W.; Skinner, Dewey F.; Thorsness, Charles B.
1985-01-01
A silane propane burner for an underground coal gasification process which is used to ignite the coal and to controllably retract the injection point by cutting the injection pipe. A narrow tube with a burner tip is positioned in the injection pipe through which an oxidant (oxygen or air) is flowed. A charge of silane followed by a supply of fuel, such as propane, is flowed through the tube. The silane spontaneously ignites on contact with oxygen and burns the propane fuel.
X-ray GEM Detectors for Burning Plasma Experiments
NASA Astrophysics Data System (ADS)
Puddu, S.; Bombarda, F.; Pizzicaroli, G.; Murtas, F.
2009-11-01
The harsh environment and higher values of plasma parameters to be expected in future burning plasma experiments (and even more so in future power producing fusion reactors) is prompting the development of new, advanced diagnostic systems. The detection of radiation emitted by the plasma in the X-ray spectral region is likely to play the role that visible or UV radiation have in present day experiments. GEM gas detectors, developed at CERN, are the natural evolution of Multiwire Proportional Chambers, with a number of advantages: higher counting rates, lower noise, good energy resolution, low sensitivity to background radiation. GEM's can be used in several different ways, but two specific applications are being explored in the framework of the Ignitor program, one for plasma position control and the other for high resolution spectroscopy. The diagnostic layout on the Ignitor machine is such that the detectors will not be in direct view of the plasma, at locations where they can be efficiently screened by the background radiation. Prototype detectors 10 x 10 cm^2 in area have been assembled and will be tested to assess the optimal geometrical parameters and operating conditions, regarding in particular the choice between Single and Triple GEM configurations, the gas mixture, and the problem of fan-out associated with the high number of output channels required for high resolution crystal spectrometers.
Early, James W.; Lester, Charles S.
2002-01-01
In the apparatus of the invention, a first excitation laser or other excitation light source capable of producing alternating beams of light having different wavelengths is used in tandem with one or more ignitor lasers to provide a compact, durable, engine deployable fuel ignition laser system. Reliable fuel ignition is provided over a wide range of fuel conditions by using the single remote excitation light source for pumping one or more small lasers located proximate to one or more fuel combustion zones with alternating wavelengths of light.
NASA Technical Reports Server (NTRS)
Polzin, Kurt A (Inventor); Pearson, J Boise (Inventor)
2014-01-01
An ignitron apparatus has an airtight tubular housing having a first sealed end and a second sealed end. An anode is connected at the first sealed end, projecting into the housing, and a recess at the second sealed and forms a well which contains a quantity of liquid gallium or gallium alloy making up the cathode. An ignitor projects through the liquid metal and into the housing. The inner surface of the housing includes at least one plating-reduction structure to prevent electrical shorting of the apparatus caused by plating of the liquid metal.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Colaïtis, A.; Ribeyre, X.; Le Bel, E.
The effects of Hot Electrons (HEs) generated by the nonlinear Laser-Plasma Interaction (LPI) on the dynamics of Shock Ignition Inertial Confinement Fusion targets are investigated. The coupling between the laser beam, plasma dynamics and hot electron generation and propagation is described with a radiative hydrodynamics code using an inline model based on Paraxial Complex Geometrical Optics [Colaïtis et al., Phys. Rev. E 92, 041101 (2015)]. Two targets are considered: the pure-DT HiPER target and a CH-DT design with baseline spike powers of the order of 200–300 TW. In both cases, accounting for the LPI-generated HEs leads to non-igniting targets whenmore » using the baseline spike powers. While HEs are found to increase the ignitor shock pressure, they also preheat the bulk of the imploding shell, notably causing its expansion and contamination of the hotspot with the dense shell material before the time of shock convergence. The associated increase in hotspot mass (i) increases the ignitor shock pressure required to ignite the fusion reactions and (ii) significantly increases the power losses through Bremsstrahlung X-ray radiation, thus rapidly cooling the hotspot. These effects are less prominent for the CH-DT target where the plastic ablator shields the lower energy LPI-HE spectrum. Simulations using higher laser spike powers of 500 TW suggest that the CH-DT capsule marginally ignites, with an ignition window width significantly smaller than without LPI-HEs, and with three quarters of the baseline target yield. The latter effect arises from the relation between the shock launching time and the shell areal density, which becomes relevant in presence of a LPI-HE preheating.« less
Inertial confinement fusion and fast ignitor studies
NASA Astrophysics Data System (ADS)
Willi, O.; Barringer, L.; Bell, A.; Borghesi, M.; Davies, J.; Gaillard, R.; Iwase, A.; MacKinnon, A.; Malka, G.; Meyer, C.; Nuruzzaman, S.; Taylor, R.; Vickers, C.; Hoarty, D.; Gobby, P.; Johnson, R.; Watt, R. G.; Blanchot, N.; Canaud, B.; Croso, H.; Meyer, B.; Miquel, J. L.; Reverdin, C.; Pukhov, A.; Meyer-ter-Vehn, J.
2000-03-01
Laser imprinting has been studied and, in particular, saturation of areal density perturbations induced by near single mode laser imprinting was observed. Several issues important for the foam buffered direct drive scheme have been investigated. These studies included measurements of the absolute levels of stimulated Brillouin and Raman scattering observed from laser irradiated low density foam targets, either bare or overcoated with a thin layer of gold. A novel scheme is proposed to increase the pressure in indirectly driven targets. By heating a foam supersonically that is attached to a solid target the pressure generated is not only the ablation pressure but also the combined pressure due to ablation at the foam-foil interface and the heated foam material. Planar brominated plastic foil targets overcoated with a low density foam were irradiated by a soft X ray pulse. The pressure was obtained by comparing the rear side trajectory of the driven target observed by soft X ray radiography with one dimensional radiation hydrodynamic simulations. Observations were also carried out of the transition from supersonic to subsonic propagation of an ionization front in low density chlorinated foam targets irradiated by an intense soft X ray pulse. The diagnostic for these measurements was K shell point projection absorption spectroscopy. In the fast ignitor area the channelling and guiding of picosecond laser pulses through underdense plasmas, preformed density channels and microtubes were investigated. It was observed that a large fraction of the incident laser energy can be propagated. Megagauss magnetic fields were measured, with a polarimetric technique, during and after propagation of intense picosecond pulses in preionized plasmas. Two types of toroidal fields, of opposite orientation, were detected. In addition, the production and propagation of an electron beam through solid glass targets irradiated at intensities above 1019W/cm2 were observed using optical probing techniques.
Influence of laser induced hot electrons on the threshold for shock ignition of fusion reactions
NASA Astrophysics Data System (ADS)
Colaïtis, A.; Ribeyre, X.; Le Bel, E.; Duchateau, G.; Nicolaï, Ph.; Tikhonchuk, V.
2016-07-01
The effects of Hot Electrons (HEs) generated by the nonlinear Laser-Plasma Interaction (LPI) on the dynamics of Shock Ignition Inertial Confinement Fusion targets are investigated. The coupling between the laser beam, plasma dynamics and hot electron generation and propagation is described with a radiative hydrodynamics code using an inline model based on Paraxial Complex Geometrical Optics [Colaïtis et al., Phys. Rev. E 92, 041101 (2015)]. Two targets are considered: the pure-DT HiPER target and a CH-DT design with baseline spike powers of the order of 200-300 TW. In both cases, accounting for the LPI-generated HEs leads to non-igniting targets when using the baseline spike powers. While HEs are found to increase the ignitor shock pressure, they also preheat the bulk of the imploding shell, notably causing its expansion and contamination of the hotspot with the dense shell material before the time of shock convergence. The associated increase in hotspot mass (i) increases the ignitor shock pressure required to ignite the fusion reactions and (ii) significantly increases the power losses through Bremsstrahlung X-ray radiation, thus rapidly cooling the hotspot. These effects are less prominent for the CH-DT target where the plastic ablator shields the lower energy LPI-HE spectrum. Simulations using higher laser spike powers of 500 TW suggest that the CH-DT capsule marginally ignites, with an ignition window width significantly smaller than without LPI-HEs, and with three quarters of the baseline target yield. The latter effect arises from the relation between the shock launching time and the shell areal density, which becomes relevant in presence of a LPI-HE preheating.
Proof-of-Concept Experiments on a Gallium-Based Ignitron for Pulsed Power Applications
NASA Technical Reports Server (NTRS)
Ali, H. K.; Hanson, V. S.; Polzin, K. A.; Pearson, J. B.
2015-01-01
Ignitrons are electrical switching devices that operate at switching times that are on the order of microseconds, can conduct high currents of thousands of amps, and are capable of holding off tens of thousands of volts between pulses. They consist of a liquid metal pool within an evacuated tube that serves both the cathode and the source of atoms and electrons for an arc discharge. Facing the liquid metal pool is an anode suspended above the cathode, with a smaller ignitor electrode tip located just above the surface of the cathode. The ignitron can be charged to significant voltages, with a potential difference of thousands of volts between anode and cathode. When an ignition pulse is delivered from the ignitor electrode to the cathode, a small amount of the liquid metal is vaporized and subsequently ionized, with the high voltage between the anode and cathode causing the gas to bridge the gap between the two electrodes. The electrons and ions move rapidly towards the anode and cathode, respectively, with the ions liberating still more atoms from the liquid metal cathode surface as a high-current plasma arc discharge is rapidly established. This arc continues in a self-sustaining fashion until the potential difference between the anode and cathode drops below some critical value. Ignitrons have been used in a variety of pulsed power applications, including the railroad industry, industrial chemical processing, and high-power arc welding. In addition, they might prove useful in terrestrial power grid applications, serving as high-current fault switches, quickly shunting dangerous high-current or high-voltage spikes safely to ground. The motivation for this work stemmed from the fact that high-power, high-reliability, pulsed power devices like the ignitron have been used for ground testing in-space pulsed electric thruster technologies, and the continued use of ignitrons could prove advantageous to the future development and testing of such thrusters. Previous ignitron designs have used mercury as the liquid metal cathode, owing to its presence as a liquid at room temperatures and a vapor pressure of 10 Pa (75 mtorr) at room temperature. While these are favorable properties, there are obvious environmental and personal safety concerns with the storage, handling, and use of mercury and its compounds. The purpose of the present work was to fabricate and test an ignitron that used as its cathode an alternate liquid metal that was safe to handle and store. To that end, an ignitron test article that used liquid gallium as the cathode material was developed and tested. Gallium is a metal that has a melting temperature of 29.76 C, which is slightly above room temperature, and a boiling point of over 2,300 C at atmospheric pressure. This property makes gallium the element with the largest relative difference between melting and boiling points. Gallium has a limited role in biology, and when ingested, it will be subsequently processed by the body and expelled rather than accumulating to toxic levels. The next section of this Technical Memorandum (TM) provides background information on the development of mercury-based ignitrons, which serves as the starting point for the development of the gallium-based variant. Afterwards, the experimental hardware and setup used in proof-of-concept testing of a basic gallium ignitron are presented. Experimental data, consisting of discharge voltage and current waveforms as well as high-speed imaging of the gallium arc discharge in the gallium ignitron test article, are presented to demonstrate the efficacy of the concept. Discussion of the data and suggestions on improvements for future iterations of the design are presented in the final two sections of this TM.
Weldon, W.F.
1996-05-07
The railplug is a plasma ignitor capable of injecting a high energy plasma jet into a combustion chamber of an internal combustion engine or continuous combustion system. An improved railplug is provided which has dual coaxial chambers (either internal or external to the center electrode) that provide for forced convective cooling of the electrodes using the normal pressure changes occurring in an internal combustion engine. This convective cooling reduces the temperature of the hot spot associated with the plasma initiation point, particularly in coaxial railplug configurations, and extends the useful life of the railplug. The convective cooling technique may also be employed in a railplug having parallel dual rails using dual, coaxial chambers. 10 figs.
NASA Technical Reports Server (NTRS)
Magnotti, F.; Diskin, G.; Matulaitis, J.; Chinitz, W.
1984-01-01
The use of silane (SiH4) as an effective ignitor and flame stabilizing pilot fuel is well documented. A reliable chemical kinetic mechanism for prediction of its behavior at the conditions encountered in the combustor of a SCRAMJET engine was calculated. The effects of hydrogen addition on hydrocarbon ignition and flame stabilization as a means for reduction of lengthy ignition delays and reaction times were studied. The ranges of applicability of chemical kinetic models of hydrogen-air combustors were also investigated. The CHARNAL computer code was applied to the turbulent reaction rate modeling.
Weldon, William F.
1996-01-01
The railplug is a plasma ignitor capable of injecting a high energy plasma jet into a combustion chamber of an internal combustion engine or continuous combustion system. An improved railplug is provided which has dual coaxial chambers (either internal or external to the center electrode) that provide for forced convective cooling of the electrodes using the normal pressure changes occurring in an internal combustion engine. This convective cooling reduces the temperature of the hot spot associated with the plasma initiation point, particularly in coaxial railplug configurations, and extends the useful life of the railplug. The convective cooling technique may also be employed in a railplug having parallel dual rails using dual, coaxial chambers.
Overview of NASA's Pulsed Plasma Thruster Development Program
NASA Technical Reports Server (NTRS)
Pencil, Eric J.; Kamhawi, Hani; Arrington, Lynn A.
2004-01-01
NASA's Pulsed Plasma Thruster Program consists of flight demonstration experiments, base research, and development efforts being conducted through a combination of in-house work, contracts, and collaborative programs. The program receives sponsorship from Energetics Project, the New Millennium Program, and the Small Business Innovative Research Program. The Energetics Project sponsors basic and fundamental research to increase thruster life, improve thruster performance, and reduce system mass. The New Millennium Program sponsors the in-orbit operation of the Pulsed Plasma Thruster experiment on the Earth Observing 1 spacecraft. The Small Business Innovative Research Program sponsors the development of innovative diamond-film capacitors, piezoelectric ignitors, and advanced fuels. Programmatic background, recent technical accomplishments, and future activities for each programmatic element are provided.
Relevance of advanced nuclear fusion research: Breakthroughs and obstructions
DOE Office of Scientific and Technical Information (OSTI.GOV)
Coppi, Bruno, E-mail: coppi@mit.edu
2016-03-25
An in depth understanding of the collective modes that can be excited in a wide range of high-energy plasmas is necessary to advance nuclear fusion research in parallel with other fields that include space and astrophysics in particular. Important achievements are shown to have resulted from implementing programs based on this reality, maintaining a tight connection with different areas of investigations. This involves the undertaking of a plurality of experimental approaches aimed at understanding the physics of fusion burning plasmas. At present, the most advanced among these is the Ignitor experiment involving international cooperation, that is designed to investigate burningmore » plasma regimes near ignition for the first time.« less
Fluidized bed boiler having a segmented grate
Waryasz, Richard E.
1984-01-01
A fluidized bed furnace (10) is provided having a perforate grate (9) within a housing which supports a bed of particulate material including some combustibles. The grate is divided into a plurality of segments (E2-E6, SH1-SH5, RH1-RH5), with the airflow to each segment being independently controlled. Some of the segments have evaporating surface imbedded in the particulate material above them, while other segments are below superheater surface or reheater surface. Some of the segments (E1, E7) have no surface above them, and there are ignitor combustors (32, 34) directed to fire into the segments, for fast startup of the furnace without causing damage to any heating surface.
Early, James W.; Lester, Charles S.
2002-01-01
Optical fiber switches operated by electrical activation of at least one laser light modulator through which laser light is directed into at least one polarizer are used for the sequential transport of laser light from a single laser into a plurality of optical fibers. In one embodiment of the invention, laser light from a single excitation laser is sequentially transported to a plurality of optical fibers which in turn transport the laser light to separate individual remotely located laser fuel ignitors. The invention can be operated electro-optically with no need for any mechanical or moving parts, or, alternatively, can be operated electro-mechanically. The invention can be used to switch either pulsed or continuous wave laser light.
PROGRESS ON THE STUDY OF BETA TREATMENT OF URANIUM, DECEMBER 1, 1962 TO MARCH 31, 1962
DOE Office of Scientific and Technical Information (OSTI.GOV)
Russell, R.B.; Wolff, A.K.
The effects of composition (ingot vs dingot), prior delta condition, geometry, heat treatment, and applied stress on cooling rate, grain size, and texture are described for U rods and tubes. Investigations were also made on the effect of stress and free surfaces on the texture distribution. Cooling rates were obtained for the quenching of 3- and 1.5-in. OD tubes with a 0.5-in. ID in different media, including a comparison of the rates between room temperature Houghto K and Poco No. 2 oils. The quenching rate in Houghto K was slightly greater. A study of 1.5-in. OD by 0.5-in. ID as-extrudedmore » dingot tube quenched from the beta phase into different media showed that the FEDC grain size of water- quenched tube varied between A-6 and A-7, that oil quenching produced grains between C-4 and C-5, and that the air-cooled tube had B-2 to B-3 grain size. Both ingot and dingot were similar in exhibiting severe radial texture penetration after water quenches. In general, both ingot and dingot have the same range of radial G/sub 3/ values, but with different G/sub 3/ distributions. (P.C.H.)« less
Utility experience of Phase I compliance on Chalk Point Unit 2
DOE Office of Scientific and Technical Information (OSTI.GOV)
Eberhardt, W.H.; Henry, R.J.
1995-03-01
Potomac Electric Power Company`s Chalk Point Generating Station Unit 2 has recently undergone a retrofit to comply with Phase I of the 1990 Clean Air Act Amendments (CAAA) Title IV requirements. The approach taken was to install low NOx burners and overfire air to reduce NOx emissions and switch to lower sulfur coal to comply with Phase I sulfur dioxide (SO{sub 2}) emission limits. This approach was chosen based on a unique combination of sophisticated tools, boiler modeling, experience, testing, and cooperation between the Owners, Engineers, and the equipment Manufacturers. The result was a project performed at a reasonable costmore » and minimum risk to plant reliability and performance while meeting the specified requirements of the regulations. The Unit 2 retrofit will be followed by the retrofit of its identical sister unit, Unit 1, in the late fall of 1994. In addition to the Low NOx system retrofit and coal switching, a new distributed control system (DCS), burner management system (BMS), new ignitors, and the capability to fire natural gas on both main burners and ignitors was added. A four month outage was followed by a series of optimization tests which were designed to reduce the emissions to the compliance limit while minimizing impacts on the boiler operation. After boiler startup, burner and pulverizer performance adjustments were required resulting in dramatic improvement in both boiler and burner performance. This paper describes the approach towards achieving CAAA compliance and the net results: impacts of the Low NOx system and the Phase I coal on the boiler and auxiliary plant equipment and the adjustments which had to be made to eliminate initial operating problems. Results of months of optimization testing are presented as related to emissions, furnace slagging, flame shape, unburned carbon, steam temperatures, and tube metal temperatures.« less
Starting procedure for internal combustion vessels
Harris, Harry A.
1978-09-26
A vertical vessel, having a low bed of broken material, having included combustible material, is initially ignited by a plurality of ignitors spaced over the surface of the bed, by adding fresh, broken material onto the bed to buildup the bed to its operating depth and then passing a combustible mixture of gas upwardly through the material, at a rate to prevent back-firing of the gas, while air and recycled gas is passed through the bed to thereby heat the material and commence the desired laterally uniform combustion in the bed. The procedure permits precise control of the air and gaseous fuel mixtures and material rates, and permits the use of the process equipment designed for continuous operation of the vessel.
High pressure generation by hot electrons driven ablation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Piriz, A. R.; Piriz, S. A.; Tahir, N. A.
2013-11-15
A previous model [Piriz et al. Phys. Plasmas 19, 122705 (2012)] for the ablation driven by the hot electrons generated in collisionless laser-plasma interactions in the framework of shock ignition is revisited. The impact of recent results indicating that for a laser wavelength λ = 0.35 μm the hot electron temperature θ{sub H} would be independent of the laser intensity I, on the resulting ablation pressure is considered. In comparison with the case when the scaling law θ{sub H}∼(Iλ{sup 2}){sup 1/3} is assumed, the generation of the high pressures needed for driving the ignitor shock may be more demanding. Intensitiesmore » above 10{sup 17} W/cm{sup 2} would be required for θ{sub H}=25−30 keV.« less
Laser controlled flame stabilization
Early, James W.; Thomas, Matthew E.
2001-01-01
A method and apparatus is provided for initiating and stabilizing fuel combustion in applications such as gas turbine electrical power generating engines and jet turbine engines where it is desired to burn lean fuel/air mixtures which produce lower amounts of NO.sub.x. A laser induced spark is propagated at a distance from the fuel nozzle with the laser ignitor being remotely located from the high temperature environment of the combustion chamber. A laser initiating spark generated by focusing high peak power laser light to a sufficiently tight laser spot within the fuel to cause the ionization of air and fuel into a plasma is unobtrusive to the flow dynamics of the combustion chamber of a fuel injector, thereby facilitating whatever advantage can be taken of flow dynamics in the design of the fuel injector.
Guiding of relativistic electron beams in solid targets by resistively controlled magnetic fields.
Kar, S; Robinson, A P L; Carroll, D C; Lundh, O; Markey, K; McKenna, P; Norreys, P; Zepf, M
2009-02-06
Guided transport of a relativistic electron beam in solid is achieved experimentally by exploiting the strong magnetic fields created at the interface of two metals of different electrical resistivities. This is of substantial relevance to the Fast Ignitor approach to fusion energy production [M. Tabak, Phys. Plasmas 12, 057305 (2005)10.1063/1.1871246], since it allows the electron deposition to be spatially tailored-thus adding substantial design flexibility and preventing inefficiencies due to electron beam spreading. In the experiment, optical transition radiation and thermal emission from the target rear surface provide a clear signature of the electron confinement within a high resistivity tin layer sandwiched transversely between two low resistivity aluminum slabs. The experimental data are found to agree well with numerical simulations.
Low Current Surface Flashover for Initiation of Electric Propulsion Devices
NASA Astrophysics Data System (ADS)
Dary, Omar G.
There has been a recent increase in interest in miniaturization of propulsion systems for satellites. These systems are needed to propel micro- and nano-satellites, where platforms are much smaller than conventional satellites and require smaller levels of thrust. Micro-propulsion systems for these satellites are in their infancy and they must manage with smaller power systems and smaller propellant volumes. Electric propulsion systems operating on various types of electric discharges are typically used for these needs. One of the central components of such electrical micropropulsion systems are ignitor subsystems, which are required for creation the breakdown and initiation of the main discharge. Ignitors have to provide reliable ignition for entire lifetime of the micropropulsion system. Electric breakdown in vacuum usually require high voltage potentials of hundreds of kilovolts per mm to induce breakdown. The breakdown voltage can be significantly decreased (down to several kVs per mm) if dielectric surface flashover is utilized. However, classical dielectric surface flashover operates at large electric current (100s of Amperes) and associated with overheating and damage of the electrodes/dielectric assembly after several flashover events. The central idea of this work was to eliminate the damage to the flashover electrode assembly by limiting the flashover currents to low values in milliampere range (Low Current Surface Flashover -LCSF) and utilize LCSF system as an ignition source for the main discharge on the micropropulsion system. The main objective of this research was to create a robust LCSF ignition system, capable producing a large number of surface flashover triggering events without significant damage to the LCSF electrode assembly. The thesis aims to characterize the plasma plume created at LCSF, study electrodes ablation and identify conditions required for robust triggering of main discharge utilized on micro-propulsion system. Conditioning of a new LCSF assembly (flashover current was limited to <100 mA in all experiments) was measured and breakdown voltages in the range of 8kV to 12kV were observed for the fully conditioned assembly. No damage to the LCSF electrode assembly was observed after about 104 LCSF events. The LCSF assembly created sufficient amount of seed plasma in order to bridge a vacuum gap between the high-current electrodes and to reliably ignite high-current arcs (10A-12A arc were used in this work). Ignition of the high-current arc was observed at three different cases of LCSF with limiting currents 100 mA, 33 mA and 20 mA respectively. Plasma parameter measurements were conducted with variety of Langmuir probes inside the LCSF plume. Ion currents created by the LCSF were primarily expelled directly perpendicular from the insulator surface. The plasma expansion for the LCSF assembly was measured to be 2 x 106-6 x 106 cm/s. Plasma density was measured to range 10 10-1011 cm-3. The plasma density was maximal near the LCSF assembly and quickly reduced radially. Temporal decay of the plasma was observed on a time scale of about 5 micros after the LCSF event. The results of this work are significant for creation of ignitor for micropropulsion systems. LCSF system offers reliable triggering for numerous ignition pulses for entire lifetime of the micropropulsion system and reduces complexity and volume of the system by excluding moving parts and the need for an external gas tanks.
The effect of travel speed on thermal response in CO2 laser welding of small electronic components
NASA Astrophysics Data System (ADS)
Gianoulakis, S. E.; Burchett, S. N.; Fuerschbach, P. W.; Knorovsky, G. A.
A comprehensive three-dimensional numerical investigation of the effect of beat source travel speed on temperatures and resulting thermal stresses was performed for CO2-laser welding. The test specimen was a small thermal battery header containing several stress-sensitive glass-to-metal seals surrounding the electrical connections and a temperature sensitive ignitor located under the header near the center. Predictions of the thermal stresses and temperatures in the battery header were made for several travel speeds of the laser. The travel speeds examined ranged from 10mm/sec to 50mm/sec. The results indicate that faster weld speeds result in lower temperatures and stresses for the same size weld. This is because the higher speed welds are more efficient, requiring less energy to produce a given weld. Less energy absorbed by the workpiece results in lower temperatures, which results in lower stresses.
Basic Research of Strong UV Radiating Pulse Discharge as an Ignitor of Gaseous Mixtures Combustion
2007-07-05
of Gaseous Mixtures Combustion 5a. CONTRACT NUMBER ISTC Registration No: 2681 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...NUMBER(S) ISTC 02-7008 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution is unlimited. 13. SUPPLEMENTARY...договору с Международным научно-техническим центром (МНТЦ), Москва, при финансовой поддержке <Финансирующая Сторона> ISTC Project No. 2681p Basic
Advanced Fuel Cycles for Fusion Reactors: Passive Safety and Zero-Waste Options
NASA Astrophysics Data System (ADS)
Zucchetti, Massimo; Sugiyama, Linda E.
2006-05-01
Nuclear fusion is seen as a much ''cleaner'' energy source than fission. Most of the studies and experiments on nuclear fusion are currently devoted to the Deuterium-Tritium (DT) fuel cycle, since it is the easiest way to reach ignition. The recent stress on safety by the world's community has stimulated the research on other fuel cycles than the DT one, based on 'advanced' reactions, such as the Deuterium-Helium-3 (DHe) one. These reactions pose problems, such as the availability of 3He and the attainment of the higher plasma parameters that are required for burning. However, they have many advantages, like for instance the very low neutron activation, while it is unnecessary to breed and fuel tritium. The extrapolation of Ignitor technologies towards a larger and more powerful experiment using advanced fuel cycles (Candor) has been studied. Results show that Candor does reach the passive safety and zero-waste option. A fusion power reactor based on the DHe cycle could be the ultimate response to the environmental requirements for future nuclear power plants.
Method for fabricating an ignitable heterogeneous stratified metal structure
Barbee, Jr., Troy W.; Weihs, Timothy
1996-01-01
A multilayer structure has a selectable, (i) propagating reaction front velocity V, (ii) reaction initiation temperature attained by application of external energy and (iii) amount of energy delivered by a reaction of alternating unreacted layers of the multilayer structure. Because V is selectable and controllable, a variety of different applications for the multilayer structures are possible, including but not limited to their use as ignitors, in joining applications, in fabrication of new materials, as smart materials and in medical applications and devices. The multilayer structure has a period D, and an energy release rate constant K. Two or more alternating unreacted layers are made of different materials and separated by reacted zones. The period D is equal to a sum of the widths of each single alternating reaction layer of a particular material, and also includes a sum of reacted zone widths, t.sub.i, in the period D. The multilayer structure has a selectable propagating reaction front velocity V, where V=K(1/D.sup.n).times.[1-(t.sub.i /D)]and n is about 0.8 to 1.2.
Development and Testing of a Green Monopropellant Ignition System
NASA Technical Reports Server (NTRS)
Whitmore, Stephen A.; Merkley, Daniel P.; Eilers, Shannon D.; Judson, Michael I.; Taylor, Terry L.
2013-01-01
This paper will detail the development and testing of a "green" monopropellant booster ignition system. The proposed booster ignition technology eliminates the need for a pre-heated catalyst bed, a high wattage power source, toxic pyrophoric ignition fluids, or a bi-propellant spark ignitor. The design offers the simplicity of a monopropellant feed system features non-hazardous gaseous oxygen (GOX) as the working fluid. The approach is fundamentally different from all other "green propellant" solutions in the aerospace in the industry. Although the proposed system is more correctly a "hybrid" rocket technology, since only a single propellant feed path is required, it retains all the simple features of a monopropellant system. The technology is based on the principle of seeding an oxidizing flow with a small amount of hydrocarbon.1 The ignition is initiated electrostatically with a low-wattage inductive spark. Combustion gas byproducts from the hydrocarbon-seeding ignition process can exceed 2400 C and the high exhaust temperature ensures reliable main propellant ignition. The system design is described in detail in the Hydrocarbon-Seeded Ignition System Design subsection.
Two-Dimensional Simulations of Electron Shock Ignition at the Megajoule Scale
NASA Astrophysics Data System (ADS)
Shang, W.; Betti, R.
2016-10-01
Shock ignition uses a late strong shock to ignite the hot spot of an inertial confinement fusion capsule. In the standard shock-ignition scheme, an ignitor shock is launched by the ablation pressure from a spike in laser intensity. Recent experiments on OMEGA have shown that focused beams with intensity up to 6 ×1015 W /cm2 can produce copious amounts of hot electrons. The hot electrons are produced by laser-plasma instabilities (LPI's) and can carry up to 15 % of the instantaneous laser power. Megajoule-scale targets will likely produce even more hot electrons because of the large plasma scale length. We show that it is possible to design ignition targets with low implosion velocities that can be shock ignited using LPI-generated hot electrons to obtain high energy gains. These designs are robust to low-mode asymmetries and they ignite even for highly distorted implosions. Electron shock ignition requires tens of kilojoules of hot electrons, which can only be produced on a large laser facility like the National Ignition Facility. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.
Barbee, Jr., Troy W.; Weihs, Timothy
1996-01-01
A multilayer structure has a selectable, (i) propagating reaction front velocity V, (ii) reaction initiation temperature attained by application of external energy and (iii) amount of energy delivered by a reaction of alternating unreacted layers of the multilayer structure. Because V is selectable and controllable, a variety of different applications for the multilayer structures are possible, including but not limited to their use as ignitors, in joining applications, in fabrication of new materials, as smart materials and in medical applications and devices. The multilayer structure has a period D, and an energy release rate constant K. Two or more alternating unreacted layers are made of different materials and separated by reacted zones. The period D is equal to a sum of the widths of each single alternating reaction layer of a particular material, and also includes a sum of reacted zone widths, t.sub.i, in the period D. The multilayer structure has a selectable propagating reaction front velocity V, where V=K(1/D.sup.n).times.[1-(t.sub.i /D)] and n is about 0.8 to 1.2.
Plasma Chamber and First Wall of the Ignitor Experiment^*
NASA Astrophysics Data System (ADS)
Cucchiaro, A.; Coppi, B.; Bianchi, A.; Lucca, F.
2005-10-01
The new designs of the Plasma Chamber (PC) and of the First Wall (FW) system are based on updated scenarios for vertical plasma disruption (VDE) as well as estimates for the maximum thermal wall loadings at ignition. The PC wall thickness has been optimized to reduce the deformation during the worst disruption event without sacrificing the dimensions of the plasma column. A non linear dynamic analysis of the PC has been performed on a 360^o model of it, taking into account possible toroidal asymmetries of the halo current. Radial EM loads obtained by scaling JET measurements have been also considered. The low-cycle fatigue analysis confirms that the PC is able to meet a lifetime of few thousand cycles for the most extreme combinations of magnetic fields and plasma currents. The FW, made of Molybdenum (TZM) tiles covering the entire inner surface of the PC, has been designed to withstand thermal and EM loads, both under normal operating conditions and in case of disruption. Detailed elasto-plastic structural analyses of the most (EM) loaded tile-carriers show that these are compatible with the adopted fabrication requirements. ^*Sponsored in part by ENEA of Italy and by the U.S. DOE.
Modeling of SSME fuel preburner ASI
NASA Technical Reports Server (NTRS)
Liang, Pak-Yan
1992-01-01
The Augmented Spark Ignitor (ASI) is a LOX/H2/electrical spark system that functions as an ignition source and sustainer for stable combustion. It is used in the Space Shuttle Main Engine (SSME) preburner combustor, the SMME main combustion chamber, the J-1 and J-2 engines, as well as proposed designs of the Space Transportation Main Engine (STME) main combustor and gas generators. An undertaking to characterize the flow of the ASI is documented. The code consists of a marriage of the Implicit-Continuous Eulerian/Arbitrary Lagrangian Code (ICE-ALE) Navier-Stokes solver with the Volume-of-Fluid (VOF) Methodology for tracking of two immiscible fluids with sharp discontinuities. Spray droplets are represented by discrete numerical parcels tracked in a Lagrangian fashion. Numerous physical sub-models are also incorporated to describe the processes of atomization, droplet collision, droplet breakup, evaporation, and droplet and gas phase turbulence. An equilibrium chemistry model accounting for 8 active gaseous species is also used. Taking advantage of this symmetry plane, half of the actual ASI is modeled with a 3-D grid that geometrically resolves the LOX ports, the spark plug locations, and the hydrogen injection slots.
The PLX- α Plasma Guns: Progress and Plans
NASA Astrophysics Data System (ADS)
Witherspoon, F. D.; Brockington, S.; Case, A.; Cruz, E.; Luna, M.; Thio, Y. C. Francis; LANL PLX-α Team
2017-10-01
The ALPHA coaxial plasma guns are being developed to support a 60-gun scaling study of spherically imploding plasma liners as a standoff driver for plasma-jet-driven magneto-inertial fusion (PJMIF). Seven complete guns have been delivered to LANL with 6 guns currently undergoing simultaneous test firings on PLX. The guns are designed to operate over a range of parameters: 0.5-5.0 mg of Ar, Ne, N2, Kr, and Xe; 20-60 km/s; 2 × 1016 cm-3 muzzle density; and up to 7.5 kJ stored energy per gun. Each coaxial gun incorporates a fast dense gas injection and triggering system, a compact low-weight pfn with integral sparkgap switching, and a contoured coaxial gap to suppress the blow-by instability. Optimizing parameter scans performed at HyperV have achieved : 4 mg at >50 km/s and length of 10 cm. Peak axial density 30 cm from the muzzle is 2 ×1016 cm-3. We will provide an overview of the experimental results, along with plans for further improvements in reliability, maintainability, fabricability, and plasma jet performance, with the latter focused on further improvements in the fast gas valve and the ignitors. This work supported by the ARPA-E ALPHA Program under contract DE-AR0000566 and Strong Atomics, LLC.
NASA Astrophysics Data System (ADS)
Mehrangiz, M.; Ghasemizad, A.
2017-06-01
Deuteron fast ignition of a conically guided pre-compressed DT fuel is investigated. For this purpose, the acceleration of the deuterated thin foil by the intense laser beam is evaluated. The acceleration values and the number of foil-generated deuterons are calculated in terms of the laser pulse duration. Using the created deuterons as the fast ignitors, we investigate the fast ignition scheme by comparing fully degenerate, partial degenerate and classical types of DT plasma. The total energy gain of deuterons "beam fusion" is calculated to show the efficiency of beam reactions in increasing fusion rate. Besides, the stopping time and stopping range of incident deuterons are evaluated. Our numerical results indicate that degeneracy increases the beam-target collisions. Thus, it prepares the ignition situation sooner than the classical plasma. Moreover, the number of generated deuterons and their acceleration depend on the foil thickness and laser parameters. We show that when a 4ps laser with intensity of 10^{19} W/cm^2 focused onto a 20μm foil, 35× 10^{15} deuterons are generated. Moreover, under our analysis, in order to have a practicable fast ignition, 18% of the laser energy is necessary to convert into a deuteron driver.
Disruptions generated runaways in the FTU high field tokamak
NASA Astrophysics Data System (ADS)
Poli, F. M.; Esposito, B.; Maddaluno, G.; Martin-Solis, J. R.
2001-10-01
Disruptions in FTU are usually accompanied by the generation of a strong pulse of photoneutrons (YN 10^12n/s), resulting from photonuclear reactions induced by the bremsstrahlung radiation emitted when runaway electrons (REs) strike the plasma facing components. Measurements of YN during major disruptions on TS [1] showed variations of three orders of magnitude when the toroidal field Bt increases from 1.8T to 3.9T. Similar results were found on JT-60 [2], where no REs are produced for low Bt (<2.2T) and a large YN was measured for higher fields (up to 4T). The range of Bt available in FTU (4T-8T) allows to extend such analysis so that useful predictions can be obtained for operation in next-step high field tokamaks (IGNITOR, ITER). The dependence of YN on Bt is investigated in several FTU disruptions. YN increases with Bt for B_t=4T-6T, while no variation is found for B_t=6T-8T: the role played by ne and Ip on such trend is discussed. [1]P.Joyer,G.Martin,Contr.Fusion and Plasma Heating,Proc.17^thEPS Conf.Amsterdam(1990) [2]R.Yoshino et al.,Nucl.Fus.39 151 (1999)
NASA Technical Reports Server (NTRS)
Fendell, Francis; Rungaldier, Harald
1999-01-01
An experimental apparatus for the examination of a planar, virtually strain-rate-free diffusion flame in microgravity has been designed and fabricated. Such a diffusion flame is characterized by relatively large spatial scale and high symmetry (to facilitate probing), and by relatively long fluid-residence time (to facilitate investigation of rates associated with sooting phenomena). Within the squat rectangular apparatus, with impervious, noncatalytic isothermal walls of stainless steel, a thin metallic splitter plate subdivides the contents into half-volumes. One half-volume initially contains fuel vapor diluted with an inert gas, and the other, oxidizer diluted with another inert gas-so that the two domains have equal pressure, density, and temperature. As the separator is removed, by translation in its own plane, through a tightly fitting slit in one side wall, a line ignitor in the opposite side wall initiates a triple-flame propagation across the narrow layer of combustible mixture formed near midheight in the chamber. The planar diffusion flame so emplaced is quickly disrupted in earth gravity. In microgravity, the planar flame persists, and travels ultimately into the half-volume containing the stoichiometrically deficient reactant; the flame eventually becomes extinguished owing to reactant depletion and heat loss to the walls.
Evaluation of externally heated pulsed MPD thruster cathodes
NASA Astrophysics Data System (ADS)
Myers, Roger M.; Domonkos, Matthew; Gallimore, Alec D.
1993-12-01
Recent interest in solar electric orbit transfer vehicles (SEOTV's) has prompted a reevaluation of pulsed magnetoplasmadynamic (MPD) thruster systems due to their ease of power scaling and reduced test facility requirements. In this work the use of externally heated cathodes was examined in order to extend the lifetime of these thrusters to the 1000 to 3000 hours required for SEOTV missions. A pulsed MPD thruster test facility was assembled, including a pulse-forming network (PFN), ignitor supply and propellant feed system. Results of cold cathode tests used to validate the facility, PFN, and propellant feed system design are presented, as well as a preliminary evaluation of externally heated impregnated tungsten cathodes. The cold cathode thruster was operated on both argon and nitrogen propellants at peak discharge power levels up to 300 kW. The results confirmed proper operation of the pulsed thruster test facility, and indicated that large amounts of gas were evolved from the BaO-CaO-Al2O3 cathodes during activation. Comparison of the expected space charge limited current with the measured vacuum current when using the heated cathode indicate that either that a large temperature difference existed between the heater and the cathode or that the surface work function was higher than expected.
Evaluation of externally heated pulsed MPD thruster cathodes
NASA Technical Reports Server (NTRS)
Myers, Roger M.; Domonkos, Matthew; Gallimore, Alec D.
1993-01-01
Recent interest in solar electric orbit transfer vehicles (SEOTV's) has prompted a reevaluation of pulsed magnetoplasmadynamic (MPD) thruster systems due to their ease of power scaling and reduced test facility requirements. In this work the use of externally heated cathodes was examined in order to extend the lifetime of these thrusters to the 1000 to 3000 hours required for SEOTV missions. A pulsed MPD thruster test facility was assembled, including a pulse-forming network (PFN), ignitor supply and propellant feed system. Results of cold cathode tests used to validate the facility, PFN, and propellant feed system design are presented, as well as a preliminary evaluation of externally heated impregnated tungsten cathodes. The cold cathode thruster was operated on both argon and nitrogen propellants at peak discharge power levels up to 300 kW. The results confirmed proper operation of the pulsed thruster test facility, and indicated that large amounts of gas were evolved from the BaO-CaO-Al2O3 cathodes during activation. Comparison of the expected space charge limited current with the measured vacuum current when using the heated cathode indicate that either that a large temperature difference existed between the heater and the cathode or that the surface work function was higher than expected.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
This final safety evaluation report (FSER) documents the technical review of the System 80+ standard design by the US Nuclear Regulatory Commission (NRC) staff. The application for the System 80+ design was submitted by Combustion Engineering, Inc., now Asea Brown Boveri-Combustion Engineering (ABB-CE) as an application for design approval and subsequent design certification pursuant to 10 CFR {section} 52.45. System 80+ is a pressurized water reactor with a rated power of 3914 megawatts thermal (MWt) and a design power of 3992 MWt at which accidents are analyzed. Many features of the System 80+ are similar to those of Abb-CE`s Systemmore » 80 design from which it evolved. Unique features of the System 80+ design included: a large spherical, steel containment; an in-containment refueling water storage tank; a reactor cavity flooding system, hydrogen ignitors, and a safety depressurization system for severe accident mitigation; a combustion gas turbine for an alternate ac source; and an advanced digitally based control room. On the basis of its evaluation and independent analyses, the NRC staff concludes that ABB-CE`s application for design certification meets the requirements of Subpart B of 10 CFR Part 52 that are applicable and technically relevant to the System 80+ standard design. This document, Volume 1, contains Chapters 1 through 14 of this report.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Not Available
This final safety evaluation report (FSER) documents the technical review of the System 80+ standard design by the US Nuclear Regulatory Commission (NRC) staff. The application for the system 80+ design was submitted by Combustion Engineering, Inc., now Asea Brown Boveri-Combustion Engineering (ABB-CE) as an application for design approval and subsequent design certification pursuant to 10 CFR {section} 52.45. System 80+ is a pressurized water reactor with a rated power of 3914 megawatts thermal (MWt) and a design power of 3992 MWt at which accidents are analyzed. Many features of the System 80+ are similar to those of ABB-CE`s Systemmore » 80 design from which it evolved. Unique features of the System 80+ design include: a large spherical, steel containment; an in-containment refueling water storage tank; a reactor cavity flooding system, hydrogen ignitors and a safety depressurization system for severe accident mitigation; a combustion gas turbine for an alternate ac source; and an advanced digitally based control room. On the basis of its evaluation and independent analyses, the NRC staff concludes that ABB-CE`s application for design certification meets the requirements of Subpart B of 10 CFR Part 52 that are applicable and technically relevant to the System 80+ standard design. This document, Volume 2, contains Chapters 15 through 22 and Appendices A through E.« less
Technical Evaluation Motor no. 5 (TEM-5)
NASA Technical Reports Server (NTRS)
Cook, M.
1990-01-01
Technical Evaluation Motor No. 5 (TEM-5) was static test fired at the Thiokol Corporation Static Test Bay T-97. TEM-5 was a full scale, full duration static test fire of a high performance motor (HPM) configuration solid rocket motor (SRM). The primary purpose of TEM static tests is to recover SRM case and nozzle hardware for use in the redesigned solid rocket motor (RSRM) flight program. Inspection and instrumentation data indicate that the TEM-5 static test firing was successful. The ambient temperature during the test was 41 F and the propellant mean bulk temperature (PMBT) was 72 F. Ballistics performance values were within the specified requirements. The overall performance of the TEM-5 components and test equipment was nominal. Dissembly inspection revealed that joint putty was in contact with the inner groove of the inner primary seal of the ignitor adapter-to-forward dome (inner) joint gasket; this condition had not occurred on any previous static test motor or flight RSRM. While no qualification issues were addressed on TEM-5, two significant component changes were evaluated. Those changes were a new vented assembly process for the case-to-nozzle joint and the installation of two redesigned field joint protection systems. Performance of the vented case-to-nozzle joint assembly was successful, and the assembly/performance differences between the two field joint protection system (FJPS) configurations were compared.
Status report on Project Hercules
DOE Office of Scientific and Technical Information (OSTI.GOV)
Loree, D.; Giesselmann, M.; Kristiansen, M.
1993-01-01
Project Hercules is a project to improve ignitron switches which will then be used on the upgrade of Lawrence Livermore's Nova Laser for their ICF program. The goals of Hercules, which stands for High Energy Research Concerning the Ultimate Lifetime of Experimental Switches, are to lifetime test (up to 10,000 shots) prototype ignitrons or other switches with the required Nova current and coulomb parameters (300 kA, 200 C), recommend design changes, and retest the second generation switches. This report describes the design and construction of the test circuit and necessary diagnostics. The details of the design and construction of themore » test circuit and necessary diagnostics. The details of the design and construction of a 0.5 MJ electrolytic capacitor bank and a semi-automatic diagnostic/control system are described. The required test run data include peak current and corresponding tube voltage for every shot, entire current and voltage waveforms every few shots, and ignitor resistance values every few shots. Additionally, the conversion of a 120 kW, 12 kV constant voltage supply to an 8 A constant current supply with the use of six SCRs and a commercial control board will be described. The final results of this project will be lifetime data at high current and high coulomb for and improvements on some of the best of the new generation of pulsed power switches.« less
Fast heating of ultrahigh-density plasma as a step towards laser fusion ignition.
Kodama, R; Norreys, P A; Mima, K; Dangor, A E; Evans, R G; Fujita, H; Kitagawa, Y; Krushelnick, K; Miyakoshi, T; Miyanaga, N; Norimatsu, T; Rose, S J; Shozaki, T; Shigemori, K; Sunahara, A; Tampo, M; Tanaka, K A; Toyama, Y; Yamanaka, T; Zepf, M
2001-08-23
Modern high-power lasers can generate extreme states of matter that are relevant to astrophysics, equation-of-state studies and fusion energy research. Laser-driven implosions of spherical polymer shells have, for example, achieved an increase in density of 1,000 times relative to the solid state. These densities are large enough to enable controlled fusion, but to achieve energy gain a small volume of compressed fuel (known as the 'spark') must be heated to temperatures of about 108 K (corresponding to thermal energies in excess of 10 keV). In the conventional approach to controlled fusion, the spark is both produced and heated by accurately timed shock waves, but this process requires both precise implosion symmetry and a very large drive energy. In principle, these requirements can be significantly relaxed by performing the compression and fast heating separately; however, this 'fast ignitor' approach also suffers drawbacks, such as propagation losses and deflection of the ultra-intense laser pulse by the plasma surrounding the compressed fuel. Here we employ a new compression geometry that eliminates these problems; we combine production of compressed matter in a laser-driven implosion with picosecond-fast heating by a laser pulse timed to coincide with the peak compression. Our approach therefore permits efficient compression and heating to be carried out simultaneously, providing a route to efficient fusion energy production.
Review of Inertial Confinement Fusion
NASA Astrophysics Data System (ADS)
Haines, M. G.
The physics of inertial confinement fusion is reviewed. The trend to short-wavelength lasers is argued, and the distinction between direct and indirect (soft X-ray) drive is made. Key present issues include the non-linear growth of Rayleigh-Taylor (R-T) instabilities, the seeding of this instability by the initial laser imprint, the relevance of self-generated magnetic fields, and the importance of parametric instabilities (stimulated Brillouin and Raman scattering) in gas-filled hohlraums. Experiments are reviewed which explore the R-T instability in both planar and converging geometry. The employment of various optical smoothing techniques is contrasted with the overcoating of the capsule by gold coated plastic foams to reduce considerably the imprint problem. The role of spontaneously generated magnetic fields in non-symmetric plasmas is discussed. Recent hohlraum compression results are presented together with gas bag targets which replicate the long-scale-length low density plasmas expected in NIF gas filled hohlraums. The onset of first Brillouin and then Raman scattering is observed. The fast ignitor scheme is a proposal to use an intense short pulse laser to drill a hole through the coronal plasma and then, with laser excited fast electrons, create a propagating thermonuclear spark in a dense, relatively cold laser-compressed target. Some preliminary results of laser hole drilling and 2-D and 3-D PIC simulations of this and the > 10^8 Gauss self-generated magnetic fields are presented. The proposed National Ignition Facility (NIF) is described.
NASA Technical Reports Server (NTRS)
Pettegrew, Richard Dale
1996-01-01
An experimental study of ignition and flame growth over a thin solid fuel in oxidizer flow speeds from 0 to 10 cm/sec concurrent flow was performed. This study examined the differences between ignition using a resistively heated wire (woven in a sawtooth pattern over the leading edge of the fuel), and a straight resistively heated wire augmented by a chemical ignitor doped onto the leading edge of the fuel. Results showed that the chemical system yielded non-uniform ignition bursts, while the system using only the hotwire gave more uniform ignition. At speeds up to 2.5 cm/sec, the chemical system yielded non-uniform pyrolysis fronts, while the hotwire system gave more uniform pyrolysis fronts. At speeds of 5 cm/sec or greater, both systems gave uniform pyrolysis fronts. The chemically-ignited flames tended to become too dim to see faster than the hotwire-ignited flames, and the flame lengths were observed to be shorter (after the initial burst subsided) for the chemical system for all speeds. Flame and pyrolysis element velocities were measured. Temperature profiles for selected tests were measured using thermocouples at the fuel surface and in the gas phase. Comparisons between the flame element velocities and peak temperatures recorded in these tests with calculated spread rates and peak temperatures from a steady-state model are presented. Agreement was found to be within 20% for most flame elements for nominal velocities of 5 cm/sec and 7.5 cm/sec.
Development and Testing of a Green-Propellant Micro-Hybrid Thruster with Electrostatic Ignition
NASA Technical Reports Server (NTRS)
Whitmore, Stephen A.; Judson, Michael D.
2012-01-01
As early as 1937 German scientists at Peenemunde experimented with highly unstable fuel blends of nitrous oxide (N2O) and ethanol. These early tests mostly resulted in explosions and destroyed rocket engines. More recently several companies have developed experimental nitrous oxide fuel blends (NOFB) with Isp exceeding 300 sec. Although NOFBx has recently been cleared for tests on the International Space Station, this propellant remains highly experimental and has not been cleared for commercial transport by the US DOT. Recent work by Karabeyoglu et al. has raised concerns about the safety risks of mixing hydrocarbons with N2O. Liquid oxidizer/fuel blends are highly explosive and require extreme care in transport and servicing. By adding small amounts of a liquid organic fuel such as alcohol or a hydrocarbon, the odds of an explosive decomposition event are significantly increased.iv The proposed solution mitigates the explosion hazards of NOFB by separating the oxidizer from the hydrocarbon fuel formed as of a small cylindrical section of ABS thermoplastic. As N2O vapor flows across the grain segment, current enters a 1000 VDC high-tension lead in the ABS fuel grain and produces an inductive spark that vaporizes a small amount of the material. The ablated fuel vapor plus residual energy from the spark seed a localized exothermic N2O dissociation that produces sufficient heat to initiate combustion. The process is also effective when gaseous oxygen is used. A low TRL (2-3) prototype demonstrating the feasibility of controlled hydrocarbon-seeding was recently tested at Utah State University.v The unit features a miniature 2.5 cm ABS fuel grain fabricated using a Stratasys Dimension 3-D printer. The 9-N thruster was pulse-fired up to 27 consecutive times on a single ABS grain segment. Ignition was achieved by as little as 12-15 Joules energy input. This value is contrasted with the typical 30-minute pre-heat requirement for the ECAPS LMP-103S ADN-based monopropellant, requiring an energy input of 14,850 Joules for catalytic dissociation. The hydrocarbon-seeded micro-hybrid was also adapted as a non-pyrotechnic ignitor for a 900 N (200-lbf) thrust hybrid motor. The motor was successfully ignited 4 consecutive times with no hardware swaps or propellant additions. The amount of ABS seed material that can be fit into the injector cap is the only limit to the number of available repeat firings. This series of tests marks the first time a hybrid motor was ever ignited by other than a solid-propellant pyrotechnic charge or bi-propellant flame ignitor. Nitrous oxide hybrid motors are typically difficult to ignite and usually require multiple solid-propellant charges to initiate combustion, so this nonpyrotechnic ignition is a significant accomplishment. The controlled hydrocarbon-seeding approach is fundamentally different from all other green propellant solutions offered by the aerospace industry. Although the proposed system is more correctly a hybrid technology; the system retains all the simple features of a monopropellant design. To date no optimization study has been performed to identify the best grain geometry for electrostatic ignition. Fortunately, because the grain segments are fabricated using rapid-prototyping technology, changing the grain geometry is as simple as modifying the 3-D printer CAD-file. Vacuum Isp exceeding 270 seconds has been demonstrated (Ref v), a value significantly higher than those offered by competing green monopropellant options. The propellants of choice, N2O/GOX and ABS are 100% non-toxic, non-explosive, and environmentally benign. Because the inert oxidizer and fuel components are mixed only within the combustion chamber, the system retains the inherent safety of a hybrid rocket and can be piggy-backed as a secondary payload with no overall mission risk increase to the primary payload, an excellent characteristic for secondary launch systems.
BPM Motors in Residential Gas Furnaces: What are theSavings?
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lutz, James; Franco, Victor; Lekov, Alex
2006-05-12
Residential gas furnaces contain blowers to distribute warm air. Currently, furnace blowers use either a Permanent Split Capacitor (PSC) or a Brushless Permanent Magnet (BPM) motor. Blowers account for the majority of furnace electricity consumption. Therefore, accurate determination of the blower electricity consumption is important for understanding electricity consumption of furnaces. The electricity consumption of blower motors depends on the static pressure across the blower. This paper examines both types of blower motors in non-condensing non-weatherized gas furnaces at a range of static pressures. Fan performance data is based on manufacturer product literature and laboratory tests. We use field-measured staticmore » pressure in ducts to get typical system curves to calculate how furnaces would operate in the field. We contrast this with the electricity consumption of a furnace blower operating under the DOE test procedure and manufacturer rated conditions. Furnace electricity use is also affected by operating modes that happen at the beginning and end of each furnace firing cycle. These operating modes are the pre-purge and post-purge by the draft inducer, the on-delay and off-delay of the blower, and the hot surface ignitor operation. To accurately calculate this effect, we use the number of firing cycles in a typical California house in the Central Valley of California. Cooling hours are not considered in the DOE test procedure. We also account for furnace blower use by the air conditioner and stand-by power. Overall BPM motors outperform PSC motors, but the total electricity savings are significantly less than projected using the DOE test procedure conditions. The performance gains depend on the static pressure of the household ducts, which are typically much higher than in the test procedures.« less
Hendrix, J.L.
1995-04-11
A laser initiated ordnance controller apparatus which provides a safe and arm scheme with no moving parts. The safe & arm apparatus provides isolation of firing energy to explosive devices using a combination of polarization isolation and control through acousto-optical deviation of laser energy pulses. The apparatus provides constant monitoring of the systems status and performs 100% built-in-test at any time prior to ordnance ignition without the risk of premature ignition or detonation. The apparatus has a computer controller, a solid state laser, an acousto-optic deflector and RF drive circuitry, built-in-test optics and electronics, and system monitoring capabilities. The optical system is completed from the laser beam power source to the pyrotechnic ordnance through fiber optic cabling, optical splitters and optical connectors. During operation of the apparatus, a command is provided by the computer controller and, simultaneous with laser flashlamp fire, the safe & arm device is opened for approximately 200 microseconds which allows the laser pulse to transmit through the device. The arm signal also energizes the laser power supply and activates the acousto-optical deflector. When the correct fire format command is received, the acousto-optic deflector moves to the selected event channel, and the channel is verified to ensure the system is pointing to the correct position. Laser energy is transmitted through the fiber where an ignitor or detonator designed to be sensitive to optical pulses is fired at the end of the fiber channel. Simultaneous event channels may also be utilized by optically splitting a single event channel. The built-in-test may be performed anytime prior to ordnance ignition. 6 figures.
Hendrix, James L.
1995-01-01
A laser initiated ordnance controller apparatus which provides a safe and m scheme with no moving parts. The safe & arm apparatus provides isolation of firing energy to explosive devices using a combination of polarization isolation and control through acousto-optical deviation of laser energy pulses. The apparatus provides constant monitoring of the systems status and performs 100% built-in-test at any time prior to ordnance ignition without the risk of premature ignition or detonation. The apparatus has a computer controller, a solid state laser, an acousto-optic deflector and RF drive circuitry, built-in-test optics and electronics, and system monitoring capabilities. The optical system is completed from the laser beam power source to the pyrotechnic ordnance through fiber optic cabling, optical splitters and optical connectors. During operation of the apparatus, a command is provided by the computer controller and, simultaneous with laser flashlamp fire, the safe & arm device is opened for approximately 200 microseconds which allows the laser pulse to transmit through the device. The arm signal also energizes the laser power supply and activates the acousto-optical deflector. When the correct fire format command is received, the acousto-optic deflector moves to the selected event channel, and the channel is verified to ensure the system is pointing to the correct position. Laser energy is transmitted through the fiber where an ignitor or detonator designed to be sensitive to optical pulses is fired at the end of the fiber channel. Simultaneous event channels may also be utilized by optically splitting a single event channel. The built-in-test may be performed anytime prior to ordnance ignition.
The Science and Technology Case for High-Field Fusion
NASA Astrophysics Data System (ADS)
Whyte, D.
2017-10-01
This review will focus on the origin, development and new opportunities of a strategy for fusion energy based on the high-field approach. In this approach confinement devices are designed at the maximum possible value of vacuum magnetic field strength, B. The integrated electrical, mechanical and cooling engineering challenges of high-field on coil (Bcoil) , large-bore electromagnets are examined for both copper and superconductor materials. These engineering challenges are confronted because of the profound science advantages provided by high-B, which are derived and reviewed: high fusion power density, B4, in compact devices, thermonuclear plasmas with significant stability margin, and, in tokamaks, access to higher plasma density. Two distinct high-field strategies emerged in the 1980's. The first was compact, cryogenically-cooled copper devices (BPX, IGNITOR, FIRE) with Bcoil>20 T, while the second was a large-volume, Nb3Sn superconductor device with Bcoil <12 T; with the second path exclusively chosen ca. 2000 with the ITER construction decision. The reasoning, advantages and challenges of that decision are discussed. Yet since that decision, a new opportunity has arisen: compact, Rare Earth Barium Copper Oxide (REBCO) superconductor-based devices with Bcoil >20 T; a strategy that essentially combines the best components of the two previous strategies. Recent activities examining the technology and science implications of this new strategy are reviewed. On the technology side, REBCO superconductors have now been used to produce Bcoil>40 T in small-bore electromagnets, enabled by rapid progress in manufactured REBCO conductor quality, coil modularity and flexible operating temperature range. Specific tokamak designs, over a range of aspect ratios, have been developed to take scientific advantage of these features in various ways, and will be described.
Evaluation of an Ejector Ramjet Based Propulsion System for Air-Breathing Hypersonic Flight
NASA Technical Reports Server (NTRS)
Thomas, Scott R.; Perkins, H. Douglas; Trefny, Charles J.
1997-01-01
A Rocket Based Combined Cycle (RBCC) engine system is designed to combine the high thrust to weight ratio of a rocket along with the high specific impulse of a ramjet in a single, integrated propulsion system. This integrated, combined cycle propulsion system is designed to provide higher vehicle performance than that achievable with a separate rocket and ramjet. The RBCC engine system studied in the current program is the Aerojet strutjet engine concept, which is being developed jointly by a government-industry team as part of the Air Force HyTech program pre-PRDA activity. The strutjet is an ejector-ramjet engine in which small rocket chambers are embedded into the trailing edges of the inlet compression struts. The engine operates as an ejector-ramjet from take-off to slightly above Mach 3. Above Mach 3 the engine operates as a ramjet and transitions to a scramjet at high Mach numbers. For space launch applications the rockets would be re-ignited at a Mach number or altitude beyond which air-breathing propulsion alone becomes impractical. The focus of the present study is to develop and demonstrate a strutjet flowpath using hydrocarbon fuel at up to Mach 7 conditions. Freejet tests of a candidate flowpath for this RBCC engine were conducted at the NASA Lewis Research Center's Hypersonic Tunnel Facility between July and September 1996. This paper describes the engine flowpath and installation, outlines the primary objectives of the program, and describes the overall results of this activity. Through this program 15 full duration tests, including 13 fueled tests were made. The first major achievement was the further demonstration of the HTF capability. The facility operated at conditions up to 1950 K and 7.34 MPa, simulating approximately Mach 6.6 flight. The initial tests were unfueled and focused on verifying both facility and engine starting. During these runs additional aerodynamic appliances were incorporated onto the facility diffuser to enhance starting. Both facility and engine starting were achieved. Further, the static pressure distributions compared well with the results previously obtained in a 40% subscale flowpath study conducted in the LERC 1X1 supersonic wind tunnel (SWT), as well as the results of CFD analysis. Fueled performance results were obtained for the engine at both simulated Mach 6 (1670 K) and Mach 6.6 (1950 K) conditions. For all these tests the primary fuel was liquid JP-10 with gaseous silane (a mixture of 20% SiH4 and 80% H2 by volume) as an ignitor/pilot. These tests verified performance of this engine flowpath in a freejet mode. High combustor pressures were reached and significant changes in axial force were achieved due to combustion. Future test plans include redistributing the fuel to improve mixing, and consequently performance, at higher equivalence ratios.
NIF Target Designs and OMEGA Experiments for Shock-Ignition Inertial Confinement Fusion
NASA Astrophysics Data System (ADS)
Anderson, K. S.
2012-10-01
Shock ignition (SI)footnotetextR. Betti et al., Phys. Rev. Lett. 98, 155001 (2007). is being pursued as a viable option to achieve ignition on the National Ignition Facility (NIF). Shock-ignition target designs require the addition of a high-intensity (˜5 x 10^15 W/cm^2) laser spike at the end of a low-adiabat assembly pulse to launch a spherically convergent strong shock to ignite the imploding capsule. Achieving ignition with SI requires the laser spike to generate an ignitor shock with a launching pressure typically in excess of ˜300 Mbar. At the high laser intensities required during the spike pulse, stimulated Raman (SRS) and Brillouin scattering (SBS) could reflect a significant fraction of the incident light. In addition, SRS and the two-plasmon-decay instability can accelerate hot electrons into the shell and preheat the fuel. Since the high-power spike occurs at the end of the pulse when the areal density of the shell is several tens of mg/cm^2, shock-ignition fuel layers are shielded against hot electrons with energies below 150 keV. This paper will present data for a set of OMEGA experiments that were designed to study laser--plasma interactions during the spike pulse. In addition, these experiments were used to demonstrate that high-pressure shocks can be produced in long-scale-length plasmas with SI-relevant intensities. Within the constraints imposed by the hydrodynamics of strong shock generation and the laser--plasma instabilities, target designs for SI experiments on the NIF will be presented. Two-dimensional radiation--hydrodynamic simulations of SI target designs for the NIF predict ignition in the polar-drive beam configuration at sub-MJ laser energies. Design robustness to various 1-D effects and 2-D nonuniformities has been characterized. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-08NA28302.
Inertial Confinement Fusion Annual Report 1999
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kauffman, Robert L.
The ICF Program has undergone a significant change in 1999 with the decommissioning of the Nova laser and the transfer of much of the experimental program to the OMEGA laser at the University of Rochester. The Nova laser ended operations with the final experiment conducted on May 27, 1999. This marked the end to one of DOE's most successful experimental facilities. Since its commissioning in 1985, Nova performed 13,424 experiments supporting ICF, Defense Sciences, high-power laser research, and basic science research. At the time of its commissioning, Nova was the world's most powerful laser. Its early experiments demonstrated that 3ωmore » light could produce high-drive, low-preheat environment required for indirect-drive ICE. In the early 1990s, the technical program on Nova for indirect drive ignition was defined by the Nova technical contract established by National Academy Review of ICF in 1990. Successful completion of this research program contributed significantly to the recommendation by the ICF Advisory Committee in 1995 to proceed with the construction of the National Ignition Facility? Nova experiments also demonstrated the utility of high-powered lasers for studying the physics of interest to Defense Sciences. Now, high-powered lasers along with pulsed-power machines are the principal facilities for studying high energy density science in DOE's Stockpile Stewardship Program (SSP). In 1997, one beam of Nova was converted to a short pulsed beam producing a petawatt of power in subpicosecond pulses. The petawatt beam was used for pioneering research in short-pulse laser-matter interactions relevant to fast ignitor ICF and short pulsed x-ray, electron, and particle production for use as probes. Nova is being disassembled and the space is being used to support NIF construction. Nova components are being distributed to a number of other laser laboratories around the world for reuse as determined by DOE. This report summarizes the research performed by the ICF Program in FY1999. The report is divided into five sections corresponding to the major areas of program activities. These are sections on (1) ignition target physics experiments theory and modeling, (2) high energy density experimental science, (3) target development, fabrication, and handling, (4) NIF laser development, and (5) optics technology development.« less
High Energy Density Physics and Exotic Acceleration Schemes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cowan, T.; /General Atomics, San Diego; Colby, E.
2005-09-27
The High Energy Density and Exotic Acceleration working group took as our goal to reach beyond the community of plasma accelerator research with its applications to high energy physics, to promote exchange with other disciplines which are challenged by related and demanding beam physics issues. The scope of the group was to cover particle acceleration and beam transport that, unlike other groups at AAC, are not mediated by plasmas or by electromagnetic structures. At this Workshop, we saw an impressive advancement from years past in the area of Vacuum Acceleration, for example with the LEAP experiment at Stanford. And wemore » saw an influx of exciting new beam physics topics involving particle propagation inside of solid-density plasmas or at extremely high charge density, particularly in the areas of laser acceleration of ions, and extreme beams for fusion energy research, including Heavy-ion Inertial Fusion beam physics. One example of the importance and extreme nature of beam physics in HED research is the requirement in the Fast Ignitor scheme of inertial fusion to heat a compressed DT fusion pellet to keV temperatures by injection of laser-driven electron or ion beams of giga-Amp current. Even in modest experiments presently being performed on the laser-acceleration of ions from solids, mega-amp currents of MeV electrons must be transported through solid foils, requiring almost complete return current neutralization, and giving rise to a wide variety of beam-plasma instabilities. As keynote talks our group promoted Ion Acceleration (plenary talk by A. MacKinnon), which historically has grown out of inertial fusion research, and HIF Accelerator Research (invited talk by A. Friedman), which will require impressive advancements in space-charge-limited ion beam physics and in understanding the generation and transport of neutralized ion beams. A unifying aspect of High Energy Density applications was the physics of particle beams inside of solids, which is proving to be a very important field for diverse applications such as muon cooling, fusion energy research, and ultra-bright particle and radiation generation with high intensity lasers. We had several talks on these and other subjects, and many joint sessions with the Computational group, the EM Structures group, and the Beam Generation group. We summarize our groups' work in the following categories: vacuum acceleration schemes; ion acceleration; particle transport in solids; and applications to high energy density phenomena.« less
Particle in cell simulation of instabilities in space and astrophysical plasmas
NASA Astrophysics Data System (ADS)
Tonge, John William
Several plasma instabilities relevant to space physics are investigated using the parallel PIC plasma simulation code P3arsec. This thesis addresses electrostatic micro-instabilities relevant to ion ring distributions, proceeds to electromagnetic micro-instabilities pertinent to streaming plasmas, and then to the stability of a plasma held in the field of a current rod. The physical relevance of each of these instabilities is discussed, a phenomenological description is given, and analytic and simulation results are presented and compared. Instability of a magnetized plasma with a portion of the ions in a velocity ring distribution around the magnetic field is investigated using simulation and analytic theory. The physics of this distribution is relevant to solar flares, x-ray emission by comets, and pulsars. Physical parameters, including the mass ratio, are near those of a solar flare in the simulation. The simulation and analytic results show agreement in the linear regime. In the nonlinear stage the simulation shows highly accelerated electrons in agreement with the observed spectrum of x-rays emitted by solar flares. A mildly relativistic streaming electron positron plasma with no ambient magnetic field is known to be unstable to electrostatic (two-stream/beam instability) and purely electromagnetic (Weibel) modes. This instability is relevant to highly energetic interstellar phenomena, including pulsars, supernova remnants, and the early universe. It is also important for experiments in which relativistic beams penetrate a background plasma, as in fast ignitor scenarios. Cold analytic theory is presented and compared to simulations. There is good agreement in the regime where cold theory applies. The simulation and theory shows that to properly characterize the instability, directions parallel and perpendicular to propagation of the beams must be considered. A residual magnetic field is observed which may be of astro-physical significance. The stability of a plasma in the magnetic field of a current rod is investigated for various temperature and density profiles. Such a plasma obeys similar physics to a plasma in a dipole magnetic field, while the current rod is much easier to analyze theoretically and realize in simulations. The stability properties of a plasma confined in a dipole field are important for understanding a variety of space phenomena and the Levitated Dipole eXperiment (LDX). Simple energy principle calculations and simulations with a variety of temperature and density profiles show that the plasma is stable to interchange for pressure profiles ∝ r-10/3. The simulations also show that the density profile will be stationary as long as density ∝ r -2 even though the temperature profile may not be stable.
NASA Astrophysics Data System (ADS)
Syafrina, R.; Rohman, I.; Yuliani, G.
2018-05-01
This study aims to analyze the concept characteristics of solubility and solubility products that will serve as the basis for the development of virtual laboratory and students' science process skills. Characteristics of the analyzed concepts include concept definitions, concept attributes, and types of concepts. The concept analysis method uses concept analysis according to Herron. The results of the concept analysis show that there are twelve chemical concepts that become the prerequisite concept before studying the solubility and solubility and five core concepts that students must understand in the solubility and Solubility product. As many as 58.3% of the definitions of the concepts contained in high school textbooks support students' science process skills, the rest of the definition of the concept is memorized. Concept attributes that meet three levels of chemical representation and can be poured into a virtual laboratory have a percentage of 66.6%. Type of concept, 83.3% is a concept based on principle; and 16.6% concepts that state the process. Meanwhile, the science process skills that can be developed based on concept analysis are the ability to observe, calculate, measure, predict, interpret, hypothesize, apply, classify, and inference.
Concepts of formal concept analysis
NASA Astrophysics Data System (ADS)
Žáček, Martin; Homola, Dan; Miarka, Rostislav
2017-07-01
The aim of this article is apply of Formal Concept Analysis on concept of world. Formal concept analysis (FCA) as a methodology of data analysis, information management and knowledge representation has potential to be applied to a verity of linguistic problems. FCA is mathematical theory for concepts and concept hierarchies that reflects an understanding of concept. Formal concept analysis explicitly formalizes extension and intension of a concept, their mutual relationships. A distinguishing feature of FCA is an inherent integration of three components of conceptual processing of data and knowledge, namely, the discovery and reasoning with concepts in data, discovery and reasoning with dependencies in data, and visualization of data, concepts, and dependencies with folding/unfolding capabilities.
O'Brien, J K; Robeck, T R
2012-08-01
Bottlenose dolphins (Tursiops truncatus) undergoing natural breeding and artificial insemination (AI) were examined to characterize serum progesterone concentrations and determine relationships among age, parity, and reproductive outcome. Progesterone profiles of five cycle types (n = 119 total cycles from 54 animals) were characterized as follows: (i) conception and production of a live term calf (conceptive-term, n = 73); (ii) conception and abortion after Day 60 (conceptive-abortion, n = 12); (iii) unknown conception status with prolonged, elevated progesterone and absence of a fetus (conceptive-unknown, n = 14); (iv) conception failure with normal luteal phase progesterone concentrations (non-conceptive, n = 14, AI cycles only); and (v) conception failure with progesterone insufficiency occuring after spontaneous ovulation or owing to premature ovulation induction using GnRH (non-conceptive-PI, n = 6, AI cycles only). By Day 21 post-insemination (PI), progesterone concentrations were similar (P > 0.05) among conceptive-term, conceptive-abortion and conceptive-unknown, and higher (P < 0.05) for conceptive-term than non-conceptive and non-conceptive-PI cycles. Progesterone concentrations of known conceptive cycles peaked by Week 7 PI (P < 0.05) and remained elevated for the remainder of pregnancy (Weeks 8 up to 54, ≥ 5 days pre-partum). During midpregnancy (Days 121-240), conceptive-term cycles had higher (P > 0.05) progesterone concentrations than conceptive-abortion and unknown conception status cycles. Parity was not associated with reproductive outcome based on cycle type (P > 0.05). Age of females in conceptive-unknown (26.5 ± 10.1 yrs) and conceptive-abortion (22.1 ± 9.4 yrs) groups was higher (P < 0.05) than in conceptive-term (15.7 ± 7.2 yrs). The conceptive-unknown cycle type possibly represents undetected early embryonic loss occurring before Day 60 PI. Length of gestation using known conception dates was 376.1 ± 11.0 days and the range of this parameter (355-395 days) has implications for peri-parturient management procedures for the species. Copyright © 2012 Elsevier Inc. All rights reserved.
NASA Astrophysics Data System (ADS)
Kwon, So Young
Using a quasi-experimental design, the researcher investigated the comparative effects of individually-generated and collaboratively-generated computer-based concept mapping on middle school science concept learning. Qualitative data were analyzed to explain quantitative findings. One hundred sixty-one students (74 boys and 87 girls) in eight, seventh grade science classes at a middle school in Southeast Texas completed the entire study. Using prior science performance scores to assure equivalence of student achievement across groups, the researcher assigned the teacher's classes to one of the three experimental groups. The independent variable, group, consisted of three levels: 40 students in a control group, 59 students trained to individually generate concept maps on computers, and 62 students trained to collaboratively generate concept maps on computers. The dependent variables were science concept learning as demonstrated by comprehension test scores, and quality of concept maps created by students in experimental groups as demonstrated by rubric scores. Students in the experimental groups received concept mapping training and used their newly acquired concept mapping skills to individually or collaboratively construct computer-based concept maps during study time. The control group, the individually-generated concept mapping group, and the collaboratively-generated concept mapping group had equivalent learning experiences for 50 minutes during five days, excepting that students in a control group worked independently without concept mapping activities, students in the individual group worked individually to construct concept maps, and students in the collaborative group worked collaboratively to construct concept maps during their study time. Both collaboratively and individually generated computer-based concept mapping had a positive effect on seventh grade middle school science concept learning but neither strategy was more effective than the other. However, the students who collaboratively generated concept maps created significantly higher quality concept maps than those who individually generated concept maps. The researcher concluded that the concept mapping software, Inspiration(TM), fostered construction of students' concept maps individually or collaboratively for science learning and helped students capture their evolving creative ideas and organize them for meaningful learning. Students in both the individual and the collaborative concept mapping groups had positive attitudes toward concept mapping using Inspiration(TM) software.
Mougin, Fleur; Bodenreider, Olivier; Burgun, Anita
2015-01-01
Objectives Polysemy is a frequent issue in biomedical terminologies. In the Unified Medical Language System (UMLS), polysemous terms are either represented as several independent concepts, or clustered into a single, multiply-categorized concept. The objective of this study is to analyze polysemous concepts in the UMLS through their categorization and hierarchical relations for auditing purposes. Methods We used the association of a concept with multiple Semantic Groups (SGs) as a surrogate for polysemy. We first extracted multi-SG (MSG) concepts from the UMLS Metathesaurus and characterized them in terms of the combinations of SGs with which they are associated. We then clustered MSG concepts in order to identify major types of polysemy. We also analyzed the inheritance of SGs in MSG concepts. Finally, we manually reviewed the categorization of the MSG concepts for auditing purposes. Results The 1208 MSG concepts in the Metathesaurus are associated with 30 distinct pairs of SGs. We created 75 semantically homogeneous clusters of MSG concepts, and 276 MSG concepts could not be clustered for lack of hierarchical relations. The clusters were characterized by the most frequent pairs of semantic types of their constituent MSG concepts. MSG concepts exhibit limited semantic compatibility with their parent and child concepts. A large majority of MSG concepts (92%) are adequately categorized. Examples of miscategorized concepts are presented. Conclusion This work is a systematic analysis and manual review of all concepts categorized by multiple SGs in the UMLS. The correctly-categorized MSG concepts do reflect polysemy in the UMLS Metathesaurus. The analysis of inheritance of SGs proved useful for auditing concept categorization in the UMLS. PMID:19303057
CONCEPT LEARNING AND CONCEPT TEACHING.
ERIC Educational Resources Information Center
GLASER, ROBERT
REVIEWED ARE THE PSYCHOLOGICAL STUDIES OF CONCEPT LEARNING AS THEY RELATE TO CONCEPT TEACHING. AN ANALYSIS IS MADE OF THE NATURE OF CONCEPT LEARNING AS IT IS STUDIED IN THE PSYCHOLOGIST'S LABORATORY, INCLUDING THE NATURE OF CONCEPT TASKS AS THEY APPEAR IN SUBJECT MATTER LEARNING. THE PRIMARY KINDS OF CONCEPT LEARNING SITUATIONS, INCLUDING THE…
State of the science of maternal-infant bonding: a principle-based concept analysis.
Bicking Kinsey, Cara; Hupcey, Judith E
2013-12-01
to provide a principle-based analysis of the concept of maternal-infant bonding. principle-based method of concept analysis for which the data set included 44 articles published in the last decade from Pubmed, CINAHL, and PyschINFO/PsychARTICLES. literature inclusion criteria were English language, articles published in the last decade, peer-reviewed journal articles and commentary on published work, and human populations. after a brief review of the history of maternal-infant bonding, a principle-based concept analysis was completed to examine the state of the science with regard to this concept. The concept was critically examined according to the clarity of definition (epistemological principle), applicability of the concept (pragmatic principle), consistency in use and meaning (linguistic principle), and differentiation of the concept from related concepts (logical principle). Analysis of the concept revealed: (1) Maternal-infant bonding describes maternal feelings and emotions towards her infant. Evidence that the concept encompasses behavioural or biological components was limited. (2) The concept is clearly operationalised in the affective domain. (3) Maternal-infant bonding is linguistically confused with attachment, although the boundaries between the concepts are clearly delineated. despite widespread use of the concept, maternal-infant bonding is at times superficially developed and subject to confusion with related concepts. Concept clarification is warranted. A theoretical definition of the concept of maternal-infant bonding was developed to aid in the clarification, but more research is necessary to further clarify and advance the concept. nurse midwives and other practitioners should use the theoretical definition of maternal-infant bonding as a preliminary guide to identification and understanding of the concept in clinical practice. Copyright © 2013 Elsevier Ltd. All rights reserved.
STATE OF THE SCIENCE OF MATERNAL-INFANT BONDING: A PRINCIPLE-BASED CONCEPT ANALYSIS
Bicking Kinsey, Cara; Hupcey, Judith E.
2013-01-01
Objective To provide a principle-based analysis of the concept of maternal-infant bonding. Design Principle-based method of concept analysis for which the data set included 44 articles published in the last decade from Pubmed, CINAHL, and PyschINFO/PsychARTICLES. Setting Literature inclusion criteria were English language, articles published in the last decade, peer-reviewed journal articles and commentary on published work, and human populations. Measurement and Findings After brief review of the history of maternal-infant bonding, a principle-based concept analysis was completed to examine the state of the science with regard to this concept. The concept was critically examined according to the clarity of definition (epistemological principle), applicability of the concept (pragmatic principle), consistency in use and meaning (linguistic principle), and differentiation of the concept from related concepts (logical principle). Analysis of the concept revealed: (1) maternal-infant bonding describes maternal feelings and emotions towards her infant. Evidence that the concept encompasses behavioral or biological components was limited; (2) the concept is clearly operationalized in the affective domain; and (3) maternal-infant bonding is linguistically confused with attachment, although the boundaries between the concepts are clearly delineated. Key Conclusion Despite widespread use of the concept, maternal-infant bonding is at times superficially developed and subject to confusion with related concepts. Concept clarification is warranted. A theoretical definition of the concept of maternal-infant bonding was developed to aid in the clarification, but more research is necessary to further clarify and advance the concept. Implications for Practice Nurse midwives and other practitioners should use the theoretical definition of maternal-infant bonding as a preliminary guide to identification and understanding of the concept in clinical practice. PMID:23452661
Concepts and Relations in Neurally Inspired In Situ Concept-Based Computing
van der Velde, Frank
2016-01-01
In situ concept-based computing is based on the notion that conceptual representations in the human brain are “in situ.” In this way, they are grounded in perception and action. Examples are neuronal assemblies, whose connection structures develop over time and are distributed over different brain areas. In situ concepts representations cannot be copied or duplicated because that will disrupt their connection structure, and thus the meaning of these concepts. Higher-level cognitive processes, as found in language and reasoning, can be performed with in situ concepts by embedding them in specialized neurally inspired “blackboards.” The interactions between the in situ concepts and the blackboards form the basis for in situ concept computing architectures. In these architectures, memory (concepts) and processing are interwoven, in contrast with the separation between memory and processing found in Von Neumann architectures. Because the further development of Von Neumann computing (more, faster, yet power limited) is questionable, in situ concept computing might be an alternative for concept-based computing. In situ concept computing will be illustrated with a recently developed BABI reasoning task. Neurorobotics can play an important role in the development of in situ concept computing because of the development of in situ concept representations derived in scenarios as needed for reasoning tasks. Neurorobotics would also benefit from power limited and in situ concept computing. PMID:27242504
Concepts and Relations in Neurally Inspired In Situ Concept-Based Computing.
van der Velde, Frank
2016-01-01
In situ concept-based computing is based on the notion that conceptual representations in the human brain are "in situ." In this way, they are grounded in perception and action. Examples are neuronal assemblies, whose connection structures develop over time and are distributed over different brain areas. In situ concepts representations cannot be copied or duplicated because that will disrupt their connection structure, and thus the meaning of these concepts. Higher-level cognitive processes, as found in language and reasoning, can be performed with in situ concepts by embedding them in specialized neurally inspired "blackboards." The interactions between the in situ concepts and the blackboards form the basis for in situ concept computing architectures. In these architectures, memory (concepts) and processing are interwoven, in contrast with the separation between memory and processing found in Von Neumann architectures. Because the further development of Von Neumann computing (more, faster, yet power limited) is questionable, in situ concept computing might be an alternative for concept-based computing. In situ concept computing will be illustrated with a recently developed BABI reasoning task. Neurorobotics can play an important role in the development of in situ concept computing because of the development of in situ concept representations derived in scenarios as needed for reasoning tasks. Neurorobotics would also benefit from power limited and in situ concept computing.
Low self-concept in poor readers: prevalence, heterogeneity, and risk.
McArthur, Genevieve; Castles, Anne; Kohnen, Saskia; Banales, Erin
2016-01-01
There is evidence that poor readers are at increased risk for various types of low self-concept-particularly academic self-concept. However, this evidence ignores the heterogeneous nature of poor readers, and hence the likelihood that not all poor readers have low self-concept. The aim of this study was to better understand which types of poor readers have low self-concept. We tested 77 children with poor reading for their age for four types of self-concept, four types of reading, three types of spoken language, and two types of attention. We found that poor readers with poor attention had low academic self-concept, while poor readers with poor spoken language had low general self-concept in addition to low academic self-concept. In contrast, poor readers with typical spoken language and attention did not have low self-concept of any type. We also discovered that academic self-concept was reliably associated with reading and receptive spoken vocabulary, and that general self-concept was reliably associated with spoken vocabulary. These outcomes suggest that poor readers with multiple impairments in reading, language, and attention are at higher risk for low academic and general self-concept, and hence need to be assessed for self-concept in clinical practice. Our results also highlight the need for further investigation into the heterogeneous nature of self-concept in poor readers.
A phenomenographic case study: Concept maps from the perspectives of middle school students
NASA Astrophysics Data System (ADS)
Saglam, Yilmaz
The objective of this study was to investigate the experiences of middle school students when concept maps were used as a learning tool. Twenty-nine students' written responses, concept maps and videotapes were analyzed. Out of 29 students, thirteen students were interviewed using a semi-structured and open-ended interview protocol. The students' initial written responses provided us with the students' initial reactions to concept maps. The videotapes captured the students' behavior, and interpersonal interactions. The interviews probed students': (1) knowledge about drawing concept maps, (2) perception of the meaning and usefulness of concept maps, and (3) attitudes towards concept maps. The results indicated that the students viewed concept maps as useful tools in learning science. They believed that concept maps organized and summarized the information, which thereby helped them understand the topic easily. They also believed that concept maps had some cognitive benefits. However, the students viewed concept maps as hard to construct because it was difficult for the students to think of related concepts. The students' initial written responses, interviews and videotapes indicated that the students seemed to see both positive and negative aspects of concept maps. Some students' had more positive and some had more negative attitudes.
ERIC Educational Resources Information Center
Tzeng, Jeng-Yi
2014-01-01
This study examines how 98 students in Taiwan taking a typical high-school history class composed concept maps related to both an everyday concept and an academic-oriented unique concept with various degrees of freedom in concept mapping. In order to reveal the multidimensionality of history concepts, this study provided participants a 6W scaffold…
Evolutionary space platform concept study. Volume 2, part B: Manned space platform concepts
NASA Technical Reports Server (NTRS)
1982-01-01
Logical, cost-effective steps in the evolution of manned space platforms are investigated and assessed. Tasks included the analysis of requirements for a manned space platform, identifying alternative concepts, performing system analysis and definition of the concepts, comparing the concepts and performing programmatic analysis for a reference concept.
Self-Concept of Gifted Children Aged 9 to 13 Years Old
ERIC Educational Resources Information Center
Shi, Jiannong; Li, Ying; Zhang, Xingli
2008-01-01
Ninety-four gifted children and 200 nongifted children (aged 9 to 13 years old) were involved in the present study. Their self-concept was assessed by the Revised Song-Hattie Self-Concept Inventory (Zhou & He, 1996). Academic self-concepts pertaining to abilities, school achievements, and grade concepts and nonacademic self-concepts pertaining…
Social Science Concepts and the Classroom.
ERIC Educational Resources Information Center
Fancett, Verna S.; And Others
Intended to introduce teachers to the concept approach in teaching social studies materials, the five chapters of this publication discuss (1) a definition of "concept" and the term's relationship to facts and generalizations, (2) the function of concepts in the social sciences, (3) how concepts develop, (4) how concepts are related to inquiry and…
Use of Networked Collaborative Concept Mapping To Measure Team Processes and Team Outcomes.
ERIC Educational Resources Information Center
Chung, Gregory K. W. K.; O'Neil, Harold F., Jr.; Herl, Howard E.; Dennis, Robert A.
The feasibility of using a computer-based networked collaborative concept mapping system to measure teamwork skills was studied. A concept map is a node-link-node representation of content, where the nodes represent concepts and links represent relationships between connected concepts. Teamwork processes were examined for a group concept mapping…
A Catalogue of Concepts in the Pedagogical Domain of Teacher Education.
ERIC Educational Resources Information Center
Multi-State Consortium on Performance-Based Teacher Education, Albany, NY.
This catalog of concepts in the pedagogical domain of teacher education organizes the critical concepts and provides definitions, indicators, and illustrations of the concepts. Chapter 1 presents a rationale for the selection of concepts in teacher education and discusses pedagogical domain, interactive teaching, the format of concepts in this…
The AIChE "Concept Warehouse": A Web-Based Tool to Promote Concept-Based Instruction
ERIC Educational Resources Information Center
Koretsky, Milo D.; Falconer, John L.; Brooks, Bill J.; Gilbuena, Debra M.; Silverstein, David L.; Smith, Christina; Miletic, Marina
2014-01-01
This paper describes the "AIChE Concept Warehouse," a recently developed web-based instructional tool that enables faculty within the discipline of chemical engineering to better provide their students concept-based instruction. It currently houses over 2,000 concept questions and 10 concept inventories pertinent to courses throughout…
University Students' Conceptions about the Concept of Gene: Interest of Historical Approach
ERIC Educational Resources Information Center
Boujemaa, Agorram; Pierre, Clement; Sabah, Selmaoui; Salaheddine, Khzami; Jamal, Chafik; Abdellatif, Chiadli
2010-01-01
Concepts of genetics are often difficult to teach, specifically the central concept of gene. Even the scientists disagree when defining this concept. This paper investigates university students' understanding about the gene and its functions. The results show the dominance of two conceptions of the gene: the Neoclassical model and the Mendelian…
ERIC Educational Resources Information Center
Odom, Arthur L.; Kelly, Paul V.
2001-01-01
Explores the effectiveness of concept mapping, the learning cycle, expository instruction, and a combination of concept mapping/learning cycle in promoting conceptual understanding of diffusion and osmosis. Concludes that the concept mapping/learning cycle and concept mapping treatment groups significantly outperformed the expository treatment…
Undergraduate Students' Conceptions of Enthalpy, Enthalpy Change and Related Concepts
ERIC Educational Resources Information Center
Nilsson, Tor; Niedderer, Hans
2014-01-01
Research shows that students have problems understanding thermodynamic concepts and that a gap exists at the tertiary level related to more specific chemistry concepts such as enthalpy. Therefore, the aim of this study is to construct undergraduate students' conceptions of enthalpy, its change and related concepts. Three explorative small-scale…
Innatism, Concept Formation, Concept Mastery and Formal Education
ERIC Educational Resources Information Center
Winch, Christopher
2015-01-01
This article will consider the claim that the possession of concepts is innate rather than learned. Innatism about concept learning is explained through consideration of the work of Fodor and Chomsky. First, an account of concept formation is developed. Second the argument against the claim that concepts are learned through the construction of a…
Subsumption principles underlying medical concept systems and their formal reconstruction.
Bernauer, J.
1994-01-01
Conventional medical concept systems represent generic concept relations by hierarchical coding principles. Often, these coding principles constrain the concept system and reduce the potential for automatical derivation of subsumption. Formal reconstruction of medical concept systems is an approach that bases on the conceptual representation of meanings and that allows for the application of formal criteria for subsumption. Those criteria must reflect intuitive principles of subordination which are underlying conventional medical concept systems. Particularly these are: The subordinate concept results (1) from adding a specializing criterion to the superordinate concept, (2) from refining the primary category, or a criterion of the superordinate concept, by a concept that is less general, (3) from adding a partitive criterion to a criterion of the superordinate, (4) from refining a criterion by a concept that is less comprehensive, and finally (5) from coordinating the superordinate concept, or one of its criteria. This paper introduces a formalism called BERNWARD that aims at the formal reconstruction of medical concept systems according to these intuitive principles. The automatical derivation of hierarchical relations is primarily supported by explicit generic and explicit partititive hierarchies of concepts, secondly, by two formal criteria that base on the structure of concept descriptions and explicit hierarchical relations between their elements, namely: formal subsumption and part-sensitive subsumption. Formal subsumption takes only generic relations into account, part-sensitive subsumption additionally regards partive relations between criteria. This approach seems to be flexible enough to cope with unforeseeable effects of partitive criteria on subsumption. PMID:7949907
Vink, Sylvia; van Tartwijk, Jan; Verloop, Nico; Gosselink, Manon; Driessen, Erik; Bolk, Jan
2016-08-01
To determine the content of integrated curricula, clinical concepts and the underlying basic science concepts need to be made explicit. Preconstructed concept maps are recommended for this purpose. They are mainly constructed by experts. However, concept maps constructed by residents are hypothesized to be less complex, to reveal more tacit basic science concepts and these basic science concepts are expected to be used for the organization of the maps. These hypotheses are derived from studies about knowledge development of individuals. However, integrated curricula require a high degree of cooperation between clinicians and basic scientists. This study examined whether there are consistent variations regarding the articulation of integration when groups of experienced clinicians and basic scientists and groups of residents and basic scientists-in-training construct concept maps. Seven groups of three clinicians and basic scientists on experienced level and seven such groups on resident level constructed concept maps illuminating clinical problems. They were guided by instructions that focused them on articulation of integration. The concept maps were analysed by features that described integration. Descriptive statistics showed consistent variations between the two expertise levels. The concept maps of the resident groups exceeded those of the experienced groups in articulated integration. First, they used significantly more links between clinical and basic science concepts. Second, these links connected basic science concepts with a greater variety of clinical concepts than the experienced groups. Third, although residents did not use significantly more basic science concepts, they used them significantly more frequent to organize the clinical concepts. The conclusion was drawn that not all hypotheses could be confirmed and that the resident concept maps were more elaborate than expected. This article discusses the implications for the role that residents and basic scientists-in-training might play in the construction of preconstructed concept maps and the development of integrated curricula.
Hierarchical and Multidimensional Academic Self-Concept of Commercial Students.
Yeung; Chui; Lau
1999-10-01
Adapting the Marsh (1990) Academic Self-Description Questionnaire (ASDQ), this study examined the academic self-concept of students in a school of commerce in Hong Kong (N = 212). Confirmatory factor analysis found that students clearly distinguished among self-concept constructs in English, Chinese, Math and Statistics, Economics, and Principles of Accounting, and each of these constructs was highly associated with a global Academic self-concept construct, reflecting the validity of each construct in measuring an academic component of self-concept. Domain-specific self-concepts were more highly related with students' intention of course selection in corresponding areas than in nonmatching areas, further supporting the multidimensionality of the students' academic self-concept. Students' self-concepts in the five curriculum domains can be represented by the global Academic self-concept, supporting the hierarchical structure of students' academic self-concept in an educational institution with a specific focus, such as commercial studies. The academic self-concepts of the commercial students are both multidimensional and hierarchical. Copyright 1999 Academic Press.
NASA Astrophysics Data System (ADS)
WANG, Qingrong; ZHU, Changfeng
2017-06-01
Integration of distributed heterogeneous data sources is the key issues under the big data applications. In this paper the strategy of variable precision is introduced to the concept lattice, and the one-to-one mapping mode of variable precision concept lattice and ontology concept lattice is constructed to produce the local ontology by constructing the variable precision concept lattice for each subsystem, and the distributed generation algorithm of variable precision concept lattice based on ontology heterogeneous database is proposed to draw support from the special relationship between concept lattice and ontology construction. Finally, based on the standard of main concept lattice of the existing heterogeneous database generated, a case study has been carried out in order to testify the feasibility and validity of this algorithm, and the differences between the main concept lattice and the standard concept lattice are compared. Analysis results show that this algorithm above-mentioned can automatically process the construction process of distributed concept lattice under the heterogeneous data sources.
Low self-concept in poor readers: prevalence, heterogeneity, and risk
Castles, Anne; Kohnen, Saskia; Banales, Erin
2016-01-01
There is evidence that poor readers are at increased risk for various types of low self-concept—particularly academic self-concept. However, this evidence ignores the heterogeneous nature of poor readers, and hence the likelihood that not all poor readers have low self-concept. The aim of this study was to better understand which types of poor readers have low self-concept. We tested 77 children with poor reading for their age for four types of self-concept, four types of reading, three types of spoken language, and two types of attention. We found that poor readers with poor attention had low academic self-concept, while poor readers with poor spoken language had low general self-concept in addition to low academic self-concept. In contrast, poor readers with typical spoken language and attention did not have low self-concept of any type. We also discovered that academic self-concept was reliably associated with reading and receptive spoken vocabulary, and that general self-concept was reliably associated with spoken vocabulary. These outcomes suggest that poor readers with multiple impairments in reading, language, and attention are at higher risk for low academic and general self-concept, and hence need to be assessed for self-concept in clinical practice. Our results also highlight the need for further investigation into the heterogeneous nature of self-concept in poor readers. PMID:27867764
An Analysis of Teachers' Concept Confusion Concerning Electric and Magnetic Fields
ERIC Educational Resources Information Center
Hekkenberg, Ans; Lemmer, Miriam; Dekkers, Peter
2015-01-01
In an exploratory study, 36 South African physical science teachers' understanding of basic concepts concerning electric and magnetic fields was studied from a perspective of possible concept confusion. Concept confusion is said to occur when features of one concept are incorrectly attributed to a different concept, in the case of this study to…
Mining Concept Maps to Understand University Students' Learning
ERIC Educational Resources Information Center
Yoo, Jin Soung; Cho, Moon-Heum
2012-01-01
Concept maps, visual representations of knowledge, are used in an educational context as a way to represent students' knowledge, and identify mental models of students; however there is a limitation of using concept mapping due to its difficulty to evaluate the concept maps. A concept map has a complex structure which is composed of concepts and…
Clinical caring science as a scientific discipline.
Rehnsfeldt, Arne; Arman, Maria; Lindström, Unni Å
2017-09-01
Clinical caring science will be described from a theory of science perspective. The aim of this theoretical article to give a comprehensive overview of clinical caring science as a human science-based discipline grounded in a theory of science argumentation. Clinical caring science seeks idiographic or specific variations of the ontology, concepts and theories, formulated by caring science. The rationale is the insight that the research questions do not change when they are addressed in different contexts. The academic subject contains a concept order with ethos concepts, core and basic concepts and practice concepts that unites systematic caring science with clinical caring science. In accordance with a hermeneutic tradition, the idea of the caring act is based on the degree to which the theory base is hermeneutically appropriated by the caregiver. The better the ethos, essential concepts and theories are understood, the better the caring act can be understood. In order to understand the concept order related to clinical caring science, an example is given from an ongoing project in a disaster context. The concept order is an appropriate way of making sense of the essence of clinical caring science. The idea of the concept order is that concepts on all levels need to be united with each other. A research project in clinical caring science can start anywhere on the concept order, either in ethos, core concepts, basic concepts, practice concepts or in concrete clinical phenomena, as long as no parts are locked out of the concept order as an entity. If, for example, research on patient participation as a phenomenon is not related to core and basic concepts, there is a risqué that the research becomes meaningless. © 2016 Nordic College of Caring Science.
Concept similarity and related categories in information retrieval using formal concept analysis
NASA Astrophysics Data System (ADS)
Eklund, P.; Ducrou, J.; Dau, F.
2012-11-01
The application of formal concept analysis to the problem of information retrieval has been shown useful but has lacked any real analysis of the idea of relevance ranking of search results. SearchSleuth is a program developed to experiment with the automated local analysis of Web search using formal concept analysis. SearchSleuth extends a standard search interface to include a conceptual neighbourhood centred on a formal concept derived from the initial query. This neighbourhood of the concept derived from the search terms is decorated with its upper and lower neighbours representing more general and special concepts, respectively. SearchSleuth is in many ways an archetype of search engines based on formal concept analysis with some novel features. In SearchSleuth, the notion of related categories - which are themselves formal concepts - is also introduced. This allows the retrieval focus to shift to a new formal concept called a sibling. This movement across the concept lattice needs to relate one formal concept to another in a principled way. This paper presents the issues concerning exploring, searching, and ordering the space of related categories. The focus is on understanding the use and meaning of proximity and semantic distance in the context of information retrieval using formal concept analysis.
Diagnosing Students’ conception on atomic structure using open ended questions
NASA Astrophysics Data System (ADS)
Fitriza, Z.; Gazali, F.
2018-05-01
This study aims to diagnose students’ conception on atomic structure concepts using open ended questions. For this reason, a 7 items of assay test was administered to 135 senior high school students from different schools in West Sumatera. The data were collected using a an open ended test which is covering the concept used in the topic Atomic Structure. The open ended test of students’ conceptual was developed to identify the alternative conceptions that student might have regarding the concepts in Atomic Structure, to measure the level of students’ conceptions, and the way of students’ thinking concerning the concepts. The results showed that students find difficulties about some concepts of Atomic structure such as atom, atomic model, electron configuration, period and group.The result of this study illuminated the concepts to be underlined in developing teaching and learning approach concerning the topic of Atomic Structure.
Were, Martin C; Mamlin, Burke W; Tierney, William M; Wolfe, Ben; Biondich, Paul G
2007-10-11
The challenges of creating and maintaining concept dictionaries are compounded in resource-limited settings. Approaches to alleviate this burden need to be based on information derived in these settings. We created a concept dictionary and evaluated new concept proposals for an open source EMR in a resource-limited setting. Overall, 87% of the concepts in the initial dictionary were used. There were 5137 new concepts proposed, with 77% of these proposed only once. Further characterization of new concept proposals revealed that 41% were due to deficiency in the existing dictionary, and 19% were synonyms to existing concepts. 25% of the requests contained misspellings, 41% were complex terms, and 17% were ambiguous. Given the resource-intensive nature of dictionary creation and maintenance, there should be considerations for centralizing the concept dictionary service, using standards, prioritizing concept proposals, and redesigning the user-interface to reduce this burden in settings with limited resources.
Were, Martin C.; Mamlin, Burke W.; Tierney, William M.; Wolfe, Ben; Biondich, Paul G.
2007-01-01
The challenges of creating and maintaining concept dictionaries are compounded in resource-limited settings. Approaches to alleviate this burden need to be based on information derived in these settings. We created a concept dictionary and evaluated new concept proposals for an open source EMR in a resource-limited setting. Overall, 87% of the concepts in the initial dictionary were used. There were 5137 new concepts proposed, with 77% of these proposed only once. Further characterization of new concept proposals revealed that 41% were due to deficiency in the existing dictionary, and 19% were synonyms to existing concepts. 25% of the requests contained misspellings, 41% were complex terms, and 17% were ambiguous. Given the resource-intensive nature of dictionary creation and maintenance, there should be considerations for centralizing the concept dictionary service, using standards, prioritizing concept proposals, and redesigning the user-interface to reduce this burden in settings with limited resources. PMID:18693945
NASA Technical Reports Server (NTRS)
Hanley, G. M.
1981-01-01
Modifications to the reference concept were studied and the best approaches defined. The impact of the high efficiency multibandgap solar array on the reference concept design is considered. System trade studies for several solid state concepts, including the sandwich concept and a separate antenna/solar concept, are described. Two solid state concepts were selected and a design definition is presented for each. Magnetrons as an alternative to the reference klystrons for dc/RF conversion are evaluated. System definitions are presented for the preferred klystron and solid state concepts. Supporting systems are analyzed, with major analysis in the microwave, structures, and power distribution areas. Results of studies for thermal control, attitude control, stationkeeping, and details of a multibandgap solar cell study are included. Advanced laser concepts and the meteorological effects of a laser beam power transmission concept are considered.
Building Integrated Design Practice under the Concept of Sustainable Development
NASA Astrophysics Data System (ADS)
Liu, Xuexin
2018-03-01
With the continuous development of social economy, people are more demanding for architecture. Some advanced design concepts are gradually applied to the design of buildings. Under the concept of sustainable development, building integration design has also been widely used to promote the rapid development of architectural design. Integrated design concepts and sustainable development concepts play an important role to meet people’s requirements. This article will explore the concept of sustainable development under the concept of integrated architectural design and practice analysis, propose appropriate measures.
Consilience and a Hierarchy of Species Concepts: Advances Toward Closure on the Species Puzzle
Mayden, Richard L.
1999-01-01
Numerous concepts exist for biological species. This diversity of ideas derives from a number of sources ranging from investigative study of particular taxa and character sets to philosophical aptitude and world view to operationalism and nomenclatorial rules. While usually viewed as counterproductive, in reality these varied concepts can greatly enhance our efforts to discover and understand biological diversity. Moreover, this continued "turf war" and dilemma over species can be resolved if the various concepts are viewed in a hierarchical system and each evaluated for its inherent level of consilience. Under this paradigm a theoretically appropriate, highly consilient concept of species capable of colligating the abundant types of species diversity offers the best guidance for developing and employing secondary operational concepts for identifying diversity. Of all the concepts currently recognized, only the non-operational Evolutionary Species Concept corresponds to the requisite parameters and, therefore, should serve as the theoretical concept appropriate for the category Species. As operational concepts, the remaining ideas have been incompatible with one another in their ability to encompass species diversity because each has restrictive criteria as to what qualifies as a species. However, the operational concepts can complement one another and do serve a vital role under the Evolutionary Species Concept as fundamental tools necessary for discovering diversity compatible with the primary theoretical concept. Thus, the proposed hierarchical system of primary and secondary concepts promises both the most productive framework for mutual respect for varied concepts and the most efficient and effective means for revealing species diversity. PMID:19270881
ERIC Educational Resources Information Center
Birgül, Arzu Ergisi; Zeteroglu, Elvan Sahin; Derman, Meral Taner
2017-01-01
The aim of this study is to examine the effect of the activities enhanced concerning time concept on time concept acquisition of children. The research is a quantitative study in experimental model with pretest-posttest control group aiming to examine the effect of the activities enhanced concerning time concept on time concept acquisition of…
Wilson-Mendenhall, Christine D.; Simmons, W. Kyle; Martin, Alex; Barsalou, Lawrence W.
2014-01-01
Concepts develop for many aspects of experience, including abstract internal states and abstract social activities that do not refer to concrete entities in the world. The current study assessed the hypothesis that, like concrete concepts, distributed neural patterns of relevant, non-linguistic semantic content represent the meanings of abstract concepts. In a novel neuroimaging paradigm, participants processed two abstract concepts (convince, arithmetic) and two concrete concepts (rolling, red) deeply and repeatedly during a concept-scene matching task that grounded each concept in typical contexts. Using a catch trial design, neural activity associated with each concept word was separated from neural activity associated with subsequent visual scenes to assess activations underlying the detailed semantics of each concept. We predicted that brain regions underlying mentalizing and social cognition (e.g., medial prefrontal cortex, superior temporal sulcus) would become active to represent semantic content central to convince, whereas brain regions underlying numerical cognition (e.g., bilateral intraparietal sulcus) would become active to represent semantic content central to arithmetic. The results supported these predictions, suggesting that the meanings of abstract concepts arise from distributed neural systems that represent concept-specific content. PMID:23363408
An evolving-requirements technology assessment process for advanced propulsion concepts
NASA Astrophysics Data System (ADS)
McClure, Erin Kathleen
The following dissertation investigates the development of a methodology suitable for the evaluation of advanced propulsion concepts. At early stages of development, both the future performance of these concepts and their requirements are highly uncertain, making it difficult to forecast their future value. Developing advanced propulsion concepts requires a huge investment of resources. The methodology was developed to enhance the decision-makers understanding of the concepts, so that they could mitigate the risks associated with developing such concepts. A systematic methodology to identify potential advanced propulsion concepts and assess their robustness is necessary to reduce the risk of developing advanced propulsion concepts. Existing advanced design methodologies have evaluated the robustness of technologies or concepts to variations in requirements, but they are not suitable to evaluate a large number of dissimilar concepts. Variations in requirements have been shown to impact the development of advanced propulsion concepts, and any method designed to evaluate these concepts must incorporate the possible variations of the requirements into the assessment. In order to do so, a methodology was formulated to be capable of accounting for two aspects of the problem. First, it had to systemically identify a probabilistic distribution for the future requirements. Such a distribution would allow decision-makers to quantify the uncertainty introduced by variations in requirements. Second, the methodology must be able to assess the robustness of the propulsion concepts as a function of that distribution. This dissertation describes in depth these enabling elements and proceeds to synthesize them into a new method, the Evolving Requirements Technology Assessment (ERTA). As a proof of concept, the ERTA method was used to evaluate and compare advanced propulsion systems that will be capable of powering a hurricane tracking, High Altitude, Long Endurance (HALE) unmanned aerial vehicle (UAV). The use of the ERTA methodology to assess HALE UAV propulsion concepts demonstrated that potential variations in requirements do significantly impact the assessment and selection of propulsion concepts. The proof of concept also demonstrated that traditional forecasting techniques, such as the cross impact analysis, could be used to forecast the requirements for advanced propulsion concepts probabilistically. "Fitness", a measure of relative goodness, was used to evaluate the concepts. Finally, stochastic optimizations were used to evaluate the propulsion concepts across the range of requirement sets that were considered.
Inservice Elementary and Middle School Teachers' Conceptions of Photosynthesis and Respiration
NASA Astrophysics Data System (ADS)
Krall, Rebecca Mcnall; Lott, Kimberly H.; Wymer, Carol L.
2009-02-01
The purpose of this descriptive study was to investigate inservice elementary and middle school teachers’ conceptions of photosynthesis and respiration, basic concepts they are expected to teach. A forced-choice instrument assessing selected standards-based life science concepts with non-scientific conceptions embedded in distracter options was utilized to assess 76 inservice elementary and middle school teachers from the central Appalachian region. Outcomes from four tasks assessing photosynthesis and respiration concepts are discussed. Findings revealed similarities between non-scientific conceptions the teachers demonstrated and non-scientific conceptions reported in the research literature on elementary and middle school students’ understanding of the concepts. Findings also informed subsequent inservice teacher professional development efforts in life science and the development of a biology course for preservice elementary teachers.
Space Mission Concept Development Using Concept Maturity Levels
NASA Technical Reports Server (NTRS)
Wessen, Randii R.; Borden, Chester; Ziemer, John; Kwok, Johnny
2013-01-01
Over the past five years, pre-project formulation experts at the Jet Propulsion Laboratory (JPL) has developed and implemented a method for measuring and communicating the maturity of space mission concepts. Mission concept development teams use this method, and associated tools, prior to concepts entering their Formulation Phases (Phase A/B). The organizing structure is Concept Maturity Level (CML), which is a classification system for characterizing the various levels of a concept's maturity. The key strength of CMLs is the ability to evolve mission concepts guided by an incremental set of assessment needs. The CML definitions have been expanded into a matrix form to identify the breadth and depth of analysis needed for a concept to reach a specific level of maturity. This matrix enables improved assessment and communication by addressing the fundamental dimensions (e.g., science objectives, mission design, technical risk, project organization, cost, export compliance, etc.) associated with mission concept evolution. JPL's collaborative engineering, dedicated concept development, and proposal teams all use these and other CML-appropriate design tools to advance their mission concept designs. This paper focuses on mission concept's early Pre-Phase A represented by CMLs 1- 4. The scope was limited due to the fact that CMLs 5 and 6 are already well defined based on the requirements documented in specific Announcement of Opportunities (AO) and Concept Study Report (CSR) guidelines, respectively, for competitive missions; and by NASA's Procedural Requirements NPR 7120.5E document for Projects in their Formulation Phase.
Lindgren, Kristen P; Neighbors, Clayton; Gasser, Melissa L; Ramirez, Jason J; Cvencek, Dario
2017-05-01
This paper provides an overview of the self-concept as it relates to substance use. Self-concept has a long history in psychological theory and research; however, substance self-concept (e.g., viewing one's self as a drinker or smoker) is an understudied area of research with the potential to expand existing conceptualizations of substance use, addiction, and prevention and treatment efforts, and should receive greater research attention. First, we review and provide a theoretical framework of substance self-concept that draws from dual process models and distinguishes between implicit and explicit self-concept. Next, we summarize key findings related to substance use in the extant literature, focusing on alcohol and tobacco (smoking). Across both substances, there is converging evidence that substance self-concept is associated with substance use outcomes, including quantity and frequency of use and problems associated with use, and that change in substance self-concept is associated with recovery from substance misuse. Recommendations for the substance self-concept research agenda include routine assessment of substance self-concept, expanded use of implicit measures, investigation of moderators of substance self-concept, and targeting substance self-concept directly in prevention and intervention efforts. Ultimately, we suggest that substance self-concept is a promising, but understudied, construct. Greater research attention to substance self-concept could clarify its potential as an important risk factor for hazardous use and addiction as well as its utility as a prevention and treatment target.
Biological embedding: evaluation and analysis of an emerging concept for nursing scholarship.
Nist, Marliese Dion
2017-02-01
The purpose of this paper was to report the analysis of the concept of biological embedding. Research that incorporates a life course perspective is becoming increasingly prominent in the health sciences. Biological embedding is a central concept in life course theory and may be important for nursing theories to enhance our understanding of health states in individuals and populations. Before the concept of biological embedding can be used in nursing theory and research, an analysis of the concept is required to advance it towards full maturity. Concept analysis. PubMed, CINAHL and PsycINFO were searched for publications using the term 'biological embedding' or 'biological programming' and published through 2015. An evaluation of the concept was first conducted to determine the concept's level of maturity and was followed by a concept comparison, using the methods for concept evaluation and comparison described by Morse. A consistent definition of biological embedding - the process by which early life experience alters biological processes to affect adult health outcomes - was found throughout the literature. The concept has been used in several theories that describe the mechanisms through which biological embedding might occur and highlight its role in the development of health trajectories. Biological embedding is a partially mature concept, requiring concept comparison with an overlapping concept - biological programming - to more clearly establish the boundaries of biological embedding. Biological embedding has significant potential for theory development and application in multiple academic disciplines, including nursing. © 2016 John Wiley & Sons Ltd.
Screening studies of advanced control concepts for airbreathing engines
NASA Technical Reports Server (NTRS)
Ouzts, Peter J.; Lorenzo, Carl F.; Merrill, Walter C.
1993-01-01
The application of advanced control concepts to airbreathing engines may yield significant improvements in aircraft/engine performance and operability. Accordingly, the NASA Lewis Research Center has conducted screening studies of advanced control concepts for airbreathing engines to determine their potential impact on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed concepts was formulated by NASA and industry. These concepts were evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation, three target aircraft/engine combinations were considered: a military high performance fighter mission, a high speed civil transport mission, and a civil tiltrotor mission. Each of the advanced control concepts considered in the study were defined and described. The concept's potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts were also determined. Finally, the concepts were ranked with respect to the target aircraft/engine missions.
Social Accountable Medical Education: A concept analysis.
Abdolmaleki, Mohammadreza; Yazdani, Shahram; Momeni, Sedigheh; Momtazmanesh, Nader
2017-07-01
Considering the pervasiveness of social accountable medical education concept around the world and the growing trend of literature in this regard as well as various interpretations made about this concept, we found it necessary to analyze the concept of social accountable medical education. In this study, the modified version of McKenna's approach to concept analysis was used to determine the concept, explain structures and substructures and determine the border concepts neighboring and against social accountability in medical education. By studying the selected sources,the components of the concept were obtained to identify it and express an analytic definition of social accountability in medical education system. Then, a model case with all attributes of the given concept and the contrary and related concepts were mentioned to determine the boundary between the main concept and auxiliary ones. According to the results of this study in the field of social accountability, the detailed and transparent analytical definition of social accountable medical education can be used in future studies as well as the function and evaluation of medical education system.
Social Accountable Medical Education: A concept analysis
ABDOLMALEKI, MOHAMMADREZA; YAZDANI, SHAHRAM; MOMENI, SEDIGHEH; MOMTAZMANESH, NADER
2017-01-01
Introduction: Considering the pervasiveness of social accountable medical education concept around the world and the growing trend of literature in this regard as well as various interpretations made about this concept, we found it necessary to analyze the concept of social accountable medical education. Methods: In this study, the modified version of McKenna’s approach to concept analysis was used to determine the concept, explain structures and substructures and determine the border concepts neighboring and against social accountability in medical education. Results: By studying the selected sources,the components of the concept were obtained to identify it and express an analytic definition of social accountability in medical education system. Then, a model case with all attributes of the given concept and the contrary and related concepts were mentioned to determine the boundary between the main concept and auxiliary ones. Conclusion: According to the results of this study in the field of social accountability, the detailed and transparent analytical definition of social accountable medical education can be used in future studies as well as the function and evaluation of medical education system. PMID:28761884
The allocation of valenced concepts onto 3D space.
Marmolejo-Ramos, Fernando; Tirado, Carlos; Arshamian, Edward; Vélez, Jorge Iván; Arshamian, Artin
2018-06-01
The valence-space metaphor research area investigates the metaphorical mapping of valenced concepts onto space. Research findings from this area indicate that positive, neutral, and negative concepts are associated with upward, midward, and downward locations, respectively, in the vertical plane. The same research area has also indicated that such concepts seem to have no preferential location on the horizontal plane. The approach-avoidance effect consists in decreasing the distance between positive stimuli and the body (i.e. approach) and increasing the distance between negative stimuli and the body (i.e. avoid). Thus, the valence-space metaphor accounts for the mapping of valenced concepts onto the vertical and horizontal planes, and the approach-avoidance effect accounts for the mapping of valenced concepts onto the "depth" plane. By using a cube conceived for the study of allocation of valenced concepts onto 3D space, we show in three studies that positive concepts are placed in upward locations and near the participants' body, negative concepts are placed in downward locations and far from the participants' body, and neutral concepts are placed in between these concepts in both planes.
Psychometric Analysis of the Thermochemistry Concept Inventory
ERIC Educational Resources Information Center
Wren, David; Barbera, Jack
2014-01-01
Assessing conceptual understanding of foundational topics before instruction on higher-order concepts can provide chemical educators with information to aid instructional design. This study provides an instrument that can be used to identify students' alternative conceptions regarding thermochemistry concepts. The Thermochemistry Concept Inventory…
Construction and reconstruction concept in mathematics instruction
NASA Astrophysics Data System (ADS)
Mumu, Jeinne; Charitas Indra Prahmana, Rully; Tanujaya, Benidiktus
2017-12-01
The purpose of this paper is to describe two learning activities undertaken by lecturers, so that students can understand a mathematical concept. The mathematical concept studied in this research is the Vector Space in Linear Algebra instruction. Classroom Action Research used as a research method with pre-service mathematics teacher at University of Papua as the research subject. Student participants are divided into two parallel classes, 24 students in regular class, and remedial class consist of 18 students. Both approaches, construct and reconstruction concept, are implemented on both classes. The result shows that concept construction can only be done in regular class while in remedial class, learning with concept construction approach is not able to increase students' understanding on the concept taught. Understanding the concept of a student in a remedial class can only be carried out using the concept reconstruction approach.
Similarity-Based Recommendation of New Concepts to a Terminology
Chandar, Praveen; Yaman, Anil; Hoxha, Julia; He, Zhe; Weng, Chunhua
2015-01-01
Terminologies can suffer from poor concept coverage due to delays in addition of new concepts. This study tests a similarity-based approach to recommending concepts from a text corpus to a terminology. Our approach involves extraction of candidate concepts from a given text corpus, which are represented using a set of features. The model learns the important features to characterize a concept and recommends new concepts to a terminology. Further, we propose a cost-effective evaluation methodology to estimate the effectiveness of terminology enrichment methods. To test our methodology, we use the clinical trial eligibility criteria free-text as an example text corpus to recommend concepts for SNOMED CT. We computed precision at various rank intervals to measure the performance of the methods. Results indicate that our automated algorithm is an effective method for concept recommendation. PMID:26958170
Survey of Key Concepts in Enactivist Theory and Methodology
ERIC Educational Resources Information Center
Reid, David A.; Mgombelo, Joyce
2015-01-01
This article discusses key concepts within enactivist writing, focussing especially on concepts involved in the enactivist description of cognition as embodied action: perceptually guided action, embodiment, and structural coupling through recurrent sensorimotor patterns. Other concepts on which these concepts depend are also discussed, including…
Garn, Alex C; Morin, Alexandre J S; Martin, Jeffrey; Centeio, Erin; Shen, Bo; Kulik, Noel; Somers, Cheryl; McCaughtry, Nate
2016-06-01
This study investigated a reciprocal effects model (REM) of children's body fat self-concept and physical self-concept, and objectively measured school physical activity at different intensities. Grade four students (N = 376; M age = 9.07, SD = .61; 55% boys) from the midwest region of the United States completed measures of physical self-concept and body fat self-concept, and wore accelerometers for three consecutive school days at the beginning and end of one school year. Findings from structural equation modeling analyses did not support reciprocal effects. However, children's body fat self-concept predicted future physical self-concept and moderate-to-vigorous physical activity (MVPA). Multigroup analyses explored the moderating role of weight status, sex, ethnicity, and sex*ethnicity within the REM. Findings supported invariance, suggesting that the observed relations were generalizable for these children across demographic groups. Links between body fat self-concept and future physical self-concept and MVPA highlight self-enhancing effects that can promote children's health and well-being.
ERIC Educational Resources Information Center
Beasley, Emily Kristin; Garn, Alex C.
2013-01-01
This study examined the relationships among identified regulation, physical self-concept, global self-concept, and leisure-time physical activity with a sample of middle and high school girls (N = 319) enrolled in physical education. Based on Marsh's theory of self-concept, it was hypothesized that a) physical self-concept would mediate the…
Threshold concepts in prosthetics.
Hill, Sophie
2017-12-01
Curriculum documents identify key concepts within learning prosthetics. Threshold concepts provide an alternative way of viewing the curriculum, focussing on the ways of thinking and practicing within prosthetics. Threshold concepts can be described as an opening to a different way of viewing a concept. This article forms part of a larger study exploring what students and staff experience as difficult in learning about prosthetics. To explore possible threshold concepts within prosthetics. Qualitative, interpretative phenomenological analysis. Data from 18 students and 8 staff at two universities with undergraduate prosthetics and orthotics programmes were generated through interviews and questionnaires. The data were analysed using an interpretative phenomenological analysis approach. Three possible threshold concepts arose from the data: 'how we walk', 'learning to talk' and 'considering the person'. Three potential threshold concepts in prosthetics are suggested with possible implications for prosthetics education. These possible threshold concepts involve changes in both conceptual and ontological knowledge, integrating into the persona of the individual. This integration occurs through the development of memories associated with procedural concepts that combine with disciplinary concepts. Considering the prosthetics curriculum through the lens of threshold concepts enables a focus on how students learn to become prosthetists. Clinical relevance This study provides new insights into how prosthetists learn. This has implications for curriculum design in prosthetics education.
Lindgren, Kristen P.; Neighbors, Clayton; Gasser, Melissa L.; Ramirez, Jason J.; Cvencek, Dario
2017-01-01
Background This paper provides an overview of the self-concept as it relates to substance use. Self-concept has a long history in psychological theory and research; however, substance self-concept (e.g., viewing one’s self as a drinker or smoker) is an understudied area of research with the potential to expand existing conceptualizations of substance use, addiction, and prevention and treatment efforts, and should receive greater research attention. Objectives First, we review and provide a theoretical framework of substance self-concept that draws from dual process models and distinguishes between implicit and explicit self-concept. Next, we summarize key findings related to substance use in the extant literature, focusing on alcohol and tobacco (smoking). Results Across both substances, there is converging evidence that substance self-concept is associated with substance use outcomes, including quantity and frequency of use and problems associated with use, and that change in substance self-concept is associated with recovery from substance misuse. Recommendations for the substance self-concept research agenda include routine assessment of substance self-concept, expanded use of implicit measures, investigation of moderators of substance self-concept, and targeting substance self-concept directly in prevention and intervention efforts. Conclusion Ultimately, we suggest that substance self-concept is a promising, but understudied, construct. Greater research attention to substance self-concept could clarify its potential as an important risk factor for hazardous use and addiction as well as its utility as a prevention and treatment target. PMID:27715328
Development of Concepts in the History of Quantum Theory
ERIC Educational Resources Information Center
Heisenberg, Werner
1975-01-01
Traces the development of quantum theory from the concept of the discrete stationary states, to the generalized concept of state, to the search for the elementary particle. States that the concept of the elementary particle should be replaced by the concept of a fundamental symmetry. (MLH)
Concept Mapping: A Critical Thinking Technique
ERIC Educational Resources Information Center
Harris, Charles M.; Zha, Shenghua
2013-01-01
Concept mapping, graphically depicting the structure of abstract concepts, is based on the observation that pictures and line drawings are often more easily comprehended than the words that represent an abstract concept. The efficacy of concept mapping for facilitating critical thinking was assessed in four sections of an introductory psychology…
Evidence of coordination as a cure for concept eliminativism.
Scarantino, Andrea
2010-06-01
I argue that Machery stacks the deck against hybrid theories of concepts by relying on an unduly restrictive understanding of coordination between concept parts. Once a less restrictive notion of coordination is introduced, the empirical case for hybrid theories of concepts becomes stronger, and the appeal of concept eliminativism weaker.
Self-Concept Is a Concept Worth Considering
ERIC Educational Resources Information Center
Shields, Nora
2009-01-01
There is a growing recognition of the importance of self-concept in the pediatric rehabilitation research literature. There also is confusion and inconsistency in the definitions of and the terminology used to describe self-concept. What is agreed is that self-concept is multidimensional, comprising a child's perception of their personal…
ERIC Educational Resources Information Center
West, Charles K.; And Others
1980-01-01
Research on relationships between self-concept and school achievement and between self-concept of academic ability and school achievement is reviewed. Demographic research is also examined regarding differences relating to sex, socio-economic status, ethnicity, race, birth order, and age. (Author/MLW)
A Comparison Study: Assessing Teachers' Conceptions with the Chemistry Concepts Inventory
ERIC Educational Resources Information Center
Kruse, Rebecca A.; Roehrig, Gillian H.
2005-01-01
The conceptions of chemistry teachers with diverse backgrounds within a large urban district are assessed. The Chemistry Concepts Inventory (CCI) and Mulford and Robinson's research study were utilized for reference and conceptual factors contributing to teachers' conceptions such as degree major and credential status were analyzed from data…
ERIC Educational Resources Information Center
Rusanen, Anna-Mari; Poyhonen, Samuli
2013-01-01
In this article we focus on the concept of concept in conceptual change. We argue that (1) theories of higher learning must often employ two different notions of concept that should not be conflated: psychological and scientific concepts. The usages for these two notions are partly distinct and thus straightforward identification between them is…
Thai Grade 10 and 11 Students' Understanding of Stoichiometry and Related Concepts
ERIC Educational Resources Information Center
Dahsah, Chanyah; Coll, Richard Kevin
2008-01-01
The research reported in this case study explores the understanding of stoichiometry and related concepts of Thai science students in grades 10 and 11 after major national curriculum reforms. Students' conceptions and alternative conceptions were investigated using a questionnaire--the "Stoichiometry Concept Questionnaire" (SCQ) (N =…
Categorizing and Promoting Reversibility of Mathematical Concepts
ERIC Educational Resources Information Center
Simon, Martin A.; Kara, Melike; Placa, Nicora; Sandir, Hakan
2016-01-01
Reversibility of concepts, a key aspect of mathematical development, is often problematic for learners. In this theoretical paper, we present a typology we have developed for categorizing the different reverse concepts that can be related to a particular initial concept and explicate the relationship among these different reverse concepts. We…
Concepts in Activities and Discourses
ERIC Educational Resources Information Center
Greeno, James G.
2012-01-01
The articles in this special issue make valuable contributions toward a scientific understanding of concepts that is broader than the traditional view that has focused on categorizing by individuals. I propose considering concepts for categorization as a special case of concepts. At their clearest, they can be referred to as "formal concepts," or…
ERIC Educational Resources Information Center
Banerjee, Konika; Haque, Omar S.; Spelke, Elizabeth S.
2013-01-01
Previous research with adults suggests that a catalog of minimally counterintuitive concepts, which underlies supernatural or religious concepts, may constitute a cognitive optimum and is therefore cognitively encoded and culturally transmitted more successfully than either entirely intuitive concepts or maximally counterintuitive concepts. This…
Increasing Self Concept: An Educational Perspective.
ERIC Educational Resources Information Center
Fuller, Mary Lou
1984-01-01
This monograph is designed to help educators develop a better understanding of children's self-concept, the effects of children's self-concept on their school experience, and ways educators can have a positive effect on self-concept. The first section defines self-concept and presents two case studies; the second discusses factors influencing the…
Words and Concepts. What Works Clearinghouse Intervention Report
ERIC Educational Resources Information Center
What Works Clearinghouse, 2007
2007-01-01
"Words and Concepts" is a computer software program that focuses on building oral language skills related to vocabulary, comprehension, word relationships, and other concepts in six units--vocabulary, categorization, word identification by function, word association, concept of same, and concept of different. It can be used by adults and…
Increasing Educational Achievement via Self Concept Change.
ERIC Educational Resources Information Center
Scheirer, Mary Ann; Kraut, Robert E.
1979-01-01
Literature linking self-concept and achievement, and evaluation research on educational programs to improve self-concept are analyzed in terms of several self-concept theories. Evidence for a causal connection between self-concept and achievement is negative. Researchers have failed to explore other theoretical approaches to educational change.…
The Impact of Vision Impairment on Students' Self-Concept
ERIC Educational Resources Information Center
Datta, Poulomee; Talukdar, Joy
2016-01-01
This study investigated the self-concept of students with vision impairment who were placed in specialist and mainstream educational settings in South Australia. Self-Concept was explored across six dimensions, namely Physical, Moral, Personal, Family, Social and Academic Self-Concepts and the Total Self-Concept. The "Tennessee Self-Concept…
Family Relationships and Adolescent Self-Concept.
ERIC Educational Resources Information Center
Massey, Catherine J.
Previous research relating the quality of the relationship with the mother, father, and sibling to adolescent self-concept only investigated social and general self-concept and not various social and cognitive dimensions of self-concept. This study investigated family relationships and their link to the several domains of self-concept.…
Inservice Elementary and Middle School Teachers' Conceptions of Photosynthesis and Respiration
ERIC Educational Resources Information Center
Krall, Rebecca McNall; Lott, Kimberly H.; Wymer, Carol L.
2009-01-01
The purpose of this descriptive study was to investigate inservice elementary and middle school teachers' conceptions of photosynthesis and respiration, basic concepts they are expected to teach. A forced-choice instrument assessing selected standards-based life science concepts with non-scientific conceptions embedded in distracter options was…
Student Conceptions about Energy Transformations: Progression from General Chemistry to Biochemistry
ERIC Educational Resources Information Center
Wolfson, Adele J.; Rowland, Susan L.; Lawrie, Gwendolyn A.; Wright, Anthony H.
2014-01-01
Students commencing studies in biochemistry must transfer and build on concepts they learned in chemistry and biology classes. It is well established, however, that students have difficulties in transferring critical concepts from general chemistry courses; one key concept is "energy." Most previous work on students' conception of energy…
Architecture is Elementary: Visual Thinking through Architectural Concepts.
ERIC Educational Resources Information Center
Winters, Nathan B.
This book presents very basic but important concepts about architecture and outlines some of the most important concepts used by great architects. These concepts are taught at levels of perceptual maturity applicable to adults and children alike and progress from levels one through seven as the concepts become progressively intertwined. The…
Middle Grade Students' Concept Images of Algebraic Concepts
ERIC Educational Resources Information Center
Tekin-Sitrava, Reyhan
2017-01-01
This study investigates middle school students' concept images of algebraic concepts which are term, constant term, variable, and coefficient. Also, the study aimed to explore their performances in defining these concepts correctly. A phenomenological method was used to support methodological perspective and to reveal the findings of the study.…
Drawings as Representations of Children's Conceptions
ERIC Educational Resources Information Center
Ehrlen, Karin
2009-01-01
Drawings are often used to obtain an idea of children's conceptions. Doing so takes for granted an unambiguous relation between conceptions and their representations in drawings. This study was undertaken to gain knowledge of the relation between children's conceptions and their representation of these conceptions in drawings. A theory of…
On the Role of Concepts in Learning and Instructional Design
ERIC Educational Resources Information Center
Jonassen, David H.
2006-01-01
The field of instructional design has traditionally treated concepts as discrete learning outcomes. Theoretically, learning concepts requires correctly isolating and applying attributes of specific objects into their correct categories. Similarity views of concept learning are unable to account for all of the rules governing concept formation,…
Bottleneck Concepts in Psychology: Exploratory First Steps
ERIC Educational Resources Information Center
Gurung, Regan A. R.; Landrum, R. Eric
2013-01-01
The authors take an initial step in identifying potential bottleneck concepts in psychology, that is, concepts that are deceptively difficult, perhaps due to student overconfidence. In order to first identify bottleneck concepts, faculty (n = 65) rated the difficulty of 91 psychological concepts from across the discipline. Students (n = 35) rated…
Threshold Concepts and Conceptions: Student Learning in Introductory Management Courses
ERIC Educational Resources Information Center
Wright, April L.; Gilmore, Anne
2012-01-01
This article explores how insights from the broader education literature on threshold concepts and conceptions can be applied to improve the teaching of undergraduate introductory management courses. The authors propose that these courses are underpinned by the threshold conception, or "underlying game," that management is a practice…
Evolutionary space platform concept study. Volume 1: Executive summary
NASA Technical Reports Server (NTRS)
1982-01-01
The Evolutionary Space Platform Concept Study encompassed a 10 month effort to define, evaluate and compare approaches and concepts for evolving unmanned and manned capability platforms beyond the current Space Platform concepts to an evolutionary goal of establishing a permanent manned presence in space. Areas addressed included: special emphasis trade studies on the current unmanned concept, assessment of manned platform concepts, and utility analysis of a manned platform for defense related missions.
Teaching concepts of energy to nigerian children in the 7-11 year-old age range
NASA Astrophysics Data System (ADS)
Urevbu, Andrew O.
This study investigated the level of concept attainment of selected energy concepts for possible inclusion in the Nigerian (Bendel State) Primary Science Project (BPSP). Using an experimental design suggested by Solomon (1949), subjects were taught energy concepts at three levels - descriptive, comparative and quantitative. Results showed that levels of concept comprehension were hierarchical with a signficant decrease in achievement from descriptive to comparative and quantitative concepts. The results of this study suggest the need to describe levels of concept for particular grades in the elementary school curriculum and to match curriculum with thinking strategies of children.
NASA Innovation Fund 2010 Project Elastically Shaped Future Air Vehicle Concept
NASA Technical Reports Server (NTRS)
Nguyen, Nhan
2010-01-01
This report describes a study conducted in 2010 under the NASA Innovation Fund Award to develop innovative future air vehicle concepts. Aerodynamic optimization was performed to produce three different aircraft configuration concepts for low drag, namely drooped wing, inflected wing, and squashed fuselage. A novel wing shaping control concept is introduced. This concept describes a new capability of actively controlling wing shape in-flight to minimize drag. In addition, a novel flight control effector concept is developed to enable wing shaping control. This concept is called a variable camber continuous trailing edge flap that can reduce drag by as much as 50% over a conventional flap. In totality, the potential benefits of fuel savings offered by these concepts can be significant.
McMillan, Kim; Perron, Amélie
2013-02-01
This article aims to clarify the concept of change fatigue and deems further exploration of the concept within the discipline of nursing is relevant and necessary. The concept of change fatigue has evolved from the discipline of management as a means to explore organization change and its associated triumphs and failures. Change fatigue has typically been described as one and the same as change resistance, with very little literature acknowledging that they are in fact distinct concepts. Concept clarification has highlighted the striking differences and few similarities that exist between the concepts of change fatigue and change resistance. Further exploration and subsequent research on the concept of change fatigue is needed within the discipline of nursing. The concept not only presents new and alternative perspectives on the processes of organization change, but provides opportunity for theory development that recognizes the impact organizational change has on nurses' work lives.
A Hierarchical Biology Concept Framework: A Tool for Course Design
Khodor, Julia; Halme, Dina Gould; Walker, Graham C.
2004-01-01
A typical undergraduate biology curriculum covers a very large number of concepts and details. We describe the development of a Biology Concept Framework (BCF) as a possible way to organize this material to enhance teaching and learning. Our BCF is hierarchical, places details in context, nests related concepts, and articulates concepts that are inherently obvious to experts but often difficult for novices to grasp. Our BCF is also cross-referenced, highlighting interconnections between concepts. We have found our BCF to be a versatile tool for design, evaluation, and revision of course goals and materials. There has been a call for creating Biology Concept Inventories, multiple-choice exams that test important biology concepts, analogous to those in physics, astronomy, and chemistry. We argue that the community of researchers and educators must first reach consensus about not only what concepts are important to test, but also how the concepts should be organized and how that organization might influence teaching and learning. We think that our BCF can serve as a catalyst for community-wide discussion on organizing the vast number of concepts in biology, as a model for others to formulate their own BCFs and as a contribution toward the creation of a comprehensive BCF. PMID:15257339
NASA Astrophysics Data System (ADS)
Liew, Keng-Hou; Lin, Yu-Shih; Chang, Yi-Chun; Chu, Chih-Ping
2013-12-01
Examination is a traditional way to assess learners' learning status, progress and performance after a learning activity. Except the test grade, a test sheet hides some implicit information such as test concepts, their relationships, importance, and prerequisite. The implicit information can be extracted and constructed a concept map for considering (1) the test concepts covered in the same question means these test concepts have strong relationships, and (2) questions in the same test sheet means the test concepts are relative. Concept map has been successfully employed in many researches to help instructors and learners organize relationships among concepts. However, concept map construction depends on experts who need to take effort and time for the organization of the domain knowledge. In addition, the previous researches regarding to automatic concept map construction are limited to consider all learners of a class, which have not considered personalized learning. To cope with this problem, this paper proposes a new approach to automatically extract and construct concept map based on implicit information in a test sheet. Furthermore, the proposed approach also can help learner for self-assessment and self-diagnosis. Finally, an example is given to depict the effectiveness of proposed approach.
Ruiz Fernandez, Susana; Bury, Nils-Alexander; Gerjets, Peter; Fischer, Martin H.; Bock, Otmar L.
2016-01-01
The aim of the present study was to test the functional relevance of the spatial concepts UP or DOWN for words that use these concepts either literally (space) or metaphorically (time, valence). A functional relevance would imply a symmetrical relationship between the spatial concepts and words related to these concepts, showing that processing words activate the related spatial concepts on one hand, but also that an activation of the concepts will ease the retrieval of a related word on the other. For the latter, the rotation angle of participant’s body position was manipulated either to an upright or a head-down tilted body position to activate the related spatial concept. Afterwards participants produced in a within-subject design previously memorized words of the concepts space, time and valence according to the pace of a metronome. All words were related either to the spatial concept UP or DOWN. The results including Bayesian analyses show (1) a significant interaction between body position and words using the concepts UP and DOWN literally, (2) a marginal significant interaction between body position and temporal words and (3) no effect between body position and valence words. However, post-hoc analyses suggest no difference between experiments. Thus, the authors concluded that integrating sensorimotor experiences is indeed of functional relevance for all three concepts of space, time and valence. However, the strength of this functional relevance depends on how close words are linked to mental concepts representing vertical space. PMID:27812155
Identifying Opportunities for Vertical Integration of Biochemistry and Clinical Medicine.
Wendelberger, Karen J.; Burke, Rebecca; Haas, Arthur L.; Harenwattananon, Marisa; Simpson, Deborah
1998-01-01
Objectives: Retention of basic science knowledge, as judged by National Board of Medical Examiners' (NBME) data, suffers due to lack of apparent relevance and isolation of instruction from clinical application, especially in biochemistry. However, the literature reveals no systematic process for identifying key biochemical concepts and associated clinical conditions. This study systematically identified difficult biochemical concepts and their common clinical conditions as a critical step towards enhancing relevance and retention of biochemistry.Methods: A multi-step/ multiple stakeholder process was used to: (1) identify important biochemistry concepts; (2) determine students' perceptions of concept difficulty; (3) assess biochemistry faculty, student, and clinical teaching scholars' perceived relevance of identified concepts; and (4) identify associated common clinical conditions for relevant and difficult concepts. Surveys and a modified Delphi process were used to gather data, subsequently analyzed using SPSS for Windows.Results: Sixteen key biochemical concepts were identified. Second year medical students rated 14/16 concepts as extremely difficult while fourth year students rated nine concepts as moderately to extremely difficult. On average, each teaching scholar generated common clinical conditions for 6.2 of the 16 concepts, yielding a set of seven critical concepts and associated clinical conditions.Conclusions: Key stakeholders in the instructional process struggle to identify biochemistry concepts that are critical, difficult to learn and associated with common clinical conditions. However, through a systematic process beginning with identification of concepts and associated clinical conditions, relevance of basic science instruction can be enhanced.
NASA Astrophysics Data System (ADS)
Dosanjh, Navdeep Kaur
2011-12-01
There is great concern over students' poor science achievement in the United States. Due to the lack of science achievement, students are not pursing science related careers resulting in an increase in outsourcing to other countries. Learning strategies such as concept mapping may ameliorate this situation by providing students with tools that encourage meaningful learning. The purpose of this quasi-experimental study was to measure the effects of three concept mapping learning strategies (concept identifying, proposition identifying, student generated) on urban middle school students' understanding of the circulatory system. Three intact classes of seventh-grade students were assigned to one of the three concept mapping strategies. The students were given a pretest on the circulatory system then learned and used their respective concept mapping strategies while learning about the circulatory system. At the conclusion of the study, students' science achievement was measured by performance on an achievement test and rubric scores of their respective concept identifying, proposition identifying, and student generated concept maps. The results of the study suggest that all three of the concept mapping strategies are effective in increasing students' science achievement. Additionally, the moderate significant correlations between the posttest and concept map scores of the current study established that concept maps are a useful measure of student knowledge. Lastly, the results of the current study also suggest that the concept identifying mapping strategy may be a useful scaffold in instructing students how to develop student generated concept maps.
Van Houdt, Sabine; Sermeus, Walter; Vanhaecht, Kris; De Lepeleire, Jan
2014-12-24
Strategies to improve care coordination between primary and hospital care do not always have the desired results. This is partly due to incomplete understanding of the key concepts of care coordination. An in-depth analysis of existing theoretical frameworks for the study of care coordination identified 14 interrelated key concepts. In another study, these 14 key concepts were further explored in patients' experiences. Additionally, "patient characteristics" was identified as a new key concept in patients' experiences and the previously identified key concept "quality of relationship" between healthcare professionals was extended to "quality of relationship" with the patient. Together, these 15 interrelated key concepts resulted in a new theoretical framework. The present study aimed at improving our understanding of the 15 previously identified key concepts and to explore potentially previous unidentified key concepts and the links between these by exploring how healthcare professionals experience care coordination. A qualitative design was used. Six focus groups were conducted including primary healthcare professionals involved in the care of patients who had breast cancer surgery at three hospitals in Belgium. Data were analyzed using constant comparative analysis. All 15 previously identified key concepts of care coordination were further explored in healthcare professionals' experiences. Links between these 15 concepts were identified, including 9 newly identified links. The concept "external factors" was linked with all 6 concepts relating to (inter)organizational mechanisms; "task characteristics", "structure", "knowledge and information technology", "administrative operational processes", "cultural factors" and "need for coordination". Five of these concepts related to 3 concepts of relational coordination; "roles", "quality of relationship" and "exchange of information". The concept of "task characteristics" was only linked with "roles" and "exchange of information". The concept "patient characteristics" related with the concepts "need for coordination" and "patient outcome". Outcome was influenced by "roles", "quality of relationship" and "exchange of information". External factors and the (inter)organizational mechanism should enhance "roles" and "quality of relationship" between healthcare professionals and with the patient as well as "exchange of information", and setting and sharing of common "goals" to improve care coordination and quality of care.
Zheng, Ling; Chen, Yan; Elhanan, Gai; Perl, Yehoshua; Geller, James; Ochs, Christopher
2018-05-28
In previous research, we have demonstrated for a number of ontologies that structurally complex concepts (for different definitions of "complex") in an ontology are more likely to exhibit errors than other concepts. Thus, such complex concepts often become fertile ground for quality assurance (QA) in ontologies. They should be audited first. One example of complex concepts is given by "overlapping concepts" (to be defined below.) Historically, a different auditing methodology had to be developed for every single ontology. For better scalability and efficiency, it is desirable to identify family-wide QA methodologies. Each such methodology would be applicable to a whole family of similar ontologies. In past research, we had divided the 685 ontologies of BioPortal into families of structurally similar ontologies. We showed for four ontologies of the same large family in BioPortal that "overlapping concepts" are indeed statistically significantly more likely to exhibit errors. In order to make an authoritative statement concerning the success of "overlapping concepts" as a methodology for a whole family of similar ontologies (or of large subhierarchies of ontologies), it is necessary to show that "overlapping concepts" have a higher likelihood of errors for six out of six ontologies of the family. In this paper, we are demonstrating for two more ontologies that "overlapping concepts" can successfully predict groups of concepts with a higher error rate than concepts from a control group. The fifth ontology is the Neoplasm subhierarchy of the National Cancer Institute thesaurus (NCIt). The sixth ontology is the Infectious Disease subhierarchy of SNOMED CT. We demonstrate quality assurance results for both of them. Furthermore, in this paper we observe two novel, important, and useful phenomena during quality assurance of "overlapping concepts." First, an erroneous "overlapping concept" can help with discovering other erroneous "non-overlapping concepts" in its vicinity. Secondly, correcting erroneous "overlapping concepts" may turn them into "non-overlapping concepts." We demonstrate that this may reduce the complexity of parts of the ontology, which in turn makes the ontology more comprehensible, simplifying maintenance and use of the ontology. Copyright © 2018. Published by Elsevier Inc.
Alternative conceptions of introductory geoscience students and a method to decrease them
NASA Astrophysics Data System (ADS)
Kortz, Karen Melissa
College students often leave introductory geoscience courses with alternative conceptions, and these alternative conceptions are a barrier to their grasp of geological conceptions. This dissertation clarifies the problem and suggests pedagogical strategies for correcting it. It is an integration of research on students' conceptions of geoscience topics with the application of that knowledge to the development of materials to change these conceptions to be more scientifically accurate. This research identifies and documents alternative conceptions students have in several key geoscience topics and the consequences of these alternative conception in terms of preventing understanding. After documenting the alternative conceptions, I investigate their sources. In addition, I develop ways in which the alternative conceptions can be addressed in classrooms in terms of non-traditional teaching techniques, and I assess the success of these methods. Chapter 1 addresses alternative conceptions in general introductory geoscience topics. I use known student alternative conceptions to develop a series of interactive materials to help reduce students' alternative conceptions. After their development, I assess the efficacy of these materials, and my research indicates that they are successful in helping students better learn the geoscience concepts. Chapter 2 deals with a particularly difficult topic for students---that of phylogenetic systematics. Students have an intuitive way of categorizing organisms, and this categorization is different from the system used by experts within the field. My investigation indicates the conceptual change required of students to fully understand the topic leads to great difficulties with learning. Drawing upon results of the research in Chapter 1, I developed and assessed interactive materials to help students better understand phylogenetic systematics. Using the insight gained from Chapters 1 and 2, Chapters 3 and 4 further examine students' conceptions in an area critical to understanding geology: rocks and their formation. My research indicates that students view rocks as objects independent from the processes that form and change them. In addition, I document students' alternative conceptions of rocks. Using these alternative conceptions, I look more deeply into the underlying factors that cause the difficulties students have with learning rocks, their formation, and their importance to the geosciences.
NASA Astrophysics Data System (ADS)
Powers, Angela R.
2000-10-01
This study explored the relationship between secondary chemistry students' conceptual representations of acid-base chemistry, as shown in student-constructed concept maps, and their ability to solve acid-base problems, represented by their score on an 18-item paper and pencil test, the Acid-Base Concept Assessment (ABCA). The ABCA, consisting of both multiple-choice and short-answer items, was originally designed using a question-type by subtopic matrix, validated by a panel of experts, and refined through pilot studies and factor analysis to create the final instrument. The concept map task included a short introduction to concept mapping, a prototype concept map, a practice concept-mapping activity, and the instructions for the acid-base concept map task. The instruments were administered to chemistry students at two high schools; 108 subjects completed both instruments for this study. Factor analysis of ABCA results indicated that the test was unifactorial for these students, despite the intention to create an instrument with multiple "question-type" scales. Concept maps were scored both holistically and by counting valid concepts. The two approaches were highly correlated (r = 0.75). The correlation between ABCA score and concept-map score was 0.29 for holistically-scored concept maps and 0.33 for counted-concept maps. Although both correlations were significant, they accounted for only 8.8 and 10.2% of variance in ABCA scores, respectively. However, when the reliability of the instruments used is considered, more than 20% of the variance in ABCA scores may be explained by concept map scores. MANOVAs for ABCA and concept map scores by instructor, student gender, and year in school showed significant differences for both holistic and counted concept-map scores. Discriminant analysis revealed that the source of these differences was the instruction variable. Significant differences between classes receiving different instruction were found in the frequency of concepts listed by students for 9 of 10 concepts evaluated. Mean ABCA scores did not differ significantly between the two instruction groups. The results of this study failed to provide evidence of conceptual distinctions among different "types" of problem-solving items. The results suggested that several factors influence success in chemistry problem solving, including concept knowledge and organization. Further research into the nature of chemistry problems and problem solving is recommended.
Saleem, Haneefa T; Surkan, Pamela J; Kerrigan, Deanna; Kennedy, Caitlin E
2016-01-01
Safer conception interventions can significantly reduce the risk of horizontal HIV transmission between HIV-serodiscordant partners. However, prior to implementing safer conception interventions, it is essential to understand potential barriers to their adoption so that strategies can be developed to overcome these barriers. This paper examines potential barriers to the adoption of safer conception strategies by HIV-affected couples in Iringa, Tanzania using an ecological framework. We interviewed 30 HIV-positive women, 30 HIV-positive men and 30 health providers engaged in delivering HIV-related services. We also conducted direct observations at five health facilities. Findings suggest that there are multiple barriers to safer conception that operate at the individual, relational, environmental, structural, and super-structural levels. The barriers to safer conception identified are complex and interact across these levels. Barriers at the individual level included antiretroviral adherence, knowledge of HIV status, knowledge and acceptability of safer conception strategies, and poor nutrition. At the relational level, unplanned pregnancies, non-disclosure of status, gendered power dynamics within relationships, and patient-provider interactions posed a threat to safer conception. HIV stigma and distance to health facilities were environmental barriers to safer conception. At the structural level there were multiple barriers to safer conception, including limited safer conception policy guidelines for people living with HIV (PLHIV), lack of health provider training in safer conception strategies and preconception counseling for PLHIV, limited resources, and lack of integration of HIV and sexual and reproductive health services. Poverty and gender norms were super-structural factors that influenced and reinforced barriers to safer conception, which influenced and operated across different levels of the framework. Multi-level interventions are needed to ensure adoption of safer conception strategies and reduce the risk of HIV transmission between partners within HIV-serodiscordant couples.
Martin, A J; Debus, R L
1998-12-01
There is a need for research to (a) explore more fully the academic outcomes that follow from under-/over-rating of self-concept and (b) identify factors that predict the nature of self-reports of self-concept as well as under- and over-rating of this self-concept. The study examines the link between students' self-appraisals of both mathematics self-concept and under-/over-rating of this self-concept and educational outcomes in mathematics such as achievement and motivation (future plans for mathematics). Ego-dimensions (ego-orientation and competence-valuation) and public self-consciousness were examined as two factors that might contribute to predicting these self-appraisals. Findings are drawn from a sample of 382 male and female high school students ranging in age from 14 to 16 years. Students responded to a questionnaire (at Time 1) that assessed self-concept, motivation orientation, competence-valuation, self-consciousness, and mathematics motivation. Teachers rated each student using a brief mathematics self-concept scale. Higher mathematics self-concept and over-rating of this self-concept were predictive of higher levels of mathematics motivation and later mathematics achievement (Time 2). Findings also indicate that ego-orientation and competence-valuation are positively associated with mathematics self-concept and over-rating, whilst public self-consciousness negatively predicts mathematics self-concept and is also associated with a tendency to under-rate oneself in this domain.
Nursing intellectual capital theory: operationalization and empirical validation of concepts.
Covell, Christine L; Sidani, Souraya
2013-08-01
To present the operationalization of concepts in the nursing intellectual capital theory and the results of a methodological study aimed at empirically validating the concepts. The nursing intellectual capital theory proposes that the stocks of nursing knowledge in an organization are embedded in two concepts, nursing human capital and nursing structural capital. The theory also proposes that two concepts in the work environment, nurse staffing and employer support for nursing continuing professional development, influence nursing human capital. A cross-sectional design. A systematic three-step process was used to operationalize the concepts of the theory. In 2008, data were collected for 147 inpatient units from administrative departments and unit managers in 6 Canadian hospitals. Exploratory factor analyses were conducted to determine if the indicator variables accurately reflect their respective concepts. The proposed indicator variables collectively measured the nurse staffing concept. Three indicators were retained to construct nursing human capital: clinical expertise and experience concept. The nursing structural capital and employer support for nursing continuing professional development concepts were not validated empirically. The nurse staffing and the nursing human capital: clinical expertise and experience concepts will be brought forward for further model testing. Refinement for some of the indicator variables of the concepts is indicated. Additional research is required with different sources of data to confirm the findings. © 2012 Blackwell Publishing Ltd.
The Musical Self-Concept of Chinese Music Students.
Petersen, Suse; Camp, Marc-Antoine
2016-01-01
The relationship between self-concept and societal settings has been widely investigated in several Western and Asian countries, with respect to the academic self-concept in an educational environment. Although the musical self-concept is highly relevant to musical development and performance, there is a lack of research exploring how the musical self-concept evolves in different cultural settings and societies. In particular, there have been no enquiries yet in the Chinese music education environment. This study's goal was the characterization of musical self-concept types among music students at a University in Beijing, China. The Musical Self-Concept Inquiry-including ability, emotional, physical, cognitive, and social facets-was used to assess the students' musical self-concepts (N = 97). The data analysis led to three significantly distinct clusters and corresponding musical self-concept types. The types were especially distinct, in the students' perception of their musical ambitions and abilities; their movement, rhythm and dancing affinity; and the spiritual and social aspects of music. The professional aims and perspectives, and the aspects of the students' sociodemographic background also differed between the clusters. This study is one of the first research endeavors addressing musical self-concepts in China. The empirical identification of the self-concept types offers a basis for future research on the connections between education, the development of musical achievement, and the musical self-concept in societal settings with differing understandings of the self.
The Musical Self-Concept of Chinese Music Students
Petersen, Suse; Camp, Marc-Antoine
2016-01-01
The relationship between self-concept and societal settings has been widely investigated in several Western and Asian countries, with respect to the academic self-concept in an educational environment. Although the musical self-concept is highly relevant to musical development and performance, there is a lack of research exploring how the musical self-concept evolves in different cultural settings and societies. In particular, there have been no enquiries yet in the Chinese music education environment. This study’s goal was the characterization of musical self-concept types among music students at a University in Beijing, China. The Musical Self-Concept Inquiry—including ability, emotional, physical, cognitive, and social facets—was used to assess the students’ musical self-concepts (N = 97). The data analysis led to three significantly distinct clusters and corresponding musical self-concept types. The types were especially distinct, in the students’ perception of their musical ambitions and abilities; their movement, rhythm and dancing affinity; and the spiritual and social aspects of music. The professional aims and perspectives, and the aspects of the students’ sociodemographic background also differed between the clusters. This study is one of the first research endeavors addressing musical self-concepts in China. The empirical identification of the self-concept types offers a basis for future research on the connections between education, the development of musical achievement, and the musical self-concept in societal settings with differing understandings of the self. PMID:27303337
Extraction of a group-pair relation: problem-solving relation from web-board documents.
Pechsiri, Chaveevan; Piriyakul, Rapepun
2016-01-01
This paper aims to extract a group-pair relation as a Problem-Solving relation, for example a DiseaseSymptom-Treatment relation and a CarProblem-Repair relation, between two event-explanation groups, a problem-concept group as a symptom/CarProblem-concept group and a solving-concept group as a treatment-concept/repair concept group from hospital-web-board and car-repair-guru-web-board documents. The Problem-Solving relation (particularly Symptom-Treatment relation) including the graphical representation benefits non-professional persons by supporting knowledge of primarily solving problems. The research contains three problems: how to identify an EDU (an Elementary Discourse Unit, which is a simple sentence) with the event concept of either a problem or a solution; how to determine a problem-concept EDU boundary and a solving-concept EDU boundary as two event-explanation groups, and how to determine the Problem-Solving relation between these two event-explanation groups. Therefore, we apply word co-occurrence to identify a problem-concept EDU and a solving-concept EDU, and machine-learning techniques to solve a problem-concept EDU boundary and a solving-concept EDU boundary. We propose using k-mean and Naïve Bayes to determine the Problem-Solving relation between the two event-explanation groups involved with clustering features. In contrast to previous works, the proposed approach enables group-pair relation extraction with high accuracy.
Politicizing science: conceptions of politics in science and technology studies.
Brown, Mark B
2015-02-01
This essay examines five ideal-typical conceptions of politics in science and technology studies. Rather than evaluating these conceptions with reference to a single standard, the essay shows how different conceptions of politics serve distinct purposes: normative critique, two approaches to empirical description, and two views of democracy. I discuss each conception of politics with respect to how well it fulfills its apparent primary purpose, as well as its implications for the purpose of studying a key issue in contemporary democratic societies: the politicization of science. In this respect, the essay goes beyond classifying different conceptions of politics and also recommends the fifth conception as especially conducive to understanding and shaping the processes whereby science becomes a site or object of political activity. The essay also employs several analytical distinctions to help clarify the differences among conceptions of politics: between science as 'political' (adjective) and science as a site of 'politics' (noun), between spatial-conceptions and activity-conceptions of politics, between latent conflicts and actual conflicts, and between politics and power. The essay also makes the methodological argument that the politics of science and technology is best studied with concepts and methods that facilitate dialogue between actors and analysts. The main goal, however, is not to defend a particular view of politics, but to promote conversation on the conceptions of politics that animate research in social studies of science and technology.
On the Concept Image of Complex Numbers
ERIC Educational Resources Information Center
Nordlander, Maria Cortas; Nordlander, Edvard
2012-01-01
A study of how Swedish students understand the concept of complex numbers was performed. A questionnaire was issued reflecting the student view of own perception. Obtained answers show a variety of concept images describing how students adopt the concept of complex numbers. These concept images are classified into four categories in order to…
The Analysis of High School Students' Conceptions of Learning in Different Domains
ERIC Educational Resources Information Center
Sadi, Özlem
2015-01-01
The purpose of this study is to investigate whether or not conceptions of learning diverge in different science domains by identifying high school students' conceptions of learning in physics, chemistry and biology. The Conceptions of Learning Science (COLS) questionnaire was adapted for physics (Conceptions of Learning Physics, COLP), chemistry…
Concept Mapping as a Learning Tool for the Employment Relations Degree
ERIC Educational Resources Information Center
Martinez-Canas, Ricardo; Ruiz-Palomino, Pablo
2011-01-01
Concept mapping is a technique to represent relationships between concepts that can help students to improve their meaningful learning. Using the cognitive theories proposed by Ausubel (1968), concept maps can help instructors and students to enhance their logical thinking and study skills by revealing connections among concepts that can simplify…
Conceptions of Parents, Conceptions of Self, and Conceptions of God.
ERIC Educational Resources Information Center
Buri, John R.; Mueller, Rebecca A.
Different theorists have suggested that an individual's view of God may be related to one's view of one's father, one's mother, or one's self. A study was conducted to examine the relationship of college students' conceptions of the wrathfulness-kindliness of God to their conceptions of their father's and mother's permissiveness, authoritarianism,…
The Curious Case of the "Refrigerator-TV": Similarity and Hybridization
ERIC Educational Resources Information Center
Gibbert, Michael; Hampton, James A.; Estes, Zachary; Mazursky, David
2012-01-01
This article examines the role of similarity in the hybridization of concepts, focusing on hybrid products as an applied test case. Hybrid concepts found in natural language, such as "singer songwriter," typically combine similar concepts, whereas dissimilar concepts rarely form hybrids. The hybridization of dissimilar concepts in products such as…
How to Help Your Students Recall New Concepts Better.
ERIC Educational Resources Information Center
Hodges, Daniel L.
Students' difficulties in assimilating new concepts can be a barrier to learning and may be exacerbated if the concepts are introduced in terms of detailed verbal definitions. Cognitive psychology suggests that a better approach to teaching new concepts may be to use prototypical examples of the concept as building-blocks from which verbal…
ERIC Educational Resources Information Center
Lee, Jae Hwa; Segev, Aviv
2012-01-01
Maps such as concept maps and knowledge maps are often used as learning materials. These maps have nodes and links, nodes as key concepts and links as relationships between key concepts. From a map, the user can recognize the important concepts and the relationships between them. To build concept or knowledge maps, domain experts are needed.…
Using the Concept Attainment Strategy to Enhance Reading Comprehension
ERIC Educational Resources Information Center
Boulware, Beverly J.; Crow, Mary Lynn
2008-01-01
The Concept Attainment Strategy is an instructional technique proposed by Jerome Bruner that targets the "big idea" or concept underlining concrete or abstract examples. This strategy focuses on the developing comprehension of words and ideas associated with a concept rather than on its name or what the concept is called. Specifically it develops…
Identification and Assessment of Taiwanese Children's Conceptions of Learning Mathematics
ERIC Educational Resources Information Center
Chiu, Mei-Shiu
2012-01-01
The aim of the present study was to identify children's conceptions of learning mathematics and to assess the identified conceptions. Children's conceptions are identified by interviewing 73 grade 5 students in Taiwan. The interviews are analyzed using qualitative data analysis methods, which results in a structure of 5 major conceptions, each…
Determining the Exchangeability of Concept Map and Problem-Solving Essay Scores
ERIC Educational Resources Information Center
Hollenbeck, Keith; Twyman, Todd; Tindal, Gerald
2006-01-01
This study investigated the score exchangeability of concept maps with problem-solving essays. Of interest was whether sixth-grade students' concept maps predicted their scores on essay responses that used concept map content. Concept maps were hypothesized to be alternatives to performance assessments for content-area domain knowledge in science.…
Concept Development and the Development of the God Concept in the Child: A Bibliography.
ERIC Educational Resources Information Center
Pitts, V. Peter, Comp.
This is a 600-reference bibliography on the development of children's conceptions and artistic representations of God. References are presented in 12 categories: (1) The God Concept, (2) Concept Development, (3) Child Development and Developmental Child Psychology, (4) Religious Education, (5) Children's Religious Thought and Development, (6)…
Native Language Self-Concept and Reading Self-Concept: Same or Different?
ERIC Educational Resources Information Center
Arens, A. Katrin; Yeung, Alexander Seeshing; Hasselhorn, Marcus
2014-01-01
In assessing verbal academic self-concept with preadolescents, researchers have used scales for students' self-concepts in reading and in their native language interchangeably. The authors conducted 3 studies with German students to test whether reading and German (i.e., native language) self-concepts can be treated as the same or different…
An Analysis of Prospective Teachers' Knowledge for Constructing Concept Maps
ERIC Educational Resources Information Center
Subramaniam, Karthigeyan; Esprívalo Harrell, Pamela
2015-01-01
Background: Literature contends that a teacher's knowledge of concept map-based tasks influence how their students perceive the task and execute the creation of acceptable concept maps. Teachers who are skilled concept mappers are able to (1) understand and apply the operational terms to construct a hierarchical/non-hierarchical concept map; (2)…
Concept Mapping as a Tool to Develop and Measure Students' Understanding in Science
ERIC Educational Resources Information Center
Tan, Sema; Erdimez, Omer; Zimmerman, Robert
2017-01-01
Concept maps measured a student's understanding of the complexity of concepts, and interrelationships. Novak and Gowin (1984) claimed that the continuous use of concept maps increased the complexity and interconnectedness of students' understanding of relationships between concepts in a particular science domain. This study has two purposes; the…
Exploring Concepts from Abstract Algebra Using Variations of Generalized Woven Figure Eights
ERIC Educational Resources Information Center
Taylor, Tara; Knoll, Eva; Landry, Wendy
2016-01-01
Students often struggle with concepts from abstract algebra. Typical classes incorporate few ways to make the concepts concrete. Using a set of woven paper artifacts, this paper proposes a way to visualize and explore concepts (symmetries, groups, permutations, subgroups, etc.). The set of artifacts used to illustrate these concepts is derived…
Study Sequence Matters for the Inductive Learning of Cognitive Concepts
ERIC Educational Resources Information Center
Sana, Faria; Yan, Veronica X.; Kim, Joseph A.
2017-01-01
The sequence in which problems of different concepts are studied during instruction impacts concept learning. For example, several problems of a given concept can be studied together (blocking) or several problems of different concepts can be studied together (interleaving). In the current study, we demonstrate that the 2 sequences impact concept…
Concept Teaching in Instrumental Music Education: A Literature Review
ERIC Educational Resources Information Center
Tan, Leonard
2017-01-01
This article is a review of research literature on the teaching of concepts in instrumental music education. It is organized in four parts (a) the value of concept teaching in large instrumental ensembles, (b) time spent teaching concepts during rehearsals, (c) approaches to concept teaching, and (d) implications for music education. Research has…
Lacking a Formal Concept of Limit: Advanced Non-Mathematics Students' Personal Concept Definitions
ERIC Educational Resources Information Center
Beynon, Kenneth A.; Zollman, Alan
2015-01-01
This mixed-methods study examines the conceptual understanding of limit among 22 undergraduate engineering students from two different sections of the same introductory differential equations course. The participants' concepts of limit (concept images and personal concept definitions) were examined using written tasks followed by one-on-one…
ERIC Educational Resources Information Center
Fang, Ning
2012-01-01
A concept pair is a pair of concepts that are fundamentally different but closely related. To develop a solid conceptual understanding in dynamics (a foundational engineering science course) and physics, students must understand the fundamental difference and relationship between two concepts that are included in each concept pair. However, all…
Constructing Concept Maps to Encourage Meaningful Learning in Science Classroom
ERIC Educational Resources Information Center
Akcay, Hakan
2017-01-01
The purpose of this activity is to demonstrate science teaching and assessing what is learned via using concept maps. Concept mapping is a technique for visually representing the structure of information. Concept mapping allows students to understand the relationships between concepts of science by creating a visual map of the connections. Concept…
ERIC Educational Resources Information Center
Streveler, Ruth; Geist, Monica; Ammerman, Ravel; Sulzbach, Candace; Miller, Ronald; Olds, Barbara; Nelson, Mary
2007-01-01
This study extends ongoing work to identify difficult concepts in thermal and transport science and measure students' understanding of those concepts via a concept inventory. Two research questions provided the focal point: "What important concepts in electric circuits and engineering mechanics do students find difficult to learn?" and…
Concept Mapping: A Unique Means for Negotiating Meaning in Professional Studies
ERIC Educational Resources Information Center
Mackinnon, Gregory R.; Keppell, Mike
2005-01-01
Concept mapping (Novak & Gowin, 1984) has been used extensively as a graphic organiser in classroom teaching. This article addresses two particular approaches to using concept mapping that go beyond classroom planning into the realm of "idea-exchange" with concept mapping as mediator. The notion of "negotiative concept mapping" is examined in two…
Identifying Threshold Concepts in the Careers of Educational Developers
ERIC Educational Resources Information Center
Timmermans, Julie A.
2014-01-01
The purpose of this multiple case study was to identify threshold concepts in the careers of educational developers. Twenty-one common threshold concepts emerged, with one threshold concept common among all participants: Facilitating a change process. The remaining 20 threshold concepts were captured in the following three categories: (1) Ways of…
Experiences of Academic Staff in Using Threshold Concepts within a Reformed Curriculum
ERIC Educational Resources Information Center
Rodger, Sylvia; Turpin, Merrill; O'Brien, Mia
2015-01-01
Threshold concepts were used to underpin a major curriculum reform endeavour in occupational therapy. After rigorous interrogation of troublesome knowledge and ensuring that the emergent concepts conformed to the five characteristics of previously proposed threshold concepts, we identified five threshold concepts. Two years into the rollout of the…
NASA Technical Reports Server (NTRS)
Jones, Denise R.
1990-01-01
A piloted simulation study was conducted comparing three different input methods for interfacing to a large-screen, multiwindow, whole-flight-deck display for management of transport aircraft systems. The thumball concept utilized a miniature trackball embedded in a conventional side-arm controller. The touch screen concept provided data entry through a capacitive touch screen. The voice concept utilized a speech recognition system with input through a head-worn microphone. No single input concept emerged as the most desirable method of interacting with the display. Subjective results, however, indicate that the voice concept was the most preferred method of data entry and had the most potential for future applications. The objective results indicate that, overall, the touch screen concept was the most effective input method. There was also significant differences between the time required to perform specific tasks and the input concept employed, with each concept providing better performance relative to a specific task. These results suggest that a system combining all three input concepts might provide the most effective method of interaction.
Self-concept, self-esteem, gender, race, and information technology use.
Jackson, Linda A; Zhao, Yong; Witt, Edward A; Fitzgerald, Hiram E; von Eye, Alexander; Harold, Rena
2009-08-01
This research addressed two fundamental questions regarding self-concept, self-esteem, gender, race, and information technology use. First, is technology use related to dimensions of self-concept and/or to self-esteem? Second, are there gender and/or race differences in self-concept, self-esteem, and technology use? Five hundred youth, average age 12 years old, one third African American and two thirds Caucasian American, completed multidimensional measures of self-concept, the Rosenberg Self-Esteem scale, and measures of frequency of Internet use, Internet use for communication (e-mail and instant messaging), video game playing, and cell phone use. Findings indicated that technology use predicted dimensions of self-concept and self-esteem, with video game playing having a negative influence and Internet use having a positive influence on self-concept dimensions. Gender differences were observed on several self-concept dimensions, but contrary to expectations, girls did not score higher than boys in social self-concept. Only one race difference was observed: African Americans had lower behavioral self-concept than did Caucasian Americans. Implications of the benefits and liabilities of youth's current and projected technology use are discussed.
NASA Astrophysics Data System (ADS)
Tapilouw, M. C.; Firman, H.; Redjeki, S.; Chandra, D. T.
2018-05-01
To refresh natural environmental concepts in science, science teacher have to attend a teacher training. In teacher training, all participant can have a good sharing and discussion with other science teacher. This study is the first step of science teacher training program held by education foundation in Bandung and attended by 20 science teacher from 18 Junior High School. The major aim of this study is gathering science teacher’s idea of environmental concepts. The core of questions used in this study are basic competencies linked with environmental concepts, environmental concepts that difficult to explain, the action to overcome difficulties and references in teaching environmental concepts. There are four major findings in this study. First finding, most environmental concepts are taught in 7th grade. Second finding, most difficult environmental concepts are found in 7th grade. Third finding, there are five actions to overcome difficulties. Fourth finding, science teacher use at least four references in mastering environmental concepts. After all, teacher training can be a solution to reduce difficulties in teaching environmental concepts.
The effect of altering self-descriptive behavior on self-concept and classroom behavior.
Lane, J; Muller, D
1977-09-01
This research examined the impact of operant reinforcement of positive self-descriptive behavior on the self-concepts and classroom behavior of 60 fifth-grade students. Three groups of 10 male and 10 female low self-concept students wrote a series of eight essays describing their school performance. The first group (P) received written reinforcement for positive self-descriptions of their school performance. The second group (G) received an equal number of reinforcements for general statements. The third group (C) received no reinforcement for written statements. Three areas of self-concept were measured with the Primary Self-Concept Inventory: personal-self, social-self, and intellectual-self. A frequency count was also made of nine classroom behaviors thought to be influenced by self-concept. The P group displayed increases in the frequency of positive self-descriptive statement and in intellectual self-concept but no changes in personal self-concept, social self-concept, or the nine classroom behaviors. The G and C groups showed no change in self-description, self-concept, or the nine classroom behaviors.
Learning style preference and student aptitude for concept maps.
Kostovich, Carol T; Poradzisz, Michele; Wood, Karen; O'Brien, Karen L
2007-05-01
Acknowledging that individuals' preferences for learning vary, faculty in an undergraduate nursing program questioned whether a student's learning style is an indicator of aptitude in developing concept maps. The purpose of this research was to describe the relationship between nursing students' learning style preference and aptitude for concept maps. The sample included 120 undergraduate students enrolled in the adult health nursing course. Students created one concept map and completed two instruments: the Learning Style Survey and the Concept Map Survey. Data included Learning Style Survey scores, grade for the concept map, and grade for the adult health course. No significant difference was found between learning style preference and concept map grades. Thematic analysis of the qualitative survey data yielded further insight into students' preferences for creating concept maps.
NASA Technical Reports Server (NTRS)
Mulqueen, J. A.; Addona, B. M.; Gwaltney, D. A.; Holt, K. A.; Hopkins, R. C.; Matis, J. A.; McRight, P. S.; Popp, C. G.; Sutherlin, S. G.; Thomas, H. D.;
2012-01-01
The primary purpose of this study was to define a point-of-departure prephase A mission concept for the cryogenic propellant storage and transfer technology demonstration mission to be conducted by the NASA Office of the Chief Technologist (OCT). The mission concept includes identification of the cryogenic propellant management technologies to be demonstrated, definition of a representative mission timeline, and definition of a viable flight system design concept. The resulting mission concept will serve as a point of departure for evaluating alternative mission concepts and synthesizing the results of industry- defined mission concepts developed under the OCT contracted studies
Characteristic of student’s false concessive failure on fractions concept
NASA Astrophysics Data System (ADS)
Kurniawan, H.; Sutawidjaja, A.; As’ari, A. R.; Muksar, M.
2018-03-01
False concessive failure of students is students construction failure in achieving goals, where the process is false, the results obtained is true. This failure occurs because the schemes are not connected to each other, so it cannot form a new scheme. This research is a qualitative research that aim to describe the characteristics of students' false concessive failure on fractional concepts. This fractional concept is a fraction of the same part of the whole. To be able to solve the concept of this fraction, students must possess the concept of partition, the concept of addition and the concept of multiplication of the fraction.
Women, Physical Activity, and Quality of Life: Self-concept as a Mediator.
Gonzalo Silvestre, Tamara; Ubillos Landa, Silvia
2016-02-22
The objectives of this research are: (a) analyze the incremental validity of physical activity's (PA) influence on perceived quality of life (PQL); (b) determine if PA's predictive power is mediated by self-concept; and (c) study if results vary according to a unidimensional or multidimensional approach to self-concept measurement. The sample comprised 160 women from Burgos, Spain aged 18 to 45 years old. Non-probability sampling was used. Two three-step hierarchical regression analyses were applied to forecast PQL. The hedonic quality-of-life indicators, self-concept, self-esteem, and PA were included as independent variables. The first regression analysis included global self-concept as predictor variable, while the second included its five dimensions. Two mediation analyses were conducted to see if PA's ability to predict PQL was mediated by global and physical self-concept. Results from the first regression shows that self-concept, satisfaction with life, and PA were significant predictors. PA slightly but significantly increased explained variance in PQL (2.1%). In the second regression, substituting global self-concept with its five constituent factors, only the physical dimension and satisfaction with life predicted PQL, while PA ceased to be a significant predictor. Mediation analysis revealed that only physical self-concept mediates the relationship between PA and PQL (z = 1.97, p < .050), and not global self-concept. Physical self-concept was the strongest predictor and approximately 32.45 % of PA's effect on PQL was mediated by it. This study's findings support a multidimensional view of self-concept, and represent a more accurate image of the relationship between PQL, PA, and self-concept.
Thyberg, Mikael; Arvidsson, Patrik; Thyberg, Ingrid; Nordenfelt, Lennart
2015-01-01
To argue for and propose bipartite concepts of functioning and disability, to tally with the structure of the ICF classification list, concepts of social models and clinical needs. The ICF concepts are discussed in relation to the history of ideas regarding disability concepts and the needs for such concepts in interdisciplinary rehabilitation. Bipartite concepts are presented; they refer to actual functioning, simply body functions/structures and participation, including functioning in standardized environments. Participation refers to actually performed "activities", with "activities" simply denoting things that people may do. Bipartite concepts are congruent with the ICF classification and the structure of social models of disability, suitable for clinical and interdisciplinary use and easy to understand. The issue of standardized environments represents a methodological issue rather than the conceptual issue of defining functioning and disability. An individual perspective on activity and activity limitations, i.e. the middle part of the tripartite ICF concept, is somewhat similar to concepts of traditional language that were regarded as too generalizing already in 1912, when the interactional concept of "disability in a social sense" was introduced in rehabilitation practices. Bipartite concepts of functioning and disability are recommended for interdisciplinary use of the ICF. The ICF classification is useful, but the ICF concept of activities in an individual perspective is confusing. We suggest a use of the term "activities" simply to denote things that people may do and "participation" to denote actually performed activities. Estimations of ability should be explicit about how they are related to environmental factors.
Biological Embedding: Evaluation and Analysis of an Emerging Concept for Nursing Scholarship
Nist, Marliese Dion
2016-01-01
Aim The purpose of this paper is to report the analysis of the concept of biological embedding. Background Research that incorporates a life course perspective is becoming increasingly prominent in the health sciences. Biological embedding is a central concept in life course theory and may be important for nursing theories to enhance our understanding of health states in individuals and populations. Before the concept of biological embedding can be used in nursing theory and research, an analysis of the concept is required to advance it toward full maturity. Design Concept analysis. Data Sources PubMed, CINAHL and PsycINFO were searched for publications using the term ‘biological embedding’ or ‘biological programming’ and published through 2015. Methods An evaluation of the concept was first conducted to determine the concept’s level of maturity and was followed by a concept comparison, using the methods for concept evaluation and comparison described by Morse. Results A consistent definition of biological embedding – the process by which early life experience alters biological processes to affect adult health outcomes – was found throughout the literature. The concept has been used in several theories that describe the mechanisms through which biological embedding might occur and highlight its role in the development of health trajectories. Biological embedding is a partially mature concept, requiring concept comparison with an overlapping concept – biological programming – to more clearly establish the boundaries of biological embedding. Conclusions Biological embedding has significant potential for theory development and application in multiple academic disciplines, including nursing. PMID:27682606
Brain Representations of Basic Physics Concepts
NASA Astrophysics Data System (ADS)
Just, Marcel Adam
2017-09-01
The findings concerning physics concepts build on the remarkable new ability to determine the neural signature (or activation pattern) corresponding to an individual concept using fMRI brain imaging. Moreover, the neural signatures can be decomposed into meaningful underlying dimensions, identifying the individual, interpretable components of the neural representation of a concept. The investigation of physics concepts representations reveals how relatively recent physics concepts (formalized only in the last few centuries) are stored in the millenia-old information system of the human brain.
Castro, Eva Marie; Van Regenmortel, Tine; Vanhaecht, Kris; Sermeus, Walter; Van Hecke, Ann
2016-12-01
The concepts of patient empowerment, patient participation and patient-centeredness have been introduced as part of the trend towards a more participatory health care and have largely been used interchangeably. Although these concepts have been discussed for a number of years, their exact meaning in hospital care remains somewhat unclear. This absence of theoretical and conceptual clarity has led to (1) poor understanding and communication among researchers, health practitioners and policy makers and (2) problems in measurement and comparison between studies across different hospitals. This paper examines all three concepts through a concept analysis based on the method of Avant and Walker (2005) [1] and the simultaneous concept analysis of Haase et al. (1992) [2]. Through these methods, the antecedents, attributes, consequences and empirical referents of each concept are determined. In addition, similarities and differences between the three concepts are identified and a definition offered for each concept. Furthermore, the interrelatedness between the key concepts is mapped, and definitions are proposed. It can be concluded that patient empowerment is a much broader concept than just patient participation and patient-centeredness. The present study may provide a useful framework that researchers, policy makers and health care providers can use to facilitate patient empowerment. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Kramer, Lynda J.; Busquets, Anthony M.
2000-01-01
A simulation experiment was performed to assess situation awareness (SA) and workload of pilots while monitoring simulated autoland operations in Instrument Meteorological Conditions with three advanced display concepts: two enhanced electronic flight information system (EFIS)-type display concepts and one totally synthetic, integrated pictorial display concept. Each concept incorporated sensor-derived wireframe runway and iconic depictions of sensor-detected traffic in different locations on the display media. Various scenarios, involving conflicting traffic situation assessments, main display failures, and navigation/autopilot system errors, were used to assess the pilots' SA and workload during autoland approaches with the display concepts. From the results, for each scenario, the integrated pictorial display concept provided the pilots with statistically equivalent or substantially improved SA over the other display concepts. In addition to increased SA, subjective rankings indicated that the pictorial concept offered reductions in overall pilot workload (in both mean ranking and spread) over the two enhanced EFIS-type display concepts. Out of the display concepts flown, the pilots ranked the pictorial concept as the display that was easiest to use to maintain situational awareness, to monitor an autoland approach, to interpret information from the runway and obstacle detecting sensor systems, and to make the decision to go around.
Gevers, D W M; Kremers, S P J; de Vries, N K; van Assema, P
2014-08-01
Inconsistencies in measurements of food parenting practices continue to exist. Fundamental to this problem is the lack of clarity about what is understood by different concepts of food parenting practices. The purpose of this study was to clarify food parenting practice concepts related to snacking. A three round Delphi study among an international group of experts (n = 63) was conducted. In the first round, an open-ended survey was used to collect food parenting practice descriptions and concept labels associated with those practices. In the second round, participants were asked to match up descriptions with the appropriate concept labels. The third and final round allowed participants to reconsider how descriptions and concept labels were matched, taking into account the opinions expressed in round two. Round one produced 408 descriptions of food parenting practices and 110 different concept names. Round two started with 116 descriptions of food parenting practices and 20 concept names. On 40 descriptions, consensus regarding the underlying concept name was reached in round two. Of the remaining 76 descriptions, consensus on 47 descriptions regarding the underlying concept name was reached in round three. The present study supports the essential process of consensus development with respect to food parenting practices concepts. Copyright © 2014 Elsevier Ltd. All rights reserved.
Waters, C Kenneth
2004-01-01
What should philosophers of science accomplish when they analyze scientific concepts and interpret scientific knowledge? What is concept analysis if it is not a description of the way scientists actually think? I investigate these questions by using Hans Reichenbach's account of the descriptive, critical, and advisory tasks of philosophy of science to examine Karola Stotz and Paul Griffiths' idea that poll-based methodologies can test philosophical analyses of scientific concepts. Using Reichenbach's account as a point of departure, I argue that philosophy of science should identify and clarify epistemic virtues and describe scientific knowledge in relation to these virtues. The role of concept analysis is to articulate scientific concepts in ways that help reveal epistemic virtues and limitations of particular sciences. This means an analysis of the gene concept(s) should help clarify the explanatory power and limitations of gene-based explanations, and should help account for the investigative utility and biases of gene-centered sciences. I argue that a philosophical analysis of gene concept(s) that helps achieve these critical aims should not be rejected on the basis of poll-based studies even if such studies could show that professional biologists don't actually use gene terminology in precise ways corresponding to the philosophical analysis.
A brain-based account of “basic-level” concepts
Bauer, Andrew James; Just, Marcel Adam
2017-01-01
This study provides a brain-based account of how object concepts at an intermediate (basic) level of specificity are represented, offering an enriched view of what it means for a concept to be a basic-level concept, a research topic pioneered by Rosch and others (Rosch et al., 1976). Applying machine learning techniques to fMRI data, it was possible to determine the semantic content encoded in the neural representations of object concepts at basic and subordinate levels of abstraction. The representation of basic-level concepts (e.g. bird) was spatially broad, encompassing sensorimotor brain areas that encode concrete object properties, and also language and heteromodal integrative areas that encode abstract semantic content. The representation of subordinate-level concepts (robin) was less widely distributed, concentrated in perceptual areas that underlie concrete content. Furthermore, basic-level concepts were representative of their subordinates in that they were neurally similar to their typical but not atypical subordinates (bird was neurally similar to robin but not woodpecker). The findings provide a brain-based account of the advantages that basic-level concepts enjoy in everyday life over subordinate-level concepts: the basic level is a broad topographical representation that encompasses both concrete and abstract semantic content, reflecting the multifaceted yet intuitive meaning of basic-level concepts. PMID:28826947
Self-concepts of exercise in frail older adults with heart failure: a literature review.
Xie, Boqin; Arslanian-Engoren, Cynthia
2015-01-01
The co-occurrence of frailty and heart failure (HF) in older adults (65 years or older) can adversely affect the ability to engage in self-care management behaviors, which may alter self-concepts and decrease quality of life. Little is known about how frailty and HF influence older adults' self-concepts or how these self-concepts affect exercise behaviors. Therefore, the aims of this literature review were to identify the self-concepts of older frail adults with HF and to identify how these self-concepts affect their exercise behaviors. Guided by the schema model of self-concept, publications before April 2013 that examined the impact of the self-concepts of older adults with HF and/or frailty on exercise behavior were reviewed. As a result, 6 articles were included. Three of the 6 articles focused on frailty, and 3 of the 6 articles focused on HF. However, no study was found that specifically examined the self-concepts of frail older adults with HF. The self-concepts of older adults with HF and/or frailty are multifaceted and include both cognitive resources (facilitating exercise) and cognitive liabilities (hindering exercise). Studies are needed to determine how the co-occurrence of frailty and HF impact self-concepts and exercise behaviors in older adults.
A brain-based account of "basic-level" concepts.
Bauer, Andrew James; Just, Marcel Adam
2017-11-01
This study provides a brain-based account of how object concepts at an intermediate (basic) level of specificity are represented, offering an enriched view of what it means for a concept to be a basic-level concept, a research topic pioneered by Rosch and others (Rosch et al., 1976). Applying machine learning techniques to fMRI data, it was possible to determine the semantic content encoded in the neural representations of object concepts at basic and subordinate levels of abstraction. The representation of basic-level concepts (e.g. bird) was spatially broad, encompassing sensorimotor brain areas that encode concrete object properties, and also language and heteromodal integrative areas that encode abstract semantic content. The representation of subordinate-level concepts (robin) was less widely distributed, concentrated in perceptual areas that underlie concrete content. Furthermore, basic-level concepts were representative of their subordinates in that they were neurally similar to their typical but not atypical subordinates (bird was neurally similar to robin but not woodpecker). The findings provide a brain-based account of the advantages that basic-level concepts enjoy in everyday life over subordinate-level concepts: the basic level is a broad topographical representation that encompasses both concrete and abstract semantic content, reflecting the multifaceted yet intuitive meaning of basic-level concepts. Copyright © 2017 Elsevier Inc. All rights reserved.
Two-Phase chief complaint mapping to the UMLS metathesaurus in Korean electronic medical records.
Kang, Bo-Yeong; Kim, Dae-Won; Kim, Hong-Gee
2009-01-01
The task of automatically determining the concepts referred to in chief complaint (CC) data from electronic medical records (EMRs) is an essential component of many EMR applications aimed at biosurveillance for disease outbreaks. Previous approaches that have been used for this concept mapping have mainly relied on term-level matching, whereby the medical terms in the raw text and their synonyms are matched with concepts in a terminology database. These previous approaches, however, have shortcomings that limit their efficacy in CC concept mapping, where the concepts for CC data are often represented by associative terms rather than by synonyms. Therefore, herein we propose a concept mapping scheme based on a two-phase matching approach, especially for application to Korean CCs, which uses term-level complete matching in the first phase and concept-level matching based on concept learning in the second phase. The proposed concept-level matching suggests the method to learn all the terms (associative terms as well as synonyms) that represent the concept and predict the most probable concept for a CC based on the learned terms. Experiments on 1204 CCs extracted from 15,618 discharge summaries of Korean EMRs showed that the proposed method gave significantly improved F-measure values compared to the baseline system, with improvements of up to 73.57%.
Hay, I; Ashman, A; van Kraayenoord, C E
1997-09-01
The formation and measurement of self-concept were the foci of this research. The study aimed to investigate the influence of achievement on academic self-concept and to compare the Perception of Ability Scale for Students (PASS, Boersma & Chapman, 1992) with the Self-Description Questionnaire-1 (SDQ-1, Marsh, 1988). The participants were 479 grade 5 (mean age 126.6 months) coeducational Australian students, located in 18 schools. An intra-class research design was used to investigate the influence of frame-of-reference on self-concept development. As students' academic scores rose above their class mean their self-concepts increased and as students' academic scores fell below their class mean their self-concepts decreased. Students' difference from class mean predicted their self-concept scores. This finding was consistently shown across the reading, spelling, and mathematics domains using test and teaching rating data. A comparison between the PASS and the SDQ-1 demonstrated concurrent validity across self-concept domains. The findings support the notions that the social environment is a significant agent that influences self-concept, and that teacher ratings and standardised tests of achievement and the PASS and the SDQ-1 are valid measures for self-concept research.
The Effects of a Concept Map-Based Support Tool on Simulation-Based Inquiry Learning
ERIC Educational Resources Information Center
Hagemans, Mieke G.; van der Meij, Hans; de Jong, Ton
2013-01-01
Students often need support to optimize their learning in inquiry learning environments. In 2 studies, we investigated the effects of adding concept-map-based support to a simulation-based inquiry environment on kinematics. The concept map displayed the main domain concepts and their relations, while dynamic color coding of the concepts displayed…
ERIC Educational Resources Information Center
Adesope, Olusola O.; Cavagnetto, Andy; Hunsu, Nathaniel J.; Anguiano, Carlos; Lloyd, Joshua
2017-01-01
This study used a between-subjects experimental design to examine the effects of three different computer-based instructional strategies (concept map, refutation text, and expository scientific text) on science learning. Concept maps are node-link diagrams that show concepts as nodes and relationships among the concepts as labeled links.…
Coming To Know: The Role of the Concept Map--Mirror, Assistant, Master?
ERIC Educational Resources Information Center
McAleese, Ray
This paper explains the process of creating and managing concept maps, using reflection as a focus for its argument. Section 1, What is a Concept Map?, highlights the background and definition of concept mapping, explains how maps signify virtual conceptual structures, looks at structural knowledge, provides an example of a concept map, and…
Measurement of Academic Self-Concept in College Students.
ERIC Educational Resources Information Center
Reynolds, William M.; And Others
Academic self-concept has been viewed by numerous investigators as an important facet of general self-concept. The Academic Self-Concept Scale (ASCS) was developed as a measure of academic self-concept in college students. The initial item pool consisted of 59 items worded to conform to a four-pont Likert-type response format. On the basis of…
Concept Maps for Evaluating Learning of Sustainable Development
ERIC Educational Resources Information Center
Shallcross, David C.
2016-01-01
Concept maps are used to assess student and cohort learning of sustainable development. The concept maps of 732 first-year engineering students were individually analyzed to detect patterns of learning and areas that were not well understood. Students were given 20 minutes each to prepare a concept map of at least 20 concepts using paper and pen.…
Kant and Rawls on the Cultivation of Virtue
ERIC Educational Resources Information Center
Brewer, Talbot
2013-01-01
In "Two Conceptions of Virtue," Thomas Hill reconstructs the conceptions of virtue, and of proper moral upbringing, found in Kant and Rawls. Here I offer some brief reflections on these conceptions of virtue and its cultivation. I argue that Kant's conception of virtue is grounded in a mistaken conception of desire, and that this…
Family Conflict and Children's Self-Concepts: A Comparison of Intact and Single-Parent Families.
ERIC Educational Resources Information Center
Raschke, Helen J.; Raschke, Vernon J.
1979-01-01
Using the Piers-Harris Children's Self-Concept Scale to measure self-concept, and self-reports for family structure and family conflict, no significant differences in self-concept scores of children from intact, single-parent, reconstituted, or other types of families were found. Self-concept scores were significantly lower for children reporting…
ERIC Educational Resources Information Center
Kaya, Osman Nafiz; Kilic, Ziya
2004-01-01
Student-centered approach of scoring the concept maps consisted of three elements namely symbol system, individual portfolio and scoring scheme. We scored student-constructed concept maps based on 5 concept map criteria: validity of concepts, adequacy of propositions, significance of cross-links, relevancy of examples, and interconnectedness. With…
THE THEME-CONCEPT UNIT IN LITERATURE.
ERIC Educational Resources Information Center
HILLOCKS, GEORGE, JR.
A SUGGESTED UNIT FRAMEWORK WAS DEVELOPED AS A METHOD OF TEACHING SEVENTH-GRADE LITERATURE AT EUCLID CENTRAL JUNIOR HIGH SCHOOL IN EUCLID, OHIO. THE UNIT WAS DIVIDED INTO SIX MAJOR SECTIONS--(1) DEVELOPMENT OF THE CONCEPT, (2) APPLICATION OF THE CONCEPT UNDER THE GUIDANCE OF A TEACHER, (3) REVISION OF THE CONCEPT, (4) APPLICATION OF THE CONCEPT BY…
ERIC Educational Resources Information Center
Al khawaldeh, Salem A.; Al Olaimat, Ali M.
2010-01-01
The present study conducted to investigate the contribution of conceptual change texts, accompanied by concept mapping instruction to eleventh-grade students' understanding of cellular respiration concepts, and their retention of this understanding. Cellular respiration concepts test was developed as a result of examination of related literature…
NASA Technical Reports Server (NTRS)
Frisbee, Robert H.
1991-01-01
A variety of Advanced Propulsion Concepts (APC) is discussed. The focus is on those concepts that are sufficiently near-term that they could be developed for the Space Exploration Initiative. High-power (multi-megawatt) electric propulsion, solar sails, tethers, and extraterrestrial resource utilization concepts are discussed. A summary of these concepts and some general conclusions on their technology development needs are presented.
Conceptual Coherence of Non-Newtonian Worldviews in Force Concept Inventory Data
ERIC Educational Resources Information Center
Scott, Terry F.; Schumayer, Dániel
2017-01-01
The Force Concept Inventory is one of the most popular and most analyzed multiple-choice concept tests used to investigate students' understanding of Newtonian mechanics. The correct answers poll a set of underlying Newtonian concepts and the coherence of these underlying concepts has been found in the data. However, this inventory was constructed…
What Do Pre-Service Physics Teachers Know and Think about Concept Mapping?
ERIC Educational Resources Information Center
Didis, Nilüfer; Özcan, Özgür; Azar, Ali
2014-01-01
In order to use concept maps in physics classes effectively, teachers' knowledge and ideas about concept mapping are as important as the physics knowledge used in mapping. For this reason, we aimed to examine pre-service physics teachers' knowledge on concept mapping, their ideas about the implementation of concept mapping in physics…
What Can a Concept Do? Rethinking Education's Queer Assemblages
ERIC Educational Resources Information Center
Rasmussen, Mary Lou; Allen, Louisa
2014-01-01
In a discussion of Deleuze's theorization of concepts, Todd May asks "what can a concept do with that which cannot be identified?" Or to put it another way, May writes--"A concept is a way of addressing the difference that lies beneath the identities we experience." This is not to say that identities, concepts, and experiences…
SCIENCE BRIEF: ADVANCED CONCEPTS
Research on advanced concepts will evaluate and demonstrate the application of innovative infrastructure designs, management procedures and operational approaches. Advanced concepts go beyond simple asset management. The infusion of these advanced concepts into established wastew...
NASA Technical Reports Server (NTRS)
Yoerkie, Charles A.; Gintoli, P. J.; Ingraham, S. T.; Moore, J. A.
1986-01-01
The goal of this research is the understanding of helicopter internal noise mechanisms and the development, design, and testing of noise control concepts which will produce significant reductions in the acoustic environment to which passengers are exposed. The Phase 3 effort involved the identification and evaluation of current and advanced treatment concepts, including isolation of structure-borne paths. In addition, a plan was devised for the full-scale evaluation of an isolation concept. Specific objectives were as follows: (1) identification and characterization of various noise control concepts; (2) implementation of noise control concepts within the S-76 SEA (statistical energy analysis) model; (3) definition and evaluation of a preliminary acoustic isolation design to reduce structure-borne transmission of acoustic frequency main gearbox gear clash vibrations into the airframe; (4) formulation of a plan for the full-scale validation of the isolation concept; and (5) prediction of the cabin noise environment with various noise control concepts installed.
Linked Forests: Semantic similarity of geographical concepts "forest"
NASA Astrophysics Data System (ADS)
Čerba, Otakar; Jedlička, Karel
2016-01-01
Linked Data represents the new trend in geoinformatics and geomatics. It produces a structure of objects (in a form of concepts or terms) interconnected by object relations expressing a type of semantic relationships of various concepts. The research published in this article studies, if objects connected by above mentioned relations are more similar than objects representing the same phenomenon, but standing alone. The phenomenon "forest" and relevant geographical concepts were chosen as the domain of the research. The concepts similarity (Tanimoto coefficient as a specification of Tversky index) was computed on the basis of explicit information provided by thesauri containing particular concepts. Overall in the seven thesauri (AGROVOC, EuroVoc, GEMET, LusTRE/EARTh, NAL, OECD and STW) there was tested if the "forest" concept interconnected by the relation skos:exactMatch are more similar than other, not interlinked concepts. The results of the research are important for the sharing and combining of geographical data, information and knowledge. The proposed methodology can be reused to a comparison of other geographical concepts.
NASA Astrophysics Data System (ADS)
McKenzie, A. W.
Cost and performance of various thermal storage concepts in a liquid metal receiver solar thermal power system application have been evaluated. The objectives of this study are to provide consistently calculated cost and performance data for thermal storage concepts integrated into solar thermal systems. Five alternative storage concepts are evaluated for a 100-MW(e) liquid metal-cooled receiver solar thermal power system for 1, 6, and 15 hours of storage: sodium 2-tank (reference system), molten draw salt 2-tank, sand moving bed, air/rock, and latent heat (phase change) with tube-intensive heat exchange (HX). The results indicate that the all sodium 2-tank thermal storage concept is not cost-effective for storage in excess of 3 or 4 hours; the molten draw salt 2-tank storage concept provides significant cost savings over the reference sodium 2-tank concept; and the air/rock storage concept with pressurized sodium buffer tanks provides the lowest evaluated cost of all storage concepts considered above 6 hours of storage.
Chan, Joel; Schunn, Christian
2015-01-01
Research on innovation often highlights analogies from sources outside the current problem domain as a major source of novel concepts; however, the mechanisms underlying this relationship are not well understood. We analyzed the temporal interplay between far analogy use and creative concept generation in a professional design team's brainstorming conversations, investigating the hypothesis that far analogies lead directly to very novel concepts via large steps in conceptual spaces (jumps). Surprisingly, we found that concepts were more similar to their preceding concepts after far analogy use compared to baseline situations (i.e., without far analogy use). Yet far analogies increased the team's concept generation rate compared to baseline conditions. Overall, these results challenge the view that far analogies primarily lead to novel concepts via jumps in conceptual spaces and suggest alternative pathways from far analogies to novel concepts (e.g., iterative, deep exploration within a functional space). Copyright © 2014 Cognitive Science Society, Inc.
A concept analysis of forensic risk.
Kettles, A M
2004-08-01
Forensic risk is a term used in relation to many forms of clinical practice, such as assessment, intervention and management. Rarely is the term defined in the literature and as a concept it is multifaceted. Concept analysis is a method for exploring and evaluating the meaning of words. It gives precise definitions, both theoretical and operational, for use in theory, clinical practice and research. A concept analysis provides a logical basis for defining terms through providing defining attributes, case examples (model, contrary, borderline, related), antecedents and consequences and the implications for nursing. Concept analysis helps us to refine and define a concept that derives from practice, research or theory. This paper will use the strategy of concept analysis to find a working definition for the concept of forensic risk. In conclusion, the historical background and literature are reviewed using concept analysis to bring the term into focus and to define it more clearly. Forensic risk is found to derive both from forensic practice and from risk theory. A proposed definition of forensic risk is given.
Intersection of migration and turnover theories-What can we learn?
Brewer, Carol S; Kovner, Christine T
2014-01-01
The international migration of nurses has become a major issue in the international health and workforce policy circles, but analyses are not based on a comprehensive theory. The purpose of this article was to compare the concepts of an integrated nursing turnover theory with the concepts of one international migration framework. An integrated turnover theory is compared with a frequently used migration framework using examples of each. Migration concepts relate well to turnover concepts, but the relative importance and strength of various concepts may differ. For example, identification, development, and measurement of the concept of national commitment, if it exists, is parallel to organizational commitment and may be fruitful in understanding the processes that lead to nurse migration. The turnover theory provides a framework for examining migration concepts and considering how these concepts could relate to each other in a future theory of migration. Ultimately, a better understanding of the relationships and strengths of these concepts could lead to more effective policy. Copyright © 2014 Elsevier Inc. All rights reserved.
Crossing the Threshold: Bringing Biological Variation to the Foreground
Batzli, Janet M.; Knight, Jennifer K.; Hartley, Laurel M.; Maskiewicz, April Cordero; Desy, Elizabeth A.
2016-01-01
Threshold concepts have been referred to as “jewels in the curriculum”: concepts that are key to competency in a discipline but not taught explicitly. In biology, researchers have proposed the idea of threshold concepts that include such topics as variation, randomness, uncertainty, and scale. In this essay, we explore how the notion of threshold concepts can be used alongside other frameworks meant to guide instructional and curricular decisions, and we examine the proposed threshold concept of variation and how it might influence students’ understanding of core concepts in biology focused on genetics and evolution. Using dimensions of scientific inquiry, we outline a schema that may allow students to experience and apply the idea of variation in such a way that it transforms their future understanding and learning of genetics and evolution. We encourage others to consider the idea of threshold concepts alongside the Vision and Change core concepts to provide a lens for targeted instruction and as an integrative bridge between concepts and competencies. PMID:27856553
Concept Analysis and the Advance of Nursing Knowledge: State of the Science.
Rodgers, Beth L; Jacelon, Cynthia S; Knafl, Kathleen A
2018-04-24
Despite an overwhelming increase in the number of concept analyses published since the early 1970s, there are significant limitations to the impact of this work in promoting progress in nursing science. We conducted an extensive review of concept analyses published between 1972 and 2017 to identify patterns in analysis and followed this with exploration of an exemplar related to the concept of normalization to demonstrate the capabilities of analysis for promoting concept development and progress. Scoping review of peer-reviewed literature published in the Cumulative Index to Nursing and Allied Health Literature (CINAHL) in which the terms "concept analysis," "concept clarification," and "concept derivation" appeared in any part of the reference. The original search returned 3,489 articles. This initial pool was refined to a final sample of 958 articles published in 223 journals and addressing 604 concepts. A review of citations of the original analysis of the concept of normalization resulted in 75 articles selected for closer examination of the process of concept development. Review showed a clear pattern of repetition of analysis of the same concept, growth in number of published analyses, preponderance of first authors with master's degrees, and 43 distinct descriptions of methods. Review of the 75 citations to the normalization analysis identified multiple ways concept analysis can inform subsequent research and theory development. Conceptual work needs to move beyond the level of "concept analysis" involving clear linkage to the resolution of problems in the discipline. Conceptual work is an important component of progress in the knowledge base of a discipline, and more effective use of concept development activities are needed to maximize the potential of this important work. It is important to the discipline that we facilitate progress in nursing science on a theoretical and conceptual level as a part of cohesive and systematic development of the discipline. The absence of effective concepts impedes the ability to recognize, discuss, define, and conduct studies important to clinical practice and research. This article reflects the pressing need as well as the potential for concept analysis work to be approached in a way that promotes nursing science and enables conceptually sound research to improve clinical care. © 2018 Sigma Theta Tau International.
Examing nursing students' understanding of the cardiovascular system in a BSN program
NASA Astrophysics Data System (ADS)
Stuart, Parker Emerson
This study investigated the alignment of important cardiovascular system (CVS) concepts identified by expert nurses with nursing student's knowledge. Specifically, it focused on the prevalence of nursing students' alternative conceptions for these important concepts as a potential reason for a theory-practice gap in nursing (Corlett, 2000; Jordan, 1994). This is the first study to target nursing student alternative conceptions exclusively whereas other studies focused on diverse groups of undergraduates' CVS knowledge (Michael et al., 2002). The study was divided into two phases and used a case study approach with each phase of the study representing a single case. The first phase of the study sought to understand what CVS concepts expert nurses deemed relevant to their daily practice and how these experts used these concepts. The second phase identified nursing student alternative conceptions through the use of open-ended scenarios based on the results of phase I. For the first phase of the study involved four CVS expert nurses practicing in emergency rooms and cardiac intensive care units at two local hospitals. Interviews were used to elicit important CVS concepts. The expert nurses identified five broad concepts as important to their practice. These concepts were a) cardiovascular anatomical concepts; b) cardiovascular physiological concepts; c) homeostasis and diseases of the CVS; d) the interdependence and interaction of the CVS with other organ systems and e) the intersection of the CVS and technology in patient diagnosis and treatment. These finding reinforce concepts already being taught to nursing students but also suggest that instruction should focus more on how the CVS interacts with other organ systems and how technology and the CVS interact. The presence of alternative conceptions in the nursing students was examined through the use of open-ended questions. A total of 17 students fully completed the scenario questions. Results indicate that this group of nursing students hold some CVS alternative conceptions. Overall, the alternative conceptions can be grouped into four categories: a) CVS anatomy, b) blood flow and pressure, c) anthropomorphic views and d) miscellaneous alternative conceptions. These findings suggest there is indeed a misalignment between expert nurses' and nursing students' knowledge of the CVS with this misalignment potentially contributing to the theory-practice gap.
Concept Mapping Using Cmap Tools to Enhance Meaningful Learning
NASA Astrophysics Data System (ADS)
Cañas, Alberto J.; Novak, Joseph D.
Concept maps are graphical tools that have been used in all facets of education and training for organizing and representing knowledge. When learners build concept maps, meaningful learning is facilitated. Computer-based concept mapping software such as CmapTools have further extended the use of concept mapping and greatly enhanced the potential of the tool, facilitating the implementation of a concept map-centered learning environment. In this chapter, we briefly present concept mapping and its theoretical foundation, and illustrate how it can lead to an improved learning environment when it is combined with CmapTools and the Internet. We present the nationwide “Proyecto Conéctate al Conocimiento” in Panama as an example of how concept mapping, together with technology, can be adopted by hundreds of schools as a means to enhance meaningful learning.
Nakamura, Keita; Kikumoto, Mamoru
2018-07-01
The Leverett concept is used conventionally to model the relationship between the capillary pressures and the degrees of saturation in the water-nonaqueous phase liquid (NAPL)-air three-phase system in porous media. In this paper, the limitation of the Leverett concept that the concept is not applicable in the case of nonspreading NAPLs is discussed through microscopic consideration. A new concept that can be applied in the case of nonspreading NAPLs as well as spreading NAPLs is then proposed. The validity of the proposed concept is confirmed by comparing with past experimental data and simulation results obtained using the conventional model based on the Leverett concept. It is confirmed that the proposed concept can correctly predict the observed distributions of NAPLs, including those of nonspreading ones. Copyright © 2018. Published by Elsevier B.V.
NASA Technical Reports Server (NTRS)
Guynn, Mark D.; Freh, Joshua E.; Olson, Erik D.
2004-01-01
This report describes the analytical modeling and evaluation of an unconventional commercial transport aircraft concept designed to address aircraft noise and emission issues. A blended-wing-body configuration with advanced technology hydrogen fuel cell electric propulsion is considered. Predicted noise and emission characteristics are compared to a current technology conventional configuration designed for the same mission. The significant technology issues which have to be addressed to make this concept a viable alternative to current aircraft designs are discussed. This concept is one of the "Quiet Green Transport" aircraft concepts studied as part of NASA's Revolutionary Aerospace Systems Concepts (RASC) Program. The RASC Program was initiated to develop revolutionary concepts that address strategic objectives of the NASA Enterprises, such as reducing aircraft noise and emissions, and to identify advanced technology requirements for the concepts.
The semantic richness of abstract concepts
Recchia, Gabriel; Jones, Michael N.
2012-01-01
We contrasted the predictive power of three measures of semantic richness—number of features (NFs), contextual dispersion (CD), and a novel measure of number of semantic neighbors (NSN)—for a large set of concrete and abstract concepts on lexical decision and naming tasks. NSN (but not NF) facilitated processing for abstract concepts, while NF (but not NSN) facilitated processing for the most concrete concepts, consistent with claims that linguistic information is more relevant for abstract concepts in early processing. Additionally, converging evidence from two datasets suggests that when NSN and CD are controlled for, the features that most facilitate processing are those associated with a concept's physical characteristics and real-world contexts. These results suggest that rich linguistic contexts (many semantic neighbors) facilitate early activation of abstract concepts, whereas concrete concepts benefit more from rich physical contexts (many associated objects and locations). PMID:23205008
Reddy, Avneel; Ownsworth, Tamara; King, Joshua; Shields, Cassandra
2017-12-01
This study aimed to investigate the influence of the "good-old-days" bias, neuropsychological functioning and cued recall of life events on self-concept change. Forty seven adults with TBI (70% male, 1-5 years post-injury) and 47 matched controls rated their past and present self-concept on the Head Injury Semantic Differential Scale (HISD) III. TBI participants also completed a battery of neuropsychological tests. The matched control group of 47 were from a sample of 78 uninjured participants who were randomised to complete either the Social Readjustment Rating Scale-Revised (cued recall) or HISD (non-cued recall) first. Consistent with the good-old-days bias, participants with TBI rated their pre-injury self-concept as more positive than their present self-concept and the present self-concept of controls (p < .05). More positive pre-injury self-concept ratings were related to lower estimated premorbid IQ and poorer verbal fluency and delayed memory (p < .05). For uninjured participants, cued recall, life events and event appraisals each accounted for unique variance in self-concept change (p < .01) after controlling for negative affect. The cued recall group rated their past self-concept as significantly more negative than the non-cued group (p < .01). Overall, the good-old-days bias, neuropsychological functioning and cued recall influenced reports of self-concept change by affecting retrospective ratings of past self-concept. Further research is needed to investigate the impact of contextual cues on self-concept change after TBI.
NASA Astrophysics Data System (ADS)
Lawson, Anton E.; Baker, William P.; Didonato, Lisa; Verdi, Michael P.; Johnson, Margaret A.
Two hypotheses about theoretical concept acquisition, application, and change were tested. College biology students classified as intuitive, transitional, or reflective (hypothetico-deductive) reasoners were first taught two theoretical concepts (molecular polarity and bonding) to explain the mixing of dye with water, but not with oil, when all three were shaken in a container. The students were then tested in a context in which they misapplied the concepts in an attempt to explain the gradual spread of blue dye in standing water. Next students were taught another theoretical concept (diffusion), with and without the use of physical analogues. They were retested to see which students acquired the concept of diffusion and which students changed from use of the incorrect polarity and bonding concepts (i.e., the misconceptions) to use of the diffusion concept to correctly explain the dye's gradual spread. As predicted, the experimental/analogy group scored significantly higher than the control group on a posttest question that required the definition of diffusion. Also as predicted, hypothetico-deductive reasoning skill was significantly related to correct application of the diffusion concept and to a change from the misapplication of the polarity and bonding concepts to the correct application of the diffusion concept to explain the gradual spread of the blue dye. Thus, the results support the hypotheses that physical analogues are helpful in theoretical concept acquisition and that hypothetico-deductive reasoning is needed for successful concept application and change. Educational implications are drawn.
NASA Technical Reports Server (NTRS)
Spearman, M. L.
1984-01-01
The aerodynamic characteristics of some lifting reentry concepts are examined with a view to the applicability of such concepts to the design of possible transatmospheric vehicles (TAV). A considerable amount of research has been done in past years with vehicle concepts suitable for manned atmospheric-entry, atmospheric flight, and landing. Some of the features of these concepts that permit flight in or out of the atmosphere with maneuver capability should be useful in the mission requirements of TAV's. The concepts illustrated include some hypersonic-body shapes with and without variable geometry surfaces, and a blunt lifting-body configuration. The merits of these concepts relative to the aerodynamic behavior of a TAV are discussed.
Nomadic concepts in the history of biology.
Surman, Jan; Stráner, Katalin; Haslinger, Peter
2014-12-01
The history of scientific concepts has firmly settled among the instruments of historical inquiry. In our section we approach concepts from the perspective of nomadic concepts (Isabelle Stengers). Instead of following the evolution of concepts within one disciplinary network, we see them as subject to constant reification and change while crossing and turning across disciplines and non-scientific domains. This introduction argues that understanding modern biology is not possible without taking into account the constant transfers and translations that affected concepts. We argue that this approach does not only engage with nomadism between disciplines and non-scientific domains, but reflects on and involves the metaphoric value of concepts as well. Copyright © 2014 Elsevier Ltd. All rights reserved.
Lay Worker Health Literacy: A Concept Analysis and Operational Definition.
Cadman, Kathleen Paco
2017-10-01
The concept of lay worker health literacy is created by concurrently analyzing and synthesizing two intersecting concepts, lay workers and health literacy. Articulation of this unique intersection is the result of implementing a simplified Wilson's Concept Analysis Procedure. This process incorporates the following components: a) selecting a concept, b) determining the aims/purposes of analysis, c) identifying all uses of the concept, d) determining defining attributes, e) identifying a model case, f) identifying borderline, related, contrary, and illegitimate cases, g) identifying antecedents and consequences, and h) defining empirical referents. Furthermore, as current literature provides no operational definition for lay worker health literacy, one is created to contribute cohesion to the concept. © 2017 Wiley Periodicals, Inc.
NASA Technical Reports Server (NTRS)
Chu, Robert L.; Bayha, Tom D.; Davis, HU; Ingram, J. ED; Shukla, Jay G.
1992-01-01
Composite Wing and Fuselage Structural Design/Manufacturing Concepts have been developed and evaluated. Trade studies were performed to determine how well the concepts satisfy the program goals of 25 percent cost savings, 40 percent weight savings with aircraft resizing, and 50 percent part count reduction as compared to the aluminum Lockheed L-1011 baseline. The concepts developed using emerging technologies such as large scale resin transfer molding (RTM), automatic tow placed (ATP), braiding, out-of-autoclave and automated manufacturing processes for both thermoset and thermoplastic materials were evaluated for possible application in the design concepts. Trade studies were used to determine which concepts carry into the detailed design development subtask.
ERIC Educational Resources Information Center
Hamilton, Bonita
2011-01-01
Students' academic self-concepts have a reciprocal relationship with their academic performance, so high academic self-concepts are desirable. Yet, academic self-concepts typically decline during the late elementary and early middle school years. Little is known about how students' academic self-concepts are influenced to change. Fifth and sixth…
ERIC Educational Resources Information Center
Marsh, Herbert W.; Pekrun, Reinhard; Murayama, Kou; Arens, A. Katrin; Parker, Philip D.; Guo, Jiesi; Dicke, Theresa
2018-01-01
Our newly proposed integrated academic self-concept model integrates 3 major theories of academic self-concept formation and developmental perspectives into a unified conceptual and methodological framework. Relations among math self-concept (MSC), school grades, test scores, and school-level contextual effects over 6 years, from the end of…
ERIC Educational Resources Information Center
López-Íñiguez, Guadalupe; Pozo, Juan Ignacio
2014-01-01
While many studies have considered the association between teachers' and students' conceptions of teaching and learning and classroom practices, few studies have researched the influence of teachers' conceptions on students' conceptions. Our objective was to analyze the influence of music teachers' conceptions on student…
Setting the Scope of Concept Inventories for Introductory Computing Subjects
ERIC Educational Resources Information Center
Goldman, Ken; Gross, Paul; Heeren, Cinda; Herman, Geoffrey L.; Kaczmarczyk, Lisa; Loui, Michael C.; Zilles, Craig
2010-01-01
A concept inventory is a standardized assessment tool intended to evaluate a student's understanding of the core concepts of a topic. In order to create a concept inventory it is necessary to accurately identify these core concepts. A Delphi process is a structured multi-step process that uses a group of experts to achieve a consensus opinion. We…
ERIC Educational Resources Information Center
Jin, Haiyue; Wong, Khoon Yoong
2015-01-01
Conceptual understanding is a major aim of mathematics education, and concept map has been used in non-mathematics research to uncover the relations among concepts held by students. This article presents the results of using concept map to assess conceptual understanding of basic algebraic concepts held by a group of 48 grade 8 Chinese students.…
ERIC Educational Resources Information Center
Winch, Christopher
2016-01-01
This article shows the relationship between know-how and conceptual ability with particular reference to professional education. It is argued that although concept mastery is necessary to expert performance, it is not sufficient. Starting with Geach's account of concepts, distinctions are made between concept acquisition and concept mastery. An…
ERIC Educational Resources Information Center
Vink, Sylvia; van Tartwijk, Jan; Verloop, Nico; Gosselink, Manon; Driessen, Erik; Bolk, Jan
2016-01-01
To determine the content of integrated curricula, clinical concepts and the underlying basic science concepts need to be made explicit. Preconstructed concept maps are recommended for this purpose. They are mainly constructed by experts. However, concept maps constructed by residents are hypothesized to be less complex, to reveal more tacit basic…
An Intelligent Web-Based System for Diagnosing Student Learning Problems Using Concept Maps
ERIC Educational Resources Information Center
Acharya, Anal; Sinha, Devadatta
2017-01-01
The aim of this article is to propose a method for development of concept map in web-based environment for identifying concepts a student is deficient in after learning using traditional methods. Direct Hashing and Pruning algorithm was used to construct concept map. Redundancies within the concept map were removed to generate a learning sequence.…
ERIC Educational Resources Information Center
Durukan, Ümmü Gülsüm; Saglam-Arslan, Aysegül
2015-01-01
Learners face a variety of concepts during the instructional process they experience. These concepts are mostly introduced by teachers; thus, the competences of teachers in terms of teaching concepts are vitally important. The aim of this study is to detect the understanding levels of teacher candidates about basic astronomy concepts. The method…
ERIC Educational Resources Information Center
Preckel, Franzis; Rach, Hannah; Scherrer, Vsevolod
2016-01-01
The present study investigated changes in self-esteem, academic self-concept, intellectual self-concept, and social self-concepts of acceptance, assertion, relations with same-sex peers and relations with other-sex peers with 177 gifted students participating in a 16-day summer school in Germany. Students were assessed three times by self-report…
ERIC Educational Resources Information Center
Harris, Margaret L.; Tabachnick, B. Robert
This paper describes test development efforts for measuring achievement of selected concepts in social studies. It includes descriptive item and test statistics for the tests developed. Twelve items were developed for each of 30 concepts. Subject specialists categorized the concepts into three major areas: Geographic Region, Man and Society, and…
Advanced controls for airbreathing engines, volume 3: Allison gas turbine
NASA Technical Reports Server (NTRS)
Bough, R. M.
1993-01-01
The application of advanced control concepts to airbreathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for airbreathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two-phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 3 of these reports describes the studies performed by the Allison Gas Turbine Division.
Advanced control for airbreathing engines, volume 1: Pratt and Whitney
NASA Technical Reports Server (NTRS)
Ralph, J. A.
1993-01-01
The application of advanced control concepts to air breathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for air breathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 1 of these reports describes the studies performed by Pratt & Whitney.
Technical Interchange Meeting Guidelines Breakout
NASA Technical Reports Server (NTRS)
Fong, Rob
2002-01-01
Along with concept developers, the Systems Evaluation and Assessment (SEA) sub-element of VAMS will develop those scenarios and metrics required for testing the new concepts that reside within the System-Level Integrated Concepts (SLIC) sub-element in the VAMS project. These concepts will come from the NRA process, space act agreements, a university group, and other NASA researchers. The emphasis of those concepts is to increase capacity while at least maintaining the current safety level. The concept providers will initially develop their own scenarios and metrics for self-evaluation. In about a year, the SEA sub-element will become responsible for conducting initial evaluations of the concepts using a common scenario and metric set. This set may derive many components from the scenarios and metrics used by the concept providers. Ultimately, the common scenario\\metric set will be used to help determine the most feasible and beneficial concepts. A set of 15 questions and issues, discussed below, pertaining to the scenario and metric set, and its use for assessing concepts, was submitted by the SEA sub-element for consideration during the breakout session. The questions were divided among the three breakout groups. Each breakout group deliberated on its set of questions and provided a report on its discussion.
Advanced control for airbreathing engines, volume 2: General Electric aircraft engines
NASA Technical Reports Server (NTRS)
Bansal, Indar
1993-01-01
The application of advanced control concepts to air breathing engines may yield significant improvements in aircraft/engine performance and operability. Screening studies of advanced control concepts for air breathing engines were conducted by three major domestic aircraft engine manufacturers to determine the potential impact of concepts on turbine engine performance and operability. The purpose of the studies was to identify concepts which offered high potential yet may incur high research and development risk. A target suite of proposed advanced control concepts was formulated and evaluated in a two phase study to quantify each concept's impact on desired engine characteristics. To aid in the evaluation specific aircraft/engine combinations were considered: a Military High Performance Fighter mission, a High Speed Civil Transport mission, and a Civil Tiltrotor mission. Each of the advanced control concepts considered in the study are defined and described. The concept potential impact on engine performance was determined. Relevant figures of merit on which to evaluate the concepts are determined. Finally, the concepts are ranked with respect to the target aircraft/engine missions. A final report describing the screening studies was prepared by each engine manufacturer. Volume 2 of these reports describes the studies performed by GE Aircraft Engines.
Understanding network concepts in modules
2007-01-01
Background Network concepts are increasingly used in biology and genetics. For example, the clustering coefficient has been used to understand network architecture; the connectivity (also known as degree) has been used to screen for cancer targets; and the topological overlap matrix has been used to define modules and to annotate genes. Dozens of potentially useful network concepts are known from graph theory. Results Here we study network concepts in special types of networks, which we refer to as approximately factorizable networks. In these networks, the pairwise connection strength (adjacency) between 2 network nodes can be factored into node specific contributions, named node 'conformity'. The node conformity turns out to be highly related to the connectivity. To provide a formalism for relating network concepts to each other, we define three types of network concepts: fundamental-, conformity-based-, and approximate conformity-based concepts. Fundamental concepts include the standard definitions of connectivity, density, centralization, heterogeneity, clustering coefficient, and topological overlap. The approximate conformity-based analogs of fundamental network concepts have several theoretical advantages. First, they allow one to derive simple relationships between seemingly disparate networks concepts. For example, we derive simple relationships between the clustering coefficient, the heterogeneity, the density, the centralization, and the topological overlap. The second advantage of approximate conformity-based network concepts is that they allow one to show that fundamental network concepts can be approximated by simple functions of the connectivity in module networks. Conclusion Using protein-protein interaction, gene co-expression, and simulated data, we show that a) many networks comprised of module nodes are approximately factorizable and b) in these types of networks, simple relationships exist between seemingly disparate network concepts. Our results are implemented in freely available R software code, which can be downloaded from the following webpage: http://www.genetics.ucla.edu/labs/horvath/ModuleConformity/ModuleNetworks PMID:17547772
Chiang, Michael F; Casper, Daniel S; Cimino, James J; Starren, Justin
2005-02-01
To assess the adequacy of 5 controlled medical terminologies (International Classification of Diseases 9, Clinical Modification [ICD9-CM]; Current Procedural Terminology 4 [CPT-4]; Systematized Nomenclature of Medicine, Clinical Terms [SNOMED-CT]; Logical Identifiers, Names, and Codes [LOINC]; Medical Entities Dictionary [MED]) for representing concepts in ophthalmology. Noncomparative case series. Twenty complete ophthalmology case presentations were sequentially selected from a publicly available ophthalmology journal. Each of the 20 cases was parsed into discrete concepts, and each concept was classified along 2 axes: (1) diagnosis, finding, or procedure and (2) ophthalmic or medical concept. Electronic or paper browsers were used to assign a code for every concept in each of the 5 terminologies. Adequacy of assignment for each concept was scored on a 3-point scale. Findings from all 20 case presentations were combined and compared based on a coverage score, which was the average score for all concepts in that terminology. Adequacy of assignment for concepts in each terminology, based on a 3-point Likert scale (0, no match; 1, partial match; 2, complete match). Cases were parsed into 1603 concepts. SNOMED-CT had the highest mean overall coverage score (1.625+/-0.667), followed by MED (0.974+/-0.764), LOINC (0.781+/-0.929), ICD9-CM (0.280+/-0.619), and CPT-4 (0.082+/-0.337). SNOMED-CT also had higher coverage scores than any of the other terminologies for concepts in the diagnosis, finding, and procedure categories. Average coverage scores for ophthalmic concepts were lower than those for medical concepts. Controlled terminologies are required for electronic representation of ophthalmology data. SNOMED-CT had significantly higher content coverage than any other terminology in this study.
The body and the fading away of abstract concepts and words: a sign language analysis
Borghi, Anna M.; Capirci, Olga; Gianfreda, Gabriele; Volterra, Virginia
2014-01-01
One of the most important challenges for embodied and grounded theories of cognition concerns the representation of abstract concepts, such as “freedom.” Many embodied theories of abstract concepts have been proposed. Some proposals stress the similarities between concrete and abstract concepts showing that they are both grounded in perception and action system while other emphasize their difference favoring a multiple representation view. An influential view proposes that abstract concepts are mapped to concrete ones through metaphors. Furthermore, some theories underline the fact that abstract concepts are grounded in specific contents, as situations, introspective states, emotions. These approaches are not necessarily mutually exclusive, since it is possible that they can account for different subsets of abstract concepts and words. One novel and fruitful way to understand the way in which abstract concepts are represented is to analyze how sign languages encode concepts into signs. In the present paper we will discuss these theoretical issues mostly relying on examples taken from Italian Sign Language (LIS, Lingua dei Segni Italiana), the visual-gestural language used within the Italian Deaf community. We will verify whether and to what extent LIS signs provide evidence favoring the different theories of abstract concepts. In analyzing signs we will distinguish between direct forms of involvement of the body and forms in which concepts are grounded differently, for example relying on linguistic experience. In dealing with the LIS evidence, we will consider the possibility that different abstract concepts are represented using different levels of embodiment. The collected evidence will help us to discuss whether a unitary embodied theory of abstract concepts is possible or whether the different theoretical proposals can account for different aspects of their representation. PMID:25120515
Knowledge of the brain-death concept among secondary school teachers.
Ríos, A; Febrero, B; López-Navas, A; Martínez-Alarcón, L; Sánchez, J; Guzmán, D; Ramírez, P; Parrilla, P
2012-01-01
The concept of brain death (BD) is not very well known in the population, and its unknown nature is one of the main factors that could lead to an attitude against organ donation. The teaching sector has an important influence on the education of adolescents, and for this reason the teacher's knowledge of these concepts is fundamental to spread the correct meaning of the concept to young people. To analyze the concept of BD among teachers of compulsory secondary education (CSE) in southeast Spain and to determine teachers' influence on attitude toward organ donation. Ten CSE level schools were selected and stratified according to geographical location in southeast spain. A random sample was taken of CSE teachers. The knowledge of the concept of BD and attitude toward donation were analyzed using a validated questionnaire, which was self-administered and completed anonymously. Sixty-four percent (n = 180) of respondents knew the BD concept and they considered it to be the death of an individual. Of the rest, 34% (n = 95) did not know this concept, and the remaining 3% (n = 8) believed it did not mean a person's death. Those who understood the concept of BD were more in favor of deceased donation than those who held the wrong concept (82% versus 75%; P < .01). The knowledge of the concept of BD is associated with variables directly and indirectly related with donation and transplantation (P < .05). A third of the CSE teaching staff did not know or understand the BD concept as the death of an individual. The knowledge of BD positively affects attitude toward organ donation. Given that teachers are a source of information, the basic training of CSE teaching staff in basic concepts such as BD would be important. Copyright © 2012 Elsevier Inc. All rights reserved.
Concept formation: a supportive process for early career nurses.
Thornley, Tracey; West, Sandra
2010-09-01
Individuals come to understand abstract constructs such as that of the 'expert' through the formation of concepts. Time and repeated opportunity for observation to support the generalisation and abstraction of the developing concept are essential if the concept is to form successfully. Development of an effective concept of the 'expert nurse' is critical for early career nurses who are attempting to integrate theory, values and beliefs as they develop their clinical practice. This study explores the use of a concept development framework in a grounded theory study of the 'expert nurse'. Qualitative. Using grounded theory methods for data collection and analysis, semi-structured interviews were conducted with registered nurses. The participants were asked to describe their concept of the 'expert nurse' and to discuss their experience of developing this. Participants reported forming their concept of the 'expert nurse', after multiple opportunities to engage with nurses identified as 'expert'. This identification did not necessarily relate to the designated position of the 'expert nurse' or assigned mentors. When the early career nurse does not successfully form a concept of the 'expert nurse', difficulties in personal and professional development including skill/knowledge development may arise. To underpin development of their clinical practice effectively, early career nurses need to be provided with opportunities that facilitate the purposive formation of their own concept of the 'expert nurse'. Formation of this concept is not well supported by the common practice of assigning mentors. Early career nurses must be provided with the time and the opportunity to individually develop and refine their concept of the 'expert nurse'. To achieve this, strategies including providing opportunities to engage with expert nurses and discussion of the process of concept formation and its place in underpinning personal judgments may be of assistance. © 2010 Blackwell Publishing Ltd.
Time Concepts for Elementary School Children.
ERIC Educational Resources Information Center
Muir, Sharon Pray
1990-01-01
Points out that children have difficulty learning time concepts. Presents instructional activities for concepts associated with clocks, calendars, and chronology. Outlines Jerome Bruner's three different stages of representation for each concept: enactive, iconic, and symbolic. (DB)
NASA Astrophysics Data System (ADS)
Rebich, S.
2003-12-01
The concept mapping technique has been proposed as a method for examining the evolving nature of students' conceptualizations of scientific concepts, and promises insight into a dimension of learning different from the one accessible through more conventional classroom testing techniques. The theory behind concept mapping is based on an assumption that knowledge acquisition is accomplished through "linking" of new information to an existing knowledge framework, and that meaningful (as opposed to arbitrary or verbatim) links allow for deeper understanding and conceptual change. Reflecting this theory, concept maps are constructed as a network of related concepts connected by labeled links that illustrate the relationship between the concepts. Two concepts connected by one such link make up a "proposition", the basic element of the concept map structure. In this paper, we examine the results of a pre- and post-test assessment program for an upper-division undergraduate geography course entitled "Mock Environmental Summit," which was part of a research project on assessment. Concept mapping was identified as a potentially powerful assessment tool for this course, as more conventional tools such as multiple-choice tests did not seem to provide a reliable indication of the learning students were experiencing as a result of the student-directed research, presentations, and discussions that make up a substantial portion of the course. The assessment program began at the beginning of the course with a one-hour training session during which students were introduced to the theory behind concept mapping, provided with instructions and guidance for constructing a concept map using the CMap software developed and maintained by the Institute for Human and Machine Cognition at the University of West Florida, and asked to collaboratively construct a concept map on a topic not related to the one to be assessed. This training session was followed by a 45-minute "pre-test" on the topic of global climate change, for which students were provided with a list of questions to guide their thoughts during the concept map construction. Following the pre-test, students were not exposed to further concept mapping until the end of the course, when they were asked to complete a "post-test" consisting of exactly the same task. In addition to a summary of our results, this paper presents an overview of available digital concept-mapping tools, proposed scoring techniques, and design principles to keep in mind when designing a concept-mapping assessment program. We also discuss our experience with concept map assessment, the insights it provided into the evolution in student understanding of global climate change that resulted from the course, and our ideas about the potential role of concept mapping in an overall assessment program for interdisciplinary and/or student-directed curricula.
Alienation, authenticity and the self.
Rae, Gavin
2010-01-01
While many commentators have held that the concept "alienation" is of crucial importance when attempting to understand human existence, others have held that it is an inherently empty concept that we should abandon. In this article, I refute the latters' charge by showing that each conception of "alienation" is underpinned by a normative ontological conception of the preferable, or authentic, self and show that the concept "alienation" has ethical, existential and socio-political uses. From this I conclude that, when properly understood, the concept "alienation" can provide us with vital insights into human existence.
Simulation of human decision making
Forsythe, J Chris [Sandia Park, NM; Speed, Ann E [Albuquerque, NM; Jordan, Sabina E [Albuquerque, NM; Xavier, Patrick G [Albuquerque, NM
2008-05-06
A method for computer emulation of human decision making defines a plurality of concepts related to a domain and a plurality of situations related to the domain, where each situation is a combination of at least two of the concepts. Each concept and situation is represented in the computer as an oscillator output, and each situation and concept oscillator output is distinguishable from all other oscillator outputs. Information is input to the computer representative of detected concepts, and the computer compares the detected concepts with the stored situations to determine if a situation has occurred.
Social autopoiesis: A concept in search of a theory
NASA Astrophysics Data System (ADS)
Broonen, Jean Paul
1998-07-01
This paper is a brief report on the issue of extension of the concept of autopoiesis to social systems. The arguments developed by four groups of authors to bring a response to that issue are summarized: Maturana and Varela, the fathers of the concept of autopoieis; Zeleny & Hufford who proposed a simple extension of the concept to social systems; Luhmann and Hejel with two different transformations of the concept; Morgan and his metaphorical perspective. The determinist vs teleological conception of (social) autopoiesis explicitly or implicitly sustained by several authors is emphasized.
Min, Hua; Zheng, Ling; Perl, Yehoshua; Halper, Michael; De Coronado, Sherri; Ochs, Christopher
2017-05-18
Ontologies are knowledge structures that lend support to many health-information systems. A study is carried out to assess the quality of ontological concepts based on a measure of their complexity. The results show a relation between complexity of concepts and error rates of concepts. A measure of lateral complexity defined as the number of exhibited role types is used to distinguish between more complex and simpler concepts. Using a framework called an area taxonomy, a kind of abstraction network that summarizes the structural organization of an ontology, concepts are divided into two groups along these lines. Various concepts from each group are then subjected to a two-phase QA analysis to uncover and verify errors and inconsistencies in their modeling. A hierarchy of the National Cancer Institute thesaurus (NCIt) is used as our test-bed. A hypothesis pertaining to the expected error rates of the complex and simple concepts is tested. Our study was done on the NCIt's Biological Process hierarchy. Various errors, including missing roles, incorrect role targets, and incorrectly assigned roles, were discovered and verified in the two phases of our QA analysis. The overall findings confirmed our hypothesis by showing a statistically significant difference between the amounts of errors exhibited by more laterally complex concepts vis-à-vis simpler concepts. QA is an essential part of any ontology's maintenance regimen. In this paper, we reported on the results of a QA study targeting two groups of ontology concepts distinguished by their level of complexity, defined in terms of the number of exhibited role types. The study was carried out on a major component of an important ontology, the NCIt. The findings suggest that more complex concepts tend to have a higher error rate than simpler concepts. These findings can be utilized to guide ongoing efforts in ontology QA.
The change in students' understanding of the mole concept in introductory college chemistry
NASA Astrophysics Data System (ADS)
Smith, Shane Harvie
This study investigated the difference between the students' understanding of the mole concept in chemistry at the beginning and at the end of the first semester of introductory chemistry courses. The study also identified the relationship between the criterion variable understanding of the mole concept in chemistry and the independent variables of cognitive level, type of introductory college chemistry class, and the number of lectures spent teaching the mole concept. In addition, this study examined (a) the students' misconceptions and (b) the aspects of the traditional teaching methods used in the introductory college chemistry courses that helped the students' understanding of the mole concept. This study was conducted using 180 volunteer students in their first semester of an introductory college chemistry course. These students were given a pretest instrument called the Mole Concepts Examination (MCE) to measure their understanding of the mole concept, the Group Assessment of Logical Thinking (GALT) to measure the students' cognitive level of logical thinking, and a posttest of the MCE to measure the students' understanding of the mole concept at the end of the semester. In addition, an interview was given to a selected group of 18 students to find out if the students remember the teaching techniques used to help them understand the mole concept and to determine some of the misconceptions that the students retained at the end of the semester. Results indicated a statistically significant relationship between students' understanding of the mole concept and their cognitive level. There was no significant relationship between students' understanding of the mole concept and the type of class, or the number of lectures spent teaching the mole concept. Qualitative results indicated that students were able to explain their answers to the posttest questions; students were able to identify some instructional techniques that helped them to understand the mole concept, and students of all cognitive levels retained misconceptions about the mole concept at the end of the semester.
A concept analysis of befriending.
Balaam, Marie-Clare
2015-01-01
To report an analysis of the concept of befriending. Befriending is an intervention used in a range of nursing, health and social care settings to provide support for individuals who are socially isolated or lack social support. However, in many cases befriending and its impact remains poorly understood and under researched. Concept analysis provides clarification of the concept and basis for further research and development. Concept analysis. AMED, Psyc Articles, Psych Info, Medline, MedlinePlus, Social Science Index and CINHAL databases were searched for literature published between 1993-2013 using the search term Befriending. Walker and Avant's method of concept analysis was chosen. This combined with insights from Risjord's work produced a theoretical concept analysis which focused on the concept in peer reviewed academic literature. There are currently several ways the mechanisms of befriending and its effects on individuals and communities are understood. It is possible however to identify key attributes which define the concept and differentiate it from related concepts, such as peer support and mentoring. Key attributes are that it is an organised intervention, involving the creation of an emotionally connected friend-like relationship, where there is a negotiation of power. This concept analysis has clarified current understandings and uses of befriending. It provides the basis for widening the focus of research into the effectiveness and impact of befriending on those who are befriended, those who befriend and the communities where befriending takes place. © 2014 John Wiley & Sons Ltd.
Conception and pregnancy during the Persian Gulf War: the risk to women veterans.
Araneta, Maria Rosario G; Kamens, Deborah R; Zau, Andrew C; Gastañaga, Victor M; Schlangen, Karen M; Hiliopoulos, Katia M; Gray, Gregory C
2004-02-01
To enumerate Gulf-War (GW) exposed conceptions and to compare reproductive outcomes of GW-exposed pregnancies with postwar conceptions of women Gulf War veterans (GWV) and women nondeployed veterans (NDV). Deployment data and inpatient records from 153 military hospitals identified servicewomen who were pregnant between August 1990 and May 1992 and belonged to military units that were deployed to the Gulf War. Postal surveys were used in 1997 and 1998 to elicit reproductive history; responses were validated against military hospitalization records. Reproductive outcomes of GW-exposed pregnancies were compared with postwar conceptions of women GWVs and NDVs. 3285 women had a pregnancy-related admission; of these, 1558 completed the questionnaire. Self-reported reproductive outcomes and dates, gestational data, and individual deployment dates identified 415 Gulf War-exposed pregnancies, 298 GWV postwar conceptions, and 427 NDV conceptions. Compared with NDV conceptions, adverse reproductive outcomes were similar among GW-exposed pregnancies. However, spontaneous abortions [NDV: 9.1%, GWV postwar: 22.8%, adjusted odds ratio (OR)=2.92, 95% confidence interval (CI): 1.9, 4.6] and ectopic pregnancies (NDV: 1.4%, GWV postwar: 10.7%, adjusted OR=7.70, 95% CI, 3.0, 20) were elevated for GWV postwar conceptions. GW-exposed conceptions and nondeployed conceptions had similar outcomes. However, GWV postwar conceptions were at increased risk for ectopic pregnancies and spontaneous abortions.
Systems evaluation of thermal bus concepts
NASA Technical Reports Server (NTRS)
Stalmach, D. D.
1982-01-01
Thermal bus concepts, to provide a centralized thermal utility for large, multihundred kilowatt space platforms, were studied and the results are summarized. Concepts were generated, defined, and screened for inclusion in system level thermal bus trades. Parametric trade studies were conducted in order to define the operational envelope, performance, and physical characteristics of each. Two concepts were selected as offering the most promise for thermal bus development. All of four concepts involved two phase flow in order to meet the required isothermal nature of the thermal bus. Two of the concepts employ a mechanical means to circulate the working fluid, a liquid pump in one case and a vapor compressor in another. Another concept utilizes direct osmosis as the driving force of the thermal bus. The fourth concept was a high capacity monogroove heat pipe. After preliminary sizing and screening, three of these concepts were selected to carry into the trade studies. The monogroove heat pipe concept was deemed unsuitable for further consideration because of its heat transport limitations. One additional concept utilizing capillary forces to drive the working fluid was added. Parametric system level trade studies were performed. Sizing and weight calculations were performed for thermal bus sizes ranging from 5 to 350 kW and operating temperatures in the range of 4 to 120 C. System level considerations such as heat rejection and electrical power penalties and interface temperature losses were included in the weight calculations.
NASA Astrophysics Data System (ADS)
Rahaju, E. B.
2018-01-01
Defining a quadrilateral concept is one part of mathematics learning in junior high school. Defining a concept can be influenced by the concept’s image. While the image of the concept is influenced by the experience associated with the concept, the characteristics of the concept, the mental picture of the concept, and the reconstruction of the definition made by the person against a concept. The thinking process of a person in defining a concept is influenced by cognitive style. This study aimed to describe the thinking process of a student in defining the quadrilateral concept based on her cognitive style. The subject of this research was a student on grade VII with Field Independent cognitive style (FI). This research concludes that the subject of FI in defining quadrilateral concepts, begins by forming a sense through listing the characteristics of quadrilateral. In determining the characteristics of a quadrilateral, subjects tend to organize all quadrilateral models that have been grouped. This suggests that the subject of FI is easier to capture the similarities found in the models that have been grouped. Based on the characteristics, the subject can conclude to make a simple definition of a quadrilateral by eliminating one by one characteristic are not essential. Subjects can make definitions that meet necessary and sufficient conditions on square, rectangular, parallelogram and trapezoid.
[Concept analysis of the nursing profession, published from 1994 to 2008].
Palese, A; Dante, A; Gherbezza, S; Venturato, E; Maragnolli, O; Ambrosi, E; Saiani, L
2012-01-01
Concept analysis is a research method in which concepts are examined in a logical and systematic fashion to form clear and rigorous conceptual definitions. To describe the concept analyses published between 1994 and 2008 and identify the emerging tendencies in the Nursing discipline, a two-staged study has been developed. In the first stage a systematic review of the literature was conducted: research published in the journals indexed in the MedLine, CINAHL and Cochrane databases were judged eligible, if they reported the theme of 'concept analysis' and 'nursing' in the title or in their key words and were published in English language. In the second stage, the articles that emerged were subjected to a content analysis. Some 158 concept analyses emerged, on average 10/year (range 1-22, median 11, +/- 5.6): these regarded 129 different concepts. Ninety-one (57.6%) concepts were focused on the nursing profession, while 67 (42.4%) were focused on the patients. Although in a few cases the effort made by the researchers moved toward the definition of new concepts, in others it appeared oriented toward including in Nursing some typical concepts from other disciplines, thus tracing an expansion of the domain of the Nursing discipline. Monitoring over time the concepts analysed constitutes an important research area to comprehend, both at a national and international level, the progressive evolution of the Nursing discipline.
Trois Conceptions de l'apprentissage (Three Conceptions of Learning).
ERIC Educational Resources Information Center
Janitza, Jean
1990-01-01
Three broad conceptions of second-language learning and teaching (behaviorist, cognitive, and a third labeled "voluntarist") are described and compared, and issues in the choice between these different conceptions for classroom use are examined. (MSE)
Construction of the mathematical concept of pseudo thinking students
NASA Astrophysics Data System (ADS)
Anggraini, D.; Kusmayadi, T. A.; Pramudya, I.
2018-05-01
Thinking process is a process that begins with the acceptance of information, information processing and information calling in memory with structural changes that include concepts or knowledges. The concept or knowledge is individually constructed by each individual. While, students construct a mathematical concept, students may experience pseudo thinking. Pseudo thinking is a thinking process that results in an answer to a problem or construction to a concept “that is not true”. Pseudo thinking can be classified into two forms there are true pseudo and false pseudo. The construction of mathematical concepts in students of pseudo thinking should be immediately known because the error will have an impact on the next construction of mathematical concepts and to correct the errors it requires knowledge of the source of the error. Therefore, in this article will be discussed thinking process in constructing of mathematical concepts in students who experience pseudo thinking.
Pan, Xuequn; Cimino, James J
2014-01-01
Clinicians and clinical researchers often seek information in electronic health records (EHRs) that are relevant to some concept of interest, such as a disease or finding. The heterogeneous nature of EHRs can complicate retrieval, risking incomplete results. We frame this problem as the presence of two gaps: 1) a gap between clinical concepts and their representations in EHR data and 2) a gap between data representations and their locations within EHR data structures. We bridge these gaps with a knowledge structure that comprises relationships among clinical concepts (including concepts of interest and concepts that may be instantiated in EHR data) and relationships between clinical concepts and the database structures. We make use of available knowledge resources to develop a reproducible, scalable process for creating a knowledge base that can support automated query expansion from a clinical concept to all relevant EHR data.
Concept analysis of mentoring.
2013-10-01
The purpose of a concept analysis is to examine the structure and function of a concept by defining its attributes and internal structure. Concept analysis can clarify an overused or vague concept and promote mutual understanding by providing a precise operational definition. Mentoring is a concept more fully used by other fields, such as business, than in nursing and may not always translate well for use in nursing. Therefore, clarifying the meaning of the existing concept of mentoring and developing an operational definition for use in nursing are aims of this concept analysis. Mentoring is broadly based and concentrates on developing areas such as career progression, scholarly achievements, and personal development. Mentoring relationships are based around developing reciprocity and accountability between each partner. Mentoring is seen related to transition in practice, role acquisition, and socialization, as a way to support new colleagues. Mentorship is related to nurses' success in nursing practice linked to professionalism, nursing quality improvement, and self-confidence.
NASA Technical Reports Server (NTRS)
Guynn, Mark D.; Olson, Erik D.
2002-01-01
This report describes the analytical modeling and evaluation of an unconventional commercial transport aircraft concept designed to address aircraft noise and emission issues. A strut-braced wing configuration with overwing, ultra-high bypass ratio, hydrogen fueled turbofan engines is considered. Estimated noise and emission characteristics are compared to a conventional configuration designed for the same mission and significant benefits are identified. The design challenges and technology issues which would have to be addressed to make the concept a viable alternative to current aircraft designs are discussed. This concept is one of the "Quiet Green Transport" aircraft concepts studied as part of NASA's Revolutionary Aerospace Systems Concepts (RASC) Program. The RASC Program seeks to develop revolutionary concepts that address strategic objectives of the NASA Enterprises, such as reducing aircraft noise and emissions, and to identify enabling advanced technology requirements for the concepts.
[Clinical reasoning in nursing, concept analysis].
Côté, Sarah; St-Cyr Tribble, Denise
2012-12-01
Nurses work in situations of complex care requiring great clinical reasoning abilities. In literature, clinical reasoning is often confused with other concepts and it has no consensual definition. To conduct a concept analysis of a nurse's clinical reasoning in order to clarify, define and distinguish it from the other concepts as well as to better understand clinical reasoning. Rodgers's method of concept analysis was used, after literature was retrieved with the use of clinical reasoning, concept analysis, nurse, intensive care and decision making as key-words. The use of cognition, cognitive strategies, a systematic approach of analysis and data interpretation, generating hypothesis and alternatives are attributes of clinical reasoning. The antecedents are experience, knowledge, memory, cues, intuition and data collection. The consequences are decision making, action, clues and problem resolution. This concept analysis helped to define clinical reasoning, to distinguish it from other concepts used synonymously and to guide future research.
Concept Analysis of Illness Engulfment in Schizophrenia.
Vining, Danny; Robinson, Jennifer C
2016-06-01
Schizophrenia has a significant risk of damaging an individual's self-concept. Through the process of illness engulfment an individual's self-concept becomes reorganized entirely around the experience of having schizophrenia. The purpose of this manuscript is to clarify the structure and function of the concept of illness engulfment in schizophrenia using Walker and Avant's (2011) method of concept analysis. Data came from a review of scholarly literature, as well as contemporary and historical art, literature, music, and other media forms. The analysis discussed two defining attributes of experience of illness and impact on self-concept with a total of seven indicators. The article listed antecedents, consequences, and discussed the Modified Engulfment Scale as empirical referents. Fictional cases were developed to illustrate the concept. Finally, the concept of illness engulfment was discussed within the framework of the Roy Adaptation Model. Copyright © 2016 Elsevier Inc. All rights reserved.
Identifying UMLS concepts from ECG Impressions using KnowledgeMap
Denny, Joshua C.; Spickard, Anderson; Miller, Randolph A; Schildcrout, Jonathan; Darbar, Dawood; Rosenbloom, S. Trent; Peterson, Josh F.
2005-01-01
Electrocardiogram (ECG) impressions represent a wealth of medical information for potential decision support and drug-effect discovery. Much of this information is inaccessible to automated methods in the free-text portion of the ECG report. We studied the application of the KnowledgeMap concept identifier (KMCI) to map Unified Medical Language System (UMLS) concepts from ECG impressions. ECGs were processed by KMCI and the results scored for accuracy by multiple raters. Reviewers also recorded unidentified concepts through the scoring interface. Overall, KMCI correctly identified 1059 out of 1171 concepts for a recall of 0.90. Precision, indicating the proportion of ECG concepts correctly identified, was 0.94. KMCI was particularly effective at identifying ECG rhythms (330/333), perfusion changes (65/66), and noncardiac medical concepts (11/11). In conclusion, KMCI is an effective method for mapping ECG impressions to UMLS concepts. PMID:16779029
A Description of the "Crow's Foot" Tunnel Concept
NASA Technical Reports Server (NTRS)
Parrish, Russell V.; Williams, Steven P.; Arthur, Jarvis J., III; Kramer, Lynda J.; Bailey, Randall E.; Prinzel, Lawrence J., III; Norman, R. Michael
2006-01-01
NASA Langley Research Center has actively pursued the development and the use of pictorial or three-dimensional perspective displays of tunnel-, pathway- or highway-in-the-sky concepts for presenting flight path information to pilots in all aircraft categories (e.g., transports, General Aviation, rotorcraft) since the late 1970s. Prominent among these efforts has been the development of the crow s foot tunnel concept. The crow's foot tunnel concept emerged as the consensus pathway concept from a series of interactive workshops that brought together government and industry display designers, test pilots, and airline pilots to iteratively design, debate, and fly various pathway concepts. Over years of use in many simulation and flight test activities at NASA and elsewhere, modifications have refined and adapted the tunnel concept for different applications and aircraft categories (i.e., conventional transports, High Speed Civil Transport, General Aviation). A description of those refinements follows the definition of the original tunnel concept.
Blomfield, Corey J; Barber, Bonnie L
2009-06-01
The relationship between Australian adolescents' participation in extracurricular activities and their self-concepts was investigated. A total of 1489 adolescents (56% female; mean age 13.8 years) completed measures of social self-concept, academic self-concept, and general self-worth, and reported on their extracurricular activity participation. In general, participation in any type of extracurricular activity was associated with a higher social and academic self-concept, and general self-worth, compared to no participation. Adolescents who participated in both sports and non-sports also reported a more positive social self-concept and general self-worth, compared to those who only participated in one of the activity types. This research provides support for extracurricular activities as a context facilitative of positive self-concept, and demonstrates the importance of a mixed participation profile for an adolescent's self-concept.
ERIC Educational Resources Information Center
Khan, Suhail Ahmed
2010-01-01
The self-concept is the sum of all your thoughts, feelings and belief about yourself. The self-concept may be positive or negative. This paper focuses on self-concepts of Secondary School Teachers and its relationship with their adjustment. The research was carried out in Aurangabad, Maharashtra on a sample of 50 teachers. Self-concept of teachers…
The ontic conception of scientific explanation.
Wright, Cory
2015-12-01
Wesley Salmon's version of the ontic conception of explanation is a main historical root of contemporary work on mechanistic explanation. This paper examines and critiques the philosophical merits of Salmon's version, and argues that his conception's most fundamental construct is either fundamentally obscure, or else reduces to a non-ontic conception of explanation. Either way, the ontic conception is a misconception. Copyright © 2015 Elsevier Ltd. All rights reserved.
ERIC Educational Resources Information Center
McCauley, James B.; Zajic, Matthew C.; Oswald, Tasha M.; Swain-Lerro, Lindsey E.; McIntyre, Nancy C.; Harris, Michelle A.; Trzesniewski, Kali; Mundy, Peter C.; Solomon, Marjorie
2018-01-01
A typically developing student's perceptions of his or her own capabilities (academic self-concept), is predictive of later academic achievement. However, little is known about academic self-concept in youth with autism spectrum disorder (ASD). To understand whether students math self-concept and reading self-concept predicted their performance,…
ERIC Educational Resources Information Center
Acuña, Santiago Roger; Aymes, Gabriela López; Medrano, Carlos Sergio López
2014-01-01
This paper analyzes the use of collaborative concept maps in multimedia learning tasks. Specifically, the effect of a cognitive aid (providing students a list of main concepts to generate a concept map) on the performance of collaborative concept mapping and on the level of collaboration in this task is discussed. The study was carried out with 57…
ERIC Educational Resources Information Center
Jesness, Bradley
This paper examines concepts in information-processing theory which are likely to be relevant to development and characterizes the methods and data upon which the concepts are based. Among the concepts examined are those which have slight empirical grounds. Other concepts examined are those which seem to have empirical bases but which are…
ERIC Educational Resources Information Center
Johnson, Brittney; McCracken, I. Moriah
2016-01-01
In 2015, threshold concepts formed the foundation of two disciplinary documents: The "ACRL Framework for Information Literacy" (2015) and "Naming What We Know: Threshold Concepts of Writing Studies" (2015). While there is no consensus in the fields about the value of threshold concepts in teaching, reading the six Frames in the…
NASA Astrophysics Data System (ADS)
Marks Krpan, Catherine Anne
In order to promote science literacy in the classroom, students need opportunities in which they can personalize their understanding of the concepts they are learning. Current literature supports the use of concept maps in enabling students to make personal connections in their learning of science. Because they involve creating explicit connections between concepts, concept maps can assist students in developing metacognitive strategies and assist educators in identifying misconceptions in students' thinking. The literature also notes that concept maps can improve student achievement and recall. Much of the current literature focuses primarily on concept mapping at the secondary and university levels, with limited focus on the elementary panel. The research rarely considers teachers' thoughts and ideas about the concept mapping process. In order to effectively explore concept mapping from the perspective of elementary teachers, I felt that an action research approach would be appropriate. Action research enabled educators to debate issues about concept mapping and test out ideas in their classrooms. It also afforded the participants opportunities to explore their own thinking, reflect on their personal journeys as educators and play an active role in their professional development. In an effort to explore concept mapping from the perspective of elementary educators, an action research group of 5 educators and myself was established and met regularly from September 1999 until June 2000. All of the educators taught in the Toronto area. These teachers were interested in exploring how concept mapping could be used as a learning tool in their science classrooms. In summary, this study explores the journey of five educators and myself as we engaged in collaborative action research. This study sets out to: (1) Explore how educators believe concept mapping can facilitate teaching and student learning in the science classroom. (2) Explore how educators implement concept mapping in their classrooms. (3) Identify challenges educators experience when they implement concept mapping. (4) Explore factors that impact on facilitating collaborative action research. (5) Provide insight into my growth as an action research facilitator.
Concept Development of the Eindhoven Diabetes Education Simulator Project.
Maas, Anne H; van der Molen, Pieta; van de Vijver, Reinier; Chen, Wei; van Pul, Carola; Cottaar, Eduardus J E; van Riel, Natal A W; Hilbers, Peter A J; Haak, Harm R
2016-04-01
This study was designed to define the concept of an educational diabetes game following a user-centered design approach. The concept development of the Eindhoven Diabetes Education Simulator (E-DES) project can be divided in two phases: concept generation and concept evaluation. Four concepts were designed by the multidisciplinary development team based on the outcomes of user interviews. Four other concepts resulted from the Diabetes Game Jam. Several users and experts evaluated the concepts. These user evaluations and a feasibility analysis served as input for an overall evaluation and discussion by the development team resulting in the final concept choice. The four concepts of the development team are a digital board game, a quiz platform, a lifestyle simulator, and a puzzle game. The Diabetes Game Jam resulted in another digital board game, two mobile swipe games, and a fairy tale-themed adventure game. The combined user evaluations and feasibility analysis ranked the quiz platform and the digital board game equally high. Each of these games fits one specific subgroup of users best: the quiz platform best fits an eager-to-learn, more individualistic patient, whereas the board game best fits a less-eager-to-learn, family-oriented patient. The choice for a specific concept is therefore highly dependent on the choice of our specific target audience. The user-centered design approach with multiple evaluations has enabled us to choose the most promising concept from eight different options. A digital board game is chosen for further development because the target audience for E-DES is the less-motivated, family-oriented patients.
Using rule-based natural language processing to improve disease normalization in biomedical text.
Kang, Ning; Singh, Bharat; Afzal, Zubair; van Mulligen, Erik M; Kors, Jan A
2013-01-01
In order for computers to extract useful information from unstructured text, a concept normalization system is needed to link relevant concepts in a text to sources that contain further information about the concept. Popular concept normalization tools in the biomedical field are dictionary-based. In this study we investigate the usefulness of natural language processing (NLP) as an adjunct to dictionary-based concept normalization. We compared the performance of two biomedical concept normalization systems, MetaMap and Peregrine, on the Arizona Disease Corpus, with and without the use of a rule-based NLP module. Performance was assessed for exact and inexact boundary matching of the system annotations with those of the gold standard and for concept identifier matching. Without the NLP module, MetaMap and Peregrine attained F-scores of 61.0% and 63.9%, respectively, for exact boundary matching, and 55.1% and 56.9% for concept identifier matching. With the aid of the NLP module, the F-scores of MetaMap and Peregrine improved to 73.3% and 78.0% for boundary matching, and to 66.2% and 69.8% for concept identifier matching. For inexact boundary matching, performances further increased to 85.5% and 85.4%, and to 73.6% and 73.3% for concept identifier matching. We have shown the added value of NLP for the recognition and normalization of diseases with MetaMap and Peregrine. The NLP module is general and can be applied in combination with any concept normalization system. Whether its use for concept types other than disease is equally advantageous remains to be investigated.
Cheong, Sau Kuan; Lang, Cathryne P; Johnston, Leanne M
2018-02-01
Self-concept is an individual's perception of him/herself. Research into the self-concept of children with cerebral palsy (CP) has been sparse due to the lack of a population-specific self-concept instrument. Using the new myTREEHOUSE Self-Concept Assessment, this study investigated the self-concept of children with CP in relation to age, gender, motor, communication and cognitive function. Children with CP aged 8-12 years (n = 50; 29 males; mean 10 years 2 months; GMFCS-E&R I = 36, II = 8, III = 5, IV = 1) completed myTREEHOUSE and a standardised intelligence measure. Most children reported positive self-concept from all three myTREEHOUSE Performance Perspectives and over half (60%) fell within the Low range for the Personal Concern Score. Self-concept was not associated with age, gender, motor function, or communication function. However, for cognitive function, associations were observed for Social Skills (Below Average > Average cognitive function; Cohen's d = 1.07) and Learning Skills (Above Average > Average cognitive function; Cohen's d = 0.95) domains when rated from a Personal Performance Perspective. As the first study of the self-concept of children with CP using a CP-specific assessment, this study offers important insights into what children with CP think about themselves. Generally, the self-concept of children with CP was sound. Future research on environmental facilitators and barriers to robust self-concept development is recommended. Copyright © 2017 Elsevier Ltd. All rights reserved.
The ability of children to generalize selected science concepts
NASA Astrophysics Data System (ADS)
Abdullah, Kemal Bin; Lowell, Walter E.
The study investigated the ability of primary and elementary school subjects to generalize two science concepts, Insect and Animal with and without instruction in the form of a mental set. It also examined the effects of age, IQ, and sex on the ability of the children to generalize these concepts. Two instruments measuring the ability to generalize the concepts Insect and Animal were developed. The results indicate that of the independent variables investigated, age and mental set significantly affected the ability to generalize the concepts Insect and Animal. It was found that the younger children's concepts were least developed and with age these concepts became more developed and more conceptual in nature. The ability to use information given in a mental set was found to be a function of age. The children in this study were more able to generalize the concept Insect than the concept Animal. The results suggest that children with age and instruction axe better able to master less general concepts than more geaeral ones. In addition, the study demonstrated that children are able to improve their learning of general concepts provided a great number and variety of instances and noninstances of the concept are used in the instruction.It was also found that the younger children were more perceptually bound than the older children. The younger children were unable to overcome the pull of perceptual attractiveness that the noninstances held for them despite instruction. The results suggest that teachers of such children should be aware of the conceptual level of the content being taught to such children to ensure appropriate and meaningful learning takes place.
Audulv, Åsa; Packer, Tanya; Hutchinson, Susan; Roger, Kerstin S; Kephart, George
2016-11-01
The aim of this study was to report: (1) an analysis of the concepts of coping, adaptation and self-management in the context of managing a neurological condition; and (2) the overlap between the concepts. The three concepts are often confused or used interchangeably. Understanding similarities and differences between concepts will avoid misunderstandings in care. The varied and often unpredictable symptoms and degenerative nature of neurological conditions make this an ideal population in which to examine the concepts. Concept analysis. Articles were extracted from a large literature review about living with a neurological condition. The original searches were conducted using SCOPUS, EMBASE, CINAHL and Psych INFO. Seventy-seven articles met the inclusion criteria of: (1) original article concerning coping, adaptation or self-management of a neurological condition; (2) written in English; and (3) published between 1999-2011. The concepts were examined according to Morse's concept analysis method; structural elements were then compared. Coping and adaptation to a neurological condition showed statistically significant overlap with a common focus on internal management. In contrast, self-management appears to focus on disease-controlling and health-related management strategies. Coping appears to be the most mature concept, whereas self-management is least coherent in definition and application. All three concepts are relevant for people with neurological conditions. Healthcare teams need to be cautious when using these terms to avoid miscommunication and to ensure clients have access to all needed interventions. Viewing the three concepts as a complex whole may be more aligned with client experience. © 2016 John Wiley & Sons Ltd.
Pyrolysis system evaluation study
NASA Technical Reports Server (NTRS)
1974-01-01
An evaluation of two different pyrolysis concepts which recover energy from solid waste was conducted in order to determine the merits of each concept for integration into a Integrated Utility System (IUS). The two concepts evaluated were a Lead Bath Furnace Pyrolysis System and a Slagging Vertical Shaft, Partial Air Oxidation Pyrolysis System. Both concepts will produce a fuel gas from the IUS waste and sewage sludge which can be used to offset primary fuel consumption in addition to the sanitary disposal of the waste. The study evaluated the thermal integration of each concept as well as the economic impact on the IUS resulting from integrating each pyrolysis concepts. For reference, the pyrolysis concepts were also compared to incineration which was considered the baseline IUS solid waste disposal system.
Deep first formal concept search.
Zhang, Tao; Li, Hui; Hong, Wenxue; Yuan, Xiamei; Wei, Xinyu
2014-01-01
The calculation of formal concepts is a very important part in the theory of formal concept analysis (FCA); however, within the framework of FCA, computing all formal concepts is the main challenge because of its exponential complexity and difficulty in visualizing the calculating process. With the basic idea of Depth First Search, this paper presents a visualization algorithm by the attribute topology of formal context. Limited by the constraints and calculation rules, all concepts are achieved by the visualization global formal concepts searching, based on the topology degenerated with the fixed start and end points, without repetition and omission. This method makes the calculation of formal concepts precise and easy to operate and reflects the integrity of the algorithm, which enables it to be suitable for visualization analysis.
DOT National Transportation Integrated Search
2013-10-01
This document serves as an Operational Concept for the Applications for the Environment: Real-Time Information Synthesis (AERIS) Eco-Lanes Transformative Concept. The Eco-Lanes Transformative Concept features dedicated lanes on freeways optimized for...
Static investigation of two STOL nozzle concepts with pitch thrust-vectoring capability
NASA Technical Reports Server (NTRS)
Mason, M. L.; Burley, J. R., II
1986-01-01
A static investigation of the internal performance of two short take-off and landing (STOL) nozzle concepts with pitch thrust-vectoring capability has been conducted. An axisymmetric nozzle concept and a nonaxisymmetric nozzle concept were tested at dry and afterburning power settings. The axisymmetric concept consisted of a circular approach duct with a convergent-divergent nozzle. Pitch thrust vectoring was accomplished by vectoring the approach duct without changing the nozzle geometry. The nonaxisymmetric concept consisted of a two dimensional convergent-divergent nozzle. Pitch thrust vectoring was implemented by blocking the nozzle exit and deflecting a door in the lower nozzle flap. The test nozzle pressure ratio was varied up to 10.0, depending on model geometry. Results indicate that both pitch vectoring concepts produced resultant pitch vector angles which were nearly equal to the geometric pitch deflection angles. The axisymmetric nozzle concept had only small thrust losses at the largest pitch deflection angle of 70 deg., but the two-dimensional convergent-divergent nozzle concept had large performance losses at both of the two pitch deflection angles tested, 60 deg. and 70 deg.
Investigation of virtual reality concept based on system analysis of conceptual series
NASA Astrophysics Data System (ADS)
Romanova, A.; Shuklin, D. A.; Kalinkina, M. E.; Gotskaya, I. B.; Ponomarev, Y. E.
2018-05-01
The paper covers approaches to the definition of virtual reality from the point of view of the humanitarian sciences and technology. Each approach analyzing problems of concept perception of methods interpreted by representatives of philosophy, psychology and sociology is singled out. Terminological analysis of the basic concepts is carried out and their refinement is constructed in the process of comparing the concepts of virtuality and virtual reality. Using the analysis of selected sources, a number of singularity characteristics of the given concept are singled out and its definition is specified. Results consist in combining the interpretation of all approaches to determine the concept of virtual reality. Due to the use of a comprehensive approach to the definition of the investigated concept, which allows us to consider the object of research as a set of elements that are subject to study with the help of a corresponding set of methods, one can conclude that the concept under study is complex and multifaceted. The authors noted that virtual reality technologies have a flexible concept depending on the field of application.
Adolescent self-concept and health into adulthood.
Park, Jungwee
2003-01-01
This article examines factors associated with adolescent self-concept and the impact of adolescent self-concept on psychological and physical health and health behaviour in young adulthood. The data are from the household cross-sectional (1994/95) and longitudinal (1994/95 to 2000/01) components of Statistics Canada's National Population Health Survey. Scores on self-concept indicators in 1994/95 were compared between the sexes and age groups (12 to 15 versus 16 to 19). Multivariate analyses were used to examine cross-sectional and longitudinal associations between adolescent self-concept and depression, self-perceived health, physical activity and obesity, controlling for other possible confounders. Self-concept tends to be low among girls compared with boys. Cross-sectionally, adolescent self-concept was associated with household income and emotional support. For girls and for young adolescents, a weak self-concept in 1994/95 was related to the incidence of depression over the next six years; it was also predictive of physical inactivity among boys, and obesity among both sexes. A strong self-concept had a positive long-term effect on girls' self-perceived health.
Kneer, Julia; Glock, Sabine; Beskes, Sara; Bente, Gary
2012-11-01
Violent digital game play has repeatedly been discussed to be strongly related to aggression and emotional instability. Thus, digital game players have to defend against these prejudices through emphasizing positive game-related concepts such as achievement, social interaction, and immersion. We experimentally investigated which positive- and negative-concept players and nonplayers activate when being primed with digital games. Participants were either exposed to violent or nonviolent game content and were required to work on a lexical decision task. Results showed that response latencies for the concept aggression and emotional instability were faster than for neutral concepts (not associated with digital games), but slower than for the positive concepts sociality and competition. Both players and nonplayers felt the need to defend against prejudices and emphasized positive concepts. Neither their own gaming experience nor the game content influenced the results. Being a part of the net generation is sufficient to suppress negative game-related concepts and to support positive game-related concepts to protect digital games as common leisure activity among peers.
NASA Astrophysics Data System (ADS)
Kurniati, D. R.; Rohman, I.
2018-05-01
This study aims to analyze the concepts and science process skills in bomb calorimeter experiment as a basis for developing the virtual laboratory of bomb calorimeter. This study employed research and development method (R&D) to gain the answer to the proposed problems. This paper discussed the concepts and process skills analysis. The essential concepts and process skills associated with bomb calorimeter are analyze by optimizing the bomb calorimeter experiment. The concepts analysis found seven fundamental concepts to be concerned in developing the virtual laboratory that are internal energy, burning heat, perfect combustion, incomplete combustion, calorimeter constant, bomb calorimeter, and Black principle. Since the concept of bomb calorimeter, perfect and incomplete combustion created to figure out the real situation and contain controllable variables, in virtual the concepts displayed in the form of simulation. Meanwhile, the last four concepts presented in the form of animation because no variable found to be controlled. The process skills analysis detect four notable skills to be developed that are ability to observe, design experiment, interpretation, and communication skills.
Corvids Outperform Pigeons and Primates in Learning a Basic Concept.
Wright, Anthony A; Magnotti, John F; Katz, Jeffrey S; Leonard, Kevin; Vernouillet, Alizée; Kelly, Debbie M
2017-04-01
Corvids (birds of the family Corvidae) display intelligent behavior previously ascribed only to primates, but such feats are not directly comparable across species. To make direct species comparisons, we used a same/different task in the laboratory to assess abstract-concept learning in black-billed magpies ( Pica hudsonia). Concept learning was tested with novel pictures after training. Concept learning improved with training-set size, and test accuracy eventually matched training accuracy-full concept learning-with a 128-picture set; this magpie performance was equivalent to that of Clark's nutcrackers (a species of corvid) and monkeys (rhesus, capuchin) and better than that of pigeons. Even with an initial 8-item picture set, both corvid species showed partial concept learning, outperforming both monkeys and pigeons. Similar corvid performance refutes the hypothesis that nutcrackers' prolific cache-location memory accounts for their superior concept learning, because magpies rely less on caching. That corvids with "primitive" neural architectures evolved to equal primates in full concept learning and even to outperform them on the initial 8-item picture test is a testament to the shared (convergent) survival importance of abstract-concept learning.
[Concept analysis "Competency-based education"].
Loosli, Clarence
2016-03-01
Competency-based education (CBE) stands out at global level as the best educational practice. Indeed, CBE is supposed to improve the quality of care provided by newly graduated nurses. Yet, there is a dearth of knowledge in nursing literature regarding CBE concept's definition. CBE is implemented differently in each entity even inside the same discipline in a single country. What accounts for CBE in nursing education ? to clarify CBE concept meaning according to literature review in order to propose a definition. Wilson concept analysis method framed our literature review through two databases: CINHAL and ERIC. following the 11 Wilson techniques analysis, we identified CBE concept as a multidimensional concept clustering three dimensions : learning, teaching and assessment. nurses educators are accountable for providing performants newly graduated professional to the society. Schools should struggle for the visibility and the transparency of means they are using to accomplish their educational activities. This first attempt to understand CBE concept opens a matter of debate concerning further development and clarification of the concept. This first description of CBE concept is a step toward its identification and assessment.
Fast Adapting Ensemble: A New Algorithm for Mining Data Streams with Concept Drift
Ortíz Díaz, Agustín; Ramos-Jiménez, Gonzalo; Frías Blanco, Isvani; Caballero Mota, Yailé; Morales-Bueno, Rafael
2015-01-01
The treatment of large data streams in the presence of concept drifts is one of the main challenges in the field of data mining, particularly when the algorithms have to deal with concepts that disappear and then reappear. This paper presents a new algorithm, called Fast Adapting Ensemble (FAE), which adapts very quickly to both abrupt and gradual concept drifts, and has been specifically designed to deal with recurring concepts. FAE processes the learning examples in blocks of the same size, but it does not have to wait for the batch to be complete in order to adapt its base classification mechanism. FAE incorporates a drift detector to improve the handling of abrupt concept drifts and stores a set of inactive classifiers that represent old concepts, which are activated very quickly when these concepts reappear. We compare our new algorithm with various well-known learning algorithms, taking into account, common benchmark datasets. The experiments show promising results from the proposed algorithm (regarding accuracy and runtime), handling different types of concept drifts. PMID:25879051
Concept Analysis: Health-Promoting Behaviors Related to Human Papilloma Virus (HPV) Infection.
McCutcheon, Tonna; Schaar, Gina; Parker, Karen L
2015-01-01
The concept of health-promoting behaviors incorporates ideas presented in the Ottawa Charter of Public Health and the nursing-based Health Promotion Model. Despite the fact that the concept of health-promoting behaviors has a nursing influence, literature suggests nursing has inadequately developed and used this concept within nursing practice. A further review of literature regarding health promotion behaviors and the human papilloma virus suggest a distinct gap in nursing literature. This article presents a concept analysis of health-promoting behaviors related to the human papilloma virus in order to encourage the application of the concept into nursing practice, promote continued nursing research regarding this concept, and further expand the application of health-promoting behaviors to other situations and populations within the nursing discipline. Attributes of health-promoting behaviors are presented and include empowerment, participation, community, and a positive concept of health. Antecedents, consequences, and empirical referents are also presented, as are model, borderline, and contrary cases to help clarify the concept. Recommendations for human papilloma virus health-promoting behaviors within the nursing practice are also provided. © 2014 Wiley Periodicals, Inc.
Tribology: Friction, lubrication, and wear technology
NASA Technical Reports Server (NTRS)
Blau, Peter J.
1993-01-01
The topics are presented in viewgraph form and include the following: introduction and definitions of terms; friction concepts; lubrication technology concepts; wear technology concepts; and tribological transitions. This document is designed for educators who seek to teach these concepts to their students.
DOT National Transportation Integrated Search
2013-10-01
This document serves as an Operational Concept for the Applications for the Environment: Real-Time Information Synthesis (AERIS) Low Emissions Zones Transformative Concept. The Low Emissions Zone Transformative Concept includes the ability for an ent...
On the Distinction Between the Motivating Operation and Setting Event Concepts.
Nosik, Melissa R; Carr, James E
2015-10-01
In recent decades, behavior analysts have generally used two different concepts to speak about motivational influences on operant contingencies: setting event and motivating operation. Although both concepts still appear in the contemporary behavior-analytic literature and were designed to address the same antecedent phenomena, the concepts are quite different. The purpose of the present article is to describe and distinguish the concepts and to illustrate their current usage.
NASA Technical Reports Server (NTRS)
Dickman, Glen J.; Keeley, J. T.
1985-01-01
This portion of the Orbit Transfer Vehicle (OTV) Concept Definition and System Analysis Study, Volume 2, Book 2, summarizes the flight vehicle concept selection process and results. It presents an overview of OTV mission and system design requirements and describes the family of OTV recommended, the reasons for this recommendation, and the associated Phase C/D Program.
Space transfer vehicle concepts and requirements. Volume 3: Program cost estimates
NASA Technical Reports Server (NTRS)
1991-01-01
The Space Transfer Vehicle (STV) Concepts and Requirements Study has been an eighteen-month study effort to develop and analyze concepts for a family of vehicles to evolve from an initial STV system into a Lunar Transportation System (LTS) for use with the Heavy Lift Launch Vehicle (HLLV). The study defined vehicle configurations, facility concepts, and ground and flight operations concepts. This volume reports the program cost estimates results for this portion of the study. The STV Reference Concept described within this document provides a complete LTS system that performs both cargo and piloted Lunar missions.
Pharmacology Goes Concept-Based: Course Design, Implementation, and Evaluation.
Lanz, Amelia; Davis, Rebecca G
Although concept-based curricula are frequently discussed in the nursing education literature, little information exists to guide the development of a concept-based pharmacology course. Traditionally, nursing pharmacology courses are taught with an emphasis on drug class where a prototype drug serves as an exemplar. When transitioning pharmacology to a concept-based course, special considerations are in order. How can educators successfully integrate essential pharmacological content into a curriculum structured around nursing concepts? This article presents one approach to the design and implementation of a concept-based undergraduate pharmacology course. Planning methods, supportive teaching strategies, and course evaluation procedures are discussed.
NASA Technical Reports Server (NTRS)
Howe, Steven D.; Borowski, Stanley; Motloch, Chet; Helms, Ira; Diaz, Nils; Anghaie, Samim; Latham, Thomas
1991-01-01
In response to findings from two NASA/DOE nuclear propulsion workshops, six task teams were created to continue evaluation of various propulsion concepts, from which evolved an innovative concepts subpanel to evaluate thermal propulsion concepts which did not utilize solid fuel. This subpanel endeavored to evaluate each concept on a level technology basis, and to identify critical issues, technologies, and early proof-of-concept experiments. Results of the concept studies including the liquid core fission, the gas core fission, the fission foil reactors, explosively driven systems, fusion, and antimatter are presented.
Innovative self-drying concept for thermal insulation of cold piping
DOE Office of Scientific and Technical Information (OSTI.GOV)
Korsgaard, V.
1997-11-01
In the paper an innovative Self-Drying concept, the Hygro-Wick concept, for thermal insulation of cold piping is described. The concept is based on the wicking action of certain fabrics to remove by capillary suction condensed water vapor from the pipe surface to the outer surface of the insulation/jacket, from whence it will evaporate/diffuse into the ambient air. Hence the concept will prevent long term accumulation of moisture in the insulation material. Theoretical and experimental results for two different embodiments of the concept is given: The Self-Drying system and the Self-Sealing system.
Obesogenic environment: a concept analysis and pediatric perspective.
Gauthier, Kristine I; Krajicek, Marilyn J
2013-07-01
A concept analysis was undertaken to examine the attributes, characteristics, and uses of the concept of obesogenic environment within a pediatric context. Utilizing a modified version of Walker and Avant's method, the attributes and characteristics of obesogenic environment were identified as it pertains to children. Based on the review of the literature and previous definitions applied to adults, a definition of the concept of obesogenic environment within a pediatric context was developed; examples of sample cases illustrate the concept further. Defining the concept of obesogenic environment has utility for nursing theory development, practice, research, and education. © 2013, Wiley Periodicals, Inc.
Evolution of Structural Empowerment: Moving From Shared to Professional Governance.
Clavelle, Joanne T; Porter O'Grady, Tim; Weston, Marla J; Verran, Joyce A
2016-06-01
The aim of this study is to describe the maturation of the concept of shared governance to professional governance as a framework for structural empowerment. An analysis of the literature and concept clarification of structural empowerment and shared governance demonstrate that the concept and attributes of shared governance have evolved toward professional governance. A comprehensive, deductive literature review and concept clarification of structural empowerment, shared governance, and related constructs was completed. The concept and practice of shared governance has matured to a concept of professional governance with the attributes of accountability, professional obligation, collateral relationships, and effective decision-making.
Iterating between lessons on concepts and procedures can improve mathematics knowledge.
Rittle-Johnson, Bethany; Koedinger, Kenneth
2009-09-01
Knowledge of concepts and procedures seems to develop in an iterative fashion, with increases in one type of knowledge leading to increases in the other type of knowledge. This suggests that iterating between lessons on concepts and procedures may improve learning. The purpose of the current study was to evaluate the instructional benefits of an iterative lesson sequence compared to a concepts-before-procedures sequence for students learning decimal place-value concepts and arithmetic procedures. In two classroom experiments, sixth-grade students from two schools participated (N=77 and 26). Students completed six decimal lessons on an intelligent-tutoring systems. In the iterative condition, lessons cycled between concept and procedure lessons. In the concepts-first condition, all concept lessons were presented before introducing the procedure lessons. In both experiments, students in the iterative condition gained more knowledge of arithmetic procedures, including ability to transfer the procedures to problems with novel features. Knowledge of concepts was fairly comparable across conditions. Finally, pre-test knowledge of one type predicted gains in knowledge of the other type across experiments. An iterative sequencing of lessons seems to facilitate learning and transfer, particularly of mathematical procedures. The findings support an iterative perspective for the development of knowledge of concepts and procedures.
Validation and structural analysis of the kinematics concept test
NASA Astrophysics Data System (ADS)
Lichtenberger, A.; Wagner, C.; Hofer, S. I.; Stern, E.; Vaterlaus, A.
2017-06-01
The kinematics concept test (KCT) is a multiple-choice test designed to evaluate students' conceptual understanding of kinematics at the high school level. The test comprises 49 multiple-choice items about velocity and acceleration, which are based on seven kinematic concepts and which make use of three different representations. In the first part of this article we describe the development and the validation process of the KCT. We applied the KCT to 338 Swiss high school students who attended traditional teaching in kinematics. We analyzed the response data to provide the psychometric properties of the test. In the second part we present the results of a structural analysis of the test. An exploratory factor analysis of 664 student answers finally uncovered the seven kinematics concepts as factors. However, the analysis revealed a hierarchical structure of concepts. At the higher level, mathematical concepts group together, and then split up into physics concepts at the lower level. Furthermore, students who seem to understand a concept in one representation have difficulties transferring the concept to similar problems in another representation. Both results have implications for teaching kinematics. First, teaching mathematical concepts beforehand might be beneficial for learning kinematics. Second, instructions have to be designed to teach students the change between different representations.
[An evolutionary analysis of the concept of self-care].
Mailhot, Tanya; Cossette, Sylvie; Alderson, Marie
2013-03-01
The nursing community seems to agree on the general meaning of "self-care" as a concept allowing the individual to take care of his health. Yet the terms self-care and other "self-concepts" are often used interchangeably. Since this concept is central to nursing, it appeared crucial to lead an effort to clarify and to deepen the understanding of its development within the field of nursing. The objective of this evolutionary concept analysis was to identify the state of precision or clarity of the concept in the available nursing literature. The identification of attributes, antecedents and consequences has highlighted the characteristics as it has been used by various authors and ultimately provides a basis for further research. After this analysis, it is possible to propose that the concept of self-care refers to an activity initiated, consciously and following learning, which is appropriate to the situation and focused on a goal. Furthermore, this concept is widely used in contexts of long-term illnesses and much less so in contexts of acute diseases. In conclusion, work remains to be done to better differentiate the concept of self-care from other self-concepts when used in situations where a third party is involved in the realization of self-care.
McMillan, Kimberly
2014-04-01
This paper aimed to explore the evolution of the concept of sustainability to facilitate further knowledge development in the discipline of nursing. The concept of 'sustainability' emerged in the 1950s as a result of the environmental movement. The concept has been adapted by the discipline of management and is increasingly discussed in the context of health care. The concept remains ambiguous in the discipline of nursing, resulting in a struggle to articulate the role of nursing in the sustainability movement. Rodgers evolutionary method of concept analysis was used. Literature was searched from 1987-2011, including English, peer reviewed texts in the databases CINAHL and ABI/INFORM global. Two book chapters and grey literature were also included. References were read and analysed according to antecedents, attributes, consequences, surrogate terms and related terms. Defining antecedents, attributes and consequences highlight the complexity and diversity of the concept. Attributes include: sustainability as a condition of change, as process, as outcome, as dependent of multiple stakeholders, and as social consciousness. 'Sustainability' is a fragile concept highly dependent on the processes and stakeholders involved in its fruition. There is a distinct difference in the level of concept clarity between the disciplines of management and nursing. The complexities associated with the concept of 'Sustainability' have led to its ambiguity. Nursing must, however, work to further clarify the concept to fully understand nursing's potential role in the sustainability movement. © 2013 John Wiley & Sons Ltd.
Banerjee, Konika; Haque, Omar S.; Spelke, Elizabeth S.
2013-01-01
Previous research with adults suggests that a catalog of minimally counterintuitive concepts, which underlies supernatural or religious concepts, may constitute a cognitive optimum, and is therefore cognitively encoded and culturally transmitted more successfully than either entirely intuitive concepts or maximally counterintuitive concepts. The current study examines whether children's concept recall similarly is sensitive to the degree of conceptual counterintuitiveness (operationalized as a concept's number of ontological domain violations) for items presented in the context of a fictional narrative. Seven-to-nine-year old children who listened to a story including both intuitive and counterintuitive concepts recalled the counterintuitive concepts containing one (Experiment 1) or two (Experiment 2) but not three (Experiment 3) violations of intuitive ontological expectations significantly more and in greater detail than the intuitive concepts, both immediately after hearing the story and one week later. We conclude that one or two violations of expectation may be a cognitive optimum for children: they are more inferentially rich and therefore more memorable, whereas three or more violations diminish memorability for target concepts. These results suggest that the cognitive bias for minimally counterintuitive ideas is present and active early in human development, near the start of formal religious instruction. This finding supports a growing literature suggesting that diverse, early- emerging, evolved psychological biases predispose humans to hold and perform religious beliefs and practices whose primary form and content is not derived from arbitrary custom or the social environment alone. PMID:23631765
How unique is continuity of care? A review of continuity and related concepts.
Uijen, Annemarie A; Schers, Henk J; Schellevis, François G; van den Bosch, Wil J H M
2012-06-01
The concept of 'continuity of care' has changed over time and seems to be entangled with other care concepts, for example coordination and integration of care. These concepts may overlap, and differences between them often remain unclear. In order to clarify the confusion of tongues and to identify core values of these patient-centred concepts, we provide a historical overview of continuity of care and four related concepts: coordination of care, integration of care, patient-centred care and case management. We identified and reviewed articles including a definition of one of these concepts by performing an extensive literature search in PubMed. In addition, we checked the definition of these concepts in the Oxford English Dictionary. Definitions of continuity, coordination, integration, patient-centred care and case management vary over time. These concepts show both great entanglement and also demonstrate differences. Three major common themes could be identified within these concepts: personal relationship between patient and care provider, communication between providers and cooperation between providers. Most definitions of the concepts are formulated from the patient's perspective. The identified themes appear to be core elements of care to patients. Thus, it may be valuable to develop an instrument to measure these three common themes universally. In the patient-centred medical home, such an instrument might turn out to be an important quality measure, which will enable researchers and policy makers to compare care settings and practices and to evaluate new care interventions from the patient perspective.
48 CFR 34.005-3 - Concept exploration contracts.
Code of Federal Regulations, 2010 CFR
2010-10-01
... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Concept exploration... SPECIAL CATEGORIES OF CONTRACTING MAJOR SYSTEM ACQUISITION General 34.005-3 Concept exploration contracts. Whenever practicable, contracts to be performed during the concept exploration phase shall be for...
Reconceptualization of African American Self-Concept.
ERIC Educational Resources Information Center
Braithwaite, Harold, Jr.; And Others
1994-01-01
Focuses on how African American students define self-concept, and whether there is a specific black self-concept. Questionnaires completed by 60 undergraduates at a historically black college provide insight into student self-esteem and support the existence of a specific black self-concept. (SLD)
Linear separability in superordinate natural language concepts.
Ruts, Wim; Storms, Gert; Hampton, James
2004-01-01
Two experiments are reported in which linear separability was investigated in superordinate natural language concept pairs (e.g., toiletry-sewing gear). Representations of the exemplars of semantically related concept pairs were derived in two to five dimensions using multidimensional scaling (MDS) of similarities based on possession of the concept features. Next, category membership, obtained from an exemplar generation study (in Experiment 1) and from a forced-choice classification task (in Experiment 2) was predicted from the coordinates of the MDS representation using log linear analysis. The results showed that all natural kind concept pairs were perfectly linearly separable, whereas artifact concept pairs showed several violations. Clear linear separability of natural language concept pairs is in line with independent cue models. The violations in the artifact pairs, however, yield clear evidence against the independent cue models.
The Utility of Concept Maps to Facilitate Higher-Level Learning in a Large Classroom Setting
Carr-Lopez, Sian M.; Vyas, Deepti; Patel, Rajul A.; Gnesa, Eric H.
2014-01-01
Objective. To describe the utility of concept mapping in a cardiovascular therapeutics course within a large classroom setting. Design. Students enrolled in a cardiovascular care therapeutics course completed concept maps for each major chronic cardiovascular condition. A grading rubric was used to facilitate peer-assessment of the concept map. Assessment. Students were administered a survey at the end of the course assessing their perceptions on the usefulness of the concept maps during the course and also during APPEs to assess utility beyond the course. Question item analyses were conducted on cumulative final examinations comparing student performance on concept-mapped topics compared to nonconcept-mapped topics. Conclusion. Concept maps help to facilitate meaningful learning within the course and the majority of students utilized them beyond the course. PMID:26056408
Sensor failure detection system. [for the F100 turbofan engine
NASA Technical Reports Server (NTRS)
Beattie, E. C.; Laprad, R. F.; Mcglone, M. E.; Rock, S. M.; Akhter, M. M.
1981-01-01
Advanced concepts for detecting, isolating, and accommodating sensor failures were studied to determine their applicability to the gas turbine control problem. Five concepts were formulated based upon such techniques as Kalman filters and a screening process led to the selection of one advanced concept for further evaluation. The selected advanced concept uses a Kalman filter to generate residuals, a weighted sum square residuals technique to detect soft failures, likelihood ratio testing of a bank of Kalman filters for isolation, and reconfiguring of the normal mode Kalman filter by eliminating the failed input to accommodate the failure. The advanced concept was compared to a baseline parameter synthesis technique. The advanced concept was shown to be a viable concept for detecting, isolating, and accommodating sensor failures for the gas turbine applications.
Health: A Developing Concept in Nursing.
Alslman, Eman Tariq; Ahmad, Muayyad M; Bani Hani, Manar Ali; Atiyeh, Huda Mohammad
2017-04-01
The purpose of this paper is to evaluate the level of maturity of the concept of health in the nursing discipline. The four principles of Morse and colleagues were used to evaluate the level of maturity of the health concept-epistemological, logical, pragmatical, and linguistical. This evaluation suggests that the concept of health in nursing is immature, defined inconsistently, and with different instruments. Health is a central concept for nursing. Additional concept development and clarification are needed. For the concept of health to be conceptualized, it is important that nurses have consensus regarding the definition of health. The nursing discipline should define health in a manner that is consistent with its philosophical presuppositions. Further, it should be measurable, empirically based, and capture the outcomes that are sensitive to the nursing interventions. © 2015 NANDA International, Inc.
The complex patient: A concept clarification.
Manning, Eli; Gagnon, Marilou
2017-03-01
Over the last decade, the concept of the "complex patient" has not only been more widely used in multidisciplinary healthcare teams and across various healthcare disciplines, but it has also become more vacuous in meaning. The uptake of the concept of the "complex patient" spans across disciplines, such as medicine, nursing, and social work, with no consistent definition. We review the chronological evolution of this concept and its surrogate terms, namely "comorbidity," "multimorbidity," "polypathology," "dual diagnosis," and "multiple chronic conditions." Drawing on key principles of concept clarification, we highlight disciplinary usage in the literature published between 2005 and 2015 in health sciences, attending to overlaps and revealing nuances of the complex patient concept. Finally, we discuss the implications of this concept for practice, research, and theory. © 2017 John Wiley & Sons Australia, Ltd.
Sociometric types and academic self-concept in adolescents.
Inglés, Cándido J; Aparisi, David; Delgado, Beatriz; Torregrosa, María S; García-Fernández, José M
2017-11-01
The aim of this study was to analyze the relationship between sociometric types, behavioral categories, and academic self-concept in a sample of 1,349 (51.7% boys) Spanish adolescents, ranging in age from 12 to 16 years. the students’ sociometric nomination was performed using the Programa Socio (Partner Program), and academic self-concept was measured with the Self Description Questionnaire (SDQ-II; Marsh, 1992). results show that academic self-concept was a significant predictor of sociometric types and behavioral categories, as students with high scores on academic self-concept were more likely to be positively rated by their peers (popular, leaders, collaborators and good students) than students with low scores on student academic self-concept. these results reinforce the emphasis on academic self-concept research and its relevance to educational practice.
Spanish semantic feature production norms for 400 concrete concepts.
Vivas, Jorge; Vivas, Leticia; Comesaña, Ana; Coni, Ana García; Vorano, Agostina
2017-06-01
Semantic feature production norms provide many quantitative measures of different feature and concept variables that are necessary to solve some debates surrounding the nature of the organization, both normal and pathological, of semantic memory. Despite the current existence of norms for different languages, there are still no published norms in Spanish. This article presents a new set of norms collected from 810 participants for 400 living and nonliving concepts among Spanish speakers. These norms consist of empirical collections of features that participants used to describe the concepts. Four files were elaborated: a concept-feature file, a concept-concept matrix, a feature-feature matrix, and a significantly correlated features file. We expect that these norms will be useful for researchers in the fields of experimental psychology, neuropsychology, and psycholinguistics.
Dugan, J M; Berrios, D C; Liu, X; Kim, D K; Kaizer, H; Fagan, L M
1999-01-01
Our group has built an information retrieval system based on a complex semantic markup of medical textbooks. We describe the construction of a set of web-based knowledge-acquisition tools that expedites the collection and maintenance of the concepts required for text markup and the search interface required for information retrieval from the marked text. In the text markup system, domain experts (DEs) identify sections of text that contain one or more elements from a finite set of concepts. End users can then query the text using a predefined set of questions, each of which identifies a subset of complementary concepts. The search process matches that subset of concepts to relevant points in the text. The current process requires that the DE invest significant time to generate the required concepts and questions. We propose a new system--called ACQUIRE (Acquisition of Concepts and Queries in an Integrated Retrieval Environment)--that assists a DE in two essential tasks in the text-markup process. First, it helps her to develop, edit, and maintain the concept model: the set of concepts with which she marks the text. Second, ACQUIRE helps her to develop a query model: the set of specific questions that end users can later use to search the marked text. The DE incorporates concepts from the concept model when she creates the questions in the query model. The major benefit of the ACQUIRE system is a reduction in the time and effort required for the text-markup process. We compared the process of concept- and query-model creation using ACQUIRE to the process used in previous work by rebuilding two existing models that we previously constructed manually. We observed a significant decrease in the time required to build and maintain the concept and query models.
NASA Astrophysics Data System (ADS)
Yalçınkaya, Eylem; Taştan-Kırık, Özgecan; Boz, Yezdan; Yıldıran, Demet
2012-07-01
Background: Case-based learning (CBL) is simply teaching the concept to the students based on the cases. CBL involves a case, which is a scenario based on daily life, and study questions related to the case, which allows students to discuss their ideas. Chemical kinetics is one of the most difficult concepts for students in chemistry. Students have generally low levels of conceptual understanding and many alternative conceptions regarding it. Purpose: This study aimed to explore the effect of CBL on dealing with students' alternative conceptions about chemical kinetics. Sample: The sample consists of 53 high school students from one public high school in Turkey. Design and methods : Nonequivalent pre-test and post-test control group design was used. Reaction Rate Concept Test and semi-structured interviews were used for data collection. Convenience sampling technique was followed. For data analysis, the independent samples t-test and ANOVA was performed. Results : Both concept test and interview results showed that students instructed with cases had better understanding of core concepts of chemical kinetics and had less alternative conceptions related to the subject matter compared to the control group students, despite the fact that it was impossible to challenge all the alternative conceptions in the experimental group. Conclusions: CBL is an effective teaching method for challenging students' alternative conceptions in the context of chemical kinetics. Since using cases in small groups and whole class discussions has been found to be an effective way to cope with the alternative conceptions, it can be applied to other subjects and grade levels in high schools with a higher sample size. Furthermore, the effect of this method on academic achievement, motivation and critical thinking skills are other variables that can be investigated for future studies in the subject area of chemistry.
The Recruitment of Shifting and Inhibition in On-line Science and Mathematics Tasks.
Vosniadou, Stella; Pnevmatikos, Dimitrios; Makris, Nikos; Lepenioti, Despina; Eikospentaki, Kalliopi; Chountala, Anna; Kyrianakis, Giorgos
2018-06-13
Prior research has investigated the recruitment of inhibition in the use of science/mathematics concepts in tasks that require the rejection of a conflicting, nonscientific initial concept. The present research examines if inhibition is the only EF skill recruited in such tasks and investigates whether shifting is also involved. It also investigates whether inhibition and/or shifting are recruited in tasks in which the use of science/mathematics concepts does not require the rejection of an initial concept, or which require only the use of initial concepts. One hundred and thirty-three third- and fifth-grade children participated in two inhibition and shifting tasks and two science and mathematics conceptual understanding and conceptual change (CU&C) tasks. All the tasks were on-line, and performance was measured in accuracy and RTs. The CU&C tasks involved the use of initial concepts and of science/mathematics concepts which required conceptual changes for their initial formation. Only in one of the tasks the use of the science/mathematics concepts required the concurrent rejection of an initial concept. The results confirmed that in this task inhibition was recruited and also showed that the speed of shifting was a significant predictor of performance. Shifting was a significant predictor of performance in all the tasks, regardless of whether they involved science/mathematics or initial concepts. It is argued that shifting is likely to be recruited in complex tasks that require multiple comparisons of stimuli and the entertainment of different perspectives. Inhibition seems to be a more selective cognitive skill likely to be recruited when the use of science/mathematics concepts requires the rejection of a conflicting initial concept. © 2018 Cognitive Science Society, Inc.
Behavioral self-concept as predictor of teen drinking behaviors.
Dudovitz, Rebecca N; Li, Ning; Chung, Paul J
2013-01-01
Adolescence is a critical developmental period for self-concept (role identity). Cross-sectional studies link self-concept's behavioral conduct domain (whether teens perceive themselves as delinquent) with adolescent substance use. If self-concept actually drives substance use, then it may be an important target for intervention. In this study, we used longitudinal data from 1 school year to examine whether behavioral self-concept predicts teen drinking behaviors or vice versa. A total of 291 students from a large, predominantly Latino public high school completed a confidential computerized survey in the fall and spring of their 9th grade year. Survey measures included the frequency of alcohol use, binge drinking and at-school alcohol use in the previous 30 days; and the Harter Self-Perception Profile for Adolescents behavioral conduct subscale. Multiple regressions were performed to test whether fall self-concept predicted the frequency and type of spring drinking behavior, and whether the frequency and type of fall drinking predicted spring self-concept. Fall behavioral self-concept predicted both the frequency and type of spring drinking. Students with low versus high fall self-concept had a predicted probability of 31% versus 20% for any drinking, 20% versus 8% for binge drinking and 14% versus 4% for at-school drinking in the spring. However, neither the frequency nor the type of fall drinking significantly predicted spring self-concept. Low behavioral self-concept may precede or perhaps even drive adolescent drinking. If these results are confirmed, then prevention efforts might be enhanced by targeting high-risk teens for interventions that help develop a healthy behavioral self-concept. Copyright © 2013 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.
Integrated Composite Stiffener Structure (ICoSS) Concept for Planetary Entry Vehicles
NASA Technical Reports Server (NTRS)
Kellas, Sotiris
2016-01-01
Results from the design, manufacturing, and testing of a lightweight Integrated Composite Stiffened Structure (ICoSS) concept, intended for multi-mission planetary entry vehicles are presented. Tests from both component and full-scale tests for a typical Earth Entry Vehicle forward shell manufactured using the ICoSS concept are presented and advantages of the concept for the particular application of passive Earth Entry Vehicles over other structural concepts are discussed.
ERIC Educational Resources Information Center
Flodin, Veronica S.
2009-01-01
The purpose of this study is to analyze variations in how the gene concept is used and conceived in different sub-disciplines in biology. An examination of the development of subject matter and the use of the gene concept in a common college biology textbook shows that the gene concept is far from presented in a consistent way. The study describes…
Miura, Hiroshi; Kotani, Satoko; Kohiruimaki, Masayuki; Ohtsuka, Hiromichi; Kikuchi, Motohiro; Ohnami, Yoji
2008-06-01
The purpose of this study was to determine the relationships between conception rate and other parameters before estrus synchronization with a Controlled Internal Drug Release Device (CIDR) and estradiol benzoate (EB). In the estrus synchronization program, animals were injected with 2 mg EB and then received a CIDR. Seven days later, the CIDR was removed and the animals were given an injection of Prostaglandin F(2alpha). Twenty-four hours later, they received an injection of 1 mg EB, and they were artificially inseminated 24 h after that. This program was applied to 258 Holstein cows in Tohoku-machi (Aomori, Japan). Blood was collected at the beginning of the program, and the conception rate was determined about 40 days after insemination. The relationships among conception rate, blood biochemical values, age, body condition score and days in milk were statistically analyzed to determine better conditions for cow conception. The conception rate of the cows in the high progesterone group (more than 1 ng/ml, P(4)+) was significantly higher than that of the low progesterone group (less than 1 ng/ml, P(4)-; 47.9% vs. 28.6% P<0.01). In the P(4)- groups, the serum phospholipid level was significantly higher in the conception group than in the non-conception group, and the same tendency was seen in the P(4)+ groups. Blood urea nitrogen (BUN), albumin (Alb), and total cholesterol (TChol) were significantly higher in the conception group compared with the non-conception group, but no with P(4) was observed. We concluded that 1) the conception rate of the P(4)- group was remarkably low, that 2) the low conception rate and low P(4) level was related to a low PL level and that 3) BUN, Alb and TChol were higher in the conception group, although no relation with P(4) was found.
Gray, R H; Simpson, J L; Kambic, R T; Queenan, J T; Mena, P; Perez, A; Barbato, M
1995-05-01
Our purpose was to ascertain the effects of timing of conception on the risk of spontaneous abortion. To assess these effects, women who conceived while using natural family planning were identified in five centers worldwide between 1987 and 1993. Timing of conception was determined from 868 natural family planning charts that recorded day of intercourse and indices of ovulation (cervical mucus peak obtained according to the ovulation method and/or basal body temperature). Conceptions on days - 1 or 0 with respect to the natural family planning estimated day of ovulation were considered to be "optimally timed," and all other conceptions were considered as "non-optimally timed." The rate of spontaneous abortions per 100 pregnancies was examined in relation to timing of conception, ages, reproductive history, and other covariates with bivariate and multivariate statistical methods. There were 88 spontaneous abortions among 868 pregnancies (10.1%). The spontaneous abortion rate was similar for 361 optimally timed conceptions (9.1%) and 507 non-optimally timed conceptions (10.9%). However, among 171 women who had experienced a spontaneous abortion in a prior pregnancy, the rate of spontaneous abortion in the index pregnancy was significantly higher with non-optimally timed conceptions (22.6%) as compared with optimally timed conceptions (7.3%). This association was not observed among 697 women with no history of pregnancy loss. The adjusted relative risk of spontaneous abortion among women with non-optimally timed conceptions and a history of pregnancy loss was 2.35 (95% confidence intervals 1.42 to 3.89). The excess risk of spontaneous abortion was observed with both preovulatory and postovulatory conceptions. Overall, there is no excess risk of spontaneous abortion among the pregnancies conceived during natural family planning use. However, among women with a history of pregnancy loss, there is an increased risk of spontaneous abortion associated with preovulatory or postovulatory delayed conceptions.
Using Concept Maps to Monitor Knowledge Structure Changes in a Science Classroom
NASA Astrophysics Data System (ADS)
Cook, Leah J.
The aim of this research is to determine what differences may exist in students' structural knowledge while using a variety of concept mapping assessments. A concept map can be used as an assessment which connects concepts in a knowledge domain. A single assessment may not be powerful enough to establish how students' new knowledge relates to prior knowledge. More research is needed to establish how various aspects of the concept mapping task influence the output of map creation by students. Using multiple concept maps and pre-instruction and post-instruction VNOS instruments during a 16-week semester, this study was designed to investigate the impact of concept map training and the impact of assessment design on the created maps. Also, this study was designed to determine what differences can be observed between expert and novice maps and if similarities and differences exist between concept maps and an open-ended assessment. Participants created individual maps and the maps were analyzed for structural complexity, overall structure, and content. The concept maps were then compared by their timing, design, and scores. The results indicate that concept mapping training does significantly impact the shape and structure complexity of the map created by students. Additionally, these data support that students should be frequently reminded of appropriate concept mapping skills and opportunities so that good mapping skills will be utilized. Changing the assessment design does appear to be able to impact the overall structure and complexity of created maps, while narrowing the content focus of the map does not necessarily restrict the overall structure or the complexity. Furthermore, significant differences in structural complexity were observed between novice and expert mappers. The fluctuations of NOS concepts identified in student created maps may suggest why some students were still confused or had incorrect conceptions of NOS, despite explicit and reflective instruction throughout the semester.
Auditing complex concepts of SNOMED using a refined hierarchical abstraction network.
Wang, Yue; Halper, Michael; Wei, Duo; Gu, Huanying; Perl, Yehoshua; Xu, Junchuan; Elhanan, Gai; Chen, Yan; Spackman, Kent A; Case, James T; Hripcsak, George
2012-02-01
Auditors of a large terminology, such as SNOMED CT, face a daunting challenge. To aid them in their efforts, it is essential to devise techniques that can automatically identify concepts warranting special attention. "Complex" concepts, which by their very nature are more difficult to model, fall neatly into this category. A special kind of grouping, called a partial-area, is utilized in the characterization of complex concepts. In particular, the complex concepts that are the focus of this work are those appearing in intersections of multiple partial-areas and are thus referred to as overlapping concepts. In a companion paper, an automatic methodology for identifying and partitioning the entire collection of overlapping concepts into disjoint, singly-rooted groups, that are more manageable to work with and comprehend, has been presented. The partitioning methodology formed the foundation for the development of an abstraction network for the overlapping concepts called a disjoint partial-area taxonomy. This new disjoint partial-area taxonomy offers a collection of semantically uniform partial-areas and is exploited herein as the basis for a novel auditing methodology. The review of the overlapping concepts is done in a top-down order within semantically uniform groups. These groups are themselves reviewed in a top-down order, which proceeds from the less complex to the more complex overlapping concepts. The results of applying the methodology to SNOMED's Specimen hierarchy are presented. Hypotheses regarding error ratios for overlapping concepts and between different kinds of overlapping concepts are formulated. Two phases of auditing the Specimen hierarchy for two releases of SNOMED are reported on. With the use of the double bootstrap and Fisher's exact test (two-tailed), the auditing of concepts and especially roots of overlapping partial-areas is shown to yield a statistically significant higher proportion of errors. Copyright © 2011 Elsevier Inc. All rights reserved.
Auditing Complex Concepts of SNOMED using a Refined Hierarchical Abstraction Network
Wang, Yue; Halper, Michael; Wei, Duo; Gu, Huanying; Perl, Yehoshua; Xu, Junchuan; Elhanan, Gai; Chen, Yan; Spackman, Kent A.; Case, James T.; Hripcsak, George
2012-01-01
Auditors of a large terminology, such as SNOMED CT, face a daunting challenge. To aid them in their efforts, it is essential to devise techniques that can automatically identify concepts warranting special attention. “Complex” concepts, which by their very nature are more difficult to model, fall neatly into this category. A special kind of grouping, called a partial-area, is utilized in the characterization of complex concepts. In particular, the complex concepts that are the focus of this work are those appearing in intersections of multiple partial-areas and are thus referred to as overlapping concepts. In a companion paper, an automatic methodology for identifying and partitioning the entire collection of overlapping concepts into disjoint, singly-rooted groups, that are more manageable to work with and comprehend, has been presented. The partitioning methodology formed the foundation for the development of an abstraction network for the overlapping concepts called a disjoint partial-area taxonomy. This new disjoint partial-area taxonomy offers a collection of semantically uniform partial-areas and is exploited herein as the basis for a novel auditing methodology. The review of the overlapping concepts is done in a top-down order within semantically uniform groups. These groups are themselves reviewed in a top-down order, which proceeds from the less complex to the more complex overlapping concepts. The results of applying the methodology to SNOMED’s Specimen hierarchy are presented. Hypotheses regarding error ratios for overlapping concepts and between different kinds of overlapping concepts are formulated. Two phases of auditing the Specimen hierarchy for two releases of SNOMED are reported on. With the use of the double bootstrap and Fisher’s exact test (two-tailed), the auditing of concepts and especially roots of overlapping partial-areas is shown to yield a statistically significant higher proportion of errors. PMID:21907827
Critique of the Schema Concept.
ERIC Educational Resources Information Center
Dahlin, Bo
2001-01-01
Discusses the concept of schema and the role this concept plays in educational practice. Traces the historical development of the concept and how it came to be taken for granted that schemata exist. Suggests a return to a more phenomenological approach to learning and knowledge formation. (SLD)
Children's Developing Conceptions of the Mind and Brain.
ERIC Educational Resources Information Center
Johnson, Carl Nils; Wellman, Henry M.
1982-01-01
The development of concepts of both the mind and brain is examined in subjects from preschool age through adulthood. While young children begin with undifferentiated conceptions of the mind and brain, in subsequent developments these concepts are differentiated along ontological and functional lines. (Author/RH)
Children's Self-Concepts as Related to Family Structure and Family Concept.
ERIC Educational Resources Information Center
Parish, Joycelyn G.; Parish, Thomas S.
1983-01-01
Surveyed 426 children from intact, divorced, and reconstituted families, who responded to the Personal Attribute Inventory for Children to evaluate their families and themselves. Results showed a significant association between children's self-concepts and both their family structure and family concepts. (JAC)
ERIC Educational Resources Information Center
Su, Yucheng
2010-01-01
There are many ways to improve students' understanding of physics concepts. This article focused on drawing students' attention with picture-embedded questions. Pictures give students a direct impression or feeling about the corresponding concepts, which really makes a difference. However, the effects are limited. Some physics concepts are…
Threshold Concepts in Biochemistry
ERIC Educational Resources Information Center
Loertscher, Jennifer
2011-01-01
Threshold concepts can be identified for any discipline and provide a framework for linking student learning to curricular design. Threshold concepts represent a transformed understanding of a discipline, without which the learner cannot progress and are therefore pivotal in learning in a discipline. Although threshold concepts have been…
Possible Concepts for Waterproofing of Norwegian TBM Railway Tunnels
NASA Astrophysics Data System (ADS)
Dammyr, Øyvind; Nilsen, Bjørn; Thuro, Kurosch; Grøndal, Jørn
2014-05-01
The aim of this paper is to evaluate and compare the durability, life expectancy and maintenance needs of traditional Norwegian waterproofing concepts to the generally more rigid waterproofing concepts seen in other European countries. The focus will be on solutions for future Norwegian tunnel boring machine railway tunnels. Experiences from operation of newer and older tunnels with different waterproofing concepts have been gathered and analyzed. In the light of functional requirements for Norwegian rail tunnels, some preliminary conclusions about suitable concepts are drawn. Norwegian concepts such as polyethylene panels and lightweight concrete segments with membrane are ruled out. European concepts involving double shell draining systems (inner shell of cast concrete with membrane) and single shell undrained systems (waterproof concrete segments) are generally evaluated as favorable. Sprayable membranes and waterproof/insulating shotcrete are welcomed innovations, but more research is needed to verify their reliability and cost effectiveness compared to the typical European concepts. Increasing traffic and reliance on public transport systems in Norway result in high demand for durable and cost effective solutions.
Professional Values Competency Evaluation for Students Enrolled in a Concept-Based Curriculum.
Elliott, Annette M
2017-01-01
Although many nursing programs have transitioned toward the use of concept-based curricula, the evaluation of student learning associated with the curricular approach has been limited. An evaluation of student learning related to professional values for programs offering concept-based curricula was not evident in the literature. The purpose was to determine how a course competency related to professional values was addressed by nursing students studying in a concept-based nursing curriculum. The qualitative methodology of framework analysis was used to evaluate written assignments (N = 75). The core concept appreciation for professional values and the core concept disillusionment with unprofessional behaviors were identified in students' written reflections. The core concept of appreciation for professional values contributes to an evidence base of contemporary professional values identified in nursing. The core concept of disillusionment with unprofessional behaviors can inform curricular planning and research on how to advocate for professional behaviors. [J Nurs Educ. 2017;56(1):12-21.]. Copyright 2017, SLACK Incorporated.
NASA Astrophysics Data System (ADS)
Nugroho, O. F.; Chandra, D. T.; Sanjaya, Y.; Pendidikan Indonesia, Universitas
2017-02-01
The purpose of this study was to improve students’ concept comprehension using concept map as a consolidation phase based STAD. This study was conducted by randomized control group pretest-posttest. Data was collected by using an instrument test to evaluate the effect of concept map as a consolidation phase based STAD on students’understanding about environmental pollution. Data was analyzed using normalized gain (n-gain) and independent t-test. The n-gain analysis shows the increased of students’s understanding about environmental pollution at experimental group arehigher than at the control group. The result of this study showed that students’ comprehension at the experimental class (0,53) higher compared to the control group (0,23). Whilst the t-test analysis shows that there is a significant effect of mapping concept as a consolidation phase based STAD towards students’ concept comprehension. It can be concluded that the implementation of mapping concept based STAD may improve the students’s understanding on science concept.
The method of abstraction in the design of databases and the interoperability
NASA Astrophysics Data System (ADS)
Yakovlev, Nikolay
2018-03-01
When designing the database structure oriented to the contents of indicators presented in the documents and communications subject area. First, the method of abstraction is applied by expansion of the indices of new, artificially constructed abstract concepts. The use of abstract concepts allows to avoid registration of relations many-to-many. For this reason, when built using abstract concepts, demonstrate greater stability in the processes. The example abstract concepts to address structure - a unique house number. Second, the method of abstraction can be used in the transformation of concepts by omitting some attributes that are unnecessary for solving certain classes of problems. Data processing associated with the amended concepts is more simple without losing the possibility of solving the considered classes of problems. For example, the concept "street" loses the binding to the land. The content of the modified concept of "street" are only the relations of the houses to the declared name. For most accounting tasks and ensure communication is enough.
Self-esteem, academic self-concept, and aggression at school.
Taylor, Laramie D; Davis-Kean, Pamela; Malanchuk, Oksana
2007-01-01
The present study explores the relation between academic self-concept, self-esteem, and aggression at school. Longitudinal data from a racially diverse sample of middle-school students were analyzed to explore how academic self-concept influenced the likelihood of aggressing at school and whether high self-concept exerted a different pattern of influence when threatened. Data include self-reported academic self-concept, school-reported academic performance, and parent-reported school discipline. Results suggest that, in general, students with low self-concept in achievement domains are more likely to aggress at school than those with high self-concept. However, there is a small sample of youth who, when they receive contradictory information that threatens their reported self-concept, do aggress. Global self-esteem was not found to be predictive of aggression. These results are discussed in the context of recent debates on whether self-esteem is a predictor of aggression and the use of a more proximal vs. general self-measure in examining the self-esteem and aggression relation. Copyright 2006 Wiley-Liss; Inc.
Health Seeking in Men: A Concept Analysis.
Hooper, Gwendolyn L; Quallich, Susanne A
2016-01-01
This article describes the analysis of the concept of health seeking in men. Men have shorter life expectancies and utilize health services less often than women, leading to poor health outcomes, but a gendered basis for health seeking remains poorly defined. Walker and Avant’s framework was used to guide this concept analysis. Literature published in English from 1990-2015 was reviewed. Thematic analysis identified attributes, antecedents, and consequences of the concept. Based on the analysis, a contemporary definition for health seeking in men was constructed, rooted in the concept of health. The definition is based on the concept analysis and the defining attributes that were identified. This analysis provides a definition specifically for health seeking in American men, making it more specific and gender-based than the parent concept of “health.” This concept analysis provides conceptual clarity that can guide development of a conceptual framework that may be uniquely relevant to providers in urology. Further exploration will uncover specific cultural, social, sexual, and geographic perspectives.
Color associations among designers and non-designers for common warning and operation concepts.
Ng, Annie W Y; Chan, Alan H S
2018-07-01
This study examined color-concept associations among designers and non-designers with commonly used warning and operation concepts. This study required 199 designers and 175 non-designers to indicate their choice among nine colors to associate with each of the 38 concepts in a color-concept table. The results showed that the designers and non-designers had the same color associations and similar strengths of stereotypes for 17 concepts. The strongest color-concept stereotypes for both groups were red-danger, red-fire, and red-hot. However, the designers and non-designers had different color associations for the concepts of escape (green, red), increase (green, red), potential hazard (red, orange), fatal (black, red), and normal (white, green), while the strengths of the 16 remaining associations for both groups were not at equivalent levels. These findings provide ergonomists and design practitioners with a better understanding of population stereotypes for color coding, and consequently to effectively use colors in their user-centered designs. Copyright © 2018 Elsevier Ltd. All rights reserved.
Cancer-Related Psychological Distress: A Concept Analysis.
Gundelach, Amy; Henry, Barb
2016-12-01
Cancer-related psychological distress, as a concept, has limited research literature substantiation. Several studies report that patients with cancer suffer from significant psychological distress; however, the description of the concept of cancer-related psychological distress has not been clearly described. Theoretical work based on the concept is also unclear. This article is a report on the concept of cancer-related psychological distress to clarify the concept as separate from non-cancer-related psychological distress and promote the use of the term in nursing practice and research across the cancer trajectory. This article used a content analysis to examine the literature. The literature review for this article used CINAHL®, PsycINFO®, and PubMed to search publications from 1999-2016. Content analysis of the literature revealed that the term psychological distress was used often with regard to distress in patients with cancer, but the concept of cancer-related psychological distress was not clearly defined. Four attributes encompass the concept of cancer-related psychological distress.
NASA Astrophysics Data System (ADS)
Samsudin, A.; Suhandi, A.; Rusdiana, D.; Kaniawati, I.
2016-08-01
Interactive Conceptual Instruction (ICI) based Multimedia has been developed to represent the electric concepts turn into more real and meaningful learning. The initial design of ICI based multimedia is a multimedia computer that allows users to explore the entire electric concepts in terms of the existing conceptual and practical. Pre-service physics teachers should be provided with the learning that could optimize the conceptions held by re-conceptualizing concepts in Basic Physics II, especially the concepts about electricity. To collect and to analyze the data genuinely and comprehensively, researchers utilized a developing method of ADDIE which has comprehensive steps: analyzing, design, development, implementation, and evaluation. The ADDIE developing steps has been utilized to describe comprehensively from the phase of analysis program up until the evaluation program. Based on data analysis, it can be concluded that ICI-based multimedia could effectively increase the pre-service physics teachers’ understanding on electric conceptions for re-conceptualizing electric conceptions at Universitas Pendidikan Indonesia.
Self-concept clarity and religious orientations: prediction of purpose in life and self-esteem.
Błażek, Magdalena; Besta, Tomasz
2012-09-01
The present study concerns the relationship between self-concept clarity, religiosity, and well-being, as well as the mediating influence of religiosity on the relationship between self-concept clarity and sense of meaning in life and self-esteem. Self-concept clarity was found to be a significant predictor of sense of meaning in life and self-esteem; intrinsic religious orientation was found to be a predictor of sense of meaning in life, while the quest religious orientation was a predictor for self-esteem. The cross-products of self-concept clarity and intrinsic religious orientation were found to be related to the sense of purpose in life, which would point to religiosity being a mediator of the relationship between self-concept clarity and sense of purpose in life. The cross-products of self-concept clarity and quest religious orientation were found to be a predictor of self-esteem, which indicates a mediating effect of this religious orientation in the relationship of self-concept clarity and self-esteem.
Braking and cornering studies on an air cushion landing system
NASA Technical Reports Server (NTRS)
Daugherty, R. H.
1983-01-01
An experimental investigation was conducted to evaluate several concepts for braking and steering a vehicle equipped with an air cushion landing system (ACLS). The investigation made use of a modified airboat equipped with an ACLS. Braking concepts were characterized by the average deceleration of the vehicle. Reduced lobe flow and cavity venting braking concepts were evaluated in this program. The cavity venting braking concept demonstrated the best performance, producing decelerations on the test vehicle on the same order as moderate braking with conventional wheel brakes. Steering concepts were evaluated by recording the path taken while attempting to follow a prescribed maneuver. The steering concepts evaluated included using rudders only, using differential lobe flow, and using rudders combined with a lightly loaded, nonsteering center wheel. The latter concept proved to be the most accurate means of steering the vehicle on the ACLS, producing translational deviations two to three times higher than those from conventional nose-gear steering. However, this concept was still felt to provide reasonably precise steering control for the ACLS-equipped vehicle.
NASA Technical Reports Server (NTRS)
Jones, Denise R.; Parrish, Russell V.
1990-01-01
A piloted simulation study was conducted comparing three different input methods for interfacing to a large screen, multiwindow, whole flight deck display for management of transport aircraft systems. The thumball concept utilized a miniature trackball embedded in a conventional side arm controller. The multifunction control throttle and stick (MCTAS) concept employed a thumb switch located in the throttle handle. The touch screen concept provided data entry through a capacitive touch screen installed on the display surface. The objective and subjective results obtained indicate that, with present implementations, the thumball concept was the most appropriate for interfacing with aircraft systems/subsystems presented on a large screen display. Not unexpectedly, the completion time differences between the three concepts varied with the task being performed, although the thumball implementation consistently outperformed the other two concepts. However, pilot suggestions for improved implementations of the MCTAS and touch screen concepts could reduce some of these differences.
Verschueren, Karine; Doumen, Sarah; Buyse, Evelien
2012-01-01
This study tested the unique and joint effects of three significant relationships in young children's social lives, namely their relationships with mother, teacher, and peers, on three dimensions of self-concept (general, academic, and social). A sample of 113 children participated. Mother-child attachment quality was observed in preschool. In first grade, teacher ratings of teacher-child relationship quality, peer ratings of peer acceptance, and child reports of self-concept were administered. The results revealed domain-specific links between social relationships and self-concept dimensions. Specifically, academic self-concept related to teacher-child relationship quality, social self-concept to peer acceptance, and general self-concept to the quality of attachment to mother. Moreover, an indirect effect was revealed of earlier mother-child attachment quality on the academic dimension of self through its effect on current adult-child relationships in school. This way, the study uncovered the pathways through which significant social relationships shape the formation of young children's self-concept.
NASA Astrophysics Data System (ADS)
de Freitas, Elizabeth; Palmer, Anna
2016-12-01
The aim of this article is to investigate how new materialist philosophies of matter can help us study the emergence of scientific thought in young children's activities. We draw extensively on the work of Gilles Deleuze to help us understand scientific concepts as concrete universals. In particular, we show how the concept of force is re-animated through this approach, becoming less deterministic, and more inflected with chance and indeterminism. We show how this approach to concepts moves beyond constructivist socio-cultural theories of learning, and reveals how concepts are `material articulations of the world' intra-acting with all other matter and meaning. Finally, we discuss video data and artifacts from an ongoing ethnographic project in Stockholm entitled `Children's relations to the city'. Our analysis of the classroom video data from this project shows how concepts are not timeless transcendent abstractions, but part of an unfolding event and learning assemblage. Thus the article contributes to research on conceptual change in children, with particular focus on scientific concepts.
Seidel, Bastian M; Campbell, Steven; Bell, Erica
2015-03-21
Better understanding of clinical reasoning could reduce diagnostic error linked to 8% of adverse medical events and 30% of malpractice cases. To a greater extent than the evidence-based movement, the clinical reasoning literature asserts the importance of practitioner intuition—unconscious elements of diagnostic reasoning. The study aimed to analyse the content of case report summaries in ways that explored the importance of an evidence concept, not only in relation to research literature but also intuition. The study sample comprised all 789,712 abstracts in English for case reports contained in the database PUBMED for the period 1 January 1983 to 31 December 2012. It was hypothesised that, if evidence and intuition concepts were viewed by these clinical authors as essential to understanding their case reports, they would be more likely to be found in the abstracts. Computational linguistics software was used in 1) concept mapping of 21,631,481 instances of 201 concepts, and 2) specific concept analyses examining 200 paired co-occurrences for 'evidence' and research 'literature' concepts. 'Evidence' is a fundamentally patient-centred, intuitive concept linked to less common concepts about underlying processes, suspected disease mechanisms and diagnostic hunches. In contrast, the use of research literature in clinical reasoning is linked to more common reasoning concepts about specific knowledge and descriptions or presenting features of cases. 'Literature' is by far the most dominant concept, increasing in relevance since 2003, with an overall relevance of 13% versus 5% for 'evidence' which has remained static. The fact that the least present types of reasoning concepts relate to diagnostic hunches to do with underlying processes, such as what is suspected, raises questions about whether intuitive practitioner evidence-making, found in a constellation of dynamic, process concepts, has become less important. The study adds support to the existing corpus of research on clinical reasoning, by suggesting that intuition involves a complex constellation of concepts important to how the construct of evidence is understood. The list of concepts the study generated offers a basis for reflection on the nature of evidence in diagnostic reasoning and the importance of intuition to that reasoning.
A qualitative study on using concept maps in problem-based learning.
Chan, Zenobia C Y
2017-05-01
The visual arts, including concept maps, have been shown to be effective tools for facilitating student learning. However, the use of concept maps in nursing education has been under-explored. The aim of this study was to explore how students develop concept maps and what these concept maps consist of, and their views on the use of concept maps as a learning activity in a PBL class. A qualitative approach consisting of an analysis of the contents of the concept maps and interviews with students. The study was conducted in a school of nursing in a university in Hong Kong. A total of 38 students who attended the morning session (20 students) and afternoon session (18 students) respectively of a nursing problem-based learning class. The students in both the morning and afternoon classes were allocated into four groups (4-5 students per group). Each group was asked to draw two concept maps based on a given scenario, and then to participate in a follow-up interview. Two raters individually assessed the concept maps, and then discussed their views with each other. Among the concept maps that were drawn, four were selected. Their four core features of those maps were: a) the integration of informative and artistic elements; b) the delivery of sensational messages; c) the use of images rather than words; and d) three-dimensional and movable. Both raters were concerned about how informative the presentation was, the composition of the elements, and the ease of comprehension, and appreciated the three-dimensional presentation and effective use of images. From the results of the interview, the pros and cons of using concept maps were discerned. This study demonstrated how concept maps could be implemented in a PBL class to boost the students' creativity and to motivate them to learn. This study suggests the use of concept maps as an initiative to motivate student to learn, participate actively, and nurture their creativity. To conclude, this study explored an alternative way for students to make presentations and pioneered the use of art-based concept maps to facilitate student learning. Copyright © 2017 Elsevier Ltd. All rights reserved.
Verifying visual properties in sentence verification facilitates picture recognition memory.
Pecher, Diane; Zanolie, Kiki; Zeelenberg, René
2007-01-01
According to the perceptual symbols theory (Barsalou, 1999), sensorimotor simulations underlie the representation of concepts. We investigated whether recognition memory for pictures of concepts was facilitated by earlier representation of visual properties of those concepts. During study, concept names (e.g., apple) were presented in a property verification task with a visual property (e.g., shiny) or with a nonvisual property (e.g., tart). Delayed picture recognition memory was better if the concept name had been presented with a visual property than if it had been presented with a nonvisual property. These results indicate that modality-specific simulations are used for concept representation.
Concepts for a Space-Based Gravitational-Wave Observatory (SGO)
NASA Technical Reports Server (NTRS)
Stebbins, Robin T.
2012-01-01
The low-frequency band (0.0001 - 1 Hz) of the gravitational wave spectrum has the most interesting astrophysical sources. It is only accessible from space. The Laser Interferometer Space Antenna (LISA) concept has been the leading contender for a space-based detector in this band. Despite a strong recommendation from Astro2010, constrained budgets motivate the search for a less expensive concept, even at the loss of some science. We have explored the range of lower cost mission concepts derived from two decades of studying the LISA concept We describe LlSA-like concepts that span the range of affordable and scientifically worthwhile missions, and summarize the analyses behind them.
Decision making by superimposing information from parallel cognitive channels
NASA Astrophysics Data System (ADS)
Aityan, Sergey K.
1993-08-01
A theory of decision making with perception through parallel information channels is presented. Decision making is considered a parallel competitive process. Every channel can provide confirmation or rejection of a decision concept. Different channels provide different impact on the specific concepts caused by the goals and individual cognitive features. All concepts are divided into semantic clusters due to the goals and the system defaults. The clusters can be alternative or complimentary. The 'winner-take-all' concept nodes firing takes place within the alternative cluster. Concepts can be independently activated in the complimentary cluster. A cognitive channel affects a decision concept by sending an activating or inhibitory signal. The complimentary clusters serve for building up complex concepts by superimposing activation received from various channels. The decision making is provided by the alternative clusters. Every active concept in the alternative cluster tends to suppress the competitive concepts in the cluster by sending inhibitory signals to the other nodes of the cluster. The model accounts for a time delay in signal transmission between the nodes and explains decreasing of the reaction time if information is confirmed by different channels and increasing of the reaction time if deceiving information received from the channels.
Clinical Correlates and Mediators of Self-Concept in Youth with Chronic Tic Disorders.
Hanks, Camille E; McGuire, Joseph F; Lewin, Adam B; Storch, Eric A; Murphy, Tanya K
2016-02-01
This study investigated the clinical correlates and mediators of self-concept in youth with Chronic Tic Disorders (CTD). Ninety-seven youth aged 6-17 (M = 11.1 ± 2.89; 79.4 % male) with CTD were administered the Yale Global Tic Severity Scale, the Piers-Harris Children's Self-Concept Scale-Second Edition, and self-report and clinician-administered measures assessing behavioral and psychological difficulties and comorbid conditions. Youth with CTD had a slightly below average level of self-concept, with 20 % (n = 19) exhibiting low self-concept. Youth with CTD-only had greater self-concept relative to youth with CTD and obsessive-compulsive disorder (OCD) (p = 0.04) or CTD, OCD, and attention deficit hyperactivity disorder (ADHD) combined (p = 0.009). Medium-to-large-sized associations were observed between youth's self-concept and clinical characteristics (e.g., severity of ADHD, OCD and depressive symptoms). Youth's self-concept partially mediated the relationship between tic severity and depressive symptom severity, and the interaction between tic impairment and youth's reliance on avoidant coping strategies moderated youth's self-concept. Implications, limitations, and recommendations for future interventions are discussed.
Alternative Conceptions: Turning Adversity into Advantage
NASA Astrophysics Data System (ADS)
Ferreira, Annalize; Lemmer, Miriam; Gunstone, Richard
2017-08-01
While a vast body of research has identified difficulties in students' understanding about forces and acceleration and their related alternative conceptions, far less research suggests ways to use students' alternative conceptions to enhance conceptual understanding of a specific fundamental concept. This study focused on distinguishing between students' conceptual understanding of the Newtonian concept of gravitational acceleration being the same for all objects and students' alternative conception that heavy objects fall faster. A multiple choice questionnaire was distributed to first year physics students for three consecutive years at a university in South Africa. The results indicate that changing the direction of motion and the physics quantity asked in paired questions revealed practically significant inconsistencies in students' reasoning and conceptions. This research contributes to the body of knowledge in proposing how the alternative conception of mass-related gravitational acceleration can be used in instruction to enhance conceptual understanding of the force-mass-acceleration relationship. Understanding of this relationship not only promotes conceptual understanding of the basic Newtonian concepts of the laws of motion which forms the critical foundation on which more advanced physics courses are built, but also contributes towards students' perception of physics as a set of coherent ideas applicable in all contexts.
Self-concept and self-esteem after acquired brain injury: a control group comparison.
Ponsford, Jennie; Kelly, Amber; Couchman, Grace
2014-01-01
This study examined the multidimensional self-concept, global self-esteem and psychological adjustment of individuals with traumatic brain injury (TBI) as compared with healthy controls. Group comparison on self-report questionnaires. Forty-one individuals who had sustained a TBI were compared with an age- and gender-matched sample of 41 trauma-free control participants on the Rosenberg Self Esteem Scale, the Tennessee Self Concept Scale (second edition) and the Hospital Anxiety and Depression Scales (HADS). Participants with TBI rated significantly lower mean levels of global self-esteem and self-concept on the Rosenberg Self Esteem Scale and Tennessee Self Concept Scale than the control group. Survivors of TBI rated themselves more poorly on a range of self-dimensions, including social, family, academic/work and personal self-concept compared to controls. They also reported higher mean levels of depression and anxiety on the Hospital Anxiety and Depression Scale. Overall self-concept was most strongly associated with depressive symptoms and anxiety. Self-concept may be lowered following TBI and is associated with negative emotional consequences. Clinicians may improve the emotional adjustment of survivors of TBI by considering particular dimensions of self-concept for intervention focus.
Semantic Similarity between Web Documents Using Ontology
NASA Astrophysics Data System (ADS)
Chahal, Poonam; Singh Tomer, Manjeet; Kumar, Suresh
2018-06-01
The World Wide Web is the source of information available in the structure of interlinked web pages. However, the procedure of extracting significant information with the assistance of search engine is incredibly critical. This is for the reason that web information is written mainly by using natural language, and further available to individual human. Several efforts have been made in semantic similarity computation between documents using words, concepts and concepts relationship but still the outcome available are not as per the user requirements. This paper proposes a novel technique for computation of semantic similarity between documents that not only takes concepts available in documents but also relationships that are available between the concepts. In our approach documents are being processed by making ontology of the documents using base ontology and a dictionary containing concepts records. Each such record is made up of the probable words which represents a given concept. Finally, document ontology's are compared to find their semantic similarity by taking the relationships among concepts. Relevant concepts and relations between the concepts have been explored by capturing author and user intention. The proposed semantic analysis technique provides improved results as compared to the existing techniques.
Design and Evaluation of Nextgen Aircraft Separation Assurance Concepts
NASA Technical Reports Server (NTRS)
Johnson, Walter; Ho, Nhut; Arutyunov, Vladimir; Laue, John-Luke; Wilmoth, Ian
2012-01-01
To support the development and evaluation of future function allocation concepts for separation assurance systems for the Next Generation Air Transportation System, this paper presents the design and human-in-the-loop evaluation of three feasible function allocation concepts that allocate primary aircraft separation assurance responsibilities and workload to: 1) pilots; 2) air traffic controllers (ATC); and 3) automation. The design of these concepts also included rules of the road, separation assurance burdens for aircraft of different equipage levels, and utilization of advanced weather displays paired with advanced conflict detection and resolution automation. Results of the human-in-the-loop simulation show that: a) all the concepts are robust with respect to weather perturbation; b) concept 1 (pilots) had highest throughput, closest to assigned spacing, and fewest violations of speed and altitude restrictions; c) the energy of the aircraft during the descent phase was better managed in concepts 1 and 2 (pilots and ATC) than in concept 3 (automation), in which the situation awareness of pilots and controllers was lowest, and workload of pilots was highest. The paper also discusses further development of these concepts and their augmentation and integration with future air traffic management tools and systems that are being considered for NextGen.
[Aerobic capacity, weight status and self-concept in schoolchildren].
Gálvez Casas, Arancha; Rodríguez García, Pedro Luis; Rosa Guillamón, Andrés; García-Cantó, Eliseo; Pérez Soto, Juan José; Tárraga López, Pedro; Tárraga Marcos, Loreto
2016-01-01
To analyze the relationship between self-concept, aerobic capacity and weight status in schoolchildren. Relational descriptive design in which was assessed the weight status and aerobic capacity of 256 schoolchildren among 8-11 years. Aerobic capacity (low vs high) and the body mass index (normal-weight vs overweight-obesity) were categorized using standard criteria. The self-concept was assessed through the Piers Harris self-concept scale for children. Schoolchildren with normal-weight and high fitness level showed better levels of conductual self-concept (P=.030), physical (P<.001), lack of anxiety (P=.048), and global self-concept (P=.002). The schoolchildren with normal-weight show higher levels of conductual self-concpt (P=.016), intellectual (P=.050), physical (P<.001), life satisfaction (P=.036), and global self-concept (P=.001). The schoolchildren with a higher fitness level showed better conductual self-concept (P=.024), physical (P=.004), lack of anxiety (P=.011), social (P=.024), and global (P=.003). The results of the study strengthen the importance to transmit to the educative community the knowledge of the relationship between the variables analyzed aiming to improve the schoolchildren self-concept. Copyright © 2015 Sociedad Española de Arteriosclerosis. Published by Elsevier España. All rights reserved.
Factors relating to professional self-concept among nurse managers.
Kantek, Filiz; Şimşek, Belkıs
2017-12-01
To investigate the self-concept in nurse managers in Turkey and the effects of certain variables on professional self-concept. Professional self-concept plays a significant role in improving certain professional behaviours. Nursing managers have the potential to influence other members of the profession with their attitudes and behaviours. The study was designed as a cross-sectional descriptive study. This study was conducted with 159 nurse managers in nine different hospitals. The study data were collected with a Personal Information Form and Professional Self-concept Nursing Inventory, and the data analysis was accomplished with descriptive statistics, Cronbach's alpha coefficients and Chi-squared Automatic Interaction Detector analyses. The professional self-concept score of nurse managers was 3·33 (SD = 0·308). Professional competence subdimension had the highest scores, while professional satisfaction subdimension had the lowest. The types of hospital were found to be influential on professional self-concept. The types of hospital were reported to influence the professional self-concept of nurses. Nursing managers are visionaries who can potentially influence nursing practices and decisions. Nursing leaders must monitor and administer strategies to improve their professional self-concept. © 2017 John Wiley & Sons Ltd.
Service user involvement in mental health care: an evolutionary concept analysis.
Millar, Samantha L; Chambers, Mary; Giles, Melanie
2016-04-01
The concept of service user involvement is an evolving concept in the mental health-care literature. This study sought to explore and analyse the concept of service user involvement as used in within the field of mental health care. An evolutionary concept analysis was conducted using a literature-based sample extracted from an electronic database search. One hundred and thirty-four papers met the inclusion criteria and were analysed to discover key attributes, antecedents and consequences of service user involvement and to produce a definition of the concept. Five key attributes of service user involvement within the context of mental health care were identified: a person-centred approach, informed decision making, advocacy, obtaining service user views and feedback and working in partnership. Clarity of the attributes and definition of the concept of service user involvement aims to promote understanding of the concept among key stakeholders including mental health professionals, service users and community and voluntary organizations. The findings of the research have utility in the areas of theory and policy development, research on service user involvement in mental health care and service user involvement in mental health practice. Directions for further research regarding the concept are identified. © 2015 John Wiley & Sons Ltd.
Gao, Meng; Li, Yu-Chen; Zhang, Wei
2017-04-01
To examine the mediating effect of self-concept between interparental conflict and mental health in children and adolescents. A total of 689 students (10-18 years) were surveyed using the convenient sampling method, and their mental health, self-concept, and interparental conflict were examined by the general status questionnaire, Strengths and Difficulties Questionnaire, Self-Description Questionnaire, and Children's Perception of Interparental Conflict Scale. Structural equation modeling (SEM) and simultaneous analysis of several groups were used to construct the mediator model and analyze the data, respectively. The Bootstrap method was used to assess the significance of the mediating effects. Interparental conflict was positively correlated with mental health of children and adolescents (P<0.05), but was negatively correlated with self-concept (P<0.01). Self-concept was negatively correlated with mental health (P<0.01). Self-concept had a partial (60%) mediating effect between interparental conflict and mental health. Academic stage, but not gender, had a regulatory role on interparental conflict, mental health, and self-concept. Self-concept plays an important role between interparental conflict and mental health. It is necessary to improve self-concept level in children and adolescents exposed to interparental conflict.
A Hybrid Knowledge-Based and Data-Driven Approach to Identifying Semantically Similar Concepts
Pivovarov, Rimma; Elhadad, Noémie
2012-01-01
An open research question when leveraging ontological knowledge is when to treat different concepts separately from each other and when to aggregate them. For instance, concepts for the terms "paroxysmal cough" and "nocturnal cough" might be aggregated in a kidney disease study, but should be left separate in a pneumonia study. Determining whether two concepts are similar enough to be aggregated can help build better datasets for data mining purposes and avoid signal dilution. Quantifying the similarity among concepts is a difficult task, however, in part because such similarity is context-dependent. We propose a comprehensive method, which computes a similarity score for a concept pair by combining data-driven and ontology-driven knowledge. We demonstrate our method on concepts from SNOMED-CT and on a corpus of clinical notes of patients with chronic kidney disease. By combining information from usage patterns in clinical notes and from ontological structure, the method can prune out concepts that are simply related from those which are semantically similar. When evaluated against a list of concept pairs annotated for similarity, our method reaches an AUC (area under the curve) of 92%. PMID:22289420
Clinical Correlates and Mediators of Self-Concept in Youth with Chronic Tic Disorders
Hanks, Camille E.; McGuire, Joseph F.; Lewin, Adam B.; Storch, Eric A.
2015-01-01
This study investigated the clinical correlates and mediators of self-concept in youth with Chronic Tic Disorders (CTD). Ninety-seven youth aged 6–17 (M = 11.1 ± 2.89; 79.4 % male) with CTD were administered the Yale Global Tic Severity Scale, the Piers-Harris Children’s Self-Concept Scale—Second Edition, and self-report and clinician-administered measures assessing behavioral and psychological difficulties and comorbid conditions. Youth with CTD had a slightly below average level of self-concept, with 20 % (n = 19) exhibiting low self-concept. Youth with CTD-only had greater self-concept relative to youth with CTD and obsessive–compulsive disorder (OCD) (p = 0.04) or CTD, OCD, and attention deficit hyperactivity disorder (ADHD) combined (p = 0.009). Medium-to-large-sized associations were observed between youth’s self-concept and clinical characteristics (e.g., severity of ADHD, OCD and depressive symptoms). Youth’s self-concept partially mediated the relationship between tic severity and depressive symptom severity, and the interaction between tic impairment and youth’s reliance on avoidant coping strategies moderated youth’s self-concept. Implications, limitations, and recommendations for future interventions are discussed. PMID:25791488
LEGO-MM: LEarning structured model by probabilistic loGic Ontology tree for MultiMedia.
Tang, Jinhui; Chang, Shiyu; Qi, Guo-Jun; Tian, Qi; Rui, Yong; Huang, Thomas S
2016-09-22
Recent advances in Multimedia ontology have resulted in a number of concept models, e.g., LSCOM and Mediamill 101, which are accessible and public to other researchers. However, most current research effort still focuses on building new concepts from scratch, very few work explores the appropriate method to construct new concepts upon the existing models already in the warehouse. To address this issue, we propose a new framework in this paper, termed LEGO1-MM, which can seamlessly integrate both the new target training examples and the existing primitive concept models to infer the more complex concept models. LEGOMM treats the primitive concept models as the lego toy to potentially construct an unlimited vocabulary of new concepts. Specifically, we first formulate the logic operations to be the lego connectors to combine existing concept models hierarchically in probabilistic logic ontology trees. Then, we incorporate new target training information simultaneously to efficiently disambiguate the underlying logic tree and correct the error propagation. Extensive experiments are conducted on a large vehicle domain data set from ImageNet. The results demonstrate that LEGO-MM has significantly superior performance over existing state-of-the-art methods, which build new concept models from scratch.
Hope in terminal illness: an evolutionary concept analysis.
Johnson, Sarah
2007-09-01
to clarify the concept of hope as perceived by patients with a terminal illness, to develop hope as an evidence-based nursing concept, to contribute new knowledge and insights about hope to the relatively new field of palliative care; endeavouring to maximize the quality of life of terminally ill patients in the future. utilizing Rodgers' (2000a) evolutionary concept analysis methodology and thematic content analysis, 17 pieces of research-based literature on hope as perceived by adult patients with any terminal illness pathology, from the disciplines of nursing and medicine have been reviewed and analyzed. An exemplary case of the concept in action is presented along with the evolution of the concept hope in terminal illness. Ten essential attributes of the concept were identified: positive expectation; personal qualities; spirituality; goals; comfort; help/caring; interpersonal relationships; control; legacy; and life review. Patients' hopes and goals are scaled down and refocused in order to live in the present and enjoy the time they have left with loved ones. By completing all the steps to Rodgers' (2000a) evolutionary view of concept analysis, a working definition and clarification of the concept in its current use has been achieved. This provides a solid conceptual foundation for further study.
Semantic Similarity between Web Documents Using Ontology
NASA Astrophysics Data System (ADS)
Chahal, Poonam; Singh Tomer, Manjeet; Kumar, Suresh
2018-03-01
The World Wide Web is the source of information available in the structure of interlinked web pages. However, the procedure of extracting significant information with the assistance of search engine is incredibly critical. This is for the reason that web information is written mainly by using natural language, and further available to individual human. Several efforts have been made in semantic similarity computation between documents using words, concepts and concepts relationship but still the outcome available are not as per the user requirements. This paper proposes a novel technique for computation of semantic similarity between documents that not only takes concepts available in documents but also relationships that are available between the concepts. In our approach documents are being processed by making ontology of the documents using base ontology and a dictionary containing concepts records. Each such record is made up of the probable words which represents a given concept. Finally, document ontology's are compared to find their semantic similarity by taking the relationships among concepts. Relevant concepts and relations between the concepts have been explored by capturing author and user intention. The proposed semantic analysis technique provides improved results as compared to the existing techniques.
Lunar Surface Systems Wet-Bath Design Evaluation
NASA Technical Reports Server (NTRS)
Thompson, Shelby; Szabo, Rich; Howard, Robert
2010-01-01
The goal of the current evaluation was to examine five different wet-bath architectural design concepts. The primary means of testing the concepts required participants to physically act-out a number of functional tasks (e.g., shaving, showering, changing clothes, maintenance) in order to give judgments on the affordance of the volume as based on the design concepts. Each of the concepts was designed in such a way that certain features were exploited - for example, a concept may have a large amount of internal stowage, but minimum amount of usable space to perform tasks. The results showed that the most preferred concept was one in which stowage and usable space were balanced. This concept allowed for a moderate amount of stowage with some suggested redesign, but would not preclude additional personal items such as clothing. This concept also allowed for a greater distance to be achieved between the toilet and the sink with minimum redesign, which was desirable. Therefore, the all-in-one (i.e., toilet, sink, and shower all occupying a single volume) wet-bath concept seemed to be a viable solution in which there is a minimal amount of overall volume available with certain lunar habitat configurations.
NASA Astrophysics Data System (ADS)
Brown, Judith Ann
2000-10-01
Nine high school biology teachers from rural, suburban, and urban school settings, were interviewed about what idea, topic, or concept, if any, they use to unify their high school biology curriculum. Professional scientists and educational organizations have proposed that high school biology teachers use "biological evolution" as a unifying concept of their curriculum. Interviews, concept maps, and classroom syllabi and outlines were provided as data for these nine case studies. Each teacher was asked what topics were included in their curriculum to determine if a wide enough content was taught to warrant unification. The teachers' responses were compared to content and concepts listed in the National Science Content Standards, the Washington State Essential Academic Learning Requirements for Science, and a paper (Hurd, Bybee, Kahle, and Yager, 1980) that proposed what and how topics should be taught in the high school biology class by the year 2000. The nine teachers were asked to draw a concept map showing how these topics were interrelated and what concept, if any, "unified" them. A unifying concept is defined as a concept introduced early in the year and referred back to whenever new topics are introduced illustrating how the new topic is related to the previous ones through this unifying concept. Seven of the nine teachers did use at least one unifying concept. Two use evolution or natural selection, two use the web of life, two use the characteristics of life, and one uses scientific inquiry. The data collected in this study indicate high school teachers use these concepts such as the web of life and the characteristics of life because they believe they are easily understood by their students and less controversial than the theory of evolution. This study also presents evidence that school setting has minimal influence on what concept teachers use to unify their curriculum and that teachers have a significant amount of academic freedom to choose what they want to teach and how they want to teach it. The data suggests that teachers choose their unifying concept based on their personal beliefs of what their students will accept and on their past interactions with parents, students, and administrators when various unifying concepts were used.
The Single Crew Module Concept for Exploration
NASA Technical Reports Server (NTRS)
Chambliss, Joe
2012-01-01
Many concepts have been proposed for exploring space. In early 2010 presidential direction called for reconsidering the approach to address changes in exploration destinations, use of new technologies and development of new capabilities to support exploration of space. Considering the proposed new technology and capabilities that NASA was directed to pursue, the single crew module (SCM) concept for a more streamlined approach to the infrastructure and conduct of exploration missions was developed. The SCM concept combines many of the new promising technologies with a central concept of mission architectures that uses a single habitat module for all phases of an exploration mission. Integrating mission elements near Earth and fully fueling them prior to departure of the vicinity of Earth provides the capability of using the single habitat both in transit to an exploration destination and while exploring the destination. The concept employs the capability to return the habitat and interplanetary propulsion system to Earth vicinity so that those elements can be reused on subsequent exploration missions. This paper describes the SCM concept, provides a top level mass estimate for the elements needed and trades the concept against Many concepts have been proposed for exploring space. In early 2010 presidential direction called for reconsidering the approach to address changes in exploration destinations, use of new technologies and development of new capabilities to support exploration of space. Considering the proposed new technology and capabilities that NASA was directed to pursue, the single crew module (SCM) concept for a more streamlined approach to the infrastructure and conduct of exploration missions was developed. The SCM concept combines many of the new promising technologies with a central concept of mission architectures that uses a single habitat module for all phases of an exploration mission. Integrating mission elements near Earth and fully fueling them prior to departure of the vicinity of Earth provides the capability of using the single habitat both in transit to an exploration destination and while exploring the destination. The concept employs the capability to return the habitat and interplanetary propulsion system to Earth vicinity so that those elements can be reused on subsequent exploration missions. This paper describes the SCM concept, provides a top level mass estimate for the elements needed and trades the concept against Constellation approaches for Lunar, Near Earth Asteroid and Mars Surface missions.
How Effective Is Example Generation for Learning Declarative Concepts?
ERIC Educational Resources Information Center
Rawson, Katherine A.; Dunlosky, John
2016-01-01
Declarative concepts (i.e., key terms and corresponding definitions for abstract concepts) represent foundational knowledge that students learn in many content domains. Thus, investigating techniques to enhance concept learning is of critical importance. Various theoretical accounts support the expectation that example generation will serve this…
Dynamic Constellation Tasking and Management
2013-03-01
14 2.4. DARPA SeeMe Concept................................................................................20...11 Figure 3. DARPA SeeMe Satellite (Artist’s Concept) .................................................... 20 Figure 4...concept has not been adopted, it may one day find use with the DMC or other satellite systems. 2.4. DARPA SeeMe Concept The Defense Advance Research
What Oceanography Concepts are Taught in Ohio's Schools?
ERIC Educational Resources Information Center
Skinner, Ray, Jr.; Martin, Ralph E., Jr.
1985-01-01
A survey listing 21 major oceanographic concepts and several sub-concepts was mailed to all Ohio earth science teachers. Respondents indicated that most of the oceanography topics taught were geologically-oriented. Oceanography concepts relating to ecology, chemical, physical or life science are considered less important. (DH)
Contrasting Conceptions of Intelligence and their Educational Implications. Technical Report No. 14.
ERIC Educational Resources Information Center
Sternberg, Robert J.
The componential conception of intelligence is summarized and contrasted with the psychometric conception. A brief history of concepts of intelligence is presented, beginning with Galton's anthropometric approach and Binet's more educationally relevant approach. Spearman's, and later Thurstone's, contributions to factor analysis promoted a…
Investigating Elementary Teachers' Conceptions of Animal Classification
ERIC Educational Resources Information Center
Burgoon, Jacob N.; Duran, Emilio
2012-01-01
Numerous studies have been conducted regarding alternative conceptions about animal diversity and classification, many of which have used a cross-age approach to investigate how students' conceptions change over time. None of these studies, however, have investigated teachers' conceptions of animal classification. This study was intended to…
Relativity Concept Inventory: Development, Analysis, and Results
ERIC Educational Resources Information Center
Aslanides, J. S.; Savage, C. M.
2013-01-01
We report on a concept inventory for special relativity: the development process, data analysis methods, and results from an introductory relativity class. The Relativity Concept Inventory tests understanding of relativistic concepts. An unusual feature is confidence testing for each question. This can provide additional information; for example,…
Values Concepts of Younger Children.
ERIC Educational Resources Information Center
Schuncke, George M.; Krogh, Suzanne L.
1982-01-01
The concepts of friendship, rules, property, obedience to authority, truth, promises, and sharing are appropriate for inclusion in values education materials for elementary students. Interviewers questioned 180 children in grades K-5 about their level of understanding of each concept and their perceptions of each concept's importance to their…
A Psychometric Evaluation of the Digital Logic Concept Inventory
ERIC Educational Resources Information Center
Herman, Geoffrey L.; Zilles, Craig; Loui, Michael C.
2014-01-01
Concept inventories hold tremendous promise for promoting the rigorous evaluation of teaching methods that might remedy common student misconceptions and promote deep learning. The measurements from concept inventories can be trusted only if the concept inventories are evaluated both by expert feedback and statistical scrutiny (psychometric…
Self-Concept and Self-Esteem: A Cross-Cultural Perspective.
ERIC Educational Resources Information Center
Wood, Melinda
1991-01-01
Describes issues of self-concept and self-esteem that arise when people find themselves living in a cross-cultural environment. Discusses Western definition of self-concept and other self-concept models. Discusses self-esteem and integration and adjustment as it relates to bicultural persons. (ABL)
Concept Learning through Image Processing.
ERIC Educational Resources Information Center
Cifuentes, Lauren; Yi-Chuan, Jane Hsieh
This study explored computer-based image processing as a study strategy for middle school students' science concept learning. Specifically, the research examined the effects of computer graphics generation on science concept learning and the impact of using computer graphics to show interrelationships among concepts during study time. The 87…
Preservice Teachers' Alternative Conceptions in Elementary Science Concepts
ERIC Educational Resources Information Center
Koc, Isil; Yager, Robert E.
2016-01-01
This study was conducted to investigate the extent to which preservice teachers held alternative conceptions in elementary science concepts. Eighty-six preservice elementary teachers participated in this study. Twelve preservice elementary teachers participated in follow-up interviews. Data were collected through the use of Alternative Conceptions…
Content Structure as a Design Strategy Variable in Concept Acquisition.
ERIC Educational Resources Information Center
Tennyson, Robert D.; Tennyson, Carol L.
Three methods of sequencing coordinate concepts (simultaneous, collective, and successive) were investigated with a Bayesian, computer-based, adaptive control system. The data analysis showed that when coordinate concepts are taught simultaneously (contextually similar concepts presented at the same time), student performance is superior to either…
Assessing voids in SNOMED CT for pediatric concepts.
Wade, Geraldine; Gotlieb, Edward M; Weigle, Carl; Warren, Robert
2008-11-06
Reference terminologies such as SNOMED CT may have voids in their representation of concepts important to the practice of pediatrics. In this project, relevant pediatric concepts were extracted from an American Academy of Pediatrics guideline and were mapped to SNOMED CT. Concepts were identified that should be included in the standard reference terminology. A process for formally evaluating voids in reference terminologies for concepts needed in pediatric clinical decision-making is planned as a next step.
ERIC Educational Resources Information Center
Martinez, Guadalupe; Perez, Angel Luis; Suero, Maria Isabel; Pardo, Pedro J.
2013-01-01
A study was conducted to quantify the effectiveness of concept maps in learning physics in engineering degrees. The following research question was posed: What was the difference in learning results from the use of concept maps to study a particular topic in an engineering course? The study design was quasi-experimental and used a post-test as a…
Developing the concept of a geostationary platform. [for communication services
NASA Technical Reports Server (NTRS)
Carey, W. T.; Bowman, R. M.; Stone, G. R.
1980-01-01
A geostationary platform concept with a proliferation of low-cost earth stations is discussed. Candidate platform concepts, servicing, life, and Orbital Transfer Vehicle (OTV) options are considered. A Life Cycle Costing model is used to select the minimum cost concept meeting program criteria. It is concluded that the geostationary platform concept is a practical and economical approach to providing expanding communication services within the limitations imposed by the available frequency spectrum and orbital arc.
Predicting alienation in a sample of Nigerian Igbo subjects.
Morah, E I
1990-08-01
Seeman in 1959 suggested that alienation is a multidimensional concept. Using two aspects of Seeman's concept of alienation, powerlessness and social alienation, and two concepts derived from Lachar's 1978 Minnesota Multiphasic Personality Inventory Cookbook, emotional and self-alienation, the present work was undertaken to ascertain which concept will more likely predict feelings of alienation. A stepwise multiple regression showed that among 160 Nigerian (Igbo) subjects the feeling of powerlessness predicted alienation more than did the other concept.
Flourishing: An Evolutionary Concept Analysis.
Agenor, Christine; Conner, Norma; Aroian, Karen
2017-11-01
Mental health is an important measure of public health (WHO, 2004); however, nursing practice and research continues to prioritize mental illness, rather than well-being (Wand, 2011). Flourishing is a recent concept in the field of well-being. The term has been used sparingly in nursing practice and research, and conceptual clarification is needed to promote comprehensive understanding of the phenomenon. The purpose of this study is to critically analyze flourishing, assess the maturity of the concept, and provide recommendations for future research, education, and practice. The concept of flourishing was analyzed using the evolutionary approach to concept analysis (Rodgers, 2000). A search for articles on flourishing within the context of well-being was conducted through CINAHL, MEDLINE, and PsycINFO. A sample of 32 articles and 1 book was reviewed. Data were reviewed for concept attributes, antecedents, consequences, surrogate terms and related concepts. Four models of flourishing were identified with six overlapping attributes: meaning, positive relationships, engagement, competence, positive emotion, and self-esteem. Limited longitudinal and predictive studies have been conducted, but there is evidence for several antecedents and outcomes of flourishing. Research is ongoing primarily in psychology and sociology and is lacking in other disciplines. The concept of flourishing is immature; however, evidence is building for related concepts. A lack of consistent terminology regarding flourishing prevents knowledge development of flourishing as a distinct concept. Further multidisciplinary research is needed to establish standard operational and conceptual definitions and develop effective interventions.
An evolutionary concept analysis of futility in health care.
Morata, Lauren
2018-06-01
To report a concept analysis of futility in health care. Each member of the healthcare team: the physician, the nurse, the patient, the family and all others involved perceive futility differently. The current evidence and knowledge in regard to futility in health care manifest a plethora of definitions, meanings and interpretations without consensus. Concept analysis. Databases searched included Medline, Cumulative Index of Nursing and Allied Health Literature, Academic Search Premier, Cochrane Database of Systematic Reviews and PsycINFO. Search terms included "futil*," "concept analysis," "concept," "inefficacious," "non-beneficial," "ineffective" and "fruitless" from 1935-2016 to ensure a historical perspective of the concept. A total of 106 articles were retained to develop the concept. Rogers' evolutionary concept analysis was used to evaluate the concept of futility from ancient medicine to the present. Seven antecedents (the patient/family autonomy, surrogate decision-making movement, the patient-family/physician relationship, physician authority, legislation and court rulings, catastrophic events and advancing medical technology) lead to four major attributes (quantitative, physiologic, qualitative, and disease-specific). Ultimately, futile care could lead to consequences such as litigation, advancing technology, increasing healthcare costs, rationing, moral distress and ethical dilemmas. Futility in health care demonstrates components of a cyclical process and a consensus definition is proposed. A framework is developed to clarify the concept and articulate relationships among attributes, antecedents and consequences. Further testing of the proposed definition and framework are needed. © 2018 John Wiley & Sons Ltd.
A concept analysis of professional commitment in nursing.
García-Moyano, Loreto; Altisent, Rogelio; Pellicer-García, Begoña; Guerrero-Portillo, Sandra; Arrazola-Alberdi, Oihana; Delgado-Marroquín, María Teresa
2017-01-01
The concept of professional commitment is being widely studied at present. However, although it is considered an indicator for the most human part of nursing care, there is no clear definition for it, and different descriptors are being used indiscriminately to reference it. The aim of this study is to clarify the concept of professional commitment in nursing through the Rodgers' evolutionary concept analysis process. Systematic search using English and Spanish descriptors and concept analysis. Studies published between 2009 and June 2015, front-to-back analysis of the Nursing Ethics journal and manual check of articles cited in studies related to the Nijmegen Professionalism Scale. The procedure of concept analysis developed by Rodgers was used. Ethical considerations: Although the topic was not labeled as sensitive and subject to ethical approval, its realization was approved by the Ethical Committee of Clinical Research of Aragon (CEICA) approved the study on 18 March 2015 and also careful procedures have been followed according to ethics expressed in the Declaration of Helsinki. A total of 17 published studies. A clear definition of the concept was made, and surrogate terms, concept dimension, differential factors related to the concept, sociocultural variations and consequences for nursing practice were identified. There is a need for continuous advancement in the development of the concept, specific actions to encourage this and the improvement of evaluation methods for its study.
Initial Investigation of Operational Concept Elements for NASA's NextGen-Airportal Project Research
NASA Technical Reports Server (NTRS)
Lohr, Gary; Lee, Jonathan; Poage, James L.; Tobias, Leonard
2009-01-01
The NextGen-Airportal Project is organized into three research focus areas: Safe and Efficient Surface Operations, Coordinated Arrival/Departure Operations Management, and Airportal Transition and Integration Management. The content in this document was derived from an examination of constraints and problems at airports for accommodating future increases in air traffic, and from an examination of capabilities envisioned for NextGen. The concepts are organized around categories of constraints and problems and therefore do not precisely match, but generally reflect, the research focus areas. The concepts provide a framework for defining and coordinating research activities that are, and will be, conducted by the NextGen-Airportal Project. The concepts will help the research activities function as an integrated set focused on future needs for airport operations and will aid aligning the research activities with NextGen key capabilities. The concepts are presented as concept elements with more detailed sub-elements under each concept element. For each concept element, the following topics are discussed: constraints and problems being addressed, benefit descriptions, required technology and infrastructure, and an initial list of potential research topics. Concept content will be updated and more detail added as the research progresses. The concepts are focused on enhancing airportal capacity and efficiency in a timeframe 20 to 25 years in the future, which is similar to NextGen's timeframe.
Thine Own Self: True Self-Concept Accessibility and Meaning in Life
Schlegel, Rebecca J.; Hicks, Joshua A.; Arndt, Jamie; King, Laura A.
2016-01-01
A number of philosophical and psychological theories suggest the true self is an important contributor to well-being. The present research examined whether the cognitive accessibility of the true self-concept would predict the experience of meaning in life. To ensure that any observed effects were due to the true self-concept rather than the self-concept more generally, we utilized actual self-concept accessibility as a control variable in all studies. True and actual self-concepts were defined as including those traits which are enacted around close others versus most others (Studies 1 through 3) or as traits that refer to “who you really are” vs. “who you are during most of your activities” (Studies 4 and 5), respectively. Studies 1 and 2 showed that individual differences in true self-concept accessibility, but not differences in actual self-concept accessibility, predicted meaning in life. Study 3 showed that priming traits related to the true self led to enhanced meaning in life. Studies 4 and 5 provided correlational and experimental support for the role of true self-concept accessibility in meaning in life, even when traits were defined without reference to social relationships and when state self-esteem and self-reported authenticity were controlled. Implications for the study of the true self-concept and authenticity are discussed. PMID:19159144
Effects of Aging Stereotype Threat on Working Self-Concepts: An Event-Related Potentials Approach
Zhang, Baoshan; Lin, Yao; Gao, Qianyun; Zawisza, Magdalena; Kang, Qian; Chen, Xuhai
2017-01-01
Although the influence of stereotype threat (ST) on working self-concepts has been highlighted in recent years, its neural underpinnings are unclear. Notably, the aging ST, which largely influences older adults’ cognitive ability, mental and physical health, did not receive much attention. In order to investigate these issues, electroencephalogram (EEG) data were obtained from older adults during a modified Stroop task using neutral words, positive and negative self-concept words in aging ST vs. neutral control conditions. Results showed longer reaction times (RTs) for identifying colors of words under the aging ST compared to the neutral condition. More importantly, the negative self-concept elicited more positive late P300 amplitudes and enhanced theta band activities compared to the positive self-concept or neutral words under the aging ST condition, whereas no difference was found between these self-concepts and neutral words in the control condition. Furthermore, the aging ST induced smaller theta band synchronization and enhanced alpha band synchronization compared to the control condition. Moreover, we also observed valence differences in self-concepts where the negative self-concept words reduced early P150/N170 complex relative to neutral words. These findings suggest that priming ST could activate negative self-concepts as current working self-concept, and that this influence occurred during a late neural time course. PMID:28747885
NASA Astrophysics Data System (ADS)
Buaraphan, Khajornsak
2018-01-01
According to the constructivist theory, students' prior conceptions play an important role in their process of knowledge construction and teachers must take those prior conceptions into account when designing learning activities. The interpretive study was conducted to explore grade 8 students' conceptions about force and motion. The research participants were 42 students (21 male, 21 female) from seven Educational Opportunity Expansion Schools in Nakhon Pathom province located at the central region of Thailand. In each school, two low, two medium and two high achievers were selected. The Interview-About-Instance (IAI) technique was used to collect data. All interviews were audio recorded and subsequently transcribed verbatim. The students' conceptions were interpreted into scientific conception (SC), partial scientific conception (PC) and alternative conception (AC). The frequency of each category was counted and calculated for percentage. The results revealed that the students held a variety of prior conceptions about force and motion ranged from SC, PC to AC. Each students, including the high achievers, held mixed conceptions of force and motion. Interesting, the two dominant ACs held by the students were: a) force-implies-motion or motion-implies-force, and b) force coming only from an active agent. The science teachers need to take these ACs into account when designing the learning activities to cope with them. The implications regarding teaching and learning about force and motion are also discussed.
Novel large deployable antenna backing structure concepts for foldable reflectors
NASA Astrophysics Data System (ADS)
Fraux, V.; Lawton, M.; Reveles, J. R.; You, Z.
2013-12-01
This paper describes a number of large deployable antenna (LDA) reflector structure concepts developed at EnerSys-ABSL. Furthermore, EnerSys-ABSL has confirmed the desire to build a breadboard demonstrator of a backing deployable structure for a foldable reflector in the diameter range of 4-9 m. As part of this project EnerSys-ABSL has explored five novel deployable structure concepts. This paper presents the top level definition of these concepts together with the requirements considered in the design and selection of the preferred candidate. These new concepts are described and then compared through a trade-off analysis to identify the most suitable concept that EnerSys-ABSL would like to consider for the breadboard demonstrator. Finally, the kinematics of the chosen concept is described in more detail and future steps in the development process are highlighted.
Möller, A T; Kotzé, H F; Sieberhagen, K J
1993-02-01
The present study investigated the effects on self-concept of Rational-Emotive Therapy and auditory subliminal stimulation (separately and in combination) on 141 undergraduate students with self-concept problems. They were randomly assigned to one of four groups receiving either Rational-Emotive Therapy, subliminal stimulation, both, or a placebo treatment. Rational-Emotive Therapy significantly improved scores on all the dependent measures (cognition, self-concept, self-esteem, anxiety), except for behavior. Results for the subliminal stimulation group were similar to those of the placebo treatment except for a significant self-concept improvement and a decline in self-concept related irrational cognitions. The combined treatment yielded results similar to those of Rational-Emotive Therapy, with tentative indications of continued improvement in irrational cognitions and self-concept from posttest to follow-up.
NASA Astrophysics Data System (ADS)
Samsudin, A.; Fratiwi, N.; Amin, N.; Wiendartun; Supriyatman; Wibowo, F.; Faizin, M.; Costu, B.
2018-05-01
This study based on an importance of improving students’ conceptions and reduces students’ misconceptions on fluid dynamics concepts. Consequently, should be done the study through combining Peer Teaching Model (PTM) and PDEODE (Prediction, Discuss, Explain, Observe, Discuss and Explain) learning strategy (PTM-PDEODE). For the research methods, we used the 4D model (Defining, Designing, Developing, and Disseminating). The samples are 38 students (their ages were an average of 17 years-old) at one of the senior high schools in Bandung. The improvement of students’ conceptions was diagnosed through a four-tier test of fluid dynamics. At the disseminating phase, students’ conceptions of fluid dynamics concepts are increase after the use of PTM-PDEODE. In conclusion, the development of PTM-PDEODE is respectable enough to improve students’ conceptions on dinamics fluid.
Exploring physics concepts among novice teachers through CMAP tools
NASA Astrophysics Data System (ADS)
Suprapto, N.; Suliyanah; Prahani, B. K.; Jauhariyah, M. N. R.; Admoko, S.
2018-03-01
Concept maps are graphical tools for organising, elaborating and representing knowledge. Through Cmap tools software, it can be explored the understanding and the hierarchical structuring of physics concepts among novice teachers. The software helps physics teachers indicated a physics context, focus questions, parking lots, cross-links, branching, hierarchy, and propositions. By using an exploratory quantitative study, a total 13-concept maps with different physics topics created by novice physics teachers were analysed. The main differences of scoring between lecturer and peer-teachers’ scoring were also illustrated. The study offered some implications, especially for physics educators to determine the hierarchical structure of the physics concepts, to construct a physics focus question, and to see how a concept in one domain of knowledge represented on the map is related to a concept in another domain shown on the map.
On "spirituality," "religion," and "religions": a concept analysis.
Lazenby, J Mark
2010-12-01
With increasing research on the role of religion and spirituality in the well-being of cancer patients, it is important to define distinctly the concepts that researchers use in these studies. Using the philosophies of Frege and James, this essay argues that the terms "religion" and "spirituality" denote the same concept, a concept that is identified with the Peace/Meaning subscale of the Functional Assessment of Chronic Illness Therapy--Spiritual Well-being Scale (FACIT-Sp). The term "Religions" denotes the concept under which specific religious systems are categorized. This article shows how muddling these concepts causes researchers to make claims that their findings do not support, and it ends in suggesting that future research must include universal measures of the concept of religion/spirituality in order to investigate further the role of interventions in the spiritual care of people living with cancer.
The retroperitoneal interfascial planes: current overview and future perspectives.
Ishikawa, Kazuo; Nakao, Shota; Nakamuro, Makoto; Huang, Tai-Ping; Nakano, Hiroshi
2016-07-01
Recently, the concept of interfascial planes has become the prevalent theory among radiologists for understanding the retroperitoneal anatomy, having replaced the classic tricompartmental theory. However, it is a little known fact that the concept remains incomplete and includes embryological errors, which have been revised on the basis of our microscopic study. We believe that the concept not only provides a much clearer understanding of the retroperitoneal anatomy, but it also allows further development for diagnosis and treatment of retroperitoneal injuries and diseases, should it become an accomplished theory. We explain the history and outline of the concept of interfascial planes, correct common misunderstandings about the concept, explain the unconsciously applied therapeutic procedures based on the concept, and present future perspectives of the concept using our published and unpublished data. This knowledge could be essential to acute care physicians and surgeons sometime soon.
NASA Astrophysics Data System (ADS)
Griffioen, Jasper
1998-10-01
The concept of first-order mass transfer between mobile and immobile regions, which mathematically simplifies the concept of Fickian diffusion in stagnant areas, has often been used to describe physical nonequilibrium transport of solutes into natural porous media. This study compares the two concepts, using analytical expressions describing cyclic mass transfer into and out of stagnant layers. The results show that the first-order mass transfer concept cannot describe continuous diffusion into the immobile zone during period of net outward diffusion if the immobile zone has not filled completely during the period of net inward diffusion. This sets phenomenological limitations to the first-order mass transfer concept when short periods of relative time are involved; these limitations have to be compared with the practical limitations to the Fickian diffusion concept.
Semantic concept-enriched dependence model for medical information retrieval.
Choi, Sungbin; Choi, Jinwook; Yoo, Sooyoung; Kim, Heechun; Lee, Youngho
2014-02-01
In medical information retrieval research, semantic resources have been mostly used by expanding the original query terms or estimating the concept importance weight. However, implicit term-dependency information contained in semantic concept terms has been overlooked or at least underused in most previous studies. In this study, we incorporate a semantic concept-based term-dependence feature into a formal retrieval model to improve its ranking performance. Standardized medical concept terms used by medical professionals were assumed to have implicit dependency within the same concept. We hypothesized that, by elaborately revising the ranking algorithms to favor documents that preserve those implicit dependencies, the ranking performance could be improved. The implicit dependence features are harvested from the original query using MetaMap. These semantic concept-based dependence features were incorporated into a semantic concept-enriched dependence model (SCDM). We designed four different variants of the model, with each variant having distinct characteristics in the feature formulation method. We performed leave-one-out cross validations on both a clinical document corpus (TREC Medical records track) and a medical literature corpus (OHSUMED), which are representative test collections in medical information retrieval research. Our semantic concept-enriched dependence model consistently outperformed other state-of-the-art retrieval methods. Analysis shows that the performance gain has occurred independently of the concept's explicit importance in the query. By capturing implicit knowledge with regard to the query term relationships and incorporating them into a ranking model, we could build a more robust and effective retrieval model, independent of the concept importance. Copyright © 2013 Elsevier Inc. All rights reserved.
Concept mapping: Impact on content and organization of technical writing in science
NASA Astrophysics Data System (ADS)
Conklin, Elaine
The purpose of this quasi-experimental study was to compare the relationship between concept mapping and the content and organization of technical writing of ninth grade biology students. All students in the study completed a prewriting assessment. The experimental group received concept map instruction while the control group performed alternate tasks. After instruction, both groups completed the postwriting assessment and mean differences were compared using the t statistic for independent measures. Additionally, scores on the concept map were correlated to the scores on the postwriting assessment using the Pearson correlation coefficient. Finally, attitudes toward using concept mapping as a prewriting strategy were analyzed using the t statistic for repeated measures. Concept mapping significantly improved the depth of content; however, no statistical significance was detected for organization. Students had a significantly positive change in attitude toward using concept mapping to plan a writing assessment, organize information, and think creatively. The findings indicated concept mapping had a positive effect on the students' abilities to select concepts appropriate to respond to a writing prompt, integrate facts into complete thoughts and ideas, and apply it in novel situations. Concept maps appeared to facilitate learning how to process information and transform it into expository writing. Sustained practice in designing concept maps may influence organization as well as content. Developing a systematic approach to synthesize well-organized and coherent arguments in response to a writing task is an invaluable communication skill that has implications for the learner across disciplines and prepares them for higher education and the workforce.
CUILESS2016: a clinical corpus applying compositional normalization of text mentions.
Osborne, John D; Neu, Matthew B; Danila, Maria I; Solorio, Thamar; Bethard, Steven J
2018-01-10
Traditionally text mention normalization corpora have normalized concepts to single ontology identifiers ("pre-coordinated concepts"). Less frequently, normalization corpora have used concepts with multiple identifiers ("post-coordinated concepts") but the additional identifiers have been restricted to a defined set of relationships to the core concept. This approach limits the ability of the normalization process to express semantic meaning. We generated a freely available corpus using post-coordinated concepts without a defined set of relationships that we term "compositional concepts" to evaluate their use in clinical text. We annotated 5397 disorder mentions from the ShARe corpus to SNOMED CT that were previously normalized as "CUI-less" in the "SemEval-2015 Task 14" shared task because they lacked a pre-coordinated mapping. Unlike the previous normalization method, we do not restrict concept mappings to a particular set of the Unified Medical Language System (UMLS) semantic types and allow normalization to occur to multiple UMLS Concept Unique Identifiers (CUIs). We computed annotator agreement and assessed semantic coverage with this method. We generated the largest clinical text normalization corpus to date with mappings to multiple identifiers and made it freely available. All but 8 of the 5397 disorder mentions were normalized using this methodology. Annotator agreement ranged from 52.4% using the strictest metric (exact matching) to 78.2% using a hierarchical agreement that measures the overlap of shared ancestral nodes. Our results provide evidence that compositional concepts can increase semantic coverage in clinical text. To our knowledge we provide the first freely available corpus of compositional concept annotation in clinical text.
How do nurses in palliative care perceive the concept of self-image?
Jeppsson, Margareth; Thomé, Bibbi
2015-09-01
Nursing research indicates that serious illness and impending death influence the individual's self-image. Few studies define what self-image means. Thus it seems to be urgent to explore how nurses in palliative care perceive the concept of self-image, to get a deeper insight into the concept's applicability in palliative care. To explore how nurses in palliative care perceive the concept of self-image. Qualitative descriptive design. In-depth interviews with 17 nurses in palliative care were analysed using phenomenography. The study gained ethical approval. The concept of self-image was perceived as both a familiar and an unfamiliar concept. Four categories of description with a gradually increasing complexity were distinguished: Identity, Self-assessment, Social function and Self-knowledge. They represent the collective understanding of the concept and are illustrated in a 'self-image map'. The identity-category emerged as the most comprehensive one and includes the understanding of 'Who I am' in a multidimensional way. The collective understanding of the concept of self-image include multi-dimensional aspects which not always were evident for the individual nurse. Thus, the concept of self-image needs to be more verbalised and reflected on if nurses are to be comfortable with it and adopt it in their caring context. The 'self-image map' can be used in this reflection to expand the understanding of the concept. If the multi-dimensional aspects of the concept self-image could be explored there are improved possibilities to make identity-promoting strategies visible and support person-centred care. © 2014 Nordic College of Caring Science.
Boricua de pura cepa: Ethnic identity, cultural stress and self-concept in Puerto Rican youth.
Zhen-Duan, Jenny; Jacquez, Farrah; Sáez-Santiago, Emily
2018-05-17
The available literature on ethnic identity among Puerto Ricans has focused on those living in the United States, with little to no attention placed on examining ethnic identity and psychological constructs among youth living in Puerto Rico. Using a colonial mentality framework, the current study examined the associations between ethnic identity, cultural stress, and self-concept among adolescent boys and girls living in Puerto Rico. The current cross-sectional study surveyed participants (N = 187) recruited from several junior high schools in the metropolitan area in Puerto Rico. Relations between ethnic identity, cultural stress, and self-concept differed by gender. First, cultural stress was associated with self-concept for boys, such that higher cultural stress predicted lower self-concept. Second, among girls, cultural stress moderated the relation between ethnic identity and self-concept. Specifically, for girls experiencing high cultural stress, exploration and resolution of their ethnic identity was associated with higher ratings of self-concept. Although cultural stress has been widely understood as a phenomena associated with immigrants, our study indicated that cultural stress is important in understanding self-concept of youth living in Puerto Rico. For boys, cultural stress, but not ethnic identity, is particularly important to their self-concept. Among girls experiencing high cultural stress, exploration and resolution of ethnic identity was associated with higher self-concept. Results suggested that the cultural stress associated with the colonial context of Puerto Rico is salient in ethnic identity and self-concept development, even though Puerto Rican youth are the ethnic majority in the island. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
Symptoms and beyond: Self-concept among sexually assaulted women.
Keshet, Hadar; Gilboa-Schechtman, Eva
2017-09-01
The unique characteristics of sexual assault (SA)-a toxic mix of an interpersonal harm, a violent exploitation of one's body, and a transformation of an act of connectedness into an act of submission-are postulated to negatively affect the self-concept. We sought to deepen the understanding of self-concept impairments among sexually assaulted women with varying levels of posttraumatic distress. To this end, we compared women with a main trauma of SA to women with a main trauma of motor-vehicle accident (MVA) and to nontraumatized (NT) women on several self-concept aspects. Our main hypotheses were (a) sexually assaulted women without PTSD exhibit impaired self-concept as compared with NT women and (b) SA is related to greater self-concept impairments as compared with MVA, even when posttraumatic distress is statistically controlled. Women (N = 235: NT = 69, MVA = 87, SA = 79) completed a web-based survey including measures designed to assess the global and domain-specific contents and structure of the self-concept as well as background and clinical questionnaires. Sexually assaulted women without PTSD reported impaired self-concept as compared with NT women. Furthermore, SA was related to greater self-concept impairments as compared with MVA, even when considering participants' levels of posttraumatic distress. SA is related to unique self-concept impairments that extend beyond symptoms, emphasizing the need to assess and address self-concept impairments in sexually assaulted women. The importance of adopting a multifaceted conceptualization of the self to gain a deeper understanding of the aftermath of trauma is highlighted. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Academic self-concept in children with epilepsy and its relation to their quality of life.
Brabcova, Dana; Krsek, Pavel; Kohout, Jiri; Jost, Jiri; Zarubova, Jana
2015-04-01
Academic achievement in children with epilepsy is a highly studied topic with many important implications. However, only little attention has been devoted to academic self-concept of such children and the relation of academic self-concept to their quality of life. We aimed to examine academic self-concept in children with epilepsy, to assess its relationship to academic achievement and to determine possible correlations between academic self-concept and quality of life. The study group consisted of 182 children and adolescents aged 9-14 years who completed the student's perception of ability scale (SPAS) questionnaire to determine their academic self-concept and the modified Czech version of the CHEQOL-25 questionnaire to determine their health-related quality of life. We found that academic self-concept in children with epilepsy was on average significantly lower than in their peers without seizures, especially with regard to general school-related abilities, reading, and spelling. On the other hand, the variance in the data obtained from the group of children with epilepsy was significantly higher than in the whole population and the proportion of individuals with very high academic self-concept seems comparable among children with and without epilepsy. Moreover, it was found that correlations between academic self-concept and academic achievement are significantly lower in children with epilepsy than in the whole population. The presented results suggest that considerable attention should be paid to the role of academic self-concept in education of children with epilepsy and to the factors influencing this self-concept in this group.
Facilitating Children's Self-Concept: A Rationale and Evaluative Study
ERIC Educational Resources Information Center
Hay, Ian
2005-01-01
This study reports on the design and effectiveness of the Exploring Self-Concept program for primary school children using self-concept as the outcome measure. The program aims to provide a procedure that incorporates organisation, elaboration, thinking, and problem-solving strategies and links these to children's multidimensional self-concept.…
Self-Concept: An Operational Model for Educators.
ERIC Educational Resources Information Center
Obiakor, Festus
This document begins by discussing the important role self-concept plays in a student's academic achievement, social adjustment, and physical capability. A perceptual notion of self-concept is defined as awareness through senses. An operational notion of self-concept is defined as self-descriptive behaviors. Literature is reviewed which defines…
Thinking Process of Pseudo Construction in Mathematics Concepts
ERIC Educational Resources Information Center
Subanji; Nusantara, Toto
2016-01-01
This article aims at studying pseudo construction of student thinking in mathematical concepts, integer number operation, algebraic forms, area concepts, and triangle concepts. 391 junior high school students from four districts of East Java Province Indonesia were taken as the subjects. Data were collected by means of distributing the main…
Self-Concept Enhancement of Preschool Children.
ERIC Educational Resources Information Center
Landry, Richard G.; Pardew, E. Michelle
This study investigated whether a self-concept enhancement program would effect significant change in the self-concepts of 4-year-old middle class preschoolers as compared with classmates not in the program. All participating children (N=52) were pre- and posttested using the Thomas Self-Concept Values Test and the Developmental Profile. The…
Relationships between Self-Concept and Resilience Profiles in Young People with Disabilities
ERIC Educational Resources Information Center
Suriá Martínez, Raquel
2016-01-01
Introduction: The present study aims to identify different profiles in self-concept and resilience. In addition, statistically significant differences in self-concept domains among the profiles previously identified are analyzed. Method: The AF5 Self-Concept Questionnaire ("Cuestionario de Autoconcepto AF5") and the Resilience Scale were…
Enhancing Motivation and Acquisition of Coordinate Concepts by Using Concept Trees.
ERIC Educational Resources Information Center
Hirumi, Atsusi; Bowers, Dennis R.
1991-01-01
Examines the effects of providing undergraduate learners with graphic illustrations of coordinate concept relationships to supplement text-based instruction. Half of those reading a specific passage received a graphic concept tree. That group outperformed those who did not, reporting significantly higher amounts of attenuation, confidence, and…
A Review of Solution Chemistry Studies: Insights into Students' Conceptions
ERIC Educational Resources Information Center
Calyk, Muammer; Ayas, Alipa; Ebenezer, Jazlin V.
2005-01-01
This study has reviewed the last two decades of student conception research in solution chemistry pertaining to aims, methods of exploring students' conception, general knowledge claims, students' conceptions and difficulties, and conceptual change studies. The aims of solution chemistry studies have been to assess students' understanding level of…
Harmonising the Microsystem of the Educational Concept "Competence"
ERIC Educational Resources Information Center
Pukelis, Kestutis; Smetona, Antanas
2012-01-01
Various texts related to education policy and education research have recently started using two conjugate concepts "competency" and "competence". These terms are sometimes treated as synonyms of a single concept; however, in other cases they are separated and used as two terms of different educational concepts. English also…
Concepts of Chinese Folk Happiness
ERIC Educational Resources Information Center
Ip, Po Keung
2011-01-01
Discourses on Chinese folk happiness are often based on anecdotal narratives or qualitative analysis. Two traditional concepts of happiness popular in Chinese culture are introduced. The paper constructs a concept of Chinese folk happiness on basis of the findings of a scientific survey on the Taiwanese people regarding their concepts of…
Teachers' Conceptions of Tangent Line
ERIC Educational Resources Information Center
Paez Murillo, Rosa Elvira; Vivier, Laurent
2013-01-01
In order to study the conceptions, and their evolutions, of the tangent line to a curve an updating workshop which took place in Mexico was designed for upper secondary school teachers. This workshop was planned using the methodology of cooperative learning, scientific debate and auto reflection (ACODESA) and the conception-knowing-concept model…
The Concept of Philosophical Education
ERIC Educational Resources Information Center
Boyum, Steinar
2010-01-01
Strangely, the concept of philosophical education is not much in use, at least not as a "philosophical" concept. In this essay, Steinar Boyum attempts to outline such a philosophical concept of philosophical education. Boyum uses Plato's Allegory of the Cave, Rene Descartes's life of doubt, and Immanuel Kant's criticism of metaphysics as paradigms…
Transformative Learning and Concepts of the Self: Insights from Immigrant and Intercultural Journeys
ERIC Educational Resources Information Center
Lange, Elizabeth
2015-01-01
This article examines Canadian immigrant and intercultural learning as an insightful context for examining transformative learning. Theories of intercultural communication are explored, particularly the concept of transculturality and Bhabha's concept of "Third Space". Various concepts of the self are also compared, particularly two…
Conceptions and Practices of Assessment: A Case of Teachers Representing Improvement Conception
ERIC Educational Resources Information Center
Azis, Astuti
2015-01-01
Despite numerous quantitative studies on teachers' conceptions and practices of assessment, little research exists regarding the unique assessment environment of Indonesia. This study uses both quantitative and qualitative data to examine how Indonesian junior high school teachers understand assessment and how their conceptions of assessment…
Academics' Conceptions of Assessment and Their Assessment Practices
ERIC Educational Resources Information Center
Postareff, Liisa; Virtanen, Viivi; Katajavuori, Nina; Lindblom-Ylanne, Sari
2012-01-01
The present study focuses; firstly, on analysing academics' conceptions of the purpose of assessment; secondly, on their assessment practices; and thirdly, on the relationship between their conceptions and practices. The data consisted of interviews with 28 pharmacy teachers. The analysis resulted in a continuum of categories of conceptions, from…
Boehm Test of Basic Concepts-Revised. Review.
ERIC Educational Resources Information Center
Padula, Janice
1988-01-01
The manual for the Boehm Test of Basic Concepts-Revised (1986) is reviewed. The test measures a child's knowledge of relational concepts. The revised version, eliminating some imperfections of the original, will continue to be a useful test of verbal concept acquisition. Cautions necessary while using the test are discussed. (SLD)
A Quantitative Empirical Analysis of the Abstract/Concrete Distinction
ERIC Educational Resources Information Center
Hill, Felix; Korhonen, Anna; Bentz, Christian
2014-01-01
This study presents original evidence that abstract and concrete concepts are organized and represented differently in the mind, based on analyses of thousands of concepts in publicly available data sets and computational resources. First, we show that abstract and concrete concepts have differing patterns of association with other concepts.…
Space 2035: Technology, Transparency, and Trusted Immunity
2010-02-17
12 Figure 2: Maglev -Assisted RLV Concepts .................................................................................. 14...reusable launch vehicles (RLVs). 12, 13 14 Figure 2: Maglev -Assisted RLV Concepts 14 By 2035, several innovative concepts for space...transportation may emerge. These include magnetically-levitated and assisted ( maglev ) RLVs; a novel Space Pier concept, which comprises a series of
Students' Conceptions of the "Reality Status" of Electrons.
ERIC Educational Resources Information Center
Mashhadi, Azam; Woolnough, Brian
Science has many explanatory concepts that have been proposed to account for the observable features of things. Such explanatory concepts often have associated with them hidden or unseen "theoretical entities." The electron is a key concept in understanding phenomena described by science. The question arises, however, as to how students…
Future Engineering Professors' Conceptions of Learning and Teaching Engineering
ERIC Educational Resources Information Center
Torres Ayala, Ana T.
2012-01-01
Conceptions of learning and teaching shape teaching practices and are, therefore, important to understanding how engineering professors learn to teach. There is abundant research about professors' conceptions of teaching; however, research on the conceptions of teaching of doctoral students, the future professors, is scarce. Furthermore,…
Concept Mapping: An "Instagram" of Students' Thinking
ERIC Educational Resources Information Center
Campbell, Laurie O.
2016-01-01
Minimal research has been accumulated in the field of social studies education for Novakian concept mapping, yet there are many benefits from adding this learning tool to a teacher's instructional toolbox. The article defines Novakian concept mapping and invites readers to adopt digital Novakian concept mapping into the social studies classroom as…
Evidence-Based Concept Mapping for the Athletic Training Student
ERIC Educational Resources Information Center
Speicher, Timothy E.; Martin, Malissa; Zigmont, Jason
2013-01-01
Context: A concept map is a graphical and cognitive tool that enables learners to link together interrelated concepts using propositions or statements that answer a posed problem. As an assessment tool, concept mapping reveals a learner's research skill proficiency and cognitive processing. Background: The identification and organization of the…
Developing Concepts and Generalizations in Secondary Social Studies Programs.
ERIC Educational Resources Information Center
Murray, C. Kenneth
1978-01-01
The purpose of this paper is to explore techniques for helping students to develop concepts and generalizations. The author presents three models (Taba, DeCecco, and Fenton) for concept development, and concludes with a discussion of the taxonomy approach, the single concept technique, and the paragraph technique. (KC)
Concept Mapping: Developing Guides to Literature.
ERIC Educational Resources Information Center
Leahy, Robert
1989-01-01
Concept maps, diagrams that show the relationships among concepts in a piece of writing, can help students travel through literature to destinations that they can identify and defend. The use of concept maps for Ernest Hemingway's "The Old Man and The Sea" and Albert Camus'"The Stranger" is described. (MLW)
Students' Conceptions of a Mathematical Definition
ERIC Educational Resources Information Center
Zaslavsky, Orit; Shir, Karni
2005-01-01
This article deals with 12th-grade students' conceptions of a mathematical definition. Their conceptions of a definition were revealed through individual and group activities in which they were asked to consider a number of possible definitions of four mathematical concepts: two geometric and two analytic. Data consisted of written responses to…
Academic Self-Concept, Gender and Single-Sex Schooling
ERIC Educational Resources Information Center
Sullivan, Alice
2009-01-01
This article assesses gender differences in academic self-concept for a cohort of children born in 1958 (the National Child Development Study). It addresses the question of whether attending single-sex or co-educational schools affected students' perceptions of their own academic abilities (academic self-concept). Academic self-concept was found…
Brazilian and Nigerian International Students' Conceptions of Learning in Higher Education
ERIC Educational Resources Information Center
Ashong, Carol; Commander, Nannette
2017-01-01
The growth of international students compels examination of introspective aspects of learning experiences such as conceptions of learning. Additionally, learning conceptions profoundly impact learning outcomes (Tsai, 2009). To address the lack of research on learning conceptions of students from Africa and South America, this study examines…
Essential Map Concepts for Young Children.
ERIC Educational Resources Information Center
Hatcher, Barbara
This paper discusses four key concepts to help preschool and primary grade children develop the ability to read and understand maps. Examples of student activities to develop each of the concepts are provided. The essential concepts are representation, symbolization, perspective, and scale. Representation is vital. Children must perceive that a…
Argumentation and Concept Development: The Role of Imagination
ERIC Educational Resources Information Center
Larraín, Antonia
2017-01-01
Vygotsky stated that concepts cannot be transmitted from mind to mind but instead developed through communication. Specifically, the instructional use of language would be the means for concept development. However, there is evidence to show that school concepts are particularly difficult to develop. Argumentation has been shown to promote the…
High School Biology: A Group Approach to Concept Mapping.
ERIC Educational Resources Information Center
Brown, David S.
2003-01-01
Explains concept mapping as an instructional method in cooperative learning environments, and describes a study investigating the effectiveness of concept mapping on student learning during a photosynthesis and cellular respiration unit. Reports on the positive effects of concept mapping in the experimental group. (Contains 16 references.) (YDS)
The Relationship Between Self-Concept and Marital Adjustment for Commuter College Students
ERIC Educational Resources Information Center
Hall, William M.; Valine, Warren J.
1977-01-01
An investigation was made of the relationship between self-concept and the adjustment of commuter college students. Instruments used were the Tennessee Self Concept Scale and the Locke-Wallace Marital Adjustment Test. There was a significant relationship between self-concept and marital adjustment. (Author)
Threshold Concepts in Finance: Student Perspectives
ERIC Educational Resources Information Center
Hoadley, Susan; Kyng, Tim; Tickle, Leonie; Wood, Leigh N.
2015-01-01
Finance threshold concepts are the essential conceptual knowledge that underpin well-developed financial capabilities and are central to the mastery of finance. In this paper we investigate threshold concepts in finance from the point of view of students, by establishing the extent to which students are aware of threshold concepts identified by…
ERIC Educational Resources Information Center
Plotnick, Eric
This ERIC Digest discusses concept mapping, a technique for representing the structure of information visually. Concept mapping can be used to brainstorm, design complex structures, communicate complex ideas, aid learning by explicitly integrating new and old knowledge, and assess understanding or diagnose misunderstanding. Visual representation…