Visual properties and memorising scenes: Effects of image-space sparseness and uniformity.

PubMed

Lukavský, Jiří; Děchtěrenko, Filip

2017-10-01

Previous studies have demonstrated that humans have a remarkable capacity to memorise a large number of scenes. The research on memorability has shown that memory performance can be predicted by the content of an image. We explored how remembering an image is affected by the image properties within the context of the reference set, including the extent to which it is different from its neighbours (image-space sparseness) and if it belongs to the same category as its neighbours (uniformity). We used a reference set of 2,048 scenes (64 categories), evaluated pairwise scene similarity using deep features from a pretrained convolutional neural network (CNN), and calculated the image-space sparseness and uniformity for each image. We ran three memory experiments, varying the memory workload with experiment length and colour/greyscale presentation. We measured the sensitivity and criterion value changes as a function of image-space sparseness and uniformity. Across all three experiments, we found separate effects of 1) sparseness on memory sensitivity, and 2) uniformity on the recognition criterion. People better remembered (and correctly rejected) images that were more separated from others. People tended to make more false alarms and fewer miss errors in images from categorically uniform portions of the image-space. We propose that both image-space properties affect human decisions when recognising images. Additionally, we found that colour presentation did not yield better memory performance over grayscale images.

Gender differences in navigational memory: pilots vs. nonpilots.

PubMed

Verde, Paola; Piccardi, Laura; Bianchini, Filippo; Guariglia, Cecilia; Carrozzo, Paolo; Morgagni, Fabio; Boccia, Maddalena; Di Fiore, Giacomo; Tomao, Enrico

2015-02-01

The coding of space as near and far is not only determined by arm-reaching distance, but is also dependent on how the brain represents the extension of the body space. Recent reports suggest that the dissociation between reaching and navigational space is not limited to perception and action but also involves memory systems. It has been reported that gender differences emerged only in adverse learning conditions that required strong spatial ability. In this study we investigated navigational versus reaching memory in air force pilots and a control group without flight experience. We took into account temporal duration (working memory and long-term memory) and focused on working memory, which is considered critical in the gender differences literature. We found no gender effects or flight hour effects in pilots but observed gender effects in working memory (but not in learning and delayed recall) in the nonpilot population (Women's mean = 5.33; SD= 0.90; Men's mean = 5.54; SD= 0.90). We also observed a difference between pilots and nonpilots in the maintenance of on-line reaching information: pilots (mean = 5.85; SD=0.76) were more efficient than nonpilots (mean = 5.21; SD=0.83) and managed this type of information similarly to that concerning navigational space. In the navigational learning phase they also showed better navigational memory (mean = 137.83; SD=5.81) than nonpilots (mean = 126.96; SD=15.81) and were significantly more proficient than the latter group. There is no gender difference in a population of pilots in terms of navigational abilities, while it emerges in a control group without flight experience. We found also that pilots performed better than nonpilots. This study suggests that once selected, male and female pilots do not differ from each other in visuo-spatial abilities and spatial navigation.

Radiation Effects of Commercial Resistive Random Access Memories

NASA Technical Reports Server (NTRS)

Chen, Dakai; LaBel, Kenneth A.; Berg, Melanie; Wilcox, Edward; Kim, Hak; Phan, Anthony; Figueiredo, Marco; Buchner, Stephen; Khachatrian, Ani; Roche, Nicolas

2014-01-01

We present results for the single-event effect response of commercial production-level resistive random access memories. We found that the resistive memory arrays are immune to heavy ion-induced upsets. However, the devices were susceptible to single-event functional interrupts, due to upsets from the control circuits. The intrinsic radiation tolerant nature of resistive memory makes the technology an attractive consideration for future space applications.

Durability of carbon fiber reinforced shape memory polymer composites in space

NASA Astrophysics Data System (ADS)

Jang, Joon Hyeok; Hong, Seok Bin; Ahn, Yong San; Kim, Jin-Gyun; Nam, Yong-Youn; Lee, Geun Ho; Yu, Woong-Ryeol

2016-04-01

Shape memory polymer (SMP) is one of smart polymers which exhibit shape memory effect upon external stimuli. Recently, shape memory polymer composites (SMPCs) have been considered for space structure instead of shape memory alloys due to their deformability, lightweight and large recovery ratio, requiring characterization of their mechanical properties against harsh space environment and further prediction of the durability of SMPCs in space. As such, the durability of carbon fiber reinforced shape memory polymer composites (CF-SMPCs) was investigated using accelerated testing method based on short-term testing of CF-SMPCs in harsh condition. CF-SMPCs were prepared using woven carbon fabrics and a thermoset SMP via vacuum assisted resin transfer molding process. Bending tests with constant strain rate of CF-SMPCs were conducted using universal tensile machine (UTM) and Storage modulus test were conducted using dynamic mechanical thermal analysis (DMTA). Using the results, a master curve based on time-temperature superposition principle was then constructed, through which the mechanical properties of CF-SMPCs at harsh temperature were predicted. CF-SMPCs would be exposed to simulated space environments under ultra-violet radiations at various temperatures. The mechanical properties including flexural and tensile strength and shape memory properties of SMPCs would be measured using UTM before and after such exposures for comparison. Finally, the durability of SMPCs in space would be assessed by developing a degradation model of SMPC.

Nonvolatile Memory Technology for Space Applications

NASA Technical Reports Server (NTRS)

Oldham, Timothy R.; Irom, Farokh; Friendlich, Mark; Nguyen, Duc; Kim, Hak; Berg, Melanie; LaBel, Kenneth A.

2010-01-01

This slide presentation reviews several forms of nonvolatile memory for use in space applications. The intent is to: (1) Determine inherent radiation tolerance and sensitivities, (2) Identify challenges for future radiation hardening efforts, (3) Investigate new failure modes and effects, and technology modeling programs. Testing includes total dose, single event (proton, laser, heavy ion), and proton damage (where appropriate). Test vehicles are expected to be a variety of non-volatile memory devices as available including Flash (NAND and NOR), Charge Trap, Nanocrystal Flash, Magnetic Memory (MRAM), Phase Change--Chalcogenide, (CRAM), Ferroelectric (FRAM), CNT, and Resistive RAM.

Impact of Spatial and Verbal Short-Term Memory Load on Auditory Spatial Attention Gradients.

PubMed

Golob, Edward J; Winston, Jenna; Mock, Jeffrey R

2017-01-01

Short-term memory load can impair attentional control, but prior work shows that the extent of the effect ranges from being very general to very specific. One factor for the mixed results may be reliance on point estimates of memory load effects on attention. Here we used auditory attention gradients as an analog measure to map-out the impact of short-term memory load over space. Verbal or spatial information was maintained during an auditory spatial attention task and compared to no-load. Stimuli were presented from five virtual locations in the frontal azimuth plane, and subjects focused on the midline. Reaction times progressively increased for lateral stimuli, indicating an attention gradient. Spatial load further slowed responses at lateral locations, particularly in the left hemispace, but had little effect at midline. Verbal memory load had no (Experiment 1), or a minimal (Experiment 2) influence on reaction times. Spatial and verbal load increased switch costs between memory encoding and attention tasks relative to the no load condition. The findings show that short-term memory influences the distribution of auditory attention over space; and that the specific pattern depends on the type of information in short-term memory.

Impact of Spatial and Verbal Short-Term Memory Load on Auditory Spatial Attention Gradients

PubMed Central

Golob, Edward J.; Winston, Jenna; Mock, Jeffrey R.

2017-01-01

Short-term memory load can impair attentional control, but prior work shows that the extent of the effect ranges from being very general to very specific. One factor for the mixed results may be reliance on point estimates of memory load effects on attention. Here we used auditory attention gradients as an analog measure to map-out the impact of short-term memory load over space. Verbal or spatial information was maintained during an auditory spatial attention task and compared to no-load. Stimuli were presented from five virtual locations in the frontal azimuth plane, and subjects focused on the midline. Reaction times progressively increased for lateral stimuli, indicating an attention gradient. Spatial load further slowed responses at lateral locations, particularly in the left hemispace, but had little effect at midline. Verbal memory load had no (Experiment 1), or a minimal (Experiment 2) influence on reaction times. Spatial and verbal load increased switch costs between memory encoding and attention tasks relative to the no load condition. The findings show that short-term memory influences the distribution of auditory attention over space; and that the specific pattern depends on the type of information in short-term memory. PMID:29218024

Accessing global data from accelerator devices

DOEpatents

Bertolli, Carlo; O'Brien, John K.; Sallenave, Olivier H.; Sura, Zehra N.

2016-12-06

An aspect includes a table of contents (TOC) that was generated by a compiler being received at an accelerator device. The TOC includes an address of global data in a host memory space. The global data is copied from the address in the host memory space to an address in the device memory space. The address in the host memory space is obtained from the received TOC. The received TOC is updated to indicate that global data is stored at the address in the device memory space. A kernel that accesses the global data from the address in the device memory space is executed. The address in the device memory space is obtained based on contents of the updated TOC. When the executing is completed, the global data from the address in the device memory space is copied to the address in the host memory space.

Accessing global data from accelerator devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bertolli, Carlo; O'Brien, John K.; Sallenave, Olivier H.

2016-12-06

An aspect includes a table of contents (TOC) that was generated by a compiler being received at an accelerator device. The TOC includes an address of global data in a host memory space. The global data is copied from the address in the host memory space to an address in the device memory space. The address in the host memory space is obtained from the received TOC. The received TOC is updated to indicate that global data is stored at the address in the device memory space. A kernel that accesses the global data from the address in the devicemore » memory space is executed. The address in the device memory space is obtained based on contents of the updated TOC. When the executing is completed, the global data from the address in the device memory space is copied to the address in the host memory space.« less

Using Latent Class Modeling to Detect Bimodality in Spacing Effect Data

ERIC Educational Resources Information Center

Verkoeijen, Peter P. J. L.; Bouwmeester, Samantha

2008-01-01

A recently proposed theory of the spacing effect [Raaijmakers, J. G. W. (2003). Spacing and repetition effects in human memory: application of the SAM model. "Cognitive Science," 27, 431-452.] suggests that the spacing effect is conditional on study-phase retrieval leading to two groups of students showing different magnitudes of the spacing…

Retrieval practice improves memory in multiple sclerosis: clinical application of the testing effect.

PubMed

Sumowski, James F; Chiaravalloti, Nancy; Deluca, John

2010-03-01

The testing effect is a robust cognitive phenomenon by which memory retrieval on a test improves subsequent recall more than restudying. Also known as retrieval practice, the testing effect has been studied almost exclusively in healthy undergraduates. The current study investigated whether retrieval practice during testing leads to better delayed recall than restudy among persons with multiple sclerosis (MS), a neurologic disease associated with memory dysfunction. In a within-subjects design, 32 persons with MS and 16 demographically matched healthy controls (HC) studied 48 verbal paired associates (VPA) divided across 3 learning conditions: massed restudy (MR), spaced restudy (SR), and spaced testing (ST). Delayed VPA cued recall was measured after 45 min. There was a large main effect of learning condition (etap2 = .54, p < .001) such that both MS and HC participants produced better delayed recall for VPAs learned through ST relative to MR and SR; and SR relative to MR. This same pattern was observed for MS participants with objective memory impairment (n = 16), thereby providing the first evidence that retrieval practice improves memory more than restudy among persons with neurologically based memory impairment. Copyright 2010 APA, all rights reserved

Histone Deacetylase Inhibition Facilitates Massed Pattern-Induced Synaptic Plasticity and Memory

ERIC Educational Resources Information Center

Pandey, Kiran; Sharma, Kaushik P.; Sharma, Shiv K.

2015-01-01

Massed training is less effective for long-term memory formation than the spaced training. The role of acetylation in synaptic plasticity and memory is now well established. However, the role of this important protein modification in synaptic plasticity induced by massed pattern of stimulation or memory induced by massed training is not well…

A dissociation between engagement and learning: Enthusiastic instructions fail to reliably improve performance on a memory task.

PubMed

Motz, Benjamin A; de Leeuw, Joshua R; Carvalho, Paulo F; Liang, Kaley L; Goldstone, Robert L

2017-01-01

Despite widespread assertions that enthusiasm is an important quality of effective teaching, empirical research on the effect of enthusiasm on learning and memory is mixed and largely inconclusive. To help resolve these inconsistencies, we conducted a carefully-controlled laboratory experiment, investigating whether enthusiastic instructions for a memory task would improve recall accuracy. Scripted videos, either enthusiastic or neutral, were used to manipulate the delivery of task instructions. We also manipulated the sequence of learning items, replicating the spacing effect, a known cognitive technique for memory improvement. Although spaced study reliably improved test performance, we found no reliable effect of enthusiasm on memory performance across two experiments. We did, however, find that enthusiastic instructions caused participants to respond to more item prompts, leaving fewer test questions blank, an outcome typically associated with increased task motivation. We find no support for the popular claim that enthusiastic instruction will improve learning, although it may still improve engagement. This dissociation between motivation and learning is discussed, as well as its implications for education and future research on student learning.

A dissociation between engagement and learning: Enthusiastic instructions fail to reliably improve performance on a memory task

PubMed Central

de Leeuw, Joshua R.; Carvalho, Paulo F.; Liang, Kaley L.; Goldstone, Robert L.

2017-01-01

Despite widespread assertions that enthusiasm is an important quality of effective teaching, empirical research on the effect of enthusiasm on learning and memory is mixed and largely inconclusive. To help resolve these inconsistencies, we conducted a carefully-controlled laboratory experiment, investigating whether enthusiastic instructions for a memory task would improve recall accuracy. Scripted videos, either enthusiastic or neutral, were used to manipulate the delivery of task instructions. We also manipulated the sequence of learning items, replicating the spacing effect, a known cognitive technique for memory improvement. Although spaced study reliably improved test performance, we found no reliable effect of enthusiasm on memory performance across two experiments. We did, however, find that enthusiastic instructions caused participants to respond to more item prompts, leaving fewer test questions blank, an outcome typically associated with increased task motivation. We find no support for the popular claim that enthusiastic instruction will improve learning, although it may still improve engagement. This dissociation between motivation and learning is discussed, as well as its implications for education and future research on student learning. PMID:28732087

The effects of mental representation on performance in a navigation task

NASA Technical Reports Server (NTRS)

Barshi, Immanuel; Healy, Alice F.

2002-01-01

In three experiments, we investigated the mental representations employed when instructions were followed that involved navigation in a space displayed as a grid on a computer screen. Performance was affected much more by the number of instructional units than by the number of words per unit. Performance in a three-dimensional space was independent of the number of dimensions along which participants navigated. However, memory for and accuracy in following the instructions were reduced when the task required mentally representing a three-dimensional space, as compared with representing a two-dimensional space, although the words used in the instructions were identical in the two cases. These results demonstrate the interdependence of verbal and spatial memory representations, because individuals' immediate memory for verbal navigation instructions is affected by their mental representation of the space referred to by the instructions.

1986 Annual Conference on Nuclear and Space Radiation Effects, 23rd, Providence, RI, July 21-23, 1986, Proceedings

NASA Technical Reports Server (NTRS)

Ellis, Thomas D. (Editor)

1986-01-01

The present conference on the effects of nuclear and space radiation on electronic hardware gives attention to topics in the basic mechanisms of radiation effects, dosimetry and energy-dependent effects, electronic device radiation hardness assurance, SOI/SOS radiation effects, spacecraft charging and space radiation, IC radiation effects and hardening, single-event upset (SEU) phenomena and hardening, and EMP/SGEMP/IEMP phenomena. Specific treatments encompass the generation of interface states by ionizing radiation in very thin MOS oxides, the microdosimetry of meson energy deposited on 1-micron sites in Si, total dose radiation and engineering studies, plasma interactions with biased concentrator solar cells, the transient imprint memory effect in MOS memories, mechanisms leading to SEU, and the vaporization and breakdown of thin columns of water.

Within-session spacing improves delayed recall in children.

PubMed

Zigterman, Jessica R; Simone, Patricia M; Bell, Matthew C

2015-01-01

Multiple retrievals of a memory over a spaced manner improve long-term memory performance in infants, children, younger and older adults; however, few studies have examined spacing effects with young school-age children. To expand the understanding of the spacing benefit in children, the current study presented weakly associated English word-pairs to children aged 7-11 and cued their recall two times immediately (massed), after a delay of 5 or 10 items (spaced) or not at all (control). After this encoding session with or without two retrievals, participants were tested two times for memory of all word-pairs: immediately and 30 minutes after the encoding session. Multiple retrievals significantly improved memory on the tests. However, words repeated in a spaced design were remembered at higher rates than those that were massed, while gap size between repetitions (5 or 10) did not differentially impact performance. The data show that a within-session spacing strategy can benefit children's ability to remember word-pairs after 30 minutes. Thus, asking students to recall what they have learned within a lesson is a technique that can be used in a classroom to improve long-term recall.

Topological Schemas of Memory Spaces.

PubMed

Babichev, Andrey; Dabaghian, Yuri A

2018-01-01

Hippocampal cognitive map-a neuronal representation of the spatial environment-is widely discussed in the computational neuroscience literature for decades. However, more recent studies point out that hippocampus plays a major role in producing yet another cognitive framework-the memory space-that incorporates not only spatial, but also non-spatial memories. Unlike the cognitive maps, the memory spaces, broadly understood as "networks of interconnections among the representations of events," have not yet been studied from a theoretical perspective. Here we propose a mathematical approach that allows modeling memory spaces constructively, as epiphenomena of neuronal spiking activity and thus to interlink several important notions of cognitive neurophysiology. First, we suggest that memory spaces have a topological nature-a hypothesis that allows treating both spatial and non-spatial aspects of hippocampal function on equal footing. We then model the hippocampal memory spaces in different environments and demonstrate that the resulting constructions naturally incorporate the corresponding cognitive maps and provide a wider context for interpreting spatial information. Lastly, we propose a formal description of the memory consolidation process that connects memory spaces to the Morris' cognitive schemas-heuristic representations of the acquired memories, used to explain the dynamics of learning and memory consolidation in a given environment. The proposed approach allows evaluating these constructs as the most compact representations of the memory space's structure.

Deformation rate-, hold time-, and cycle-dependent shape-memory performance of Veriflex-E resin

NASA Astrophysics Data System (ADS)

McClung, Amber J. W.; Tandon, Gyaneshwar P.; Baur, Jeffery W.

2013-02-01

Shape-memory polymers have attracted great interest in recent years for application in reconfigurable structures (for instance morphing aircraft, micro air vehicles, and deployable space structures). However, before such applications can be attempted, the mechanical behavior of the shape-memory polymers must be thoroughly understood. The present study represents an assessment of viscous effects during multiple shape-memory cycles of Veriflex-E, an epoxy-based, thermally triggered shape-memory polymer resin. The experimental program is designed to explore the influence of multiple thermomechanical cycles on the shape-memory performance of Veriflex-E. The effects of the deformation rate and hold times at elevated temperature on the shape-memory behavior are also investigated.

Implementation of Ferroelectric Memories for Space Applications

NASA Technical Reports Server (NTRS)

Philpy, Stephen C.; Derbenwick, Gary F.; Kamp, David A.; Isaacson, Alan F.

2000-01-01

Ferroelectric random access semiconductor memories (FeRAMs) are an ideal nonvolatile solution for space applications. These memories have low power performance, high endurance and fast write times. By combining commercial ferroelectric memory technology with radiation hardened CMOS technology, nonvolatile semiconductor memories for space applications can be attained. Of the few radiation hardened semiconductor manufacturers, none have embraced the development of radiation hardened FeRAMs, due a limited commercial space market and funding limitations. Government funding may be necessary to assure the development of radiation hardened ferroelectric memories for space applications.

Encoding Strategy Changes and Spacing Effects in the Free Recall of Unmixed Lists

ERIC Educational Resources Information Center

Delaney, P.F.; Knowles, M.E.

2005-01-01

Memory for repeated items often improves when repetitions are separated by other items-a phenomenon called the spacing effect. In two experiments, we explored the complex interaction between study strategies, serial position, and spacing effects. When people studied several unmixed lists, they initially used mainly rote rehearsal, but some people…

Satellite Test of Radiation Impact on Ramtron 512K FRAM

NASA Technical Reports Server (NTRS)

MacLeod, Todd C.; Sayyah, Rana; Sims, W. Herb; Varnavas, Kosta A.; Ho, Fat D.

2009-01-01

The Memory Test Experiment is a space test of a ferroelectric memory device on a low Earth orbit satellite. The test consists of writing and reading data with a ferroelectric based memory device. Any errors are detected and are stored on board the satellite. The data is send to the ground through telemetry once a day. Analysis of the data can determine the kind of error that was found and will lead to a better understanding of the effects of space radiation on memory systems. The test will be one of the first flight demonstrations of ferroelectric memory in a near polar orbit which allows testing in a varied radiation environment. The memory devices being tested is a Ramtron Inc. 512K memory device. This paper details the goals and purpose of this experiment as well as the development process. The process for analyzing the data to gain the maximum understanding of the performance of the ferroelectric memory device is detailed.

Optoelectronic-cache memory system architecture.

PubMed

Chiarulli, D M; Levitan, S P

1996-05-10

We present an investigation of the architecture of an optoelectronic cache that can integrate terabit optical memories with the electronic caches associated with high-performance uniprocessors and multiprocessors. The use of optoelectronic-cache memories enables these terabit technologies to provide transparently low-latency secondary memory with frame sizes comparable with disk pages but with latencies that approach those of electronic secondary-cache memories. This enables the implementation of terabit memories with effective access times comparable with the cycle times of current microprocessors. The cache design is based on the use of a smart-pixel array and combines parallel free-space optical input-output to-and-from optical memory with conventional electronic communication to the processor caches. This cache and the optical memory system to which it will interface provide a large random-access memory space that has a lower overall latency than that of magnetic disks and disk arrays. In addition, as a consequence of the high-bandwidth parallel input-output capabilities of optical memories, fault service times for the optoelectronic cache are substantially less than those currently achievable with any rotational media.

Topological Schemas of Memory Spaces

PubMed Central

Babichev, Andrey; Dabaghian, Yuri A.

2018-01-01

Hippocampal cognitive map—a neuronal representation of the spatial environment—is widely discussed in the computational neuroscience literature for decades. However, more recent studies point out that hippocampus plays a major role in producing yet another cognitive framework—the memory space—that incorporates not only spatial, but also non-spatial memories. Unlike the cognitive maps, the memory spaces, broadly understood as “networks of interconnections among the representations of events,” have not yet been studied from a theoretical perspective. Here we propose a mathematical approach that allows modeling memory spaces constructively, as epiphenomena of neuronal spiking activity and thus to interlink several important notions of cognitive neurophysiology. First, we suggest that memory spaces have a topological nature—a hypothesis that allows treating both spatial and non-spatial aspects of hippocampal function on equal footing. We then model the hippocampal memory spaces in different environments and demonstrate that the resulting constructions naturally incorporate the corresponding cognitive maps and provide a wider context for interpreting spatial information. Lastly, we propose a formal description of the memory consolidation process that connects memory spaces to the Morris' cognitive schemas-heuristic representations of the acquired memories, used to explain the dynamics of learning and memory consolidation in a given environment. The proposed approach allows evaluating these constructs as the most compact representations of the memory space's structure. PMID:29740306

Spacing and Induction: Application to Exemplars Presented as Auditory and Visual Text

ERIC Educational Resources Information Center

Zulkiply, Norehan; McLean, John; Burt, Jennifer S.; Bath, Debra

2012-01-01

It is an established finding that spacing repetitions generally facilitates memory for the repeated events. However, the effect of spacing of exemplars on inductive learning is not really known. Two experiments using textual material were conducted to investigate the effect of spacing on induction. Experiment 1 and 2 extended the generality of…

Review of radiation effects on ReRAM devices and technology

NASA Astrophysics Data System (ADS)

Gonzalez-Velo, Yago; Barnaby, Hugh J.; Kozicki, Michael N.

2017-08-01

A review of the ionizing radiation effects on resistive random access memory (ReRAM) technology and devices is presented in this article. The review focuses on vertical devices exhibiting bipolar resistance switching, devices that have already exhibited interesting properties and characteristics for memory applications and, in particular, for non-volatile memory applications. Non-volatile memories are important devices for any type of electronic and embedded system, as they are for space applications. In such applications, specific environmental issues related to the existence of cosmic rays and Van Allen radiation belts around the Earth contribute to specific failure mechanisms related to the energy deposition induced by such ionizing radiation. Such effects are important in non-volatile memory as the current leading technology, i.e. flash-based technology, is sensitive to the total ionizing dose (TID) and single-event effects. New technologies such as ReRAM, if competing with or complementing the existing non-volatile area of memories from the point of view of performance, also have to exhibit great reliability for use in radiation environments such as space. This has driven research on the radiation effects of such ReRAM technology, on both the conductive-bridge RAM as well as the valence-change memories, or OxRAM variants of the technology. Initial characterizations of ReRAM technology showed a high degree of resilience to TID, developing researchers’ interest in characterizing such resilience as well as investigating the cause of such behavior. The state of the art of such research is reviewed in this article.

Distributed practice can boost evaluative conditioning by increasing memory for the stimulus pairs.

PubMed

Richter, Jasmin; Gast, Anne

2017-09-01

When presenting a neutral stimulus (CS) in close temporal and spatial proximity to a positive or negative stimulus (US) the former is often observed to adopt the valence of the latter, a phenomenon named evaluative conditioning (EC). It is already well established that under most conditions, contingency awareness is important for an EC effect to occur. In addition to that, some findings suggest that awareness of the stimulus pairs is not only relevant during the learning phase, but that it is also relevant whether memory for the pairings is still available during the measurement phase. As previous research has shown that memory is better after temporally distributed than after contiguous (massed) repetitions, it seems plausible that also EC effects are moderated by distributed practice manipulations. This was tested in the current studies. In two experiments with successful distributed practice manipulations on memory, we show that also the magnitude of the EC effect was larger for pairs learned under spaced compared to massed conditions. Both effects, on memory and on EC, are found after a within-participant and after a between-participant manipulation. However, we did not find significant differences in the EC effect for different conditions of spaced practice. These findings are in line with the assumption that EC is based on similar processes as memory for the pairings. Copyright © 2017 Elsevier B.V. All rights reserved.

Single Event Upset Analysis: On-orbit performance of the Alpha Magnetic Spectrometer Digital Signal Processor Memory aboard the International Space Station

NASA Astrophysics Data System (ADS)

Li, Jiaqiang; Choutko, Vitaly; Xiao, Liyi

2018-03-01

Based on the collection of error data from the Alpha Magnetic Spectrometer (AMS) Digital Signal Processors (DSP), on-orbit Single Event Upsets (SEUs) of the DSP program memory are analyzed. The daily error distribution and time intervals between errors are calculated to evaluate the reliability of the system. The particle density distribution of International Space Station (ISS) orbit is presented and the effects from the South Atlantic Anomaly (SAA) and the geomagnetic poles are analyzed. The impact of solar events on the DSP program memory is carried out combining data analysis and Monte Carlo simulation (MC). From the analysis and simulation results, it is concluded that the area corresponding to the SAA is the main source of errors on the ISS orbit. Solar events can also cause errors on DSP program memory, but the effect depends on the on-orbit particle density.

Non-Volatile Memory Technology Symposium 2001: Proceedings

NASA Technical Reports Server (NTRS)

Aranki, Nazeeh; Daud, Taher; Strauss, Karl

2001-01-01

This publication contains the proceedings for the Non-Volatile Memory Technology Symposium 2001 that was held on November 7-8, 2001 in San Diego, CA. The proceedings contains a a wide range of papers that cover current and new memory technologies including Flash memories, Magnetic Random Access Memories (MRAM and GMRAM), Ferro-electric RAM (FeRAM), and Chalcogenide RAM (CRAM). The papers presented in the proceedings address the use of these technologies for space applications as well as radiation effects and packaging issues.

An analytical study of physical models with inherited temporal and spatial memory

NASA Astrophysics Data System (ADS)

Jaradat, Imad; Alquran, Marwan; Al-Khaled, Kamel

2018-04-01

Du et al. (Sci. Reb. 3, 3431 (2013)) demonstrated that the fractional derivative order can be physically interpreted as a memory index by fitting the test data of memory phenomena. The aim of this work is to study analytically the joint effect of the memory index on time and space coordinates simultaneously. For this purpose, we introduce a novel bivariate fractional power series expansion that is accompanied by twofold fractional derivatives ordering α, β\\in(0,1]. Further, some convergence criteria concerning our expansion are presented and an analog of the well-known bivariate Taylor's formula in the sense of mixed fractional derivatives is obtained. Finally, in order to show the functionality and efficiency of this expansion, we employ the corresponding Taylor's series method to obtain closed-form solutions of various physical models with inherited time and space memory.

Extending Cognitive Load Theory to Incorporate Working Memory Resource Depletion: Evidence from the Spacing Effect

ERIC Educational Resources Information Center

Chen, Ouhao; Castro-Alonso, Juan C.; Paas, Fred; Sweller, John

2018-01-01

Depletion of limited working memory resources may occur following extensive mental effort resulting in decreased performance compared to conditions requiring less extensive mental effort. This "depletion effect" can be incorporated into cognitive load theory that is concerned with using the properties of human cognitive architecture,…

Neurogenesis and the Spacing Effect: Learning over Time Enhances Memory and the Survival of New Neurons

ERIC Educational Resources Information Center

Sisti, Helene M.; Glass, Arnold L.; Shors, Tracey J.

2007-01-01

Information that is spaced over time is better remembered than the same amount of information massed together. This phenomenon, known as the spacing effect, was explored with respect to its effect on learning and neurogenesis in the adult dentate gyrus of the hippocampal formation. Because the cells are generated over time and because learning…

Lexical integration of novel words without sleep.

PubMed

Lindsay, Shane; Gaskell, M Gareth

2013-03-01

Learning a new word involves integration with existing lexical knowledge. Previous work has shown that sleep-associated memory consolidation processes are important for the engagement of novel items in lexical competition. In 3 experiments we used spaced exposure regimes to investigate memory for novel words and whether lexical integration can occur within a single day. The degree to which a new spoken word (e.g., cathedruke) engaged in lexical competition with established phonological neighbors (e.g., cathedral) was employed as a marker for lexical integration. We found evidence for improvements in recognition and cued recall following a time period including sleep, but we also found lexical competition effects emerging within a single day. Spaced exposure to novel words on its own did not bring about this within-day lexical competition effect (Experiment 2), which instead occurred with either spaced or massed exposure to novel words, provided that there was also spaced exposure to the phonological neighbors (Experiments 1 and 3). Although previous studies have indicated that sleep-dependent memory consolidation may be sufficient for lexical integration, our results show it is not a necessary precondition. (c) 2013 APA, all rights reserved.

The effect of visual and interaction fidelity on spatial cognition in immersive virtual environments.

PubMed

Mania, Katerina; Wooldridge, Dave; Coxon, Matthew; Robinson, Andrew

2006-01-01

Accuracy of memory performance per se is an imperfect reflection of the cognitive activity (awareness states) that underlies performance in memory tasks. The aim of this research is to investigate the effect of varied visual and interaction fidelity of immersive virtual environments on memory awareness states. A between groups experiment was carried out to explore the effect of rendering quality on location-based recognition memory for objects and associated states of awareness. The experimental space, consisting of two interconnected rooms, was rendered either flat-shaded or using radiosity rendering. The computer graphics simulations were displayed on a stereo head-tracked Head Mounted Display. Participants completed a recognition memory task after exposure to the experimental space and reported one of four states of awareness following object recognition. These reflected the level of visual mental imagery involved during retrieval, the familiarity of the recollection, and also included guesses. Experimental results revealed variations in the distribution of participants' awareness states across conditions while memory performance failed to reveal any. Interestingly, results revealed a higher proportion of recollections associated with mental imagery in the flat-shaded condition. These findings comply with similar effects revealed in two earlier studies summarized here, which demonstrated that the less "naturalistic" interaction interface or interface of low interaction fidelity provoked a higher proportion of recognitions based on visual mental images.

Restricted sedation and absence of cognitive impairments after administration of intranasal scopolamine.

PubMed

Weerts, Aurélie P; Pattyn, Nathalie; Putcha, Lakshmi; Hoag, Stephen W; Van Ombergen, Angelique; Hallgren, Emma; Van de Heyning, Paul H; Wuyts, Floris L

2015-12-01

Space motion sickness in astronauts during spaceflight causes significant discomfort, which might impede their functionality. Pharmacological treatment has been mainly restricted to promethazine. Transdermal and oral scopolamine have also been used in space; however, their use was reduced due to unpredictable effectiveness and side effects. Recently, intranasal scopolamine administration has gained much interest, since this route ensures fast and reliable absorption with a decreased incidence of undesirable side effects. The aim of this study was to evaluate the effect of intranasal scopolamine on cognitive performance and to determine its side effects. This double-blind, placebo controlled, repeated measures study evaluated vigilant attention, short-term memory, implicit memory and working memory. Side effects were reported on a 22-item questionnaire and sleepiness was assessed by the Karolinska, Stanford and Epworth Sleepiness Scales. Scopolamine had no effect on cognitive function. Only the Karolinska score was significantly increased for scopolamine compared to placebo. Participants reported a dry mouth and dizziness after receiving scopolamine. Results show that intranasal scopolamine did not impair cognitive performance. Intranasal scopolamine might be a good alternative to promethazine for the alleviation of space motion sickness, since the agent has minimal sedative effects and does not hamper cognitive performance. © The Author(s) 2015.

Distributed state-space generation of discrete-state stochastic models

NASA Technical Reports Server (NTRS)

Ciardo, Gianfranco; Gluckman, Joshua; Nicol, David

1995-01-01

High-level formalisms such as stochastic Petri nets can be used to model complex systems. Analysis of logical and numerical properties of these models of ten requires the generation and storage of the entire underlying state space. This imposes practical limitations on the types of systems which can be modeled. Because of the vast amount of memory consumed, we investigate distributed algorithms for the generation of state space graphs. The distributed construction allows us to take advantage of the combined memory readily available on a network of workstations. The key technical problem is to find effective methods for on-the-fly partitioning, so that the state space is evenly distributed among processors. In this paper we report on the implementation of a distributed state-space generator that may be linked to a number of existing system modeling tools. We discuss partitioning strategies in the context of Petri net models, and report on performance observed on a network of workstations, as well as on a distributed memory multi-computer.

Lexico-Semantic Structure and the Word-Frequency Effect in Recognition Memory

ERIC Educational Resources Information Center

Monaco, Joseph D.; Abbott, L. F.; Kahana, Michael J.

2007-01-01

The word-frequency effect (WFE) in recognition memory refers to the finding that more rare words are better recognized than more common words. We demonstrate that a familiarity-discrimination model operating on data from a semantic word-association space yields a robust WFE in data on both hit rates and false-alarm rates. Our modeling results…

Initial Results from On-Orbit Testing of the Fram Memory Test Experiment on the Fastsat Micro-Satellite

NASA Technical Reports Server (NTRS)

MacLeond, Todd C.; Sims, W. Herb; Varnavas,Kosta A.; Ho, Fat D.

2011-01-01

The Memory Test Experiment is a space test of a ferroelectric memory device on a low Earth orbit satellite that launched in November 2010. The memory device being tested is a commercial Ramtron Inc. 512K memory device. The circuit was designed into the satellite avionics and is not used to control the satellite. The test consists of writing and reading data with the ferroelectric based memory device. Any errors are detected and are stored on board the satellite. The data is sent to the ground through telemetry once a day. Analysis of the data can determine the kind of error that was found and will lead to a better understanding of the effects of space radiation on memory systems. The test is one of the first flight demonstrations of ferroelectric memory in a near polar orbit which allows testing in a varied radiation environment. The initial data from the test is presented. This paper details the goals and purpose of this experiment as well as the development process. The process for analyzing the data to gain the maximum understanding of the performance of the ferroelectric memory device is detailed.

Strategic priming with multiple antigens can yield memory cell phenotypes optimized for infection with Mycobacterium tuberculosis: A computational study

DOE PAGES

Ziraldo, Cordelia; Gong, Chang; Kirschner, Denise E.; ...

2016-01-06

Lack of an effective vaccine results in 9 million new cases of tuberculosis (TB) every year and 1.8 million deaths worldwide. While many infants are vaccinated at birth with BCG (an attenuated M. bovis), this does not prevent infection or development of TB after childhood. Immune responses necessary for prevention of infection or disease are still unknown, making development of effective vaccines against TB challenging. Several new vaccines are ready for human clinical trials, but these trials are difficult and expensive; especially challenging is determining the appropriate cellular response necessary for protection. The magnitude of an immune response is likelymore » key to generating a successful vaccine. Characteristics such as numbers of central memory (CM) and effector memory (EM) T cells responsive to a diverse set of epitopes are also correlated with protection. Promising vaccines against TB contain mycobacterial subunit antigens (Ag) present during both active and latent infection. We hypothesize that protection against different key immunodominant antigens could require a vaccine that produces different levels of EM and CM for each Ag-specific memory population. We created a computational model to explore EM and CM values, and their ratio, within what we term Memory Design Space. Our model captures events involved in T cell priming within lymph nodes and tracks their circulation through blood to peripheral tissues. We used the model to test whether multiple Ag-specific memory cell populations could be generated with distinct locations within Memory Design Space at a specific time point post vaccination. Boosting can further shift memory populations to memory cell ratios unreachable by initial priming events. By strategically varying antigen load, properties of cellular interactions within the LN, and delivery parameters (e.g., number of boosts) of multi-subunit vaccines, we can generate multiple Ag-specific memory populations that cover a wide range of Memory Design Space. As a result, given a set of desired characteristics for Ag-specific memory populations, we can use our model as a tool to predict vaccine formulations that will generate those populations.« less

Strategic priming with multiple antigens can yield memory cell phenotypes optimized for infection with Mycobacterium tuberculosis: A computational study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ziraldo, Cordelia; Gong, Chang; Kirschner, Denise E.

Lack of an effective vaccine results in 9 million new cases of tuberculosis (TB) every year and 1.8 million deaths worldwide. While many infants are vaccinated at birth with BCG (an attenuated M. bovis), this does not prevent infection or development of TB after childhood. Immune responses necessary for prevention of infection or disease are still unknown, making development of effective vaccines against TB challenging. Several new vaccines are ready for human clinical trials, but these trials are difficult and expensive; especially challenging is determining the appropriate cellular response necessary for protection. The magnitude of an immune response is likelymore » key to generating a successful vaccine. Characteristics such as numbers of central memory (CM) and effector memory (EM) T cells responsive to a diverse set of epitopes are also correlated with protection. Promising vaccines against TB contain mycobacterial subunit antigens (Ag) present during both active and latent infection. We hypothesize that protection against different key immunodominant antigens could require a vaccine that produces different levels of EM and CM for each Ag-specific memory population. We created a computational model to explore EM and CM values, and their ratio, within what we term Memory Design Space. Our model captures events involved in T cell priming within lymph nodes and tracks their circulation through blood to peripheral tissues. We used the model to test whether multiple Ag-specific memory cell populations could be generated with distinct locations within Memory Design Space at a specific time point post vaccination. Boosting can further shift memory populations to memory cell ratios unreachable by initial priming events. By strategically varying antigen load, properties of cellular interactions within the LN, and delivery parameters (e.g., number of boosts) of multi-subunit vaccines, we can generate multiple Ag-specific memory populations that cover a wide range of Memory Design Space. As a result, given a set of desired characteristics for Ag-specific memory populations, we can use our model as a tool to predict vaccine formulations that will generate those populations.« less

Errorless learning and spaced retrieval: how do these methods fare in healthy and clinical populations?

PubMed

Haslam, Catherine; Hodder, Kathryn I; Yates, Philip J

2011-04-01

While errorless learning and spaced retrieval have both proved effective in helping many patients with acquired brain injury (ABI) and dementia learn novel information, it is not clear which of these principles we should apply to target treatment most effectively. To address this issue we conducted a systematic comparison of these principles in three experiments, comparing their effectiveness in healthy controls (N = 60), patients with ABI (N = 30), and patients with dementia (N = 15). Participants were asked to learn face-name associations, and the relative effectiveness of the principles over and above trial-and-error learning was investigated. The results were remarkably consistent across experiments: Both errorless learning and spaced retrieval produced greater accuracy in name recall than did trial-and-error learning, but recall under conditions of spaced retrieval was significantly better than that under errorless learning. We discuss the implications of these findings and suggest that spaced retrieval may be the stronger memory rehabilitation principle when it comes to learning face-name associations in people with mild to moderate memory impairment.

Whorfian effects on colour memory are not reliable.

PubMed

Wright, Oliver; Davies, Ian R L; Franklin, Anna

2015-01-01

The Whorfian hypothesis suggests that differences between languages cause differences in cognitive processes. Support for this idea comes from studies that find that patterns of colour memory errors made by speakers of different languages align with differences in colour lexicons. The current study provides a large-scale investigation of the relationship between colour language and colour memory, adopting a cross-linguistic and developmental approach. Colour memory on a delayed matching-to-sample (XAB) task was investigated in 2 language groups with differing colour lexicons, for 3 developmental stages and 2 regions of colour space. Analyses used a Bayesian technique to provide simultaneous assessment of two competing hypotheses (H1-Whorfian effect present, H0-Whorfian effect absent). Results of the analyses consistently favoured H0. The findings suggest that Whorfian effects on colour memory are not reliable and that the importance of such effects should not be overestimated.

Compact Holographic Data Storage

NASA Technical Reports Server (NTRS)

Chao, T. H.; Reyes, G. F.; Zhou, H.

2001-01-01

NASA's future missions would require massive high-speed onboard data storage capability to Space Science missions. For Space Science, such as the Europa Lander mission, the onboard data storage requirements would be focused on maximizing the spacecraft's ability to survive fault conditions (i.e., no loss in stored science data when spacecraft enters the 'safe mode') and autonomously recover from them during NASA's long-life and deep space missions. This would require the development of non-volatile memory. In order to survive in the stringent environment during space exploration missions, onboard memory requirements would also include: (1) survive a high radiation environment (1 Mrad), (2) operate effectively and efficiently for a very long time (10 years), and (3) sustain at least a billion write cycles. Therefore, memory technologies requirements of NASA's Earth Science and Space Science missions are large capacity, non-volatility, high-transfer rate, high radiation resistance, high storage density, and high power efficiency. JPL, under current sponsorship from NASA Space Science and Earth Science Programs, is developing a high-density, nonvolatile and rad-hard Compact Holographic Data Storage (CHDS) system to enable large-capacity, high-speed, low power consumption, and read/write of data in a space environment. The entire read/write operation will be controlled with electrooptic mechanism without any moving parts. This CHDS will consist of laser diodes, photorefractive crystal, spatial light modulator, photodetector array, and I/O electronic interface. In operation, pages of information would be recorded and retrieved with random access and high-speed. The nonvolatile, rad-hard characteristics of the holographic memory will provide a revolutionary memory technology meeting the high radiation challenge facing the Europa Lander mission. Additional information is contained in the original extended abstract.

Qualitative differences in memory for vista and environmental spaces are caused by opaque borders, not movement or successive presentation.

PubMed

Meilinger, Tobias; Strickrodt, Marianne; Bülthoff, Heinrich H

2016-10-01

Two classes of space define our everyday experience within our surrounding environment: vista spaces, such as rooms or streets which can be perceived from one vantage point, and environmental spaces, for example, buildings and towns which are grasped from multiple views acquired during locomotion. However, theories of spatial representations often treat both spaces as equal. The present experiments show that this assumption cannot be upheld. Participants learned exactly the same layout of objects either within a single room or spread across multiple corridors. By utilizing a pointing and a placement task we tested the acquired configurational memory. In Experiment 1 retrieving memory of the object layout acquired in environmental space was affected by the distance of the traveled path and the order in which the objects were learned. In contrast, memory retrieval of objects learned in vista space was not bound to distance and relied on different ordering schemes (e.g., along the layout structure). Furthermore, spatial memory of both spaces differed with respect to the employed reference frame orientation. Environmental space memory was organized along the learning experience rather than layout intrinsic structure. In Experiment 2 participants memorized the object layout presented within the vista space room of Experiment 1 while the learning procedure emulated environmental space learning (movement, successive object presentation). Neither factor rendered similar results as found in environmental space learning. This shows that memory differences between vista and environmental space originated mainly from the spatial compartmentalization which was unique to environmental space learning. Our results suggest that transferring conclusions from findings obtained in vista space to environmental spaces and vice versa should be made with caution. Copyright © 2016 Elsevier B.V. All rights reserved.

Bipolar resistive switching in Cu/AlN/Pt nonvolatile memory device

NASA Astrophysics Data System (ADS)

Chen, C.; Yang, Y. C.; Zeng, F.; Pan, F.

2010-08-01

Highly stable and reproducible bipolar resistive switching effects are reported on Cu/AlN/Pt devices. Memory characteristics including large memory window of 103, long retention time of >106 s and good endurance of >103 were demonstrated. It is concluded that the reset current decreases as compliance current decreases, which provides an approach to suppress power consumption. The dominant conduction mechanisms of low resistance state and high resistance state were verified by Ohmic behavior and trap-controlled space charge limited current, respectively. The memory effect is explained by the model concerning redox reaction mediated formation and rupture of the conducting filament in AlN films.

Spatial coding of ordinal information in short- and long-term memory.

PubMed

Ginsburg, Véronique; Gevers, Wim

2015-01-01

The processing of numerical information induces a spatial response bias: Faster responses to small numbers with the left hand and faster responses to large numbers with the right hand. Most theories agree that long-term representations underlie this so called SNARC effect (Spatial Numerical Association of Response Codes; Dehaene et al., 1993). However, a spatial response bias was also observed with the activation of temporary position-space associations in working memory (ordinal position effect; van Dijck and Fias, 2011). Items belonging to the beginning of a memorized sequence are responded to faster with the left hand side while items at the end of the sequence are responded to faster with the right hand side. The theoretical possibility was put forward that the SNARC effect is an instance of the ordinal position effect, with the empirical consequence that the SNARC effect and the ordinal position effect cannot be observed simultaneously. In two experiments we falsify this claim by demonstrating that the SNARC effect and the ordinal position effect are not mutually exclusive. Consequently, this suggests that the SNARC effect and the ordinal position effect result from the activation of different representations. We conclude that spatial response biases can result from the activation of both pre-existing positions in long-term memory and from temporary space associations in working memory at the same time.

Chicks incubated in hypomagnetic field need more exogenous noradrenaline for memory consolidation

NASA Astrophysics Data System (ADS)

Xiao, Ying; Wang, Qian; Xu, Mu-Ling; Jiang, Jin-Chang; Li, Bing

2009-07-01

The geomagnetic field (GMF) is one of the essential characteristics of the terrestrial environment but does not apply in outer space. The elimination of GMF may interfere with the normal activities of life in many aspects. Previous behavioral experiments have found that long-term memory is impaired in chicks incubated in a near-zero magnetic environment (i.e. hypomagnetic field or HMF). The present study was designed to evaluate the possible involvement of noradrenergic change in the functional abnormality observed before. A HMF space was produced by nullifying the natural GMF with three pairs of Helmholtz coils. The one-trial passive avoidance learning paradigm was performed on day-old chicks incubated in either the HMF space or the natural GMF. Exogenous noradrenaline was administered by intracerebral injections and the effect on memory consolidation was compared between the two categories of subjects. In the behavioral paradigm, the HMF chicks had a higher elimination rate than the GMF chicks and displayed a significant reduction in overall responsiveness. The administration of moderate doses (0.1-0.5 nmol/hemisphere) of noradrenaline led to fairly good memory retention in GMF chicks but had little effect on HMF chicks. However, long-term memory of HMF chicks could be elevated to the normal level by much higher doses (1.0-1.75 nmol/hem) of the drug. These results suggest that prolonged exposure to HMF may induce disorders in the noradrenergic system in the brain and indicate a potentiality of counteracting the ill-effect of GMF deprivation with appropriate pharmacological manipulation.

Significance of autobiographical episodes and spacing effects in incidental memory.

PubMed

Toyota, Hiroshi

2013-10-01

Participants were presented with target words on two occasions, and were asked each time to generate a memory of a past episode associated with the targets. Participants were also instructed to rate the importance (significance elaboration) or pleasantness of the pisode (pleasantness elaboration) in an orienting task, followed by an unexpect d recall test. Significance elaboration led to better recall than pleasantness elaboration, but only in the spaced presentation. The spaced presentation led to better tree recall than massed presentation with significance elaboration, but the difference between the two types of presentation was not observed with pleasantness elaboration. These results suggest that the significance of an episode is more critical than the pleasantness of an episode in determining the effectiveness of autobiographical elaboration in facilitating recall.

A Time and Place for Everything: Developmental Differences in the Building Blocks of Episodic Memory

PubMed Central

Lee, Joshua K.; Wendelken, J. Carter; Bunge, Silvia A.; Ghetti, Simona

2015-01-01

This research investigated whether episodic memory development can be explained by improvements in relational binding processes, involved in forming novel associations between events and the context in which they occurred. Memory for item-space, item-time, and item-item relations was assessed in an ethnically diverse sample of 151 children aged 7 to 11 years and 28 young adults. Item-space memory reached adult performance by 9½ years, whereas item-time and item-item memory improved into adulthood. In path analysis, item-space, but not item-time best explained item-item memory. Across age groups, relational binding related to source memory and performance on standardized memory assessments. In conclusion, relational binding development depends on relation type, but relational binding overall supports episodic memory development. PMID:26493950

Differential effects of spaced vs. massed training in long-term object-identity and object-location recognition memory.

PubMed

Bello-Medina, Paola C; Sánchez-Carrasco, Livia; González-Ornelas, Nadia R; Jeffery, Kathryn J; Ramírez-Amaya, Víctor

2013-08-01

Here we tested whether the well-known superiority of spaced training over massed training is equally evident in both object identity and object location recognition memory. We trained animals with objects placed in a variable or in a fixed location to produce a location-independent object identity memory or a location-dependent object representation. The training consisted of 5 trials that occurred either on one day (Massed) or over the course of 5 consecutive days (Spaced). The memory test was done in independent groups of animals either 24h or 7 days after the last training trial. In each test the animals were exposed to either a novel object, when trained with the objects in variable locations, or to a familiar object in a novel location, when trained with objects in fixed locations. The difference in time spent exploring the changed versus the familiar objects was used as a measure of recognition memory. For the object-identity-trained animals, spaced training produced clear evidence of recognition memory after both 24h and 7 days, but massed-training animals showed it only after 24h. In contrast, for the object-location-trained animals, recognition memory was evident after both retention intervals and with both training procedures. When objects were placed in variable locations for the two types of training and the test was done with a brand-new location, only the spaced-training animals showed recognition at 24h, but surprisingly, after 7 days, animals trained using both procedures were able to recognize the change, suggesting a post-training consolidation process. We suggest that the two training procedures trigger different neural mechanisms that may differ in the two segregated streams that process object information and that may consolidate differently. Copyright © 2013 Elsevier B.V. All rights reserved.

Inflated speedups in parallel simulations via malloc()

NASA Technical Reports Server (NTRS)

Nicol, David M.

1990-01-01

Discrete-event simulation programs make heavy use of dynamic memory allocation in order to support simulation's very dynamic space requirements. When programming in C one is likely to use the malloc() routine. However, a parallel simulation which uses the standard Unix System V malloc() implementation may achieve an overly optimistic speedup, possibly superlinear. An alternate implementation provided on some (but not all systems) can avoid the speedup anomaly, but at the price of significantly reduced available free space. This is especially severe on most parallel architectures, which tend not to support virtual memory. It is shown how a simply implemented user-constructed interface to malloc() can both avoid artificially inflated speedups, and make efficient use of the dynamic memory space. The interface simply catches blocks on the basis of their size. The problem is demonstrated empirically, and the effectiveness of the solution is shown both empirically and analytically.

Memory Boost from Spaced-Out Learning.

ERIC Educational Resources Information Center

Bower, B.

1987-01-01

Discusses what learning conditions promote memory stamina. Reviews study findings which suggested that spacing of practice during rote learning of a foreign language vocabulary can produce lasting memories. (ML)

Metacognition and the Spacing Effect: The Role of Repetition, Feedback, and Instruction on Judgments of Learning for Massed and Spaced Rehearsal

ERIC Educational Resources Information Center

Logan, Jessica M.; Castel, Alan D.; Haber, Sara; Viehman, Emily J.

2012-01-01

Although memory performance benefits from the spacing of information at encoding, judgments of learning (JOLs) are often not sensitive to the benefits of spacing. The present research examines how practice, feedback, and instruction influence JOLs for spaced and massed items. In Experiment 1, in which JOLs were made after the presentation of each…

KENNEDY SPACE CENTER, FLA. - In front of the Space Memorial Mirror at the KSC Visitor Complex, Center Director Jim Kennedy (right) speaks to visitors gathered for the memorial service honoring the crew of Columbia. At left are KSC Deputy Director Woodrow Whitlow Jr. and Executive Director of Florida Space Authority Winston Scott; at right is Dr. Stephen Feldman, president of the Astronaut Memorial Foundation. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was also invited to the memorial service held at the KSC Visitor Complex.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - In front of the Space Memorial Mirror at the KSC Visitor Complex, Center Director Jim Kennedy (right) speaks to visitors gathered for the memorial service honoring the crew of Columbia. At left are KSC Deputy Director Woodrow Whitlow Jr. and Executive Director of Florida Space Authority Winston Scott; at right is Dr. Stephen Feldman, president of the Astronaut Memorial Foundation. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was also invited to the memorial service held at the KSC Visitor Complex.

Structural Synaptic Plasticity Has High Memory Capacity and Can Explain Graded Amnesia, Catastrophic Forgetting, and the Spacing Effect

PubMed Central

Knoblauch, Andreas; Körner, Edgar; Körner, Ursula; Sommer, Friedrich T.

2014-01-01

Although already William James and, more explicitly, Donald Hebb's theory of cell assemblies have suggested that activity-dependent rewiring of neuronal networks is the substrate of learning and memory, over the last six decades most theoretical work on memory has focused on plasticity of existing synapses in prewired networks. Research in the last decade has emphasized that structural modification of synaptic connectivity is common in the adult brain and tightly correlated with learning and memory. Here we present a parsimonious computational model for learning by structural plasticity. The basic modeling units are “potential synapses” defined as locations in the network where synapses can potentially grow to connect two neurons. This model generalizes well-known previous models for associative learning based on weight plasticity. Therefore, existing theory can be applied to analyze how many memories and how much information structural plasticity can store in a synapse. Surprisingly, we find that structural plasticity largely outperforms weight plasticity and can achieve a much higher storage capacity per synapse. The effect of structural plasticity on the structure of sparsely connected networks is quite intuitive: Structural plasticity increases the “effectual network connectivity”, that is, the network wiring that specifically supports storage and recall of the memories. Further, this model of structural plasticity produces gradients of effectual connectivity in the course of learning, thereby explaining various cognitive phenomena including graded amnesia, catastrophic forgetting, and the spacing effect. PMID:24858841

Nanoscale content-addressable memory

NASA Technical Reports Server (NTRS)

Davis, Bryan (Inventor); Principe, Jose C. (Inventor); Fortes, Jose (Inventor)

2009-01-01

A combined content addressable memory device and memory interface is provided. The combined device and interface includes one or more one molecular wire crossbar memories having spaced-apart key nanowires, spaced-apart value nanowires adjacent to the key nanowires, and configurable switches between the key nanowires and the value nanowires. The combination further includes a key microwire-nanowire grid (key MNG) electrically connected to the spaced-apart key nanowires, and a value microwire-nanowire grid (value MNG) electrically connected to the spaced-apart value nanowires. A key or value MNGs selects multiple nanowires for a given key or value.

Auditory Training for Adults Who Have Hearing Loss: A Comparison of Spaced versus Massed Practice Schedules

ERIC Educational Resources Information Center

Tye-Murray, Nancy; Spehar, Brent; Barcroft, Joe; Sommers, Mitchell

2017-01-01

Purpose: The spacing effect in human memory research refers to situations in which people learn items better when they study items in spaced intervals rather than massed intervals. This investigation was conducted to compare the efficacy of meaning-oriented auditory training when administered with a spaced versus massed practice schedule. Method:…

Spatial profile of charge storage in organic field-effect transistor nonvolatile memory using polymer electret

NASA Astrophysics Data System (ADS)

She, Xiao-Jian; Liu, Jie; Zhang, Jing-Yu; Gao, Xu; Wang, Sui-Dong

2013-09-01

Spatial profile of the charge storage in the pentacene-based field-effect transistor nonvolatile memories using poly(2-vinyl naphthalene) electret is probed. The electron trapping into the electret after programming can be space dependent with more electron storage in the region closer to the contacts, and reducing the channel length is an effective approach to improve the memory performance. The deficient electron supply in pentacene is proposed to be responsible for the inhomogeneous electron storage in the electret. The hole trapping into the electret after erasing is spatially homogeneous, arising from the sufficient hole accumulation in the pentacene channel.

Analysis of memory use for improved design and compile-time allocation of local memory

NASA Technical Reports Server (NTRS)

Mcniven, Geoffrey D.; Davidson, Edward S.

1986-01-01

Trace analysis techniques are used to study memory referencing behavior for the purpose of designing local memories and determining how to allocate them for data and instructions. In an attempt to assess the inherent behavior of the source code, the trace analysis system described here reduced the effects of the compiler and host architecture on the trace by using a technical called flattening. The variables in the trace, their associated single-assignment values, and references are histogrammed on the basis of various parameters describing memory referencing behavior. Bounds are developed specifying the amount of memory space required to store all live values in a particular histogram class. The reduction achieved in main memory traffic by allocating local memory is specified for each class.

Self-corrected elaboration and spacing effects in incidental memory.

PubMed

Toyota, Hiroshi

2006-04-01

The present study investigated the effect of self-corrected elaboration on incidental memory as a function of types of presentation (massed vs spaced) and sentence frames (image vs nonimage). The subjects were presented a target word and an incongruous sentence frame and asked to correct the target to make a common sentence in the self-corrected elaboration condition, whereas in the experimenter-corrected elaboration condition they were asked to rate the appropriateness of the congruous word presented, followed by free recall test. The superiority of the self-corrected elaboration to the experimenter-corrected elaboration was observed only in some situations of combinations by the types of presentation and sentence frames. These results were discussed in terms of the effectiveness of the self-corrected elaboration.

Effects of distraction and pictorial illustration on memory for countries in older adults with probable Alzheimer's disease.

PubMed

Boudreaux, Emily O; Cherry, Katie E; Elliott, Emily M; Hicks, Jason L

2011-05-01

Eight participants with probable Alzheimer's disease (AD) were trained to recall names of countries using the spaced-retrieval memory intervention. Six training sessions were administered on alternate days over a 2-week period. Half of the participants studied a target country alone and the other half studied a target country along with eight distractor countries. Training stimuli appeared in text-only format in half of the sessions and text with a color photograph of the country in the other sessions. On each trial, participants selected the target at increasingly longer retention intervals, contingent upon successful recall. Results indicated that the mean proportion of correct trials and longest duration achieved increased across training sessions, confirming the success of the spaced-retrieval intervention. Pictorial illustrations enhanced explicit memory for target country names. Implications of these data for current views on memory remediation in cognitively impaired older adults are discussed.

Radiation Tests of Highly Scaled, High-Density, Commercial, Nonvolatile NAND Flash Memories - Update 2012

NASA Technical Reports Server (NTRS)

Irom, Farokh; Allen, Gregory R.

2012-01-01

The space radiation environment poses a certain risk to all electronic components on Earth-orbiting and planetary mission spacecraft. In recent years, there has been increased interest in the use of high-density, commercial, nonvolatile flash memories in space because of ever-increasing data volumes and strict power requirements. They are used in a wide variety of spacecraft subsystems. At one end of the spectrum, flash memories are used to store small amounts of mission-critical data such as boot code or configuration files and, at the other end, they are used to construct multi-gigabyte data recorders that record mission science data. This report examines single-event effect (SEE) and total ionizing dose (TID) response in single-level cell (SLC) 32-Gb, multi-level cell (MLC) 64-Gb, and Triple-level (TLC) 64-Gb NAND flash memories manufactured by Micron Technology with feature size of 25 nm.

Functional Connectivity among Spikes in Low Dimensional Space during Working Memory Task in Rat

PubMed Central

Tian, Xin

2014-01-01

Working memory (WM) is critically important in cognitive tasks. The functional connectivity has been a powerful tool for understanding the mechanism underlying the information processing during WM tasks. The aim of this study is to investigate how to effectively characterize the dynamic variations of the functional connectivity in low dimensional space among the principal components (PCs) which were extracted from the instantaneous firing rate series. Spikes were obtained from medial prefrontal cortex (mPFC) of rats with implanted microelectrode array and then transformed into continuous series via instantaneous firing rate method. Granger causality method is proposed to study the functional connectivity. Then three scalar metrics were applied to identify the changes of the reduced dimensionality functional network during working memory tasks: functional connectivity (GC), global efficiency (E) and casual density (CD). As a comparison, GC, E and CD were also calculated to describe the functional connectivity in the original space. The results showed that these network characteristics dynamically changed during the correct WM tasks. The measure values increased to maximum, and then decreased both in the original and in the reduced dimensionality. Besides, the feature values of the reduced dimensionality were significantly higher during the WM tasks than they were in the original space. These findings suggested that functional connectivity among the spikes varied dynamically during the WM tasks and could be described effectively in the low dimensional space. PMID:24658291

A working memory account of the interaction between numbers and spatial attention.

PubMed

van Dijck, Jean-Philippe; Abrahamse, Elger L; Acar, Freya; Ketels, Boris; Fias, Wim

2014-01-01

Rather than reflecting the long-term memory construct of a mental number line, it has been proposed that the relation between numbers and space is of a more temporary nature and constructed in working memory during task execution. In three experiments we further explored the viability of this working memory account. Participants performed a speeded dot detection task with dots appearing left or right, while maintaining digits or letters in working memory. Just before presentation of the dot, these digits or letters were used as central cues. These experiments show that the "attentional SNARC-effect" (where SNARC is the spatial-numerical association of response codes) is not observed when only the lastly perceived number cue--and no serially ordered sequence of cues--is maintained in working memory (Experiment 1). It is only when multiple items (numbers in Experiment 2; letters in Experiment 3) are stored in working memory in a serially organized way that the attentional cueing effect is observed as a function of serial working memory position. These observations suggest that the "attentional SNARC-effect" is strongly working memory based. Implications for theories on the mental representation of numbers are discussed.

Development of the Ubiquitous Spaced Retrieval-Based Memory Advancement and Rehabilitation Training Program

PubMed Central

Han, Ji Won; Oh, Kyusoo; Yoo, Sooyoung; Kim, Eunhye; Ahn, Ki-Hwan; Son, Yeon-Joo; Kim, Tae Hui; Chi, Yeon Kyung

2014-01-01

Objective The Ubiquitous Spaced Retrieval-based Memory Advancement and Rehabilitation Training (USMART) program was developed by transforming the spaced retrieval-based memory training which consisted of 24 face-to-face sessions into a self-administered program with an iPAD app. The objective of this study was to evaluate the feasibility and efficacy of USMART in elderly subjects with mild cognitive impairment (MCI). Methods Feasibility was evaluated by checking the satisfaction of the participants with a 5-point Likert scale. The efficacy of the program on cognitive functions was evaluated by the Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Assessment Battery before and after USMART. Results Among the 10 participants, 7 completed both pre- and post-USMART assessments. The overall satisfaction score was 8.0±1.0 out of 10. The mean Word List Memory Test (WLMT) scores significantly increased after USMART training after adjusting for age, educational levels, baseline Mini-Mental Status Examination scores, and the number of training sessions (pre-USMART, 16.0±4.1; post-USMART, 17.9±4.5; p=0.014, RM-ANOVA). The magnitude of the improvements in the WLMT scores significantly correlated with the number of training sessions during 4 weeks (r=0.793; p=0.033). Conclusion USMART was effective in improving memory and was well tolerated by most participants with MCI, suggesting that it may be a convenient and cost-effective alternative for the cognitive rehabilitation of elderly subjects with cognitive impairments. Further studies with large numbers of participants are necessary to examine the relationship between the number of training sessions and the improvements in memory function. PMID:24605124

New protocol for dissociating visuospatial working memory ability in reaching space and in navigational space.

PubMed

Lupo, Michela; Ferlazzo, Fabio; Aloise, Fabio; Di Nocera, Francesco; Tedesco, Anna Maria; Cardillo, Chiara; Leggio, Maria

2018-04-27

Several studies have demonstrated that the processing of visuospatial memory for locations in reaching space and in navigational space is supported by independent systems, and that the coding of visuospatial information depends on the modality of the presentation (i.e., sequential or simultaneous). However, these lines of evidence and the most common neuropsychological tests used by clinicians to investigate visuospatial memory have several limitations (e.g., they are unable to analyze all the subcomponents of this function and are not directly comparable). Therefore, we developed a new battery of tests that is able to investigate these subcomponents. We recruited 71 healthy subjects who underwent sequential and simultaneous navigational tests by using an innovative sensorized platform, as well as comparable paper tests to evaluate the same components in reaching space (Exp. 1). Consistent with the literature, the principal-component method of analysis used in this study demonstrated the presence of distinct memory for sequences in different portions of space, but no distinction was found for simultaneous presentation, suggesting that different modalities of eye gaze exploration are used when subjects have to perform different types of tasks. For this purpose, an infrared Tobii Eye-Tracking X50 system was used in both spatial conditions (Exp. 2), showing that a clear effect of the presentation modality was due to the specific strategy used by subjects to explore the stimuli in space. Given these findings, the neuropsychological battery established in the present study allows us to show basic differences in the normal coding of stimuli, which can explain the specific visuospatial deficits found in various neurological conditions.

KENNEDY SPACE CENTER, FLA. - Winston Scott, executive director of Florida Space Authority, speaks to attendees at a memorial service honoring the crew of Columbia. He stands in front of the Space Memorial Mirror at the KSC Visitor Complex. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Scott is a former astronaut who flew on Columbia in 1997. Attended by many friends, co-workers and families, the memorial service was also open to the public.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - Winston Scott, executive director of Florida Space Authority, speaks to attendees at a memorial service honoring the crew of Columbia. He stands in front of the Space Memorial Mirror at the KSC Visitor Complex. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Scott is a former astronaut who flew on Columbia in 1997. Attended by many friends, co-workers and families, the memorial service was also open to the public.

Major Robert Lawrence Memorial Tribute

NASA Image and Video Library

2017-12-08

Following an Astronauts Memorial Foundation tribute honoring U.S. Air Foce Maj. Robert Lawrence, guests place flowers at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex. Selected in 1967 for the Manned Orbiting Laboratory Program, Lawrence was the first African-American astronaut. He lost his life in a training accident 50 years ago. The ceremony took place in the Center for Space Education at the Kennedy Space Center Visitor Complex.

16Oxygen irradiation enhances cued fear memory in B6D2F1 mice

NASA Astrophysics Data System (ADS)

Raber, Jacob; Marzulla, Tessa; Kronenberg, Amy; Turker, Mitchell S.

2015-11-01

The space radiation environment includes energetic charged particles that may impact cognitive performance. We assessed the effects of 16O ion irradiation on cognitive performance of C57BL/6J × DBA/2J F1 (B6D2F1) mice at OHSU (Portland, OR) one month following irradiation at Brookhaven National Laboratory (BNL, Upton, NY). Hippocampus-dependent contextual fear memory and hippocampus-independent cued fear memory of B6D2F1 mice were tested. 16O ion exposure enhanced cued fear memory. This effect showed a bell-shaped dose response curve. Cued fear memory was significantly stronger in mice irradiated with 16O ions at a dose of 0.4 or 0.8 Gy than in sham-irradiated mice or following irradiation at 1.6 Gy. In contrast to cued fear memory, contextual fear memory was not affected following 16O ion irradiation at the doses used in this study. These data indicate that the amygdala might be particularly susceptible to effects of 16O ion exposure.

Prediction of error rates in dose-imprinted memories on board CRRES by two different methods. [Combined Release and Radiation Effects Satellite

NASA Technical Reports Server (NTRS)

Brucker, G. J.; Stassinopoulos, E. G.

1991-01-01

An analysis of the expected space radiation effects on the single event upset (SEU) properties of CMOS/bulk memories onboard the Combined Release and Radiation Effects Satellite (CRRES) is presented. Dose-imprint data from ground test irradiations of identical devices are applied to the predictions of cosmic-ray-induced space upset rates in the memories onboard the spacecraft. The calculations take into account the effect of total dose on the SEU sensitivity of the devices as the dose accumulates in orbit. Estimates of error rates, which involved an arbitrary selection of a single pair of threshold linear energy transfer (LET) and asymptotic cross-section values, were compared to the results of an integration over the cross-section curves versus LET. The integration gave lower upset rates than the use of the selected values of the SEU parameters. Since the integration approach is more accurate and eliminates the need for an arbitrary definition of threshold LET and asymptotic cross section, it is recommended for all error rate predictions where experimental sigma-versus-LET curves are available.

Estimating Neutral Atmosphere Drivers using a Physical Model

DTIC Science & Technology

2009-03-30

Araujo-Pradere, M. Fedrizzi, 2007, Memory effects in the ionosphere storm response. EGU General Assembly , Vienna, Austria Codrescu, M., T.J. Fuller...Strickland, D, 2007: Application of thermospheric general circulation models for space weather operations. J. Adv. Space Res., edited by Schmidtke

Visual Working Memory Is Independent of the Cortical Spacing Between Memoranda.

PubMed

Harrison, William J; Bays, Paul M

2018-03-21

The sensory recruitment hypothesis states that visual short-term memory is maintained in the same visual cortical areas that initially encode a stimulus' features. Although it is well established that the distance between features in visual cortex determines their visibility, a limitation known as crowding, it is unknown whether short-term memory is similarly constrained by the cortical spacing of memory items. Here, we investigated whether the cortical spacing between sequentially presented memoranda affects the fidelity of memory in humans (of both sexes). In a first experiment, we varied cortical spacing by taking advantage of the log-scaling of visual cortex with eccentricity, presenting memoranda in peripheral vision sequentially along either the radial or tangential visual axis with respect to the fovea. In a second experiment, we presented memoranda sequentially either within or beyond the critical spacing of visual crowding, a distance within which visual features cannot be perceptually distinguished due to their nearby cortical representations. In both experiments and across multiple measures, we found strong evidence that the ability to maintain visual features in memory is unaffected by cortical spacing. These results indicate that the neural architecture underpinning working memory has properties inconsistent with the known behavior of sensory neurons in visual cortex. Instead, the dissociation between perceptual and memory representations supports a role of higher cortical areas such as posterior parietal or prefrontal regions or may involve an as yet unspecified mechanism in visual cortex in which stimulus features are bound to their temporal order. SIGNIFICANCE STATEMENT Although much is known about the resolution with which we can remember visual objects, the cortical representation of items held in short-term memory remains contentious. A popular hypothesis suggests that memory of visual features is maintained via the recruitment of the same neural architecture in sensory cortex that encodes stimuli. We investigated this claim by manipulating the spacing in visual cortex between sequentially presented memoranda such that some items shared cortical representations more than others while preventing perceptual interference between stimuli. We found clear evidence that short-term memory is independent of the intracortical spacing of memoranda, revealing a dissociation between perceptual and memory representations. Our data indicate that working memory relies on different neural mechanisms from sensory perception. Copyright © 2018 Harrison and Bays.

Phase space simulation of collisionless stellar systems on the massively parallel processor

NASA Technical Reports Server (NTRS)

White, Richard L.

1987-01-01

A numerical technique for solving the collisionless Boltzmann equation describing the time evolution of a self gravitating fluid in phase space was implemented on the Massively Parallel Processor (MPP). The code performs calculations for a two dimensional phase space grid (with one space and one velocity dimension). Some results from calculations are presented. The execution speed of the code is comparable to the speed of a single processor of a Cray-XMP. Advantages and disadvantages of the MPP architecture for this type of problem are discussed. The nearest neighbor connectivity of the MPP array does not pose a significant obstacle. Future MPP-like machines should have much more local memory and easier access to staging memory and disks in order to be effective for this type of problem.

KSC-2012-1120

NASA Image and Video Library

2012-01-26

CAPE CANAVERAL, Fla. -- A memorial to the crew of space shuttle Columbia’s STS-107 mission is forever preserved at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida. Kennedy Space Center Director Robert Cabana, Deputy Director Janet Petro, and United Space Alliance’s Vice President for Aerospace Services/Florida Site Director Mark Nappi placed a wreath at the Space Mirror Memorial during Kennedy’s NASA Day of Remembrance. The Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the astronaut crews of Apollo 1 and space shuttles Challenger and Columbia. Kennedy civil service and contractor employees, along with the general public, paid their respects throughout the day. The visitor complex provided flowers for visitors to place at the memorial. Photo credit: NASA/Kim Shiflett

Natural disasters between memory and oblivion

NASA Astrophysics Data System (ADS)

Crescimbene, M.; La Longa, F.; Lanza, T.

2012-04-01

The last decades of the twentieth century and the beginning of the new millennium have been marked by a strong focus on the past and, consequently, a proliferation of studies on memory. Perhaps this great attention to memory implies a new way of thinking and experiencing time and space, two categories that deeply changed by the phenomenon of cultural globalization (Huyssen, 2003). If it is true that with new technologies, space and time have been dramatically compressed, it is also true that the horizons of our imagination have expanded to dimensions of space and time which are able to cross the boundaries of a locally circumscribed vision. So our past and our memory no longer have clear and delimited boundaries which were established by a tradition with local and national roots within specific geographical borders. The revival of studies on memory has included large Italian catastrophes occurred in the last centuries. Several initiatives, researches, exhibitions and commemorations wanted to remember these great catastrophes of our country. What is the relationship between these initiatives and the reduction of risk? What relationships are there between memory, forgetting and risk? On the issue of risk reduction the provocative phrase of Pierre Nora fits well: "We talk about memory because it no longer exists "? (Pierre Nora, Les Lieux de mémoire, Gallimard 1997). A direction to work on is indicated by Aleida Assmann (1999) that associates the idea of crisis of memory with the crisis of "living memory", that is linked to the disappearance of the eyewitnesses of the greatest tragedies of the twentieth century. When the generations who lived through L'Aquila earthquake on 6 April 2009 will die, the memory of the earthquake will vanish with them? To answer these questions and to propose communication and educational strategies capable of persisting the passage of generations, this work explores an interdisciplinary point of view, which takes into account recent studies on memory as: subjectivity, emotion, context, time and evolution, the tension between memory and oblivion, information, memory as a construction process. Today there is no single definition of memory because memory is a dynamic process: a procedural memory, which reshapes itself according to the present. So what should we do today to develop effective risk communication strategies? Starting from the assumption of Mieke Bal (1999, 9. VII), that cultural memory has to be seen "as an activity that takes place in the present, in which the past is continuously modified and re-described, even when it continues to shape the future", we can not forget that the problem of memory is always located in the relationship between those who "produce memory" and those who "benefit from it". To overcome the dichotomy between individual emotional experience and collective historical experience and to counteract the effect of oblivion, those who involved in communication and risk reduction should move towards a constructive direction of memory, capable of enhancing the past, live the present and orientate the future.

Consider the category: The effect of spacing depends on individual learning histories.

PubMed

Slone, Lauren K; Sandhofer, Catherine M

2017-07-01

The spacing effect refers to increased retention following learning instances that are spaced out in time compared with massed together in time. By one account, the advantages of spaced learning should be independent of task particulars and previous learning experiences given that spacing effects have been demonstrated in a variety of tasks across the lifespan. However, by another account, spaced learning should be affected by previous learning because past learning affects the memory and attention processes that form the crux of the spacing effect. The current study investigated whether individuals' learning histories affect the role of spacing in category learning. We examined the effect of spacing on 24 2- to 3.5-year-old children's learning of categories organized by properties to which children's previous learning experiences have biased them to attend (i.e., shape) and properties to which children are less biased to attend (i.e., texture and color). Spaced presentations led to significantly better learning of shape categories, but not of texture or color categories, compared with massed presentations. In addition, generalized estimating equations analyses revealed positive relations between the size of children's "shape-side" productive vocabularies and their shape category learning and between the size of children's "against-the-system" productive vocabularies and their texture category learning. These results suggest that children's attention to and memory for novel object categories are strongly related to their individual word-learning histories. Moreover, children's learned attentional biases affected the types of categories for which spacing facilitated learning. These findings highlight the importance of considering how learners' previous experiences may influence future learning. Copyright © 2017 Elsevier Inc. All rights reserved.

Location Memory in the Real World: Category Adjustment Effects in 3-Dimensional Space

ERIC Educational Resources Information Center

Holden, Mark P.; Newcombe, Nora S.; Shipley, Thomas F.

2013-01-01

The ability to remember spatial locations is critical to human functioning, both in an evolutionary and in an everyday sense. Yet spatial memories and judgments often show systematic errors and biases. Bias has been explained by models such as the Category Adjustment model (CAM), in which fine-grained and categorical information about locations…

KENNEDY SPACE CENTER, FLA. - Center Director Jim Kennedy speaks to attendees at a memorial service honoring the crew of Columbia. He stands in front of the Space Memorial Mirror at the KSC Visitor Complex. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Attended by many friends, co-workers and families, the memorial service was also open to the public.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - Center Director Jim Kennedy speaks to attendees at a memorial service honoring the crew of Columbia. He stands in front of the Space Memorial Mirror at the KSC Visitor Complex. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Attended by many friends, co-workers and families, the memorial service was also open to the public.

Distributed learning enhances relational memory consolidation.

PubMed

Litman, Leib; Davachi, Lila

2008-09-01

It has long been known that distributed learning (DL) provides a mnemonic advantage over massed learning (ML). However, the underlying mechanisms that drive this robust mnemonic effect remain largely unknown. In two experiments, we show that DL across a 24 hr interval does not enhance immediate memory performance but instead slows the rate of forgetting relative to ML. Furthermore, we demonstrate that this savings in forgetting is specific to relational, but not item, memory. In the context of extant theories and knowledge of memory consolidation, these results suggest that an important mechanism underlying the mnemonic benefit of DL is enhanced memory consolidation. We speculate that synaptic strengthening mechanisms supporting long-term memory consolidation may be differentially mediated by the spacing of memory reactivation. These findings have broad implications for the scientific study of episodic memory consolidation and, more generally, for educational curriculum development and policy.

Radiation Test Challenges for Scaled Commerical Memories

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Ladbury, Ray L.; Cohn, Lewis M.; Oldham, Timothy

2007-01-01

As sub-100nm CMOS technologies gather interest, the radiation effects performance of these technologies provide a significant challenge. In this talk, we shall discuss the radiation testing challenges as related to commercial memory devices. The focus will be on complex test and failure modes emerging in state-of-the-art Flash non-volatile memories (NVMs) and synchronous dynamic random access memories (SDRAMs), which are volatile. Due to their very high bit density, these device types are highly desirable for use in the natural space environment. In this presentation, we shall discuss these devices with emphasis on considerations for test and qualification methods required.

The retention and disruption of color information in human short-term visual memory.

PubMed

Nemes, Vanda A; Parry, Neil R A; Whitaker, David; McKeefry, Declan J

2012-01-27

Previous studies have demonstrated that the retention of information in short-term visual perceptual memory can be disrupted by the presentation of masking stimuli during interstimulus intervals (ISIs) in delayed discrimination tasks (S. Magnussen & W. W. Greenlee, 1999). We have exploited this effect in order to determine to what extent short-term perceptual memory is selective for stimulus color. We employed a delayed hue discrimination paradigm to measure the fidelity with which color information was retained in short-term memory. The task required 5 color normal observers to discriminate between spatially non-overlapping colored reference and test stimuli that were temporally separated by an ISI of 5 s. The points of subjective equality (PSEs) on the resultant psychometric matching functions provided an index of performance. Measurements were made in the presence and absence of mask stimuli presented during the ISI, which varied in hue around the equiluminant plane in DKL color space. For all reference stimuli, we found a consistent mask-induced, hue-dependent shift in PSE compared to the "no mask" conditions. These shifts were found to be tuned in color space, only occurring for a range of mask hues that fell within bandwidths of 29-37 deg. Outside this range, masking stimuli had little or no effect on measured PSEs. The results demonstrate that memory masking for color exhibits selectivity similar to that which has already been demonstrated for other visual attributes. The relatively narrow tuning of these interference effects suggests that short-term perceptual memory for color is based on higher order, non-linear color coding. © ARVO

The future of memory

NASA Astrophysics Data System (ADS)

Marinella, M.

In the not too distant future, the traditional memory and storage hierarchy of may be replaced by a single Storage Class Memory (SCM) device integrated on or near the logic processor. Traditional magnetic hard drives, NAND flash, DRAM, and higher level caches (L2 and up) will be replaced with a single high performance memory device. The Storage Class Memory paradigm will require high speed (< 100 ns read/write), excellent endurance (> 1012), nonvolatility (retention > 10 years), and low switching energies (< 10 pJ per switch). The International Technology Roadmap for Semiconductors (ITRS) has recently evaluated several potential candidates SCM technologies, including Resistive (or Redox) RAM, Spin Torque Transfer RAM (STT-MRAM), and phase change memory (PCM). All of these devices show potential well beyond that of current flash technologies and research efforts are underway to improve the endurance, write speeds, and scalabilities to be on-par with DRAM. This progress has interesting implications for space electronics: each of these emerging device technologies show excellent resistance to the types of radiation typically found in space applications. Commercially developed, high density storage class memory-based systems may include a memory that is physically radiation hard, and suitable for space applications without major shielding efforts. This paper reviews the Storage Class Memory concept, emerging memory devices, and possible applicability to radiation hardened electronics for space.

Exogenous temporal cues enhance recognition memory in an object-based manner.

PubMed

Ohyama, Junji; Watanabe, Katsumi

2010-11-01

Exogenous attention enhances the perception of attended items in both a space-based and an object-based manner. Exogenous attention also improves recognition memory for attended items in the space-based mode. However, it has not been examined whether object-based exogenous attention enhances recognition memory. To address this issue, we examined whether a sudden visual change in a task-irrelevant stimulus (an exogenous cue) would affect participants' recognition memory for items that were serially presented around a cued time. The results showed that recognition accuracy for an item was strongly enhanced when the visual cue occurred at the same location and time as the item (Experiments 1 and 2). The memory enhancement effect occurred when the exogenous visual cue and an item belonged to the same object (Experiments 3 and 4) and even when the cue was counterpredictive of the timing of an item to be asked about (Experiment 5). The present study suggests that an exogenous temporal cue automatically enhances the recognition accuracy for an item that is presented at close temporal proximity to the cue and that recognition memory enhancement occurs in an object-based manner.

Expedition 54's Christmas Memories

NASA Image and Video Library

2017-12-20

Flight Engineers Joe Acaba and Mark Vande Hei have been in space for three months already but they’re both about to experience something for the first time: Christmas on the International Space Station. And although it’s likely to be one they remember, both men have fond memories of Christmases past. Watch as these NASA astronauts recall childhood gifts from Santa, holiday trips to the tropics, and other cherished memories. HD Download: https://archive.org/details/jsc2017m001060_Expedition_54s_Christmas_Memories _______________________________________ FOLLOW THE SPACE STATION! Twitter: https://twitter.com/Space_Station Facebook: https://www.facebook.com/ISS Instagram: https://instagram.com/iss/

KENNEDY SPACE CENTER, FLA. - A wreath and other floral arrangements rest beneath the Astronaut Memorial Mirror at the KSC Visitor Complex following a memorial service held for the crew of Columbia on the anniversary of the tragic accident that took their lives Feb. 1, 2003. The black granite mirror honors astronauts, whose names are carved in the surface, who have given their lives for space exploration.  The service included comments by Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, and Dr. Stephen Feldman, president of the Astronaut Memorial Foundation, who placed the wreath at the mirror.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - A wreath and other floral arrangements rest beneath the Astronaut Memorial Mirror at the KSC Visitor Complex following a memorial service held for the crew of Columbia on the anniversary of the tragic accident that took their lives Feb. 1, 2003. The black granite mirror honors astronauts, whose names are carved in the surface, who have given their lives for space exploration.  The service included comments by Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, and Dr. Stephen Feldman, president of the Astronaut Memorial Foundation, who placed the wreath at the mirror.

KENNEDY SPACE CENTER, FLA. - A wreath and other floral arrangements rest beneath the Astronaut Memorial Mirror at the KSC Visitor Complex following a memorial service held for the crew of Columbia on the anniversary of the tragic accident that took their lives Feb. 1, 2003.  The service included comments by Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, and Dr. Stephen Feldman, president of the Astronaut Memorial Foundation, who placed the wreath at the mirror.  The black granite mirror honors astronauts, whose names are carved in the surface, who have given their lives for space exploration.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - A wreath and other floral arrangements rest beneath the Astronaut Memorial Mirror at the KSC Visitor Complex following a memorial service held for the crew of Columbia on the anniversary of the tragic accident that took their lives Feb. 1, 2003.  The service included comments by Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, and Dr. Stephen Feldman, president of the Astronaut Memorial Foundation, who placed the wreath at the mirror.  The black granite mirror honors astronauts, whose names are carved in the surface, who have given their lives for space exploration.

KENNEDY SPACE CENTER, FLA. - Among the visitors placing flowers in the wire mesh fence surrounding the Space Memorial Mirror is one of the Indian dancers who performed a healing ceremony during a memorial service for the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was invited to the memorial service, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - Among the visitors placing flowers in the wire mesh fence surrounding the Space Memorial Mirror is one of the Indian dancers who performed a healing ceremony during a memorial service for the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was invited to the memorial service, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

KENNEDY SPACE CENTER, FLA. - Standing in front of the Space Memorial Mirror at the KSC Visitor Complex, KSC Deputy Director Woodrow Whitlow Jr., Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott bow their heads in prayer during a memorial service remembering and honoring the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Scott is a former astronaut who flew on Columbia in 1997. The public was also invited to the memorial service.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - Standing in front of the Space Memorial Mirror at the KSC Visitor Complex, KSC Deputy Director Woodrow Whitlow Jr., Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott bow their heads in prayer during a memorial service remembering and honoring the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Scott is a former astronaut who flew on Columbia in 1997. The public was also invited to the memorial service.

A multiprocessor computer simulation model employing a feedback scheduler/allocator for memory space and bandwidth matching and TMR processing

NASA Technical Reports Server (NTRS)

Bradley, D. B.; Irwin, J. D.

1974-01-01

A computer simulation model for a multiprocessor computer is developed that is useful for studying the problem of matching multiprocessor's memory space, memory bandwidth and numbers and speeds of processors with aggregate job set characteristics. The model assumes an input work load of a set of recurrent jobs. The model includes a feedback scheduler/allocator which attempts to improve system performance through higher memory bandwidth utilization by matching individual job requirements for space and bandwidth with space availability and estimates of bandwidth availability at the times of memory allocation. The simulation model includes provisions for specifying precedence relations among the jobs in a job set, and provisions for specifying precedence execution of TMR (Triple Modular Redundant and SIMPLEX (non redundant) jobs.

Major Robert Lawrence Memorial Tribute

NASA Image and Video Library

2017-12-08

During an Astronauts Memorial Foundation tribute honoring U.S. Air Foce Maj. Robert Lawrence, his sister, Barbara Lawrence, Ph.D., far right, places a flower at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex. Selected in 1967 for the Manned Orbiting Laboratory Program, Lawrence was the first African-American astronaut. He lost his life in a training accident 50 years ago. The ceremony took place in the Center for Space Education at the Kennedy Space Center Visitor Complex.

KENNEDY SPACE CENTER, FLA. - A wreath and other floral arrangements rest beneath the Astronaut Memorial Mirror at the KSC Visitor Complex following a memorial service held for the crew of Columbia on the anniversary of the tragic accident that took their lives Feb. 1, 2003.  In the foreground are a portion of the roses and carnations left by visitors who attended the memorial.  The service included comments by Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, and Dr. Stephen Feldman, president of the Astronaut Memorial Foundation, who placed the wreath at the mirror.  The black granite mirror honors astronauts, whose names are carved in the surface, who have given their lives for space exploration.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - A wreath and other floral arrangements rest beneath the Astronaut Memorial Mirror at the KSC Visitor Complex following a memorial service held for the crew of Columbia on the anniversary of the tragic accident that took their lives Feb. 1, 2003.  In the foreground are a portion of the roses and carnations left by visitors who attended the memorial.  The service included comments by Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, and Dr. Stephen Feldman, president of the Astronaut Memorial Foundation, who placed the wreath at the mirror.  The black granite mirror honors astronauts, whose names are carved in the surface, who have given their lives for space exploration.

KENNEDY SPACE CENTER, FLA. - At the podium in front of the Space Memorial Mirror at the KSC Visitor Complex is Dr. Stephen Feldman, president of the Astronaut Memorial Foundation. He spoke to attendees at the memorial service remembering and honoring the crew of Columbia. With him (from left) are KSC Deputy Director Woodrow Whitlow Jr., Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Scott is a former astronaut who flew on Columbia in 1997. Attended by many friends, co-workers and families, the memorial service was also open to the public.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - At the podium in front of the Space Memorial Mirror at the KSC Visitor Complex is Dr. Stephen Feldman, president of the Astronaut Memorial Foundation. He spoke to attendees at the memorial service remembering and honoring the crew of Columbia. With him (from left) are KSC Deputy Director Woodrow Whitlow Jr., Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Scott is a former astronaut who flew on Columbia in 1997. Attended by many friends, co-workers and families, the memorial service was also open to the public.

A recursive solution for a fading memory filter derived from Kalman filter theory

NASA Technical Reports Server (NTRS)

Statman, J. I.

1986-01-01

A simple recursive solution for a class of fading memory tracking filters is presented. A fading memory filter provides estimates of filter states based on past measurements, similar to a traditional Kalman filter. Unlike a Kalman filter, an exponentially decaying weight is applied to older measurements, discounting their effect on present state estimates. It is shown that Kalman filters and fading memory filters are closely related solutions to a general least squares estimator problem. Closed form filter transfer functions are derived for a time invariant, steady state, fading memory filter. These can be applied in loop filter implementation of the Deep Space Network (DSN) Advanced Receiver carrier phase locked loop (PLL).

The human quest in space; Proceedings of the Twenty-fourth Goddard Memorial Symposium, Greenbelt, MD, Mar. 20, 21, 1986

NASA Technical Reports Server (NTRS)

Burdett, Gerald L. (Editor); Soffen, Gerald A. (Editor)

1987-01-01

Papers are presented on the Space Station, materials processing in space, the status of space remote sensing, the evolution of space infrastructure, and the NASA Teacher Program. Topics discussed include visionary technologies, the effect of intelligent machines on space operations, future information technology, and the role of nuclear power in future space missions. Consideration is given to the role of humans in space exploration; medical problems associated with long-duration space flights; lunar and Martian settlements, and Biosphere II (the closed ecology project).

[The effect of bemitil on conditioned-reflex memory in normal rats and under stress exposures].

PubMed

Pragina, L L; Tushmalova, N A; Inozemtsev, A N; Smirnov, A V

1999-01-01

The authors studied the effect of the actoprotector bemitil on the conditional-reflex memory of rats and its functional disorder by disturbance of the cause-effect (abatement of the avoidance reaction) or space relations. Intraperitoneal injections of 1.8 mg/kg of bemitil were given daily 30 min before the experiment. The training of animals improved authentically from experiment to experiment. Thus, the drug, possesses the nootropic properties. Exposure to stressogenic factors of various depth demonstrated the stress-protective effect of bemitil.

Subliminal encoding and flexible retrieval of objects in scenes.

PubMed

Wuethrich, Sergej; Hannula, Deborah E; Mast, Fred W; Henke, Katharina

2018-04-27

Our episodic memory stores what happened when and where in life. Episodic memory requires the rapid formation and flexible retrieval of where things are located in space. Consciousness of the encoding scene is considered crucial for episodic memory formation. Here, we question the necessity of consciousness and hypothesize that humans can form unconscious episodic memories. Participants were presented with subliminal scenes, i.e., scenes invisible to the conscious mind. The scenes displayed objects at certain locations for participants to form unconscious object-in-space memories. Later, the same scenes were presented supraliminally, i.e., visibly, for retrieval testing. Scenes were presented absent the objects and rotated by 90°-270° in perspective to assess the representational flexibility of unconsciously formed memories. During the test phase, participants performed a forced-choice task that required them to place an object in one of two highlighted scene locations and their eye movements were recorded. Evaluation of the eye tracking data revealed that participants remembered object locations unconsciously, irrespective of changes in viewing perspective. This effect of gaze was related to correct placements of objects in scenes, and an intuitive decision style was necessary for unconscious memories to influence intentional behavior to a significant degree. We conclude that conscious perception is not mandatory for spatial episodic memory formation. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

KSC-03pd0569

NASA Image and Video Library

2003-03-06

KENNEDY SPACE CENTER, FLA. - A view of the Astronaut Memorial Space Mirror at the KSC Visitor Complex. The memorial is a national tribute to 17 American astronauts who previously gave their lives to the quest to explore space. The memorial has had added attention since the loss of the Columbia crew Feb. 1, 2003, when they died in an explosion as they were returning to Earth from mission STS-107.

KSC-03pd0570

NASA Image and Video Library

2003-03-06

KENNEDY SPACE CENTER, FLA. - A view of the Astronaut Memorial Space Mirror at the KSC Visitor Complex. The memorial is a national tribute to 17 American astronauts who previously gave their lives to the quest to explore space. The memorial has had added attention since the loss of the Columbia crew Feb. 1, 2003, when they died in an explosion as they were returning to Earth from mission STS-107.

KSC-03pd0615

NASA Image and Video Library

2003-03-06

KENNEDY SPACE CENTER, FLA. -- A view of the Astronaut Memorial Space Mirror at the KSC Visitor Complex. The memorial is a national tribute to 17 American astronauts who previously gave their lives to the quest to explore space. The memorial has had added attention since the loss of the Columbia crew Feb. 1, 2003, when they died in an explosion as they were returning to Earth from mission STS-107.

Age-Related Deficits in Intentional Memory for Spatial Location in Small-Scale Space: A Meta-Analysis and Methodological Critique.

ERIC Educational Resources Information Center

Foisy, Pierre

1994-01-01

Meta analysis of 22 studies testing 1,598 subjects revealed that aging has a great effect on intentional memory for spatial location. However, methodological limits were found: fewer than half of the studies controlled for age differences in visual acuity or did not use a test phase of fixed duration. (SK)

Places, Spaces and Memory Traces: Showing Students with Learning Disabilities Ways to Remember Locations and Events on Maps.

ERIC Educational Resources Information Center

Brigham, Frederick J.

This study examined the memory-enhancing effects of elaborative and mnemonic encoding of information presented with maps, compared to more traditional, non-mnemonic maps, on recall of locations of events and information associated with those events by 72 middle school students with learning disabilities. Subjects were presented with map-like…

Social and novel contexts modify hippocampal CA2 representations of space

PubMed Central

Alexander, Georgia M.; Farris, Shannon; Pirone, Jason R.; Zheng, Chenguang; Colgin, Laura L.; Dudek, Serena M.

2016-01-01

The hippocampus supports a cognitive map of space and is critical for encoding declarative memory (who, what, when and where). Recent studies have implicated hippocampal subfield CA2 in social and contextual memory but how it does so remains unknown. Here we find that in adult male rats, presentation of a social stimulus (novel or familiar rat) or a novel object induces global remapping of place fields in CA2 with no effect on neuronal firing rate or immediate early gene expression. This remapping did not occur in CA1, suggesting this effect is specific for CA2. Thus, modification of existing spatial representations might be a potential mechanism by which CA2 encodes social and novel contextual information. PMID:26806606

A remember-know analysis of the semantic serial position function.

PubMed

Kelley, Matthew R; Neath, Ian; Surprenant, Aimée M

2014-01-01

Did the serial position functions observed in certain semantic memory tasks (e.g., remembering the order of books or films) arise because they really tapped episodic memory? To address this issue, participants were asked to make "remember-know" judgments as they reconstructed the release order of the 7 Harry Potter books and 2 sets of movies. For both classes of stimuli, the "remember" and "know" serial position functions were indistinguishable, and all showed the characteristic U-shape with marked primacy and recency effects. These results are inconsistent with a multiple memory systems view, which predicts recency effects only for "remember" responses and no recency effects for "know" responses. However, the data were consistent with a general memory principle account: the relative distinctiveness principle. According to this view, performance on both episodic and semantic memory tasks arises from the same type of processing: Items that are more separated from their close neighbors in psychological space at the time of recall will be better remembered.

Future Development of Dense Ferroelectric Memories for Space Applications

NASA Technical Reports Server (NTRS)

Philpy, Stephen C.; Derbenwick, Gary F.

2001-01-01

The availability of high density, radiation tolerant, nonvolatile memories is critical for space applications. Ferroelectric memories, when fabricated with radiation hardened complementary metal oxide semiconductors (CMOS), can be manufactured and packaged to provide high density replacements for Flash memory, which is not radiation tolerant. Previous work showed ferroelectric memory cells to be resistant to single event upsets and proton irradiation, and ferroelectric storage capacitors to be resistant to neutron exposure. In addition to radiation hardness, the fast programming times, virtually unlimited endurance, and low voltage, low power operation make ferroelectric memories ideal for space missions. Previously, a commercial double level metal 64-kilobit ferroelectric memory was presented. Although the capabilities of radiation hardened wafer fabrication facilities lag behind those of the most modern commercial wafer fabrication facilities, several paths to achieving radiation tolerant, dense ferroelectric memories are emerging. Both short and long term solutions are presented in this paper. Although worldwide major semiconductor companies are introducing commercial ferroelectric memories, funding limitations must be overcome to proceed with the development of high density, radiation tolerant ferroelectric memories.

Memory Effects on Movement Behavior in Animal Foraging

PubMed Central

Bracis, Chloe; Gurarie, Eliezer; Van Moorter, Bram; Goodwin, R. Andrew

2015-01-01

An individual’s choices are shaped by its experience, a fundamental property of behavior important to understanding complex processes. Learning and memory are observed across many taxa and can drive behaviors, including foraging behavior. To explore the conditions under which memory provides an advantage, we present a continuous-space, continuous-time model of animal movement that incorporates learning and memory. Using simulation models, we evaluate the benefit memory provides across several types of landscapes with variable-quality resources and compare the memory model within a nested hierarchy of simpler models (behavioral switching and random walk). We find that memory almost always leads to improved foraging success, but that this effect is most marked in landscapes containing sparse, contiguous patches of high-value resources that regenerate relatively fast and are located in an otherwise devoid landscape. In these cases, there is a large payoff for finding a resource patch, due to size, value, or locational difficulty. While memory-informed search is difficult to differentiate from other factors using solely movement data, our results suggest that disproportionate spatial use of higher value areas, higher consumption rates, and consumption variability all point to memory influencing the movement direction of animals in certain ecosystems. PMID:26288228

Memory Effects on Movement Behavior in Animal Foraging.

PubMed

Bracis, Chloe; Gurarie, Eliezer; Van Moorter, Bram; Goodwin, R Andrew

2015-01-01

An individual's choices are shaped by its experience, a fundamental property of behavior important to understanding complex processes. Learning and memory are observed across many taxa and can drive behaviors, including foraging behavior. To explore the conditions under which memory provides an advantage, we present a continuous-space, continuous-time model of animal movement that incorporates learning and memory. Using simulation models, we evaluate the benefit memory provides across several types of landscapes with variable-quality resources and compare the memory model within a nested hierarchy of simpler models (behavioral switching and random walk). We find that memory almost always leads to improved foraging success, but that this effect is most marked in landscapes containing sparse, contiguous patches of high-value resources that regenerate relatively fast and are located in an otherwise devoid landscape. In these cases, there is a large payoff for finding a resource patch, due to size, value, or locational difficulty. While memory-informed search is difficult to differentiate from other factors using solely movement data, our results suggest that disproportionate spatial use of higher value areas, higher consumption rates, and consumption variability all point to memory influencing the movement direction of animals in certain ecosystems.

Examining the benefits of combining two learning strategies on recall of functional information in persons with multiple sclerosis.

PubMed

Goverover, Yael; Basso, Michael; Wood, Hali; Chiaravalloti, Nancy; DeLuca, John

2011-12-01

Forgetfulness occurs commonly in people with multiple sclerosis (MS), but few treatments alleviate this problem. This study examined the combined effect of two cognitive rehabilitation strategies to improve learning and memory in MS: self-generation and spaced learning. The hypothesis was that the combination of spaced learning and self-generation would yield better learning and memory recall performance than spaced learning alone. Using a within groups design, 20 participants with MS and 18 healthy controls (HC) were presented with three tasks (learning names, appointment, and object location), each in three learning conditions (Massed, Spaced Learning, and combination of spaced and generated information). Participants were required to recall the information they learned in each of these conditions immediately and 30 min following the initial presentation. The combination of spaced learning and self-generation yielded better recall than did spaced learning alone. In turn, spaced learning resulted in better recall than the massed rehearsal condition. These findings reveal that the combination of these two learning strategies may possess utility as a cognitive rehabilitation strategy.

KENNEDY SPACE CENTER, FLA. - KSC Deputy Director Woodrow Whitlow Jr. closes the memorial service held for the crew of Columbia at the Space Memorial Mirror in the KSC Visitor Complex. He is surrounded by dancers of the Shoshone-Bannock Native American community who performed a healing ceremony during the memorial. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - KSC Deputy Director Woodrow Whitlow Jr. closes the memorial service held for the crew of Columbia at the Space Memorial Mirror in the KSC Visitor Complex. He is surrounded by dancers of the Shoshone-Bannock Native American community who performed a healing ceremony during the memorial. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

KENNEDY SPACE CENTER, FLA. - Brilliant roses and carnations frame the names of the Columbia crew carved onto the black granite surface of the Astronaut Memorial Mirror at the KSC Visitor Complex.  The flowers were left by visitors who attended a memorial service for the crew on the anniversary of the tragic accident that claimed their lives Feb. 1, 2003.  The service included comments by Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, and Dr. Stephen Feldman, president of the Astronaut Memorial Foundation, who placed the wreath at the mirror.  The mirror honors astronauts who have given their lives for space exploration.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - Brilliant roses and carnations frame the names of the Columbia crew carved onto the black granite surface of the Astronaut Memorial Mirror at the KSC Visitor Complex.  The flowers were left by visitors who attended a memorial service for the crew on the anniversary of the tragic accident that claimed their lives Feb. 1, 2003.  The service included comments by Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, and Dr. Stephen Feldman, president of the Astronaut Memorial Foundation, who placed the wreath at the mirror.  The mirror honors astronauts who have given their lives for space exploration.

KENNEDY SPACE CENTER, FLA. - Friends, co-workers and families gather at the Space Memorial Mirror for KSC’s special service remembering and honoring the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was invited to the memorial service held at the KSC Visitor Complex. Participants included Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, Dr. Stephen Feldman, president of the Astronaut Memorial Foundation, and dancers from the Shoshone-Bannock Native American community in Fort Hall, Idaho.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - Friends, co-workers and families gather at the Space Memorial Mirror for KSC’s special service remembering and honoring the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was invited to the memorial service held at the KSC Visitor Complex. Participants included Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, Dr. Stephen Feldman, president of the Astronaut Memorial Foundation, and dancers from the Shoshone-Bannock Native American community in Fort Hall, Idaho.

Efficacy of elastic memory chains versus nickel-titanium coil springs in canine retraction: A two-center split-mouth randomized clinical trial.

PubMed

Khanemasjedi, Mashallah; Moradinejad, Mehrnaz; Javidi, Pedram; Niknam, Ozra; Jahromi, Nima Haghighat; Rakhshan, Vahid

2017-12-01

The use of newly-introduced elastic memory chains (EMCs) in space closure is increasingly gaining popularity. However, no clinical studies have evaluated their efficacy. Therefore, this study was conducted. In this two-center split-mouth single-blind randomized controlled trial, 21 jaws were divided into 42 quadrants. The two treatments [canine retraction using EMCs versus nickel-titanium (NiTi) coil springs (as control)] were randomly assigned to two quadrants of each jaw. The premolar space was measured at the baseline, and in the 1st, 2nd, and 3rd months of canine retraction, by a blinded orthodontist. Space closure rates were compared using a paired t-test. The rates of space closure using NiTi springs were 1.93±0.62, 1.71±0.75, and 1.36±0.51mm/month, during the 1st, 2nd, and 3rd months of treatment, respectively. The 3-month average rates of space closure were 1.67±0.39 and 1.89±0.36mm/month in the NiTi and elastic groups, respectively (faster in the elastic group, P=0.022). The application of elastic memory chains is as effective as NiTi springs. Copyright © 2017. Published by Elsevier Masson SAS.

Mechanical analysis of carbon fiber reinforced shape memory polymer composite for self-deployable structure in space environment

NASA Astrophysics Data System (ADS)

Hong, Seok Bin; Ahn, Yong San; Jang, Joon Hyeok; Kim, Jin-Gyun; Goo, Nam Seo; Yu, Woong-Ryeol

2016-04-01

Shape memory polymer (SMP) is one of smart polymers which exhibit shape memory effect upon external stimuli. Reinforcements as carbon fiber had been used for making shape memory polymer composite (CF-SMPC). This study investigated a possibility of designing self-deployable structures in harsh space condition using CF-SMPCs and analyzed their shape memory behaviors with constitutive equation model.CF-SMPCs were prepared using woven carbon fabrics and a thermoset epoxy based SMP to obtain their basic mechanical properties including actuation in harsh environment. The mechanical and shape memory properties of SMP and CF-SMPCs were characterized using dynamic mechanical analysis (DMA) and universal tensile machine (UTM) with an environmental chamber. The mechanical properties such as flexural strength and tensile strength of SMP and CF-SMPC were measured with simple tensile/bending test and time dependent shape memory behavior was characterized with designed shape memory bending test. For mechanical analysis of CF-SMPCs, a 3D constitutive equation of SMP, which had been developed using multiplicative decomposition of the deformation gradient and shape memory strains, was used with material parameters determined from CF-SMPCs. Carbon fibers in composites reinforced tensile and flexural strength of SMP and acted as strong elastic springs in rheology based equation models. The actuation behavior of SMP matrix and CF-SMPCs was then simulated as 3D shape memory bending cases. Fiber bundle property was imbued with shell model for more precise analysis and it would be used for prediction of deploying behavior in self-deployable hinge structure.

The Role of Life-Space, Social Activity, and Depression on the Subjective Memory Complaints of Community-Dwelling Filipino Elderly: A Structural Equation Model

ERIC Educational Resources Information Center

de Guzman, Allan B.; Lagdaan, Lovely France M.; Lagoy, Marie Lauren V.

2015-01-01

Subjective memory complaints are one of the major concerns of the elderly and remain a challenging area in gerontology. There are previous studies that identify different factors affecting subjective memory complaints. However, an extended model that correlates life-space on subjective memory complaints remains a blank spot. The objective of this…

A reliability evaluation methodology for memory chips for space applications when sample size is small

NASA Technical Reports Server (NTRS)

Chen, Y.; Nguyen, D.; Guertin, S.; Berstein, J.; White, M.; Menke, R.; Kayali, S.

2003-01-01

This paper presents a reliability evaluation methodology to obtain the statistical reliability information of memory chips for space applications when the test sample size needs to be kept small because of the high cost of the radiation hardness memories.

Extending the Memory of Microcomputers

NASA Technical Reports Server (NTRS)

Wiker, G. A.

1984-01-01

Memory increased while retaining real-time capabilities. Extra memory capacity added to microprocessor without increasing memory address length and special transfer instructions by dedicating block of space in main memory to hold addresses of locations in extra memory.

Data communications in a parallel active messaging interface of a parallel computer

DOEpatents

Blocksome, Michael A.; Ratterman, Joseph D.; Smith, Brian E.

2014-09-02

Eager send data communications in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI composed of data communications endpoints that specify a client, a context, and a task, including receiving an eager send data communications instruction with transfer data disposed in a send buffer characterized by a read/write send buffer memory address in a read/write virtual address space of the origin endpoint; determining for the send buffer a read-only send buffer memory address in a read-only virtual address space, the read-only virtual address space shared by both the origin endpoint and the target endpoint, with all frames of physical memory mapped to pages of virtual memory in the read-only virtual address space; and communicating by the origin endpoint to the target endpoint an eager send message header that includes the read-only send buffer memory address.

Data communications in a parallel active messaging interface of a parallel computer

DOEpatents

Blocksome, Michael A.; Ratterman, Joseph D.; Smith, Brian E.

2014-09-16

Eager send data communications in a parallel active messaging interface (`PAMI`) of a parallel computer, the PAMI composed of data communications endpoints that specify a client, a context, and a task, including receiving an eager send data communications instruction with transfer data disposed in a send buffer characterized by a read/write send buffer memory address in a read/write virtual address space of the origin endpoint; determining for the send buffer a read-only send buffer memory address in a read-only virtual address space, the read-only virtual address space shared by both the origin endpoint and the target endpoint, with all frames of physical memory mapped to pages of virtual memory in the read-only virtual address space; and communicating by the origin endpoint to the target endpoint an eager send message header that includes the read-only send buffer memory address.

A fault-tolerant information processing concept for space vehicles.

NASA Technical Reports Server (NTRS)

Hopkins, A. L., Jr.

1971-01-01

A distributed fault-tolerant information processing system is proposed, comprising a central multiprocessor, dedicated local processors, and multiplexed input-output buses connecting them together. The processors in the multiprocessor are duplicated for error detection, which is felt to be less expensive than using coded redundancy of comparable effectiveness. Error recovery is made possible by a triplicated scratchpad memory in each processor. The main multiprocessor memory uses replicated memory for error detection and correction. Local processors use any of three conventional redundancy techniques: voting, duplex pairs with backup, and duplex pairs in independent subsystems.

Memory, Space and Time: Researching Children's Lives

ERIC Educational Resources Information Center

Moss, Dorothy

2010-01-01

This article discusses the research approach in "Pathways through Childhood", a small qualitative study drawing on memories of childhood. The research explores how wider social arrangements and social change influence children's everyday lives. The article discusses the way that the concepts of social memory, space and time have been…

Active Control of Flexible Space Structures Using the Nitinol Shape Memory Actuators

DTIC Science & Technology

1987-10-01

number) FIELD !GROUP SUBGROUP I Active Control, Nitinol Actuators, Space Structures 9. ABSTRACT (Continue on reverse if necessary and identify by block...number) Summarizes research progress in the feasibility demonstration of active vibration control using Nitinol shape memory actuators. Tests on...FLEXIBLE SPACE STRUCTURES USING NITINOL SHAPE MEMORY ACTUATORS FINAL REPORT FOR PHASE I SDIO CONTRACT #F49620-87-C-0035 0 BY DR. AMR M. BAZ KARIM R

KENNEDY SPACE CENTER, FLA. - Dr. Ed Galindo speaks to the visitors at the memorial service held at the Space Memorial Mirror for the crew of Columbia. Galindo is science educator of Shoshone-Bannock High School and introduced the dancers from the Shoshone-Bannock Native American community in Fort Hall, Idaho. The dancers performed a healing ceremony during the memorial. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - Dr. Ed Galindo speaks to the visitors at the memorial service held at the Space Memorial Mirror for the crew of Columbia. Galindo is science educator of Shoshone-Bannock High School and introduced the dancers from the Shoshone-Bannock Native American community in Fort Hall, Idaho. The dancers performed a healing ceremony during the memorial. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

Distributing learning over time: the spacing effect in children's acquisition and generalization of science concepts.

PubMed

Vlach, Haley A; Sandhofer, Catherine M

2012-01-01

The spacing effect describes the robust finding that long-term learning is promoted when learning events are spaced out in time rather than presented in immediate succession. Studies of the spacing effect have focused on memory processes rather than for other types of learning, such as the acquisition and generalization of new concepts. In this study, early elementary school children (5- to 7-year-olds; N = 36) were presented with science lessons on 1 of 3 schedules: massed, clumped, and spaced. The results revealed that spacing lessons out in time resulted in higher generalization performance for both simple and complex concepts. Spaced learning schedules promote several types of learning, strengthening the implications of the spacing effect for educational practices and curriculum. © 2012 The Authors. Child Development © 2012 Society for Research in Child Development, Inc.

New non-linear model of groundwater recharge: Inclusion of memory, heterogeneity and visco-elasticity

NASA Astrophysics Data System (ADS)

Spannenberg, Jescica; Atangana, Abdon; Vermeulen, P. D.

2017-09-01

Fractional differentiation has adequate use for investigating real world scenarios related to geological formations associated with elasticity, heterogeneity, viscoelasticity, and the memory effect. Since groundwater systems exist in these geological formations, modelling groundwater recharge as a real world scenario is a challenging task to do because existing recharge estimation methods are governed by linear equations which make use of constant field parameters. This is inadequate because in reality these parameters are a function of both space and time. This study therefore concentrates on modifying the recharge equation governing the EARTH model, by application of the Eton approach. Accordingly, this paper presents a modified equation which is non-linear, and accounts for parameters in a way that it is a function of both space and time. To be more specific, herein, recharge and drainage resistance which are parameters within the equation, became a function of both space and time. Additionally, the study entailed solving the non-linear equation using an iterative method as well as numerical solutions by means of the Crank-Nicolson scheme. The numerical solutions were used alongside the Riemann-Liouville, Caputo-Fabrizio, and Atangana-Baleanu derivatives, so that account was taken for elasticity, heterogeneity, viscoelasticity, and the memory effect. In essence, this paper presents a more adequate model for recharge estimation.

A review of emerging non-volatile memory (NVM) technologies and applications

NASA Astrophysics Data System (ADS)

Chen, An

2016-11-01

This paper will review emerging non-volatile memory (NVM) technologies, with the focus on phase change memory (PCM), spin-transfer-torque random-access-memory (STTRAM), resistive random-access-memory (RRAM), and ferroelectric field-effect-transistor (FeFET) memory. These promising NVM devices are evaluated in terms of their advantages, challenges, and applications. Their performance is compared based on reported parameters of major industrial test chips. Memory selector devices and cell structures are discussed. Changing market trends toward low power (e.g., mobile, IoT) and data-centric applications create opportunities for emerging NVMs. High-performance and low-cost emerging NVMs may simplify memory hierarchy, introduce non-volatility in logic gates and circuits, reduce system power, and enable novel architectures. Storage-class memory (SCM) based on high-density NVMs could fill the performance and density gap between memory and storage. Some unique characteristics of emerging NVMs can be utilized for novel applications beyond the memory space, e.g., neuromorphic computing, hardware security, etc. In the beyond-CMOS era, emerging NVMs have the potential to fulfill more important functions and enable more efficient, intelligent, and secure computing systems.

Sell a book and cook a dog: misery, memory and space from Siberian camps to Apartheid.

PubMed

van Dongen, Els

2004-09-01

In this article, the life story of a Polish woman in South Africa is used to illustrate that stories of exile are 'matter out of place' in host countries. Space is a central category in both the story of exiles and in the collective history of receiving countries, but it has different emotional, social, cultural and political meanings. Sometimes stories of exile are denied a place in the social memory of a society. Therefore, recollection and making sense of experienced misery in foreign contexts is often a difficult and lonely undertaking. The article links the story to macro-political processes and attempts to answer questions regarding the consequences of the lack of meaningful space for exiles to remember. Collective and national memories and ceremonies are often exclusive and offer no place for 'alien' memories. Therapeutic repertoires often fail to address the emotional value of communal sharing a socio-cultural and (meta) physical space. It is argued that because the state does not take responsibility for providing a (symbolic) space for the mourning and reconciliation of people whose memories are out of place, transcultural psychiatry - its subsystem - will have to reflect on how to provide such a space.

Major Robert Lawrence Memorial Tribute

NASA Image and Video Library

2017-12-08

During an Astronauts Memorial Foundation tribute honoring U.S. Air Foce Maj. Robert Lawrence, his sister, Barbara Lawrence, Ph.D., places a flower at the Space Mirror Memorial which honors those lost in efforts to explore space. Selected in 1967 for the Manned Orbiting Laboratory Program, Lawrence was the first African-American astronaut. He lost his life in a training accident 50 years ago. The ceremony took place in the Center for Space Education at the Kennedy visitor complex.

KENNEDY SPACE CENTER, FLA. - Roses and other flowers ring the base of the Astronaut Memorial Mirror at the KSC Visitor Complex following a memorial service held for the crew of Columbia on the anniversary of the tragic accident that took their lives Feb. 1, 2003.  The public was invited to the service and encouraged to place the flowers on the fence.  The service included comments by Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, and Dr. Stephen Feldman, president of the Astronaut Memorial Foundation.  The black granite mirror honors astronauts, whose names are carved in the surface, who have given their lives for space exploration.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - Roses and other flowers ring the base of the Astronaut Memorial Mirror at the KSC Visitor Complex following a memorial service held for the crew of Columbia on the anniversary of the tragic accident that took their lives Feb. 1, 2003.  The public was invited to the service and encouraged to place the flowers on the fence.  The service included comments by Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, and Dr. Stephen Feldman, president of the Astronaut Memorial Foundation.  The black granite mirror honors astronauts, whose names are carved in the surface, who have given their lives for space exploration.

KENNEDY SPACE CENTER, FLA. - Center Director Jim Kennedy (right) speaks to attendees at a memorial service honoring the crew of Columbia. Behind him are KSC Deputy Director Woodrow Whitlow Jr. and Executive Director of Florida Space Authority Winston Scott, who is a former astronaut who flew on Columbia in 1997. They are standing in front of the Space Memorial Mirror at the KSC Visitor Complex. Attended by many friends, co-workers and families, the memorial service was also open to the public, some of whom are seen at left. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - Center Director Jim Kennedy (right) speaks to attendees at a memorial service honoring the crew of Columbia. Behind him are KSC Deputy Director Woodrow Whitlow Jr. and Executive Director of Florida Space Authority Winston Scott, who is a former astronaut who flew on Columbia in 1997. They are standing in front of the Space Memorial Mirror at the KSC Visitor Complex. Attended by many friends, co-workers and families, the memorial service was also open to the public, some of whom are seen at left. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107.

KENNEDY SPACE CENTER, FLA. - Center Director Jim Kennedy (right) speaks to attendees at a memorial service honoring the crew of Columbia. At left are KSC Deputy Director Woodrow Whitlow Jr. and Executive Director of Florida Space Authority Winston Scott, who was an invited speaker. Scott is a former astronaut who flew on Columbia in 1997. They are standing in front of the Space Memorial Mirror at the KSC Visitor Complex. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Attended by many friends, co-workers and families, the memorial service was also open to the public.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - Center Director Jim Kennedy (right) speaks to attendees at a memorial service honoring the crew of Columbia. At left are KSC Deputy Director Woodrow Whitlow Jr. and Executive Director of Florida Space Authority Winston Scott, who was an invited speaker. Scott is a former astronaut who flew on Columbia in 1997. They are standing in front of the Space Memorial Mirror at the KSC Visitor Complex. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Attended by many friends, co-workers and families, the memorial service was also open to the public.

KSC-2011-1216

NASA Image and Video Library

2011-01-27

CAPE CANAVERAL, Fla. -- Kennedy Space Center Director and former astronaut Bob Cabana, left, United Space Alliance's Associate Program Manager for Solid Rocket Boosters Roger Elliott and Center Deputy Director Janet Petro participate in a Day of Remembrance wreath laying ceremony at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida. The ceremony honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery. The memorial displays the names of 24 United States astronauts, including the crew members of space shuttles Columbia and Challenger, Apollo 1, and those who died in training and commercial airplane accidents. The memorial is a project of the Astronauts Memorial Foundation and was paid for by Florida residents who purchased special Challenger mission automobile license plates. 2011 marks the 25th anniversary of the loss of Challenger, which broke apart over the Atlantic Ocean 73 seconds into flight on Jan. 28, 1986. Photo credit: NASA/Kim Shiflett

KSC-2011-1215

NASA Image and Video Library

2011-01-27

CAPE CANAVERAL, Fla. -- United Space Alliance's Associate Program Manager for Solid Rocket Boosters Roger Elliott, back, Kennedy Space Center Deputy Director Janet Petro, and Center Director and former astronaut Bob Cabana, participate in a Day of Remembrance wreath laying ceremony at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida. The ceremony honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery. The memorial displays the names of 24 United States astronauts, including the crew members of space shuttles Columbia and Challenger, Apollo 1, and those who died in training and commercial airplane accidents. The memorial is a project of the Astronauts Memorial Foundation and was paid for by Florida residents who purchased special Challenger mission automobile license plates. 2011 marks the 25th anniversary of the loss of Challenger, which broke apart over the Atlantic Ocean 73 seconds into flight on Jan. 28, 1986. Photo credit: NASA/Kim Shiflett

KSC-2011-1214

NASA Image and Video Library

2011-01-27

CAPE CANAVERAL, Fla. -- United Space Alliance's Associate Program Manager for Solid Rocket Boosters Roger Elliott, left, Kennedy Space Center Deputy Director Janet Petro, and Center Director and former astronaut Bob Cabana, participate in a Day of Remembrance wreath laying ceremony at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida. The ceremony honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery. The memorial displays the names of 24 United States astronauts, including the crew members of space shuttles Columbia and Challenger, Apollo 1, and those who died in training and commercial airplane accidents. The memorial is a project of the Astronauts Memorial Foundation and was paid for by Florida residents who purchased special Challenger mission automobile license plates. 2011 marks the 25th anniversary of the loss of Challenger, which broke apart over the Atlantic Ocean 73 seconds into flight on Jan. 28, 1986. Photo credit: NASA/Kim Shiflett

Fast neutron irradiation tests of flash memories used in space environment at the ISIS spallation neutron source

NASA Astrophysics Data System (ADS)

Andreani, C.; Senesi, R.; Paccagnella, A.; Bagatin, M.; Gerardin, S.; Cazzaniga, C.; Frost, C. D.; Picozza, P.; Gorini, G.; Mancini, R.; Sarno, M.

2018-02-01

This paper presents a neutron accelerated study of soft errors in advanced electronic devices used in space missions, i.e. Flash memories performed at the ChipIr and VESUVIO beam lines at the ISIS spallation neutron source. The two neutron beam lines are set up to mimic the space environment spectra and allow neutron irradiation tests on Flash memories in the neutron energy range above 10 MeV and up to 800 MeV. The ISIS neutron energy spectrum is similar to the one occurring in the atmospheric as well as in space and planetary environments, with intensity enhancements varying in the range 108- 10 9 and 106- 10 7 respectively. Such conditions are suitable for the characterization of the atmospheric, space and planetary neutron radiation environments, and are directly applicable for accelerated tests of electronic components as demonstrated here in benchmark measurements performed on flash memories.

Columbia Crew added to Astronaut Memorial Mirror

NASA Image and Video Library

2003-07-15

Workers add to the Astronaut Memorial Mirror the names of the Columbia crew who died in the STS-107 accident. Dedicated May 9, 1991, the Astronaut Memorial honors U.S. astronauts who gave their lives for space exploration. The "Space Mirror," 42 1/2 feet high by 50 feet wide, illuminates the names of the fallen astronauts cut through the monument's black granite surface. The Memorial Mirror is accessible through the KSC Visitor Complex.

Weather prediction using a genetic memory

NASA Technical Reports Server (NTRS)

Rogers, David

1990-01-01

Kanaerva's sparse distributed memory (SDM) is an associative memory model based on the mathematical properties of high dimensional binary address spaces. Holland's genetic algorithms are a search technique for high dimensional spaces inspired by evolutional processes of DNA. Genetic Memory is a hybrid of the above two systems, in which the memory uses a genetic algorithm to dynamically reconfigure its physical storage locations to reflect correlations between the stored addresses and data. This architecture is designed to maximize the ability of the system to scale-up to handle real world problems.

Three more semantic serial position functions and a SIMPLE explanation.

PubMed

Kelley, Matthew R; Neath, Ian; Surprenant, Aimée M

2013-05-01

There are innumerable demonstrations of serial position functions-with characteristic primacy and recency effects-in episodic tasks, but there are only a handful of such demonstrations in semantic memory tasks, and those demonstrations have used only two types of stimuli. Here, we provide three more examples of serial position functions when recalling from semantic memory. Participants were asked to reconstruct the order of (1) two cartoon theme song lyrics, (2) the seven Harry Potter books, and (3) two sets of movies, and all three demonstrations yielded conventional-looking serial position functions with primacy and recency effects. The data were well-fit by SIMPLE, a local distinctiveness model of memory that was originally designed to account for serial position effects in short- and long-term episodic memory. According to SIMPLE, serial position functions in both episodic and semantic memory tasks arise from the same type of processing: Items that are more separated from their close neighbors in psychological space at the time of recall will be better remembered. We argue that currently available evidence suggests that serial position functions observed when recalling items that are presumably in semantic memory arise because of the same processes as those observed when recalling items that are presumably in episodic memory.

Camera memory study for large space telescope. [charge coupled devices

NASA Technical Reports Server (NTRS)

Hoffman, C. P.; Brewer, J. E.; Brager, E. A.; Farnsworth, D. L.

1975-01-01

Specifications were developed for a memory system to be used as the storage media for camera detectors on the large space telescope (LST) satellite. Detectors with limited internal storage time such as intensities charge coupled devices and silicon intensified targets are implied. The general characteristics are reported of different approaches to the memory system with comparisons made within the guidelines set forth for the LST application. Priority ordering of comparisons is on the basis of cost, reliability, power, and physical characteristics. Specific rationales are provided for the rejection of unsuitable memory technologies. A recommended technology was selected and used to establish specifications for a breadboard memory. Procurement scheduling is provided for delivery of system breadboards in 1976, prototypes in 1978, and space qualified units in 1980.

Space Mirror Memorial

NASA Image and Video Library

2007-01-27

Former astronaut John Young addresses guests and attendees at a ceremony at the KSC Visitor Complex held in remembrance of the astronauts lost in the Apollo 1 fire: Virgil "Gus" Grissom, Edward H. White II and Roger B. Chaffee. Members of their families, along with Associate Administrator for Space Operations William Gerstenmaier, President of the Astronauts Memorial Foundation Stephen Feldman, Chairman of the Board of Directors of the Astronauts Memorial Foundation William Potter and former astronaut John Young, attended the ceremony. Behind the stage is the Space Mirror Memorial, designated as a national memorial by Congress and President George Bush in 1991 to honor fallen astronauts. Their names are emblazoned on the monument’s 42-1/2-foot-high by 50-foot-wide black granite surface as if to be projected into the heavens.

Memory as Perception of the Past: Compressed Time inMind and Brain.

PubMed

Howard, Marc W

2018-02-01

In the visual system retinal space is compressed such that acuity decreases further from the fovea. Different forms of memory may rely on a compressed representation of time, manifested as decreased accuracy for events that happened further in the past. Neurophysiologically, "time cells" show receptive fields in time. Analogous to the compression of visual space, time cells show less acuity for events further in the past. Behavioral evidence suggests memory can be accessed by scanning a compressed temporal representation, analogous to visual search. This suggests a common computational language for visual attention and memory retrieval. In this view, time functions like a scaffolding that organizes memories in much the same way that retinal space functions like a scaffolding for visual perception. Copyright © 2017 Elsevier Ltd. All rights reserved.

Multistate storage nonvolatile memory device based on ferroelectricity and resistive switching effects of SrBi2Ta2O9 films

NASA Astrophysics Data System (ADS)

Song, Zhiwei; Li, Gang; Xiong, Ying; Cheng, Chuanpin; Zhang, Wanli; Tang, Minghua; Li, Zheng; He, Jiangheng

2018-05-01

A memory device with a Pt/SrBi2Ta2O9(SBT)/Pt(111) structure was shown to have excellent combined ferroelectricity and resistive switching properties, leading to higher multistate storage memory capacity in contrast to ferroelectric memory devices. In this device, SBT polycrystalline thin films with significant (115) orientation were fabricated on Pt(111)/Ti/SiO2/Si(100) substrates using CVD (chemical vapor deposition) method. Measurement results of the electric properties exhibit reproducible and reliable ferroelectricity switching behavior and bipolar resistive switching effects (BRS) without an electroforming process. The ON/OFF ratio of the resistive switching was found to be about 103. Switching mechanisms for the low resistance state (LRS) and high resistance state (HRS) currents are likely attributed to the Ohmic and space charge-limited current (SCLC) behavior, respectively. Moreover, the ferroelectricity and resistive switching effects were found to be mutually independent, and the four logic states were obtained by controlling the periodic sweeping voltage. This work holds great promise for nonvolatile multistate memory devices with high capacity and low cost.

Nobiletin improves emotional and novelty recognition memory but not spatial referential memory.

PubMed

Kang, Jiyun; Shin, Jung-Won; Kim, Yoo-Rim; Swanberg, Kelley M; Kim, Yooseung; Bae, Jae Ryong; Kim, Young Ki; Lee, Jinwon; Kim, Soo-Yeon; Sohn, Nak-Won; Maeng, Sungho

2017-01-01

How to maintain and enhance cognitive functions for both aged and young populations is a highly interesting subject. But candidate memory-enhancing reagents are tested almost exclusively on lesioned or aged animals. Also, there is insufficient information on the type of memory these reagents can improve. Working memory, located in the prefrontal cortex, manages short-term sensory information, but, by gaining significant relevance, this information is converted to long-term memory by hippocampal formation and/or amygdala, followed by tagging with space-time or emotional cues, respectively. Nobiletin is a product of citrus peel known for cognitive-enhancing effects in various pharmacological and neurodegenerative disease models, yet, it is not well studied in non-lesioned animals and the type of memory that nobiletin can improve remains unclear. In this study, 8-week-old male mice were tested using behavioral measurements for working, spatial referential, emotional and visual recognition memory after daily administration of nobiletin. While nobiletin did not induce any change of spontaneous activity in the open field test, freezing by fear conditioning and novel object recognition increased. However, the effectiveness of spatial navigation in the Y-maze and Morris water maze was not improved. These results mean that nobiletin can specifically improve memories of emotionally salient information associated with fear and novelty, but not of spatial information without emotional saliency. Accordingly, the use of nobiletin on normal subjects as a memory enhancer would be more effective on emotional types but may have limited value for the improvement of episodic memories.

Superelasticity and cryogenic linear shape memory effects of CaFe 2As 2

DOE PAGES

Sypek, John T.; Yu, Hang; Dusoe, Keith J.; ...

2017-10-20

Shape memory materials have the ability to recover their original shape after a significant amount of deformation when they are subjected to certain stimuli, for instance, heat or magnetic fields. But, their performance is often limited by the energetics and geometry of the martensitic-austenitic phase transformation. We report a unique shape memory behavior in CaFe 2As 2, which exhibits superelasticity with over 13% recoverable strain, over 3 GPa yield strength, repeatable stress–strain response even at the micrometer scale, and cryogenic linear shape memory effects near 50 K. These properties are acheived through a reversible uni-axial phase transformation mechanism, the tetragonal/orthorhombic-to-collapsed-tetragonalmore » phase transformation. These results offer the possibility of developing cryogenic linear actuation technologies with a high precision and high actuation power per unit volume for deep space exploration, and more broadly, suggest a mechanistic path to a class of shape memory materials, ThCr 2Si 2-structured intermetallic compounds.« less

Checkpoint-Restart in User Space

DOE Office of Scientific and Technical Information (OSTI.GOV)

CRUISE implements a user-space file system that stores data in main memory and transparently spills over to other storage, like local flash memory or the parallel file system, as needed. CRUISE also exposes file contents fo remote direct memory access, allowing external tools to copy files to the parallel file system in the background with reduced CPU interruption.

An event map of memory space in the hippocampus

PubMed Central

Deuker, Lorena; Bellmund, Jacob LS; Navarro Schröder, Tobias; Doeller, Christian F

2016-01-01

The hippocampus has long been implicated in both episodic and spatial memory, however these mnemonic functions have been traditionally investigated in separate research strands. Theoretical accounts and rodent data suggest a common mechanism for spatial and episodic memory in the hippocampus by providing an abstract and flexible representation of the external world. Here, we monitor the de novo formation of such a representation of space and time in humans using fMRI. After learning spatio-temporal trajectories in a large-scale virtual city, subject-specific neural similarity in the hippocampus scaled with the remembered proximity of events in space and time. Crucially, the structure of the entire spatio-temporal network was reflected in neural patterns. Our results provide evidence for a common coding mechanism underlying spatial and temporal aspects of episodic memory in the hippocampus and shed new light on its role in interleaving multiple episodes in a neural event map of memory space. DOI: http://dx.doi.org/10.7554/eLife.16534.001 PMID:27710766

From the Lab to the Dorm Room: Metacognitive Awareness and Use of Spaced Study

ERIC Educational Resources Information Center

Susser, Jonathan A.; McCabe, Jennifer

2013-01-01

Laboratory studies have demonstrated the long-term memory benefits of studying material in multiple distributed sessions as opposed to one massed session, given an identical amount of overall study time (i.e., the "spacing effect"). The current study goes beyond the laboratory to investigate whether undergraduates know about the advantage of…

Practicality of Evaluating Soft Errors in Commercial sub-90 nm CMOS for Space Applications

NASA Technical Reports Server (NTRS)

Pellish, Jonathan A.; LaBel, Kenneth A.

2010-01-01

The purpose of this presentation is to: Highlight space memory evaluation evolution, Review recent developments regarding low-energy proton direct ionization soft errors, Assess current space memory evaluation challenges, including increase of non-volatile technology choices, and Discuss related testing and evaluation complexities.

Contemporary Spaces of Memory - Towards Transdisciplinarity in Architecture

NASA Astrophysics Data System (ADS)

Kabrońska, Joanna

2017-10-01

The paper explores new phenomena in the contemporary practice of commemoration implemented through architecture. Architectural objects related to memory can be a place where new trends and phenomena appear earlier than in other architectural objects. The text is an attempt to prove that these new spaces of memory are a kind of laboratory where new ideas taking place in architecture and related disciplines are being tested. Research focuses on the bond between the complex and difficult problem of memory and the issue of transdisciplinarity in architecture. Over the last few decades architecture has been - in comparison to other areas - a relatively closed domain of knowledge. Contemporary places of memory - different from the traditional - may be the evidence of changes. On the basis of theoretical approaches, interdisciplinary surveys, in-field analyses and case studies the paper give insight into the relationships between architecture and other areas, emerging in the recently created spaces of memory of different types. The text indicates that today both the study and the design of such places is difficult without going beyond the field of architecture. There is a need for further extensive research, but the paper confirms the potential of this research direction. Spaces of memory offer the opportunity to capture the transformation of the discipline at the moment when the process begins.

Remembering Places in Space: A Human Analog Study of the Morris Water Maze

NASA Astrophysics Data System (ADS)

Fitting, Sylvia; Allen, Gary L.; Wedell, Douglas H.

We conducted a human analog study of the Morris Water Maze, with individuals indicating a remembered location in a 3 m diameter arena over different intervals of time and with different memory loads. The primary focus of the study was to test a theory of how varying cue location and number of cues affects memory for spatial location. As expected, memory performance, as measured by proximity to the actual location, was negatively affected by increasing memory load, increasing delay interval, and decreasing the number of cues. As memory performance decremented, bias effects increased and were in accordance with the cue-based memory model described by Fitting, Wedell and Allen (2005). Specifically, remembered locations were biased toward the nearest cue and error decreased with more cues. These results demonstrate that localization processes that apply to small two-dimensional task fields may generalize to a larger traversable task field.

KSC-2012-1128

NASA Image and Video Library

2012-01-26

CAPE CANAVERAL, Fla. -- The names of U.S. space explorers who have been lost are engraved on the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida. Kennedy Space Center Director Robert Cabana, Deputy Director Janet Petro, and United Space Alliance’s Vice President for Aerospace Services/Florida Site Director Mark Nappi placed a wreath at the memorial during Kennedy’s NASA Day of Remembrance. The Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the astronaut crews of Apollo 1 and space shuttles Challenger and Columbia. Kennedy civil service and contractor employees, along with the general public, paid their respects throughout the day. The visitor complex provided flowers for visitors to place at the memorial. Photo credit: NASA/Dimitri Gerondidakis

KSC-2012-1129

NASA Image and Video Library

2012-01-26

CAPE CANAVERAL, Fla. -- NASA Kennedy Space Center civil service and contractor workers, along with visitors gather at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida for Kennedy Space Center’s NASA Day of Remembrance. Kennedy Center Director Robert Cabana, Deputy Director Janet Petro, and United Space Alliance’s Vice President for Aerospace Services/Florida Site Director Mark Nappi placed a wreath at the memorial. The Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the astronaut crews of Apollo 1 and space shuttles Challenger and Columbia. Kennedy civil service and contractor employees, along with the general public, paid their respects throughout the day. The visitor complex provided flowers for visitors to place at the memorial. Photo credit: NASA/Dimitri Gerondidakis

KSC-2012-1130

NASA Image and Video Library

2012-01-26

CAPE CANAVERAL, Fla. -- NASA Kennedy Space Center civil service and contractor workers, along with visitors gather at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida for Kennedy Space Center’s NASA Day of Remembrance. Kennedy Center Director Robert Cabana, Deputy Director Janet Petro, and United Space Alliance’s Vice President for Aerospace Services/Florida Site Director Mark Nappi placed a wreath at the memorial. The Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the astronaut crews of Apollo 1 and space shuttles Challenger and Columbia. Kennedy civil service and contractor employees, along with the general public, paid their respects throughout the day. The visitor complex provided flowers for visitors to place at the memorial. Photo credit: NASA/Dimitri Gerondidakis

KSC-2011-1217

NASA Image and Video Library

2011-01-27

CAPE CANAVERAL, Fla. -- Kennedy Space Center Director and former astronaut Bob Cabana answers media questions during a Day of Remembrance wreath laying ceremony at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida. The ceremony honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery. The memorial displays the names of 24 United States astronauts, including the crew members of space shuttles Columbia and Challenger, Apollo 1, and those who died in training and commercial airplane accidents. The memorial is a project of the Astronauts Memorial Foundation and was paid for by Florida residents who purchased special Challenger mission automobile license plates. 2011 marks the 25th anniversary of the loss of Challenger, which broke apart over the Atlantic Ocean 73 seconds into flight on Jan. 28, 1986. Photo credit: NASA/Kim Shiflett

KENNEDY SPACE CENTER, FLA. - At the Space Memorial Mirror in the KSC Visitor Complex, visitors gather around dancers from the Shoshone-Bannock Native American community, Fort Hall, Idaho, who are performing a healing ceremony during the memorial service held for the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - At the Space Memorial Mirror in the KSC Visitor Complex, visitors gather around dancers from the Shoshone-Bannock Native American community, Fort Hall, Idaho, who are performing a healing ceremony during the memorial service held for the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

KSC-2011-1212

NASA Image and Video Library

2011-01-27

CAPE CANAVERAL, Fla. -- Pictured near the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida are the members of the NASA family who lost their lives while furthering the cause of exploration and discovery. The memorial honors 24 United States astronauts, including the crew members of space shuttles Columbia and Challenger, Apollo 1, and those who died in training and commercial airplane accidents. The memorial is a project of the Astronauts Memorial Foundation and was paid for by Florida residents who purchased special Challenger mission automobile license plates. 2011 marks the 25th anniversary of the loss of Challenger, which broke apart over the Atlantic Ocean 73 seconds into flight on Jan. 28, 1986. Photo credit: NASA/Kim Shiflett

KSC-2011-1213

NASA Image and Video Library

2011-01-27

CAPE CANAVERAL, Fla. -- President and C.E.O. of The Astronauts Memorial Foundation Stephen Feldman displays a single yellow rose near the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida during a Day of Remembrance ceremony to honor members of the NASA family who lost their lives while furthering the cause of exploration and discovery. The memorial honors 24 United States astronauts, including the crew members of space shuttles Columbia and Challenger, Apollo 1, and those who died in training and commercial airplane accidents. The memorial is a project of the Astronauts Memorial Foundation and was paid for by Florida residents who purchased special Challenger mission automobile license plates. 2011 marks the 25th anniversary of the loss of Challenger, which broke apart over the Atlantic Ocean 73 seconds into flight on Jan. 28, 1986. Photo credit: NASA/Kim Shiflett

KSC-2012-1126

NASA Image and Video Library

2012-01-26

CAPE CANAVERAL, Fla. -- Roses decorate the fence surrounding the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida during Kennedy Space Center’s NASA Day of Remembrance. A large wreath was placed at the memorial by Kennedy Center Director Robert Cabana, Deputy Director Janet Petro, and United Space Alliance’s Vice President for Aerospace Services/Florida Site Director Mark Nappi. The Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the astronaut crews of Apollo 1 and space shuttles Challenger and Columbia. Kennedy civil service and contractor employees, along with the general public, paid their respects throughout the day. The visitor complex provided flowers for visitors to place at the memorial. Photo credit: NASA/Kim Shiflett

KSC-2012-1122

NASA Image and Video Library

2012-01-26

CAPE CANAVERAL, Fla. -- During Kennedy Space Center’s NASA Day of Remembrance at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida, United Space Alliance’s Vice President for Aerospace Services/Florida Site Director Mark Nappi, at left, Kennedy Deputy Director Janet Petro, and Kennedy Center Director Robert Cabana prepare to place a wreath at the memorial. The Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the astronaut crews of Apollo 1 and space shuttles Challenger and Columbia. Kennedy civil service and contractor employees, along with the general public, paid their respects throughout the day. The visitor complex provided flowers for visitors to place at the memorial. Photo credit: NASA/Kim Shiflett

KSC-2012-1131

NASA Image and Video Library

2012-01-26

CAPE CANAVERAL, Fla. -- Visitors place roses at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida during Kennedy Space Center’s NASA Day of Remembrance. Kennedy Center Director Robert Cabana, Deputy Director Janet Petro, and United Space Alliance’s Vice President for Aerospace Services/Florida Site Director Mark Nappi placed a wreath at the memorial. The Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the astronaut crews of Apollo 1 and space shuttles Challenger and Columbia. Kennedy civil service and contractor employees, along with the general public, paid their respects throughout the day. The visitor complex provided flowers for visitors to place at the memorial. Photo credit: NASA/Dimitri Gerondidakis

Do older adults use the Method of Loci? Results from the ACTIVE Study

PubMed Central

Gross, Alden L.; Brandt, Jason; Bandeen-Roche, Karen; Carlson, Michelle C.; Stuart, Elizabeth A.; Marsiske, Michael; Rebok, George W.

2013-01-01

Background The method of loci (MoL) is a complex visuospatial mnemonic strategy. Previous research suggests older adults could potentially benefit from using the MoL, but that it is too attentionally demanding for them to use in practice. We evaluated the hypotheses that training can increase the use of MoL, and that MoL use is associated with better memory. Methods We analyzed skip patterns on response forms for the Auditory Verbal Learning Test (AVLT) in the Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE, n=1,401) trial using 5 years of longitudinal follow-up. Results At baseline, 2% of participants skipped spaces. Fewer than 2% of control participants skipped spaces at any visit across 5 years, but 25% of memory-trained participants, taught the MoL, did so. Participants who skipped spaces used more serial clustering, a hallmark of the MoL (p<0.001). Trained participants who skipped spaces showed greater memory improvement after training than memory-trained participants who did not skip spaces (Cohen's d=0.84, P=0.007), and did not differ in the subsequent rate of long-term memory decline through up to 5 years of follow-up. Conclusion Despite being attentionally demanding, this study suggests that after training, the MoL is used by up to 25% of older adults, and that its use is associated with immediate memory improvement that was sustained through the course of follow-up. Findings are consistent with the notion that older adults balance complexity with novelty in strategy selection, and that changes in strategies used following memory training result in observable qualitative and quantitative differences in memory performance. PMID:24625044

Cognitive Operations on Space and Their Impact on the Precision of Location Memory

ERIC Educational Resources Information Center

Lansdale, Mark; Humphries, Joyce; Flynn, Victoria

2013-01-01

Learning about object locations in space usually involves the summation of information from different experiences of that space and requires various cognitive operations to make this possible. These processes are poorly understood and, in the extreme, may not occur--leading to mutual exclusivity of memories (Baguley, Lansdale, Lines, & Parkin,…

ReHypar: A Recursive Hybrid Chunk Partitioning Method Using NAND-Flash Memory SSD

PubMed Central

Park, Sung-Soon; Lim, Cheol-Su

2014-01-01

Due to the rapid development of flash memory, SSD is considered to be the replacement of HDD in the storage market. Although SSD retains several promising characteristics, such as high random I/O performance and nonvolatility, its high expense per capacity is the main obstacle in replacing HDD in all storage solutions. An alternative is to provide a hybrid structure where a small portion of SSD address space is combined with the much larger HDD address space. In such a structure, maximizing the space utilization of SSD in a cost-effective way is extremely important to generate high I/O performance. We developed ReHypar (recursive hybrid chunk partitioning) that enables improving the space utilization of SSD in the hybrid structure. The first objective of ReHypar is to mitigate the fragmentation overhead of SSD address space, by reusing the remaining free space of I/O units as much as possible. Furthermore, ReHypar allows defining several, logical data sections in SSD address space, with each of those sections being configured with the different I/O unit. We integrated ReHypar with ext2 and ext4 and evaluated it using two public benchmarks including IOzone and Postmark. PMID:24987741

KSC-04PD-0103

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Winston Scott, executive director of Florida Space Authority, speaks to attendees at a memorial service honoring the crew of Columbia. He stands in front of the Space Memorial Mirror at the KSC Visitor Complex. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Scott is a former astronaut who flew on Columbia in 1997. Attended by many friends, co-workers and families, the memorial service was also open to the public.

The mitigating effect of repeated memory reactivations on forgetting

NASA Astrophysics Data System (ADS)

MacLeod, Sydney; Reynolds, Michael G.; Lehmann, Hugo

2018-12-01

Memory reactivation is a process whereby cueing or recalling a long-term memory makes it enter a new active and labile state. Substantial evidence suggests that during this state the memory can be updated (e.g., adding information) and can become more vulnerable to disruption (e.g., brain insult). Memory reactivations can also prevent memory decay or forgetting. However, it is unclear whether cueing recall of a feature or component of the memory can benefit retention similarly to promoting recall of the entire memory. We examined this possibility by having participants view a series of neutral images and then randomly assigning them to one of four reactivation groups: control (no reactivation), distractor (reactivation of experimental procedures), component (image category reactivation), and descriptive (effortful description of the images). The experiment also included three retention intervals: 1 h, 9 days, and 28 days. Importantly, the participants received three reactivations equally spaced within their respective retention interval. At the end of the interval, all the participants were given an in-lab free-recall test in which they were asked to write down each image they remembered with as many details as possible. The data revealed that both the participants in the descriptive reactivation and component reactivation groups remembered significantly more than the participants in the control groups, with the effect being most pronounced in the 28-day retention interval condition. These findings suggest that memory reactivation, even component reactivation of a memory, makes memories more resistant to decay.

Angular Spacing Control for Segmented Data Pages in Angle-Multiplexed Holographic Memory

NASA Astrophysics Data System (ADS)

Kinoshita, Nobuhiro; Muroi, Tetsuhiko; Ishii, Norihiko; Kamijo, Koji; Kikuchi, Hiroshi; Shimidzu, Naoki; Ando, Toshio; Masaki, Kazuyoshi; Shimizu, Takehiro

2011-09-01

To improve the recording density of angle-multiplexed holographic memory, it is effective to increase the numerical aperture of the lens and to shorten the wavelength of the laser source as well as to increase the multiplexing number. The angular selectivity of a hologram, which determines the multiplexing number, is dependent on the incident angle of not only the reference beam but also the signal beam to the holographic recording medium. The actual signal beam, which is a convergent or divergent beam, is regarded as the sum of plane waves that have different propagation directions, angular selectivities, and optimal angular spacings. In this paper, focusing on the differences in the optimal angular spacing, we proposed a method to control the angular spacing for each segmented data page. We investigated the angular selectivity of a hologram and crosstalk for segmented data pages using numerical simulation. The experimental results showed a practical bit-error rate on the order of 10-3.

On a model of electromagnetic field propagation in ferroelectric media

NASA Astrophysics Data System (ADS)

Picard, Rainer

2007-04-01

The Maxwell system in an anisotropic, inhomogeneous medium with non-linear memory effect produced by a Maxwell type system for the polarization is investigated under low regularity assumptions on data and domain. The particular form of memory in the system is motivated by a model for electromagnetic wave propagation in ferromagnetic materials suggested by Greenberg, MacCamy and Coffman [J.M. Greenberg, R.C. MacCamy, C.V. Coffman, On the long-time behavior of ferroelectric systems, Phys. D 134 (1999) 362-383]. To avoid unnecessary regularity requirements the problem is approached as a system of space-time operator equation in the framework of extrapolation spaces (Sobolev lattices), a theoretical framework developed in [R. Picard, Evolution equations as space-time operator equations, Math. Anal. Appl. 173 (2) (1993) 436-458; R. Picard, Evolution equations as operator equations in lattices of Hilbert spaces, Glasnik Mat. 35 (2000) 111-136]. A solution theory for a large class of ferromagnetic materials confined to an arbitrary open set (with suitably generalized boundary conditions) is obtained.

KSC-04PD-0102

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. At the podium in front of the Space Memorial Mirror at the KSC Visitor Complex is Dr. Stephen Feldman, president of the Astronaut Memorial Foundation. He spoke to attendees at the memorial service remembering and honoring the crew of Columbia. With him (from left) are KSC Deputy Director Woodrow Whitlow Jr., Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Scott is a former astronaut who flew on Columbia in 1997. Attended by many friends, co-workers and families, the memorial service was also open to the public.

KENNEDY SPACE CENTER, FLA. - A member of the Shoshone-Bannock Native American community from Fort Hall, Idaho, displays a handmade item with the STS-107 logo. Dancers from Shoshone-Bannock Junior-Senior High School performed a healing ceremony during the memorial held at the Space Memorial Mirror, in the KSC Visitor Complex. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - A member of the Shoshone-Bannock Native American community from Fort Hall, Idaho, displays a handmade item with the STS-107 logo. Dancers from Shoshone-Bannock Junior-Senior High School performed a healing ceremony during the memorial held at the Space Memorial Mirror, in the KSC Visitor Complex. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

Manifestation of the shape-memory effect in polyetherurethane cellular plastics, fabric composites, and sandwich structures under microgravity

NASA Astrophysics Data System (ADS)

Babaevskii, P. G.; Kozlov, N. A.; Agapov, I. G.; Reznichenko, G. M.; Churilo, N. V.; Churilo, I. V.

2016-09-01

The results of experiments that were performed to test the feasibility of creating sandwich structures (consisting of thin-layer sheaths of polymer composites and a cellular polymer core) with the shapememory effect as models of the transformable components of space structures have been given. The data obtained indicate that samples of sandwich structures under microgravity conditions on board the International Space Station have recovered their shape to almost the same degree as under terrestrial conditions, which makes it possible to recommend them for creating components of transformable space structures on their basis.

SRAM Based Re-programmable FPGA for Space Applications

NASA Technical Reports Server (NTRS)

Wang, J. J.; Sun, J. S.; Cronquist, B. E.; McCollum, J. L.; Speers, T. M.; Plants, W. C.; Katz, R. B.

1999-01-01

An SRAM (static random access memory)-based reprogrammable FPGA (field programmable gate array) is investigated for space applications. A new commercial prototype, named the RS family, was used as an example for the investigation. The device is fabricated in a 0.25 micrometers CMOS technology. Its architecture is reviewed to provide a better understanding of the impact of single event upset (SEU) on the device during operation. The SEU effect of different memories available on the device is evaluated. Heavy ion test data and SPICE simulations are used integrally to extract the threshold LET (linear energy transfer). Together with the saturation cross-section measurement from the layout, a rate prediction is done on each memory type. The SEU in the configuration SRAM is identified as the dominant failure mode and is discussed in detail. The single event transient error in combinational logic is also investigated and simulated by SPICE. SEU mitigation by hardening the memories and employing EDAC (error detection and correction) at the device level are presented. For the configuration SRAM (CSRAM) cell, the trade-off between resistor de-coupling and redundancy hardening techniques are investigated with interesting results. Preliminary heavy ion test data show no sign of SEL (single event latch-up). With regard to ionizing radiation effects, the increase in static leakage current (static I(sub CC)) measured indicates a device tolerance of approximately 50krad(Si).

Space Mirror Memorial

NASA Image and Video Library

2007-01-27

The Space Mirror Memorial, seen in profile, is reflected in the nearby lake at the KSC Visitor Complex. The memorial is the scene of a ceremony being held in remembrance of the astronauts lost in the Apollo 1 fire: Virgil "Gus" Grissom, Edward H. White II and Roger B. Chaffee. The mirror was designated as a national memorial by Congress and President George Bush in 1991 to honor fallen astronauts. Their names are emblazoned on the monument's 42-1/2-foot-high by 50-foot-wide black granite surface as if to be projected into the heavens.

Effect of Graphene Addition on Shape Memory Behavior of Epoxy Resins

NASA Technical Reports Server (NTRS)

Williams, Tiffany; Meador, Michael; Miller, Sandi; Scheiman, Daniel

2011-01-01

Shape memory polymers (SMPs) and composites are a special class of smart materials known for their ability to change size and shape upon exposure to an external stimulus (e.g. light, heat, pH, or magnetic field). These materials are commonly used for biomedical applications; however, recent attempts have been made towards developing SMPs and composites for use in aircraft and space applications. Implementing SMPs and composites to create a shape change effect in some aircraft structures could potentially reduce drag, decrease fuel consumption, and improve engine performance. This paper discusses the development of suitable materials to use in morphing aircraft structures. Thermally responsive epoxy SMPs and nanocomposites were developed and the shape memory behavior and thermo-mechanical properties were studied. Overall, preliminary results from dynamic mechanical analysis (DMA) showed that thermally actuated shape memory epoxies and nanocomposites possessed Tgs near approximately 168 C. When graphene nanofiller was added, the storage modulus and crosslinking density decreased. On the other hand, the addition of graphene enhanced the recovery behavior of the shape memory nanocomposites. It was assumed that the addition of graphene improved shape memory recovery by reducing the crosslinking density and increasing the elasticity of the nanocomposites.

An interference model of visual working memory.

PubMed

Oberauer, Klaus; Lin, Hsuan-Yu

2017-01-01

The article introduces an interference model of working memory for information in a continuous similarity space, such as the features of visual objects. The model incorporates the following assumptions: (a) Probability of retrieval is determined by the relative activation of each retrieval candidate at the time of retrieval; (b) activation comes from 3 sources in memory: cue-based retrieval using context cues, context-independent memory for relevant contents, and noise; (c) 1 memory object and its context can be held in the focus of attention, where it is represented with higher precision, and partly shielded against interference. The model was fit to data from 4 continuous-reproduction experiments testing working memory for colors or orientations. The experiments involved variations of set size, kind of context cues, precueing, and retro-cueing of the to-be-tested item. The interference model fit the data better than 2 competing models, the Slot-Averaging model and the Variable-Precision resource model. The interference model also fared well in comparison to several new models incorporating alternative theoretical assumptions. The experiments confirm 3 novel predictions of the interference model: (a) Nontargets intrude in recall to the extent that they are close to the target in context space; (b) similarity between target and nontarget features improves recall, and (c) precueing-but not retro-cueing-the target substantially reduces the set-size effect. The success of the interference model shows that working memory for continuous visual information works according to the same principles as working memory for more discrete (e.g., verbal) contents. Data and model codes are available at https://osf.io/wgqd5/. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Living Memorials: Understanding the Social Meanings of Community-Based Memorials to September 11, 2001

Treesearch

Erika S. Svendsen; Lindsay K. Campbell

2010-01-01

Living memorials are landscaped spaces created by people to memorialize individuals, places, and events. Hundreds of stewardship groups across the United States of America created living memorials in response to the September 11, 2001 terrorist attacks. This study sought to understand how stewards value, use, and talk about their living, community-based memorials....

KSC-04PD-0109

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Standing in front of the Space Memorial Mirror at the KSC Visitor Complex, KSC Deputy Director Woodrow Whitlow Jr., Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott bow their heads in prayer during a memorial service remembering and honoring the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Scott is a former astronaut who flew on Columbia in 1997. The public was also invited to the memorial service.

Post-training gamma irradiation-enhanced contextual fear memory associated with reduced neuronal activation of the infralimbic cortex.

PubMed

Kugelman, Tara; Zuloaga, Damian G; Weber, Sydney; Raber, Jacob

2016-02-01

The brain might be exposed to irradiation under a variety of situations, including clinical treatments, nuclear accidents, dirty bomb scenarios, and military and space missions. Correctly recalling tasks learned prior to irradiation is important but little is known about post-learning effects of irradiation. It is not clear whether exposure to X-ray irradiation during memory consolidation, a few hours following training, is associated with altered contextual fear conditioning 24h after irradiation and which brain region(s) might be involved in these effects. Brain immunoreactivity patterns of the immediately early gene c-Fos, a marker of cellular activity was used to determine which brain areas might be altered in post-training irradiation memory retention tasks. In this study, we show that post-training gamma irradiation exposure (1 Gy) enhanced contextual fear memory 24h later and is associated with reduced cellular activation in the infralimbic cortex. Reduced GABA-ergic neurotransmission in parvalbumin-positive cells in the infralimbic cortex might play a role in this post-training radiation-enhanced contextual fear memory. Copyright © 2015 Elsevier B.V. All rights reserved.

Post-training gamma irradiation-enhanced contextual fear memory associated with reduced neuronal activation of the infralimbic cortex

PubMed Central

Kugelman, Tara; Zuloaga, Damian G.; Weber, Sydney; Raber, Jacob

2015-01-01

The brain might be exposed to irradiation under a variety of situations, including clinical treatments, nuclear accidents, dirty bomb scenarios, and military and space missions. Correctly recalling tasks learned prior to irradiation is important but little is known about post-learning effects of irradiation. It is not clear whether exposure to X-ray irradiation during memory consolidation, a few hours following training, is associated with altered contextual fear conditioning 24 hours after irradiation and which brain region(s) might be involved in these effects. Brain immunoreactivity patterns of the immediately early gene c-Fos, a marker of cellular activity was used to determine which brain areas might be altered in post-training irradiation memory retention tasks. In this study, we show that post-training gamma irradiation exposure (1 Gy) enhanced contextual fear memory 24 hours later and is associated with reduced cellular activation in the infralimbic cortex. Reduced GABA-ergic neurotransmission in parvalbumin-positive cells in the infralimbic cortex might play a role in this post-training radiation-enhanced contextual fear memory. PMID:26522840

Single-Event Effect Performance of a Conductive-Bridge Memory EEPROM

NASA Technical Reports Server (NTRS)

Chen, Dakai; Wilcox, Edward; Berg, Melanie; Kim, Hak; Phan, Anthony; Figueiredo, Marco; Seidleck, Christina; LaBel, Kenneth

2015-01-01

We investigated the heavy ion single-event effect (SEE) susceptibility of the industry’s first stand-alone memory based on conductive-bridge memory (CBRAM) technology. The device is available as an electrically erasable programmable read-only memory (EEPROM). We found that single-event functional interrupt (SEFI) is the dominant SEE type for each operational mode (standby, dynamic read, and dynamic write/read). SEFIs occurred even while the device is statically biased in standby mode. Worst case SEFIs resulted in errors that filled the entire memory space. Power cycle did not always clear the errors. Thus the corrupted cells had to be reprogrammed in some cases. The device is also vulnerable to bit upsets during dynamic write/read tests, although the frequency of the upsets are relatively low. The linear energy transfer threshold for cell upset is between 10 and 20 megaelectron volts per square centimeter per milligram, with an upper limit cross section of 1.6 times 10(sup -11) square centimeters per bit (95 percent confidence level) at 10 megaelectronvolts per square centimeter per milligram. In standby mode, the CBRAM array appears invulnerable to bit upsets.

Analysis of SEL on Commercial SRAM Memories and Mixed-Field Characterization of a Latchup Detection Circuit for LEO Space Applications

NASA Astrophysics Data System (ADS)

Secondo, R.; Alía, R. Garcia; Peronnard, P.; Brugger, M.; Masi, A.; Danzeca, S.; Merlenghi, A.; Vaillé, J.-R.; Dusseau, L.

2017-08-01

A single event latchup (SEL) experiment based on commercial static random access memory (SRAM) memories has recently been proposed in the framework of the European Organization for Nuclear Research (CERN) Latchup Experiment and Student Satellite nanosatellite low Earth orbit (LEO) space mission. SEL characterization of three commercial SRAM memories has been carried out at the Paul Scherrer Institut (PSI) facility, using monoenergetic focused proton beams and different acquisition setups. The best target candidate was selected and a circuit for SEL detection has been proposed and tested at CERN, in the CERN High Energy AcceleRator Mixed-field facility (CHARM). Experimental results were carried out at test locations representative of the LEO environment, thus providing a full characterization of the SRAM cross sections, together with the analysis of the single-event effect and total ionizing dose of the latchup detection circuit in relation to the particle spectra expected during mission. The setups used for SEL monitoring are described, and details of the proposed circuit components and topology are presented. Experimental results obtained both at PSI and at CHARM facilities are discussed.

Dangerous Spaces, Dangerous Memories, Dangerous Emotions: Informal Education and Heteronormativity--A Manchester UK Youth Work Vignette

ERIC Educational Resources Information Center

Batsleer, Janet

2012-01-01

This article makes a connection between youth work spaces, emotions and some elements of memory, exploring the construction of spaces dangerous for social justice in both meanings of the term "dangerous for". It investigates the contribution to social justice of lesbian and gay youth work and other non-heteronormative youth work in a…

KSC-03pd0568

NASA Image and Video Library

2003-03-06

KENNEDY SPACE CENTER, FLA. - The Astronaut Memorial Space Mirror at the KSC Visitor Complex has had added attention since the loss of the Columbia crew Feb. 1, 2003, when they died in an explosion as they were returning to Earth from mission STS-107. The memorial is a national tribute to 17 American astronauts who previously gave their lives to the quest to explore space.

Re-Living Dangerous Memories: Online Journaling to Interrogate Spaces of "Otherness" in an Educational Administration Program at a Midwestern University

ERIC Educational Resources Information Center

Friend, Jennifer; Caruthers, Loyce; McCarther, Shirley Marie

2009-01-01

This theoretical paper explores the use of online journaling in an educational administration program to interrogate spaces of "otherness"--the geographical spaces of cities where poor children and children of color live--and the dangerous memories prospective administrators may have about diversity. The cultures of most educational administration…

Locality and universality of quantum memory effects.

PubMed

Liu, B-H; Wißmann, S; Hu, X-M; Zhang, C; Huang, Y-F; Li, C-F; Guo, G-C; Karlsson, A; Piilo, J; Breuer, H-P

2014-09-11

The modeling and analysis of the dynamics of complex systems often requires to employ non-Markovian stochastic processes. While there is a clear and well-established mathematical definition for non-Markovianity in the case of classical systems, the extension to the quantum regime recently caused a vivid debate, leading to many different proposals for the characterization and quantification of memory effects in the dynamics of open quantum systems. Here, we derive a mathematical representation for the non-Markovianity measure based on the exchange of information between the open system and its environment, which reveals the locality and universality of non-Markovianity in the quantum state space and substantially simplifies its numerical and experimental determination. We further illustrate the application of this representation by means of an all-optical experiment which allows the measurement of the degree of memory effects in a photonic quantum process with high accuracy.

KSC-2011-1211

NASA Image and Video Library

2011-01-27

CAPE CANAVERAL, Fla. -- A wreath is displayed at the foot of the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida during a Day of Remembrance ceremony to honor members of the NASA family who lost their lives while furthering the cause of exploration and discovery. The memorial honors 24 United States astronauts, including the crew members of space shuttles Columbia and Challenger, Apollo 1, and those who died in training and commercial airplane accidents. The memorial is a project of the Astronauts Memorial Foundation and was paid for by Florida residents who purchased special Challenger mission automobile license plates. 2011 marks the 25th anniversary of the loss of Challenger, which broke apart over the Atlantic Ocean 73 seconds into flight on Jan. 28, 1986. Photo credit: NASA/Kim Shiflett

KSC-2011-1208

NASA Image and Video Library

2011-01-27

CAPE CANAVERAL, Fla. -- Flowers lay at the foot of the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida before a Day of Remembrance wreath laying ceremony to honor members of the NASA family who lost their lives while furthering the cause of exploration and discovery. The memorial honors 24 United States astronauts, including the crew members of space shuttles Columbia and Challenger, Apollo 1, and those who died in training and commercial airplane accidents. The memorial is a project of the Astronauts Memorial Foundation and was paid for by Florida residents who purchased special Challenger mission automobile license plates. 2011 marks the 25th anniversary of the loss of Challenger, which broke apart over the Atlantic Ocean 73 seconds into flight on Jan. 28, 1986. Photo credit: NASA/Kim Shiflett

Working memory capacity and redundant information processing efficiency.

PubMed

Endres, Michael J; Houpt, Joseph W; Donkin, Chris; Finn, Peter R

2015-01-01

Working memory capacity (WMC) is typically measured by the amount of task-relevant information an individual can keep in mind while resisting distraction or interference from task-irrelevant information. The current research investigated the extent to which differences in WMC were associated with performance on a novel redundant memory probes (RMP) task that systematically varied the amount of to-be-remembered (targets) and to-be-ignored (distractor) information. The RMP task was designed to both facilitate and inhibit working memory search processes, as evidenced by differences in accuracy, response time, and Linear Ballistic Accumulator (LBA) model estimates of information processing efficiency. Participants (N = 170) completed standard intelligence tests and dual-span WMC tasks, along with the RMP task. As expected, accuracy, response-time, and LBA model results indicated memory search and retrieval processes were facilitated under redundant-target conditions, but also inhibited under mixed target/distractor and redundant-distractor conditions. Repeated measures analyses also indicated that, while individuals classified as high (n = 85) and low (n = 85) WMC did not differ in the magnitude of redundancy effects, groups did differ in the efficiency of memory search and retrieval processes overall. Results suggest that redundant information reliably facilitates and inhibits the efficiency or speed of working memory search, and these effects are independent of more general limits and individual differences in the capacity or space of working memory.

AC Electric Field Activated Shape Memory Polymer Composite

NASA Technical Reports Server (NTRS)

Kang, Jin Ho; Siochi, Emilie J.; Penner, Ronald K.; Turner, Travis L.

2011-01-01

Shape memory materials have drawn interest for applications like intelligent medical devices, deployable space structures and morphing structures. Compared to other shape memory materials like shape memory alloys (SMAs) or shape memory ceramics (SMCs), shape memory polymers (SMPs) have high elastic deformation that is amenable to tailored of mechanical properties, have lower density, and are easily processed. However, SMPs have low recovery stress and long response times. A new shape memory thermosetting polymer nanocomposite (LaRC-SMPC) was synthesized with conductive fillers to enhance its thermo-mechanical characteristics. A new composition of shape memory thermosetting polymer nanocomposite (LaRC-SMPC) was synthesized with conductive functionalized graphene sheets (FGS) to enhance its thermo-mechanical characteristics. The elastic modulus of LaRC-SMPC is approximately 2.7 GPa at room temperature and 4.3 MPa above its glass transition temperature. Conductive FGSs-doped LaRC-SMPC exhibited higher conductivity compared to pristine LaRC SMP. Applying an electric field at between 0.1 Hz and 1 kHz induced faster heating to activate the LaRC-SMPC s shape memory effect relative to applying DC electric field or AC electric field at frequencies exceeding1 kHz.

KSC-2012-1125

NASA Image and Video Library

2012-01-26

CAPE CANAVERAL, Fla. -- The Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida gleams in the morning sunlight during Kennedy’s NASA Day of Remembrance. A large wreath was placed at the memorial by Kennedy Center Director Robert Cabana, Deputy Director Janet Petro, and United Space Alliance’s Vice President for Aerospace Services/Florida Site Director Mark Nappi. The Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the astronaut crews of Apollo 1 and space shuttles Challenger and Columbia. Kennedy civil service and contractor employees, along with the general public, paid their respects throughout the day. The visitor complex provided flowers for visitors to place at the memorial. Photo credit: NASA/Kim Shiflett

A Memory of Majorana Modes through Quantum Quench.

PubMed

Chung, Ming-Chiang; Jhu, Yi-Hao; Chen, Pochung; Mou, Chung-Yu; Wan, Xin

2016-07-08

We study the sudden quench of a one-dimensional p-wave superconductor through its topological signature in the entanglement spectrum. We show that the long-time evolution of the system and its topological characterization depend on a pseudomagnetic field Reff(k). Furthermore, Reff(k) connects both the initial and the final Hamiltonians, hence exhibiting a memory effect. In particular, we explore the robustness of the Majorana zero-mode and identify the parameter space in which the Majorana zero-mode can revive in the infinite-time limit.

KENNEDY SPACE CENTER, FLA. - A student from Shoshone-Bannock Junior-Senior High School, Fort Hall, Idaho, holds part of a flag presented by dancers from the Shoshone-Bannock Native American community, Fort Hall, Idaho, commemorating the orbiter Columbia and her crew. The dancers performed a healing ceremony during the memorial service held at the Space Memorial Mirror for the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - A student from Shoshone-Bannock Junior-Senior High School, Fort Hall, Idaho, holds part of a flag presented by dancers from the Shoshone-Bannock Native American community, Fort Hall, Idaho, commemorating the orbiter Columbia and her crew. The dancers performed a healing ceremony during the memorial service held at the Space Memorial Mirror for the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

KENNEDY SPACE CENTER, FLA. - Astronaut John Herrington speaks to the visitors at the memorial service held at the Space Memorial Mirror for the crew of Columbia. Herrington, who is a Chickasaw from Oklahoma, introduced the Shoshone-Bannock Junior-Senior High School dancers, from the Native American community at Fort Hall, Idaho, who performed a healing ceremony. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - Astronaut John Herrington speaks to the visitors at the memorial service held at the Space Memorial Mirror for the crew of Columbia. Herrington, who is a Chickasaw from Oklahoma, introduced the Shoshone-Bannock Junior-Senior High School dancers, from the Native American community at Fort Hall, Idaho, who performed a healing ceremony. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

KENNEDY SPACE CENTER, FLA. - A member of the Shoshone-Bannock Native American community from Fort Hall, Idaho, reads a tribute to the crew of Columbia while another displays a handmade item with the STS-107 logo. Dancers from Shoshone-Bannock Junior-Senior High School performed a healing ceremony during the memorial held at the Space Memorial Mirror, in the KSC Visitor Complex. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

NASA Image and Video Library

2004-02-01

KENNEDY SPACE CENTER, FLA. - A member of the Shoshone-Bannock Native American community from Fort Hall, Idaho, reads a tribute to the crew of Columbia while another displays a handmade item with the STS-107 logo. Dancers from Shoshone-Bannock Junior-Senior High School performed a healing ceremony during the memorial held at the Space Memorial Mirror, in the KSC Visitor Complex. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

Two alternate proofs of Wang's lune formula for sparse distributed memory and an integral approximation

NASA Technical Reports Server (NTRS)

Jaeckel, Louis A.

1988-01-01

In Kanerva's Sparse Distributed Memory, writing to and reading from the memory are done in relation to spheres in an n-dimensional binary vector space. Thus it is important to know how many points are in the intersection of two spheres in this space. Two proofs are given of Wang's formula for spheres of unequal radii, and an integral approximation for the intersection in this case.

KSC-2015-1211

NASA Image and Video Library

2015-01-28

CAPE CANAVERAL, Fla. – NASA’s Kennedy Space Center in Florida paid tribute to the crews of Apollo 1 and space shuttles Challenger and Columbia, as well as other NASA astronauts who lost their lives while furthering the cause of exploration and discovery, during the agency's Day of Remembrance, Jan. 28. Thad Altman, president and chief executive officer of The Astronauts Memorial Foundation, attaches a rose to the fence surrounding the Space Mirror Memorial located in the Kennedy Space Center Visitor Complex.

Order and Position in Primary Memory for Letter Strings

ERIC Educational Resources Information Center

Lee, Catherine L.; Estes, William K.

1977-01-01

A short-term recall task in which letters were spaced in different ways by distractor digits was used to separate aspects of primary and secondary memory processes and to permit examination of primary memory for position, order and item independently. Memory for order appeared derivative to memory for temporal position. (CHK)

Role of cerebellar cortical protein synthesis in transfer of memory trace of cerebellum-dependent motor learning.

PubMed

Okamoto, Takehito; Endo, Shogo; Shirao, Tomoaki; Nagao, Soichi

2011-06-15

We developed a new protocol that induces long-term adaptation of horizontal optokinetic response (HOKR) eye movement by hours of spaced training and examined the role of protein synthesis in the cerebellar cortex in the formation of memory of adaptation. Mice were trained to view 800 cycles of screen oscillation either by 1 h of massed training or by 2.5 h to 8 d of training with 0.5 h to 1 d space intervals. The HOKR gains increased similarly by 20-30% at the end of training; however, the gains increased by 1 h of massed training recovered within 24 h, whereas the gains increased by spaced training were sustained over 24 h. Bilateral floccular lidocaine microinfusions immediately after the end of training recovered the gains increased by 1 h of massed training but did not affect the gains increased by 4 h of spaced training, suggesting that the memory trace of adaptation was transferred from the flocculus to the vestibular nuclei within 4 h of spaced training. Blockade of floccular protein synthesis, examined by bilateral floccular microinfusions of anisomycin or actinomycin D 1-4 h before the training, impaired the gains increased by 4 h of spaced training but did not affect the gains increased by 1 h of massed training. These findings suggest that the transfer of the memory trace of adaptation occurs within 4 h of spaced training, and proteins synthesized in the flocculus during training period may play an important role in memory transfer.

Is spacing really the “friend of induction”?

PubMed Central

Verkoeijen, Peter P. J. L.; Bouwmeester, Samantha

2014-01-01

Inductive learning takes place when people learn a new concept or category by observing a variety of exemplars. Kornell and Bjork (2008) asked participants to learn new painting styles either by presenting different paintings of the same artist consecutively (massed presentation) or by mixing paintings of different artists (spaced presentation). In their second experiment, Kornell and Bjork (2008) showed with a final style recognition test, that spacing resulted in better inductive learning than massing. Also, by using this style recognition test, they ruled out the possibility that spacing merely resulted in a better memory for the labels of the newly learned painting styles. The findings from Kornell and Bjork’s (2008) second experiment are important because they show that the benefit of spaced learning generalizes to complex learning tasks and outcomes, and that it is not confined to rote memory learning. However, the findings from Kornell and Bjork’s (2008) second experiment have never been replicated. In the present study we performed an exact and high-powered replication of Kornell and Bjork’s (2008) second experiment with a Web-based sample. Such a replication contributes to establish the reliability of the original finding and hence to more conclusive evidence of the spacing effect in inductive learning. The findings from the present replication attempt revealed a medium-sized advantage of spacing over massing in inductive learning, which was comparable to the original effect in the experiment by Kornell and Bjork (2008). Also, the 95% confidence intervals (CI) of the effect sizes from both experiments overlapped considerably. Hence, the findings from the present replication experiment and the original experiment clearly reinforce each other. PMID:24744742

Dentate gyrus supports slope recognition memory, shades of grey-context pattern separation and recognition memory, and CA3 supports pattern completion for object memory.

PubMed

Kesner, Raymond P; Kirk, Ryan A; Yu, Zhenghui; Polansky, Caitlin; Musso, Nick D

2016-03-01

In order to examine the role of the dorsal dentate gyrus (dDG) in slope (vertical space) recognition and possible pattern separation, various slope (vertical space) degrees were used in a novel exploratory paradigm to measure novelty detection for changes in slope (vertical space) recognition memory and slope memory pattern separation in Experiment 1. The results of the experiment indicate that control rats displayed a slope recognition memory function with a pattern separation process for slope memory that is dependent upon the magnitude of change in slope between study and test phases. In contrast, the dDG lesioned rats displayed an impairment in slope recognition memory, though because there was no significant interaction between the two groups and slope memory, a reliable pattern separation impairment for slope could not be firmly established in the DG lesioned rats. In Experiment 2, in order to determine whether, the dDG plays a role in shades of grey spatial context recognition and possible pattern separation, shades of grey were used in a novel exploratory paradigm to measure novelty detection for changes in the shades of grey context environment. The results of the experiment indicate that control rats displayed a shades of grey-context pattern separation effect across levels of separation of context (shades of grey). In contrast, the DG lesioned rats displayed a significant interaction between the two groups and levels of shades of grey suggesting impairment in a pattern separation function for levels of shades of grey. In Experiment 3 in order to determine whether the dorsal CA3 (dCA3) plays a role in object pattern completion, a new task requiring less training and using a choice that was based on choosing the correct set of objects on a two-choice discrimination task was used. The results indicated that control rats displayed a pattern completion function based on the availability of one, two, three or four cues. In contrast, the dCA3 lesioned rats displayed a significant interaction between the two groups and the number of available objects suggesting impairment in a pattern completion function for object cues. Copyright © 2015 Elsevier Inc. All rights reserved.

A 1-Gigabit Memory System on a multi-Chip Module for Space Applications

NASA Technical Reports Server (NTRS)

Louie, Marianne E.; Topliffe, Douglas A.; Alkalai, Leon

1996-01-01

Current spaceborne applications desire compact, low weight, and high capacity data storage systems along with the additional requirement of radiation tolerance. This paper discusses a memory system on a multi-chip module (MCM) that is designed for space applications.

A class of designs for a sparse distributed memory

NASA Technical Reports Server (NTRS)

Jaeckel, Louis A.

1989-01-01

A general class of designs for a space distributed memory (SDM) is described. The author shows that Kanerva's original design and the selected-coordinate design are related, and that there is a series of possible intermediate designs between those two designs. In each such design, the set of addresses that activate a memory location is a sphere in the address space. We can also have hybrid designs, in which the memory locations may be a mixture of those found in the other designs. In some applications, the bits of the read and write addresses that will actually be used might be mostly zeros; that is, the addresses might lie on or near z hyperplane in the address space. The author describes a hyperplane design which is adapted to this situation and compares it to an adaptation of Kanerva's design. To study the performance of these designs, he computes the expected number of memory locations activated by both of two addresses.

Listen up, eye movements play a role in verbal memory retrieval.

PubMed

Scholz, Agnes; Mehlhorn, Katja; Krems, Josef F

2016-01-01

People fixate on blank spaces if visual stimuli previously occupied these regions of space. This so-called "looking at nothing" (LAN) phenomenon is said to be a part of information retrieval from internal memory representations, but the exact nature of the relationship between LAN and memory retrieval is unclear. While evidence exists for an influence of LAN on memory retrieval for visuospatial stimuli, evidence for verbal information is mixed. Here, we tested the relationship between LAN behavior and memory retrieval in an episodic retrieval task where verbal information was presented auditorily during encoding. When participants were allowed to gaze freely during subsequent memory retrieval, LAN occurred, and it was stronger for correct than for incorrect responses. When eye movements were manipulated during memory retrieval, retrieval performance was higher when participants fixated on the area associated with to-be-retrieved information than when fixating on another area. Our results provide evidence for a functional relationship between LAN and memory retrieval that extends to verbal information.

KSC-04PD-0107

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Friends, co-workers and families gather at the Space Memorial Mirror for KSCs special service remembering and honoring the crew of Columbia. Feb. 1 is the one- year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was invited to the memorial service held at the KSC Visitor Complex. Participants included Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, Dr. Stephen Feldman, president of the Astronaut Memorial Foundation, and dancers from the Shoshone-Bannock Native American community in Fort Hall, Idaho.

KSC-04PD-0100

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Friends, co-workers and families gather at the Space Memorial Mirror for KSCs special service remembering and honoring the crew of Columbia. Feb. 1 is the one- year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was invited to the memorial service held at the KSC Visitor Complex. Participants included Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, Dr. Stephen Feldman, president of the Astronaut Memorial Foundation, and dancers from the Shoshone-Bannock Native American community in Fort Hall, Idaho.

KSC-04PD-0101

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Friends, co-workers and families gather at the Space Memorial Mirror for KSCs special service remembering and honoring the crew of Columbia. Feb. 1 is the one- year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was invited to the memorial service held at the KSC Visitor Complex. Participants included Center Director Jim Kennedy, Deputy Director Woodrow Whitlow Jr., Executive Director of Florida Space Authority Winston Scott, Dr. Stephen Feldman, president of the Astronaut Memorial Foundation, and dancers from the Shoshone-Bannock Native American community in Fort Hall, Idaho.

Of Modeling the Radiation Hazards Along Trajectory Space Vehicles Various Purpose

NASA Astrophysics Data System (ADS)

Grichshenko, Valentina

2016-07-01

The paper discusses the results of the simulation of radiation hazard along trajectory low-orbit spacecraft for various purposes, geostationary and navigation satellites. Developed criteria of reliability of memory cells in Space, including influence of cosmic rays (CR), differences of geophysical and geomagnetic situation on SV orbit are discussed. Numerical value of vertical geomagnetic stiffness, of CR flux and assessment of correlation failures of memory cells along low-orbit spacecrafts trajectory are presented. Obtained results are used to forecasting the radiation situation along SV orbit, reliability of memory cells in the Space and to optimize nominal equipment kit and payload of Kazakhstan SV.

Evaluation of Magnetoresistive RAM for Space Applications

NASA Technical Reports Server (NTRS)

Heidecker, Jason

2014-01-01

Magnetoresistive random-access memory (MRAM) is a non-volatile memory that exploits electronic spin, rather than charge, to store data. Instead of moving charge on and off a floating gate to alter the threshold voltage of a CMOS transistor (creating different bit states), MRAM uses magnetic fields to flip the polarization of a ferromagnetic material thus switching its resistance and bit state. These polarized states are immune to radiation-induced upset, thus making MRAM very attractive for space application. These magnetic memory elements also have infinite data retention and erase/program endurance. Presented here are results of reliability testing of two space-qualified MRAM products from Aeroflex and Honeywell.

Pulaski Award Ceremony

NASA Image and Video Library

2017-11-01

The prestigious 2017 Pulaski Award is on display near a new memorial marker on the Merritt Island National Wildlife Refuge in Florida. During a joint ceremony, the Spaceport Integration Team and its partners were presented with the award and a new memorial marker was dedicated. The multi-agency team includes representatives from NASA's Kennedy Space Center, Cape Canaveral Air Force Station's 45th Space Wing, the Merritt Island National Wildlife Refuge, as well as the Florida Forest Service and Brevard County Fire Rescue. The memorial marker honors two fallen firefighters, Scott Maness and Beau Sauselein, who died fighting a wildfire on space center property in 1981. Held outdoors, the ceremony was attended by 140 guests.

KSC-07pd0174

NASA Image and Video Library

2007-01-27

KENNEDY SPACE CENTER, FLA. -- Flowers and plaque are in place in front of the Space Mirror Memorial at the KSC Visitor Complex for the ceremony held in remembrance of the astronauts lost in the Apollo 1 fire: Virgil "Gus" Grissom, Edward H. White II and Roger B. Chaffee. Members of their families, along with KSC Director Bill Parsons, Associate Administrator for Space Operations William Gerstenmaier, President of the Astronauts Memorial Foundation Stephen Feldman and Chairman of the Board of Directors of the Astronauts Memorial Foundation William Potter, attended the ceremony. The mirror was designated as a national memorial by Congress and President George Bush in 1991 to honor fallen astronauts. Their names are emblazoned on the monument’s 42-½-foot-high by 50-foot-wide black granite surface as if to be projected into the heavens. Photo credit:NASA/Kim Shiflett

KSC-07pd0180

NASA Image and Video Library

2007-01-27

KENNEDY SPACE CENTER, FLA. -- Ed White III touches his father's name engraved in the Space Mirror Memorial at the KSC Visitor Complex. White attended the ceremony held in remembrance of the astronauts lost in the Apollo 1 fire: Virgil "Gus" Grissom, Edward H. White II and Roger B. Chaffee. Members of their families, along with KSC Director Bill Parsons, Associate Administrator for Space Operations William Gerstenmaier, President of the Astronauts Memorial Foundation Stephen Feldman and Chairman of the Board of Directors of the Astronauts Memorial Foundation William Potter, attended the ceremony. The mirror was designated as a national memorial by Congress and President George Bush in 1991 to honor fallen astronauts. Their names are emblazoned on the monument’s 42-½-foot-high by 50-foot-wide black granite surface as if to be projected into the heavens. Photo credit:NASA/Kim Shiflett

KSC-07pd0183

NASA Image and Video Library

2007-01-27

KENNEDY SPACE CENTER, FLA. -- Former astronaut John Young addresses guests and attendees at a ceremony at the KSC Visitor Complex held in remembrance of the astronauts lost in the Apollo 1 fire: Virgil "Gus" Grissom, Edward H. White II and Roger B. Chaffee. Members of their families, along with Associate Administrator for Space Operations William Gerstenmaier, President of the Astronauts Memorial Foundation Stephen Feldman, Chairman of the Board of Directors of the Astronauts Memorial Foundation William Potter and former astronaut John Young, attended the ceremony. Behind the stage is the Space Mirror Memorial, designated as a national memorial by Congress and President George Bush in 1991 to honor fallen astronauts. Their names are emblazoned on the monument’s 42-1/2-foot-high by 50-foot-wide black granite surface as if to be projected into the heavens. Photo credit:NASA/George Shelton

KSC-04PD-0120

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Dr. Ed Galindo speaks to the visitors at the memorial service held at the Space Memorial Mirror for the crew of Columbia. Galindo is science educator of Shoshone-Bannock High School and introduced the dancers from the Shoshone-Bannock Native American community in Fort Hall, Idaho. The dancers performed a healing ceremony during the memorial. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

KSC-04PD-0104

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Center Director Jim Kennedy speaks to attendees at a memorial service honoring the crew of Columbia. He stands in front of the Space Memorial Mirror at the KSC Visitor Complex. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Attended by many friends, co-workers and families, the memorial service was also open to the public.

Priming guesses on a forced-recall test.

PubMed

Gibson, Janet M; Meade, Michelle L

2004-07-01

The forced-recall paradigm requires participants to fill all spaces on the memory test even if they cannot remember all the list words. In the present study, the authors used that paradigm to examine the influence of implicit memory on guessing--when participants fill remaining spaces after they cannot remember list items. They measured explicit memory as the percentage of targets that participants designated as remembered from the list and implicit memory as the percentage of targets they wrote but did not designate as remembered (beyond chance level). The authors examined implicit memory on guessing with forced recall (Experiment 1), forced cued recall with younger and older adults (Experiment 2), and forced free and cued recall under a depth-of-processing manipulation (Experiment 3). They conclude that implicit memory influences guesses of targets in the forced-recall paradigm.

System and method for memory allocation in a multiclass memory system

DOEpatents

Loh, Gabriel; Meswani, Mitesh; Ignatowski, Michael; Nutter, Mark

2016-06-28

A system for memory allocation in a multiclass memory system includes a processor coupleable to a plurality of memories sharing a unified memory address space, and a library store to store a library of software functions. The processor identifies a type of a data structure in response to a memory allocation function call to the library for allocating memory to the data structure. Using the library, the processor allocates portions of the data structure among multiple memories of the multiclass memory system based on the type of the data structure.

Centrally managed unified shared virtual address space

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilkes, John

Systems, apparatuses, and methods for managing a unified shared virtual address space. A host may execute system software and manage a plurality of nodes coupled to the host. The host may send work tasks to the nodes, and for each node, the host may externally manage the node's view of the system's virtual address space. Each node may have a central processing unit (CPU) style memory management unit (MMU) with an internal translation lookaside buffer (TLB). In one embodiment, the host may be coupled to a given node via an input/output memory management unit (IOMMU) interface, where the IOMMU frontendmore » interface shares the TLB with the given node's MMU. In another embodiment, the host may control the given node's view of virtual address space via memory-mapped control registers.« less

At the Crossroads of Hualapai History, Memory, and American Colonization: Contesting Space and Place

ERIC Educational Resources Information Center

Shepherd, Jeffrey P.

2008-01-01

Standard, even "new Indian history" narratives of relocation and removal have generally avoided critical discussions of colonialism, memory, and space. Choosing instead to emphasize the important political, economic, social, and even cultural implications of such dislocations, much of what passes as "Indian" history fails to…

Lévy processes on a generalized fractal comb

NASA Astrophysics Data System (ADS)

Sandev, Trifce; Iomin, Alexander; Méndez, Vicenç

2016-09-01

Comb geometry, constituted of a backbone and fingers, is one of the most simple paradigm of a two-dimensional structure, where anomalous diffusion can be realized in the framework of Markov processes. However, the intrinsic properties of the structure can destroy this Markovian transport. These effects can be described by the memory and spatial kernels. In particular, the fractal structure of the fingers, which is controlled by the spatial kernel in both the real and the Fourier spaces, leads to the Lévy processes (Lévy flights) and superdiffusion. This generalization of the fractional diffusion is described by the Riesz space fractional derivative. In the framework of this generalized fractal comb model, Lévy processes are considered, and exact solutions for the probability distribution functions are obtained in terms of the Fox H-function for a variety of the memory kernels, and the rate of the superdiffusive spreading is studied by calculating the fractional moments. For a special form of the memory kernels, we also observed a competition between long rests and long jumps. Finally, we considered the fractal structure of the fingers controlled by a Weierstrass function, which leads to the power-law kernel in the Fourier space. This is a special case, when the second moment exists for superdiffusion in this competition between long rests and long jumps.

The Role of Forgetting Rate in Producing a Benefit of Expanded over Equal Spaced Retrieval in Young and Older Adults

PubMed Central

Maddox, Geoffrey B.; Balota, David A.; Coane, Jennifer H.; Duchek, Janet M.

2011-01-01

The current study examined the effects of two manipulations on equal and expanded spaced retrieval schedules in young and older adults. First, we examined the role that the type of expansion (systematic vs. nonsystematic) has in producing a benefit of expanded retrieval. Second, we examined the influence of an immediate retrieval attempt to minimize forgetting after the original encoding event. It was predicted that including multiple retrieval attempts with minimal intervening spacing (best accomplished in a nonsystematic retrieval schedule) would be necessary to produce a benefit of expanded retrieval over equal spaced retrieval for older adults but not young adults due to age differences in working memory capacity. Results from two experiments revealed that the presence of an expanded over equal spaced retrieval benefit is modulated by the extent to which the spacing conditions minimize forgetting in the early retrieval attempts in the spaced conditions. As predicted, these conditions differ substantially across young and older adults. In particular, in older adults two intervening items between early retrieval attempts produce dramatic rates of forgetting compared to one intervening item, whereas younger adults can maintain performance up to five intervening events in comparable conditions. Discussion focuses on age differences in short term forgetting, working memory capacity, and the relation between forgetting rates and spaced retrieval schedules. PMID:21463056

Direct access inter-process shared memory

DOEpatents

Brightwell, Ronald B; Pedretti, Kevin; Hudson, Trammell B

2013-10-22

A technique for directly sharing physical memory between processes executing on processor cores is described. The technique includes loading a plurality of processes into the physical memory for execution on a corresponding plurality of processor cores sharing the physical memory. An address space is mapped to each of the processes by populating a first entry in a top level virtual address table for each of the processes. The address space of each of the processes is cross-mapped into each of the processes by populating one or more subsequent entries of the top level virtual address table with the first entry in the top level virtual address table from other processes.

Motivational valence alters memory formation without altering exploration of a real-life spatial environment.

PubMed

Chiew, Kimberly S; Hashemi, Jordan; Gans, Lee K; Lerebours, Laura; Clement, Nathaniel J; Vu, Mai-Anh T; Sapiro, Guillermo; Heller, Nicole E; Adcock, R Alison

2018-01-01

Volitional exploration and learning are key to adaptive behavior, yet their characterization remains a complex problem for cognitive science. Exploration has been posited as a mechanism by which motivation promotes memory, but this relationship is not well-understood, in part because novel stimuli that motivate exploration also reliably elicit changes in neuromodulatory brain systems that directly alter memory formation, via effects on neural plasticity. To deconfound interrelationships between motivation, exploration, and memory formation we manipulated motivational state prior to entering a spatial context, measured exploratory responses to the context and novel stimuli within it, and then examined motivation and exploration as predictors of memory outcomes. To elicit spontaneous exploration, we used the physical space of an art exhibit with affectively rich content; we expected motivated exploration and memory to reflect multiple factors, including not only motivational valence, but also individual differences. Motivation was manipulated via an introductory statement framing exhibit themes in terms of Promotion- or Prevention-oriented goals. Participants explored the exhibit while being tracked by video. They returned 24 hours later for recall and spatial memory tests, followed by measures of motivation, personality, and relevant attitude variables. Promotion and Prevention condition participants did not differ in terms of group-level exploration time or memory metrics, suggesting similar motivation to explore under both framing contexts. However, exploratory behavior and memory outcomes were significantly more closely related under Promotion than Prevention, indicating that Prevention framing disrupted expected depth-of-encoding effects. Additionally, while trait measures predicted exploration similarly across framing conditions, traits interacted with motivational framing context and facial affect to predict memory outcomes. This novel characterization of motivated learning implies that dissociable behavioral and biological mechanisms, here varying as a function of valence, contribute to memory outcomes in complex, real-life environments.

Motivational valence alters memory formation without altering exploration of a real-life spatial environment

PubMed Central

Hashemi, Jordan; Gans, Lee K.; Lerebours, Laura; Clement, Nathaniel J.; Vu, Mai-Anh T.; Sapiro, Guillermo; Heller, Nicole E.; Adcock, R. Alison

2018-01-01

Volitional exploration and learning are key to adaptive behavior, yet their characterization remains a complex problem for cognitive science. Exploration has been posited as a mechanism by which motivation promotes memory, but this relationship is not well-understood, in part because novel stimuli that motivate exploration also reliably elicit changes in neuromodulatory brain systems that directly alter memory formation, via effects on neural plasticity. To deconfound interrelationships between motivation, exploration, and memory formation we manipulated motivational state prior to entering a spatial context, measured exploratory responses to the context and novel stimuli within it, and then examined motivation and exploration as predictors of memory outcomes. To elicit spontaneous exploration, we used the physical space of an art exhibit with affectively rich content; we expected motivated exploration and memory to reflect multiple factors, including not only motivational valence, but also individual differences. Motivation was manipulated via an introductory statement framing exhibit themes in terms of Promotion- or Prevention-oriented goals. Participants explored the exhibit while being tracked by video. They returned 24 hours later for recall and spatial memory tests, followed by measures of motivation, personality, and relevant attitude variables. Promotion and Prevention condition participants did not differ in terms of group-level exploration time or memory metrics, suggesting similar motivation to explore under both framing contexts. However, exploratory behavior and memory outcomes were significantly more closely related under Promotion than Prevention, indicating that Prevention framing disrupted expected depth-of-encoding effects. Additionally, while trait measures predicted exploration similarly across framing conditions, traits interacted with motivational framing context and facial affect to predict memory outcomes. This novel characterization of motivated learning implies that dissociable behavioral and biological mechanisms, here varying as a function of valence, contribute to memory outcomes in complex, real-life environments. PMID:29558526

Contention Modeling for Multithreaded Distributed Shared Memory Machines: The Cray XMT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Secchi, Simone; Tumeo, Antonino; Villa, Oreste

Distributed Shared Memory (DSM) machines are a wide class of multi-processor computing systems where a large virtually-shared address space is mapped on a network of physically distributed memories. High memory latency and network contention are two of the main factors that limit performance scaling of such architectures. Modern high-performance computing DSM systems have evolved toward exploitation of massive hardware multi-threading and fine-grained memory hashing to tolerate irregular latencies, avoid network hot-spots and enable high scaling. In order to model the performance of such large-scale machines, parallel simulation has been proved to be a promising approach to achieve good accuracy inmore » reasonable times. One of the most critical factors in solving the simulation speed-accuracy trade-off is network modeling. The Cray XMT is a massively multi-threaded supercomputing architecture that belongs to the DSM class, since it implements a globally-shared address space abstraction on top of a physically distributed memory substrate. In this paper, we discuss the development of a contention-aware network model intended to be integrated in a full-system XMT simulator. We start by measuring the effects of network contention in a 128-processor XMT machine and then investigate the trade-off that exists between simulation accuracy and speed, by comparing three network models which operate at different levels of accuracy. The comparison and model validation is performed by executing a string-matching algorithm on the full-system simulator and on the XMT, using three datasets that generate noticeably different contention patterns.« less

Navigating Monogamy: Nonapeptide Sensitivity in a Memory Neural Circuit May Shape Social Behavior and Mating Decisions.

PubMed

Ophir, Alexander G

2017-01-01

The role of memory in mating systems is often neglected despite the fact that most mating systems are defined in part by how animals use space. Monogamy, for example, is usually characterized by affiliative (e.g., pairbonding) and defensive (e.g., mate guarding) behaviors, but a high degree of spatial overlap in home range use is the easiest defining feature of monogamous animals in the wild. The nonapeptides vasopressin and oxytocin have been the focus of much attention for their importance in modulating social behavior, however this work has largely overshadowed their roles in learning and memory. To date, the understanding of memory systems and mechanisms governing social behavior have progressed relatively independently. Bridging these two areas will provide a deeper appreciation for understanding behavior, and in particular the mechanisms that mediate reproductive decision-making. Here, I argue that the ability to mate effectively as monogamous individuals is linked to the ability to track conspecifics in space. I discuss the connectivity across some well-known social and spatial memory nuclei, and propose that the nonapeptide receptors within these structures form a putative "socio-spatial memory neural circuit." This purported circuit may function to integrate social and spatial information to shape mating decisions in a context-dependent fashion. The lateral septum and/or the nucleus accumbens, and neuromodulation therein, may act as an intermediary to relate socio-spatial information with social behavior. Identifying mechanisms responsible for relating information about the social world with mechanisms mediating mating tactics is crucial to fully appreciate the suite of factors driving reproductive decisions and social decision-making.

KSC-2015-1214

NASA Image and Video Library

2015-01-28

CAPE CANAVERAL, Fla. – NASA’s Kennedy Space Center in Florida paid tribute to the crews of Apollo 1 and space shuttles Challenger and Columbia, as well as other NASA astronauts who lost their lives while furthering the cause of exploration and discovery, during the agency's Day of Remembrance, Jan. 28. A wreath-laying ceremony was held at the Space Mirror Memorial located in the Kennedy Space Center Visitor Complex. Behind the memorial, the full-size mock-up of the external fuel tank and solid rocket boosters mark the entrance to the Space Shuttle Atlantis exhibit. Photo credit: NASA/Jim Grossmann

PIYAS-proceeding to intelligent service oriented memory allocation for flash based data centric sensor devices in wireless sensor networks.

PubMed

Rizvi, Sanam Shahla; Chung, Tae-Sun

2010-01-01

Flash memory has become a more widespread storage medium for modern wireless devices because of its effective characteristics like non-volatility, small size, light weight, fast access speed, shock resistance, high reliability and low power consumption. Sensor nodes are highly resource constrained in terms of limited processing speed, runtime memory, persistent storage, communication bandwidth and finite energy. Therefore, for wireless sensor networks supporting sense, store, merge and send schemes, an efficient and reliable file system is highly required with consideration of sensor node constraints. In this paper, we propose a novel log structured external NAND flash memory based file system, called Proceeding to Intelligent service oriented memorY Allocation for flash based data centric Sensor devices in wireless sensor networks (PIYAS). This is the extended version of our previously proposed PIYA [1]. The main goals of the PIYAS scheme are to achieve instant mounting and reduced SRAM space by keeping memory mapping information to a very low size of and to provide high query response throughput by allocation of memory to the sensor data by network business rules. The scheme intelligently samples and stores the raw data and provides high in-network data availability by keeping the aggregate data for a longer period of time than any other scheme has done before. We propose effective garbage collection and wear-leveling schemes as well. The experimental results show that PIYAS is an optimized memory management scheme allowing high performance for wireless sensor networks.

Adaptive memory: the survival-processing memory advantage is not due to negativity or mortality salience.

PubMed

Bell, Raoul; Röer, Jan P; Buchner, Axel

2013-05-01

Recent research has highlighted the adaptive function of memory by showing that imagining being stranded in the grasslands without any survival material and rating words according to their survival value in this situation leads to exceptionally good memory for these words. Studies examining the role of emotions in causing the survival-processing memory advantage have been inconclusive, but some studies have suggested that the effect might be due to negativity or mortality salience. In Experiments 1 and 2, we compared the survival scenario to a control scenario that implied imagining a hopeless situation (floating in outer space with dwindling oxygen supplies) in which only suicide can avoid the agony of choking to death. Although this scenario was perceived as being more negative than the survival scenario, the survival-processing memory advantage persisted. In Experiment 3, thinking about the relevance of words for survival led to better memory for these words than did thinking about the relevance of words for death. This survival advantage was found for concrete, but not for abstract, words. The latter finding is consistent with the assumption that the survival instructions encourage participants to think about many different potential uses of items to aid survival, which may be a particularly efficient form of elaborate encoding. Together, the results suggest that thinking about death is much less effective in promoting recall than is thinking about survival. Therefore, the survival-processing memory advantage cannot be satisfactorily explained by negativity or mortality salience.

Space Mirror Memorial

NASA Image and Video Library

2007-01-27

Guests are gathered on stage during a ceremony at the KSC Visitor Complex held in remembrance of the astronauts lost in the Apollo 1 fire: Virgil "Gus" Grissom, Edward H. White II and Roger B. Chaffee. Among those gathered on stage are (from left) Faith Johnson, daughter of Theodore Freeman and Martha Chaffee, daughter of Roger Chaffee, Associate Administrator for Space Operations William Gerstenmaier and KSC Director Bill Parsons, plus former astronaut John Young (second from right). Members of the astronauts' families were guests at the ceremony. At the podium is Stephen Feldman, president of the Astronauts Memorial Foundation. Behind the stage is the Space Mirror Memorial, designated as a national memorial by Congress and President George Bush in 1991 to honor fallen astronauts. Their names are emblazoned on the monument’s 42-1/2-foot-high by 50-foot-wide black granite surface as if to be projected into the heavens.

KSC-2011-1210

NASA Image and Video Library

2011-01-27

CAPE CANAVERAL, Fla. -- A flag flies at half-staff near the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida during a Day of Remembrance wreath laying ceremony to honor members of the NASA family who lost their lives while furthering the cause of exploration and discovery. The large mirror made of black granite was designated as a national memorial by Congress and President George Bush in 1991. It honors 24 United States astronauts, including the crew members of space shuttles Columbia and Challenger, Apollo 1, and those who died in training and commercial airplane accidents. The memorial is a project of the Astronauts Memorial Foundation and was paid for by Florida residents who purchased special Challenger mission automobile license plates. 2011 marks the 25th anniversary of the loss of Challenger, which broke apart over the Atlantic Ocean 73 seconds into flight on Jan. 28, 1986. Photo credit: NASA/Kim Shiflett

KSC-2011-1209

NASA Image and Video Library

2011-01-27

CAPE CANAVERAL, Fla. -- Flowers lay at the foot of the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida before a Day of Remembrance wreath laying ceremony to honor members of the NASA family who lost their lives while furthering the cause of exploration and discovery. The floral arrangement is dedicated to the Apollo 1 crew members Virgil "Gus" Grissom, Roger B. Chaffee and Edward H. White II. The memorial honors 24 United States astronauts, including the crew members of space shuttles Columbia and Challenger, Apollo 1, and those who died in training and commercial airplane accidents. The memorial is a project of the Astronauts Memorial Foundation and was paid for by Florida residents who purchased special Challenger mission automobile license plates. 2011 marks the 25th anniversary of the loss of Challenger, which broke apart over the Atlantic Ocean 73 seconds into flight on Jan. 28, 1986. Photo credit: NASA/Kim Shiflett

The effects of spaced retrieval training in improving hyperphagia of people living with dementia in residential settings.

PubMed

Hsu, Chia-Ning; Lin, Li-Chan; Wu, Shiao-Chi

2017-10-01

To investigate the effectiveness of spaced retrieval for improving hyperphagia in patients with dementia in residential care settings. Although 10-30% of patients with dementia have hyperphagia, most studies have focused on eating difficulties. Only a few studies have focused on hyperphagia. Various memory problems cause hyperphagia in patients with dementia. Spaced retrieval, a cognitive technique for information learning, can be used as a training method to improve memory loss. Recent studies showed that patients who received the training successfully memorised information learned in the training and correctly applied it to their daily lives. Single-blind experiments were performed. The 97 subjects with dementia were recruited from seven institutions. All research participants were stratified into three groups according to cognitive impairment severity and Hyperphagic Behavior Scale scores and then randomly assigned to the experimental and control groups. The experimental group received a six-week one-by-one spaced retrieval training for hyperphagia behaviour. The control group received routine care. After the intervention, the frequency and severity of hyperphagia in the patients with dementia, and food intake were significantly lower in the experimental group than in the control group. However, body mass index did not significantly differ. Our results suggest that the spaced retrieval training could decrease the frequency and severity of hyperphagia in patients with dementia. The content of this training programme is consistent with the normal manner of eating in daily life and is easy for patients to understand and perform. Therefore, it can be applied in residents' daily lives. This study confirms the efficacy of the spaced retrieval training protocol for hyperphagia in patients with dementia. In future studies, the follow-up duration can be increased to determine the long-term effectiveness of the intervention. © 2016 John Wiley & Sons Ltd.

Freeing Space for NASA: Incorporating a Lossless Compression Algorithm into NASA's FOSS System

NASA Technical Reports Server (NTRS)

Fiechtner, Kaitlyn; Parker, Allen

2011-01-01

NASA's Fiber Optic Strain Sensing (FOSS) system can gather and store up to 1,536,000 bytes (1.46 megabytes) per second. Since the FOSS system typically acquires hours - or even days - of data, the system can gather hundreds of gigabytes of data for a given test event. To store such large quantities of data more effectively, NASA is modifying a Lempel-Ziv-Oberhumer (LZO) lossless data compression program to compress data as it is being acquired in real time. After proving that the algorithm is capable of compressing the data from the FOSS system, the LZO program will be modified and incorporated into the FOSS system. Implementing an LZO compression algorithm will instantly free up memory space without compromising any data obtained. With the availability of memory space, the FOSS system can be used more efficiently on test specimens, such as Unmanned Aerial Vehicles (UAVs) that can be in flight for days. By integrating the compression algorithm, the FOSS system can continue gathering data, even on longer flights.

KSC-04PD-0106

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Center Director Jim Kennedy (right) speaks to attendees at a memorial service honoring the crew of Columbia. Behind him are KSC Deputy Director Woodrow Whitlow Jr. and Executive Director of Florida Space Authority Winston Scott, who is a former astronaut who flew on Columbia in 1997. They are standing in front of the Space Memorial Mirror at the KSC Visitor Complex. Attended by many friends, co-workers and families, the memorial service was also open to the public, some of whom are seen at left. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107.

KSC-04PD-0105

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Center Director Jim Kennedy (right) speaks to attendees at a memorial service honoring the crew of Columbia. At left are KSC Deputy Director Woodrow Whitlow Jr. and Executive Director of Florida Space Authority Winston Scott, who was an invited speaker. Scott is a former astronaut who flew on Columbia in 1997. They are standing in front of the Space Memorial Mirror at the KSC Visitor Complex. Feb. 1 is the one- year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Attended by many friends, co-workers and families, the memorial service was also open to the public.

KSC-04PD-0123

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Dancers from the Shoshone-Bannock Junior-Senior High School, Fort Hall, Idaho, perform a healing ceremony during the memorial service held at the Space Memorial Mirror for the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

KSC-04PD-0125

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Dancers from the Shoshone-Bannock Junior-Senior High School, Fort Hall, Idaho, perform a healing ceremony during the memorial service held at the Space Memorial Mirror for the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

Pulaski Award Ceremony

NASA Image and Video Library

2017-11-01

Ceremonial Pulaski tools are positioned in front of a new memorial marker Nov. 1 on the Merritt Island National Wildlife Refuge in Florida. During a joint ceremony, the Spaceport Integration Team and its partners were presented with the prestigious 2017 Pulaski Award and the new memorial marker was dedicated. The multi-agency team includes representatives from NASA's Kennedy Space Center, Cape Canaveral Air Force Station's 45th Space Wing, the Merritt Island National Wildlife Refuge, as well as the Florida Forest Service and Brevard County Fire Rescue. The memorial marker honors two fallen firefighters, Scott Maness and Beau Sauselein, who died fighting a wildfire on space center property in 1981. Held outdoors, the ceremony was attended by 140 guests.

Pulaski Award Ceremony

NASA Image and Video Library

2017-11-01

Firefighters place ceremonial Pulaski tools by a new memorial marker Nov. 1 on the Merritt Island National Wildlife Refuge in Florida. During a joint ceremony, the Spaceport Integration Team and its partners were presented with the prestigious 2017 Pulaski Award and the new memorial marker was dedicated. The multi-agency team includes representatives from NASA's Kennedy Space Center, Cape Canaveral Air Force Station's 45th Space Wing, the Merritt Island National Wildlife Refuge, as well as the Florida Forest Service and Brevard County Fire Rescue. The memorial marker honors two fallen firefighters, Scott Maness and Beau Sauselein, who died fighting a wildfire on space center property in 1981. Held outdoors, the ceremony was attended by 140 guests.

Pulaski Award Ceremony

NASA Image and Video Library

2017-11-01

Firefighters prepare to place ceremonial Pulaski tools by a new memorial marker Nov. 1 on the Merritt Island National Wildlife Refuge in Florida. During a joint ceremony, the Spaceport Integration Team and its partners were presented with the prestigious 2017 Pulaski Award and the new memorial marker was dedicated. The multi-agency team includes representatives from NASA's Kennedy Space Center, Cape Canaveral Air Force Station's 45th Space Wing, the Merritt Island National Wildlife Refuge, as well as the Florida Forest Service and Brevard County Fire Rescue. The memorial marker honors two fallen firefighters, Scott Maness and Beau Sauselein, who died fighting a wildfire on space center property in 1981. Held outdoors, the ceremony was attended by 140 guests.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Lingda; Hayes, Ari; Song, Shuaiwen

Modern GPUs employ cache to improve memory system efficiency. However, large amount of cache space is underutilized due to irregular memory accesses and poor spatial locality which exhibited commonly in GPU applications. Our experiments show that using smaller cache lines could improve cache space utilization, but it also frequently suffers from significant performance loss by introducing large amount of extra cache requests. In this work, we propose a novel cache design named tag-split cache (TSC) that enables fine-grained cache storage to address the problem of cache space underutilization while keeping memory request number unchanged. TSC divides tag into two partsmore » to reduce storage overhead, and it supports multiple cache line replacement in one cycle.« less

Testing the exclusivity effect in location memory.

PubMed

Clark, Daniel P A; Dunn, Andrew K; Baguley, Thom

2013-01-01

There is growing literature exploring the possibility of parallel retrieval of location memories, although this literature focuses primarily on the speed of retrieval with little attention to the accuracy of location memory recall. Baguley, Lansdale, Lines, and Parkin (2006) found that when a person has two or more memories for an object's location, their recall accuracy suggests that only one representation can be retrieved at a time (exclusivity). This finding is counterintuitive given evidence of non-exclusive recall in the wider memory literature. The current experiment explored the exclusivity effect further and aimed to promote an alternative outcome (i.e., independence or superadditivity) by encouraging the participants to combine multiple representations of space at encoding or retrieval. This was encouraged by using anchor (points of reference) labels that could be combined to form a single strongly associated combination. It was hypothesised that the ability to combine the anchor labels would allow the two representations to be retrieved concurrently, generating higher levels of recall accuracy. The results demonstrate further support for the exclusivity hypothesis, showing no significant improvement in recall accuracy when there are multiple representations of a target object's location as compared to a single representation.

Pigeons exhibit higher accuracy for chosen memory tests than for forced memory tests in duration matching-to-sample.

PubMed

Adams, Allison; Santi, Angelo

2011-03-01

Following training to match 2- and 8-sec durations of feederlight to red and green comparisons with a 0-sec baseline delay, pigeons were allowed to choose to take a memory test or to escape the memory test. The effects of sample omission, increases in retention interval, and variation in trial spacing on selection of the escape option and accuracy were studied. During initial testing, escaping the test did not increase as the task became more difficult, and there was no difference in accuracy between chosen and forced memory tests. However, with extended training, accuracy for chosen tests was significantly greater than for forced tests. In addition, two pigeons exhibited higher accuracy on chosen tests than on forced tests at the short retention interval and greater escape rates at the long retention interval. These results have not been obtained in previous studies with pigeons when the choice to take the test or to escape the test is given before test stimuli are presented. It appears that task-specific methodological factors may determine whether a particular species will exhibit the two behavioral effects that were initially proposed as potentially indicative of metacognition.

Independent sources of anisotropy in visual orientation representation: a visual and a cognitive oblique effect.

PubMed

Balikou, Panagiota; Gourtzelidis, Pavlos; Mantas, Asimakis; Moutoussis, Konstantinos; Evdokimidis, Ioannis; Smyrnis, Nikolaos

2015-11-01

The representation of visual orientation is more accurate for cardinal orientations compared to oblique, and this anisotropy has been hypothesized to reflect a low-level visual process (visual, "class 1" oblique effect). The reproduction of directional and orientation information also leads to a mean error away from cardinal orientations or directions. This anisotropy has been hypothesized to reflect a high-level cognitive process of space categorization (cognitive, "class 2," oblique effect). This space categorization process would be more prominent when the visual representation of orientation degrades such as in the case of working memory with increasing cognitive load, leading to increasing magnitude of the "class 2" oblique effect, while the "class 1" oblique effect would remain unchanged. Two experiments were performed in which an array of orientation stimuli (1-4 items) was presented and then subjects had to realign a probe stimulus within the previously presented array. In the first experiment, the delay between stimulus presentation and probe varied, while in the second experiment, the stimulus presentation time varied. The variable error was larger for oblique compared to cardinal orientations in both experiments reproducing the visual "class 1" oblique effect. The mean error also reproduced the tendency away from cardinal and toward the oblique orientations in both experiments (cognitive "class 2" oblique effect). The accuracy or the reproduced orientation degraded (increasing variable error) and the cognitive "class 2" oblique effect increased with increasing memory load (number of items) in both experiments and presentation time in the second experiment. In contrast, the visual "class 1" oblique effect was not significantly modulated by any one of these experimental factors. These results confirmed the theoretical predictions for the two anisotropies in visual orientation reproduction and provided support for models proposing the categorization of orientation in visual working memory.

KSC-07pd0179

NASA Image and Video Library

2007-01-27

KENNEDY SPACE CENTER, FLA. -- Former astronaut Bob Crippen places a rose in the fence surrounding the Space Mirror Memorial at the KSC Visitor Complex. The Space Mirror was designated as a national memorial by Congress and President George Bush in 1991 to honor fallen astronauts. Their names are emblazoned on the monument's 42-1/2-foot-high by 50-foot-wide black granite surface as if to be projected into the heavens. Photo credit:NASA/Kim Shiflett

Dynamic frontotemporal systems process space and time in working memory

PubMed Central

Adams, Jenna N.; Solbakk, Anne-Kristin; Endestad, Tor; Larsson, Pål G.; Ivanovic, Jugoslav; Meling, Torstein R.; Lin, Jack J.; Knight, Robert T.

2018-01-01

How do we rapidly process incoming streams of information in working memory, a cognitive mechanism central to human behavior? Dominant views of working memory focus on the prefrontal cortex (PFC), but human hippocampal recordings provide a neurophysiological signature distinct from the PFC. Are these regions independent, or do they interact in the service of working memory? We addressed this core issue in behavior by recording directly from frontotemporal sites in humans performing a visuospatial working memory task that operationalizes the types of identity and spatiotemporal information we encounter every day. Theta band oscillations drove bidirectional interactions between the PFC and medial temporal lobe (MTL; including the hippocampus). MTL theta oscillations directed the PFC preferentially during the processing of spatiotemporal information, while PFC theta oscillations directed the MTL for all types of information being processed in working memory. These findings reveal an MTL theta mechanism for processing space and time and a domain-general PFC theta mechanism, providing evidence that rapid, dynamic MTL–PFC interactions underlie working memory for everyday experiences. PMID:29601574

Evaluating the Theoretic Adequacy and Applied Potential of Computational Models of the Spacing Effect.

PubMed

Walsh, Matthew M; Gluck, Kevin A; Gunzelmann, Glenn; Jastrzembski, Tiffany; Krusmark, Michael

2018-06-01

The spacing effect is among the most widely replicated empirical phenomena in the learning sciences, and its relevance to education and training is readily apparent. Yet successful applications of spacing effect research to education and training is rare. Computational modeling can provide the crucial link between a century of accumulated experimental data on the spacing effect and the emerging interest in using that research to enable adaptive instruction. In this paper, we review relevant literature and identify 10 criteria for rigorously evaluating computational models of the spacing effect. Five relate to evaluating the theoretic adequacy of a model, and five relate to evaluating its application potential. We use these criteria to evaluate a novel computational model of the spacing effect called the Predictive Performance Equation (PPE). Predictive Performance Equation combines elements of earlier models of learning and memory including the General Performance Equation, Adaptive Control of Thought-Rational, and the New Theory of Disuse, giving rise to a novel computational account of the spacing effect that performs favorably across the complete sets of theoretic and applied criteria. We implemented two other previously published computational models of the spacing effect and compare them to PPE using the theoretic and applied criteria as guides. Copyright © 2018 Cognitive Science Society, Inc.

Implicit face prototype learning from geometric information.

PubMed

Or, Charles C-F; Wilson, Hugh R

2013-04-19

There is evidence that humans implicitly learn an average or prototype of previously studied faces, as the unseen face prototype is falsely recognized as having been learned (Solso & McCarthy, 1981). Here we investigated the extent and nature of face prototype formation where observers' memory was tested after they studied synthetic faces defined purely in geometric terms in a multidimensional face space. We found a strong prototype effect: The basic results showed that the unseen prototype averaged from the studied faces was falsely identified as learned at a rate of 86.3%, whereas individual studied faces were identified correctly 66.3% of the time and the distractors were incorrectly identified as having been learned only 32.4% of the time. This prototype learning lasted at least 1 week. Face prototype learning occurred even when the studied faces were further from the unseen prototype than the median variation in the population. Prototype memory formation was evident in addition to memory formation of studied face exemplars as demonstrated in our models. Additional studies showed that the prototype effect can be generalized across viewpoints, and head shape and internal features separately contribute to prototype formation. Thus, implicit face prototype extraction in a multidimensional space is a very general aspect of geometric face learning. Copyright © 2013 Elsevier Ltd. All rights reserved.

Very Similar Spacing-Effect Patterns in Very Different Learning/Practice Domains

PubMed Central

Kornmeier, Jürgen; Spitzer, Manfred; Sosic-Vasic, Zrinka

2014-01-01

Temporally distributed (“spaced”) learning can be twice as efficient as massed learning. This “spacing effect” occurs with a broad spectrum of learning materials, with humans of different ages, with non-human vertebrates and also invertebrates. This indicates, that very basic learning mechanisms are at work (“generality”). Although most studies so far focused on very narrow spacing interval ranges, there is some evidence for a non-monotonic behavior of this “spacing effect” (“nonlinearity”) with optimal spacing intervals at different time scales. In the current study we focused both the nonlinearity aspect by using a broad range of spacing intervals and the generality aspect by using very different learning/practice domains: Participants learned German-Japanese word pairs and performed visual acuity tests. For each of six groups we used a different spacing interval between learning/practice units from 7 min to 24 h in logarithmic steps. Memory retention was studied in three consecutive final tests, one, seven and 28 days after the final learning unit. For both the vocabulary learning and visual acuity performance we found a highly significant effect of the factor spacing interval on the final test performance. In the 12 h-spacing-group about 85% of the learned words stayed in memory and nearly all of the visual acuity gain was preserved. In the 24 h-spacing-group, in contrast, only about 33% of the learned words were retained and the visual acuity gain dropped to zero. The very similar patterns of results from the two very different learning/practice domains point to similar underlying mechanisms. Further, our results indicate spacing in the range of 12 hours as optimal. A second peak may be around a spacing interval of 20 min but here the data are less clear. We discuss relations between our results and basic learning at the neuronal level. PMID:24609081

Executive and memory correlates of age-related differences in wayfinding performances using a virtual reality application.

PubMed

Taillade, Mathieu; Sauzéon, Hélène; Dejos, Marie; Pala, Prashant Arvind; Larrue, Florian; Wallet, Grégory; Gross, Christian; N'Kaoua, Bernard

2013-01-01

The aim of this study was to evaluate in large-scale spaces wayfinding and spatial learning difficulties for older adults in relation to the executive and memory decline associated with aging. We compared virtual reality (VR)-based wayfinding and spatial memory performances between young and older adults. Wayfinding and spatial memory performances were correlated with classical measures of executive and visuo-spatial memory functions, but also with self-reported estimates of wayfinding difficulties. We obtained a significant effect of age on wayfinding performances but not on spatial memory performances. The overall correlations showed significant correlations between the wayfinding performances and the classical measures of both executive and visuo-spatial memory, but only when the age factor was not partialled out. Also, older adults underestimated their wayfinding difficulties. A significant relationship between the wayfinding performances and self-reported wayfinding difficulty estimates is found, but only when the age effect was partialled out. These results show that, even when older adults have an equivalent spatial knowledge to young adults, they had greater difficulties with the wayfinding task, supporting an executive decline view in age-related wayfinding difficulties. However, the correlation results are in favor of both the memory and executive decline views as mediators of age-related differences in wayfinding performances. This is discussed in terms of the relationships between memory and executive functioning in wayfinding task orchestration. Our results also favor the use of objective assessments of everyday navigation difficulties in virtual applications, instead of self-reported questionnaires, since older adults showed difficulties in estimating their everyday wayfinding problems.

KSC-03pd0273

NASA Image and Video Library

2003-02-03

KENNEDY SPACE CENTER, FLA. - Near the Astronauts Memorial Space Mirror at the KSC Visitor Complex, guests leave flowers as a memorial tribute to the fallen crew of Columbia. The Columbia and her crew of seven were lost on Feb. 1, 2003, over East Texas as they returned to Earth after a 16-day research mission, STS-107.

A Memory of Majorana Modes through Quantum Quench

PubMed Central

Chung, Ming-Chiang; Jhu, Yi-Hao; Chen, Pochung; Mou, Chung-Yu; Wan, Xin

2016-01-01

We study the sudden quench of a one-dimensional p-wave superconductor through its topological signature in the entanglement spectrum. We show that the long-time evolution of the system and its topological characterization depend on a pseudomagnetic field Reff(k). Furthermore, Reff(k) connects both the initial and the final Hamiltonians, hence exhibiting a memory effect. In particular, we explore the robustness of the Majorana zero-mode and identify the parameter space in which the Majorana zero-mode can revive in the infinite-time limit. PMID:27389657

Free-Space Quantum Communication with a Portable Quantum Memory

NASA Astrophysics Data System (ADS)

Namazi, Mehdi; Vallone, Giuseppe; Jordaan, Bertus; Goham, Connor; Shahrokhshahi, Reihaneh; Villoresi, Paolo; Figueroa, Eden

2017-12-01

The realization of an elementary quantum network that is intrinsically secure and operates over long distances requires the interconnection of several quantum modules performing different tasks. In this work, we report the realization of a communication network functioning in a quantum regime, consisting of four different quantum modules: (i) a random polarization qubit generator, (ii) a free-space quantum-communication channel, (iii) an ultralow-noise portable quantum memory, and (iv) a qubit decoder, in a functional elementary quantum network possessing all capabilities needed for quantum-information distribution protocols. We create weak coherent pulses at the single-photon level encoding polarization states |H ⟩ , |V ⟩, |D ⟩, and |A ⟩ in a randomized sequence. The random qubits are sent over a free-space link and coupled into a dual-rail room-temperature quantum memory and after storage and retrieval are analyzed in a four-detector polarization analysis akin to the requirements of the BB84 protocol. We also show ultralow noise and fully portable operation, paving the way towards memory-assisted all-environment free-space quantum cryptographic networks.

KSC-2015-1210

NASA Image and Video Library

2015-01-28

CAPE CANAVERAL, Fla. – NASA’s Kennedy Space Center in Florida paid tribute to the crews of Apollo 1 and space shuttles Challenger and Columbia, as well as other NASA astronauts who lost their lives while furthering the cause of exploration and discovery, during the agency's Day of Remembrance, Jan. 28. From left, President and Chief Executive Officer of The Astronauts Memorial Foundation Thad Altman, Kennedy Associate Director Kelvin Manning, and Kennedy Deputy Director Janet Petro, participated in a wreath-laying ceremony at the Space Mirror Memorial located in the Kennedy Space Center Visitor Complex.

Configurable memory system and method for providing atomic counting operations in a memory device

DOEpatents

Bellofatto, Ralph E.; Gara, Alan G.; Giampapa, Mark E.; Ohmacht, Martin

2010-09-14

A memory system and method for providing atomic memory-based counter operations to operating systems and applications that make most efficient use of counter-backing memory and virtual and physical address space, while simplifying operating system memory management, and enabling the counter-backing memory to be used for purposes other than counter-backing storage when desired. The encoding and address decoding enabled by the invention provides all this functionality through a combination of software and hardware.

Estimation and Application of Ecological Memory Functions in Time and Space

NASA Astrophysics Data System (ADS)

Itter, M.; Finley, A. O.; Dawson, A.

2017-12-01

A common goal in quantitative ecology is the estimation or prediction of ecological processes as a function of explanatory variables (or covariates). Frequently, the ecological process of interest and associated covariates vary in time, space, or both. Theory indicates many ecological processes exhibit memory to local, past conditions. Despite such theoretical understanding, few methods exist to integrate observations from the recent past or within a local neighborhood as drivers of these processes. We build upon recent methodological advances in ecology and spatial statistics to develop a Bayesian hierarchical framework to estimate so-called ecological memory functions; that is, weight-generating functions that specify the relative importance of local, past covariate observations to ecological processes. Memory functions are estimated using a set of basis functions in time and/or space, allowing for flexible ecological memory based on a reduced set of parameters. Ecological memory functions are entirely data driven under the Bayesian hierarchical framework—no a priori assumptions are made regarding functional forms. Memory function uncertainty follows directly from posterior distributions for model parameters allowing for tractable propagation of error to predictions of ecological processes. We apply the model framework to simulated spatio-temporal datasets generated using memory functions of varying complexity. The framework is also applied to estimate the ecological memory of annual boreal forest growth to local, past water availability. Consistent with ecological understanding of boreal forest growth dynamics, memory to past water availability peaks in the year previous to growth and slowly decays to zero in five to eight years. The Bayesian hierarchical framework has applicability to a broad range of ecosystems and processes allowing for increased understanding of ecosystem responses to local and past conditions and improved prediction of ecological processes.

Asymmetric Spatial Processing Under Cognitive Load.

PubMed

Naert, Lien; Bonato, Mario; Fias, Wim

2018-01-01

Spatial attention allows us to selectively process information within a certain location in space. Despite the vast literature on spatial attention, the effect of cognitive load on spatial processing is still not fully understood. In this study we added cognitive load to a spatial processing task, so as to see whether it would differentially impact upon the processing of visual information in the left versus the right hemispace. The main paradigm consisted of a detection task that was performed during the maintenance interval of a verbal working memory task. We found that increasing cognitive working memory load had a more negative impact on detecting targets presented on the left side compared to those on the right side. The strength of the load effect correlated with the strength of the interaction on an individual level. The implications of an asymmetric attentional bias with a relative disadvantage for the left (vs the right) hemispace under high verbal working memory (WM) load are discussed.

Prospective Memory in Context: Moving through a Familiar Space

ERIC Educational Resources Information Center

Smith, Rebekah E.; Hunt, R. Reed; Murray, Amy E.

2017-01-01

Successful completion of delayed intentions is a common but important aspect of daily behavior. Such behavior requires not only memory for the intended action but also recognition of the opportunity to perform that action, known collectively as prospective memory. The fact that prospective memory tasks occur in the midst of other activities is…

Intrinsic retrieval efficiency for quantum memories: A three-dimensional theory of light interaction with an atomic ensemble

NASA Astrophysics Data System (ADS)

Gujarati, Tanvi P.; Wu, Yukai; Duan, Luming

2018-03-01

Duan-Lukin-Cirac-Zoller quantum repeater protocol, which was proposed to realize long distance quantum communication, requires usage of quantum memories. Atomic ensembles interacting with optical beams based on off-resonant Raman scattering serve as convenient on-demand quantum memories. Here, a complete free space, three-dimensional theory of the associated read and write process for this quantum memory is worked out with the aim of understanding intrinsic retrieval efficiency. We develop a formalism to calculate the transverse mode structure for the signal and the idler photons and use the formalism to study the intrinsic retrieval efficiency under various configurations. The effects of atomic density fluctuations and atomic motion are incorporated by numerically simulating this system for a range of realistic experimental parameters. We obtain results that describe the variation in the intrinsic retrieval efficiency as a function of the memory storage time for skewed beam configuration at a finite temperature, which provides valuable information for optimization of the retrieval efficiency in experiments.

Persistent spatial information in the FEF during object-based short-term memory does not contribute to task performance.

PubMed

Clark, Kelsey L; Noudoost, Behrad; Moore, Tirin

2014-06-01

We previously reported the existence of a persistent spatial signal in the FEF during object-based STM. This persistent activity reflected the location at which the sample appeared, irrespective of the location of upcoming targets. We hypothesized that such a spatial signal could be used to maintain or enhance object-selective memory activity elsewhere in cortex, analogous to the role of a spatial signal during attention. Here, we inactivated a portion of the FEF with GABAa agonist muscimol to test whether the observed activity contributes to object memory performance. We found that, although RTs were slowed for saccades into the inactivated portion of retinotopic space, performance for samples appearing in that region was unimpaired. This contrasts with the devastating effects of the same FEF inactivation on purely spatial working memory, as assessed with the memory-guided saccade task. Thus, in a task in which a significant fraction of FEF neurons displayed persistent, sample location-based activity, disrupting this activity had no impact on task performance.

Skyrmion-skyrmion and skyrmion-edge repulsions in skyrmion-based racetrack memory

NASA Astrophysics Data System (ADS)

Zhang, Xichao; Zhao, G. P.; Fangohr, Hans; Liu, J. Ping; Xia, W. X.; Xia, J.; Morvan, F. J.

2015-01-01

Magnetic skyrmions are promising for building next-generation magnetic memories and spintronic devices due to their stability, small size and the extremely low currents needed to move them. In particular, skyrmion-based racetrack memory is attractive for information technology, where skyrmions are used to store information as data bits instead of traditional domain walls. Here we numerically demonstrate the impacts of skyrmion-skyrmion and skyrmion-edge repulsions on the feasibility of skyrmion-based racetrack memory. The reliable and practicable spacing between consecutive skyrmionic bits on the racetrack as well as the ability to adjust it are investigated. Clogging of skyrmionic bits is found at the end of the racetrack, leading to the reduction of skyrmion size. Further, we demonstrate an effective and simple method to avoid the clogging of skyrmionic bits, which ensures the elimination of skyrmionic bits beyond the reading element. Our results give guidance for the design and development of future skyrmion-based racetrack memory.

The effect of memory and context changes on color matches to real objects.

PubMed

Allred, Sarah R; Olkkonen, Maria

2015-07-01

Real-world color identification tasks often require matching the color of objects between contexts and after a temporal delay, thus placing demands on both perceptual and memory processes. Although the mechanisms of matching colors between different contexts have been widely studied under the rubric of color constancy, little research has investigated the role of long-term memory in such tasks or how memory interacts with color constancy. To investigate this relationship, observers made color matches to real study objects that spanned color space, and we independently manipulated the illumination impinging on the objects, the surfaces in which objects were embedded, and the delay between seeing the study object and selecting its color match. Adding a 10-min delay increased both the bias and variability of color matches compared to a baseline condition. These memory errors were well accounted for by modeling memory as a noisy but unbiased version of perception constrained by the matching methods. Surprisingly, we did not observe significant increases in errors when illumination and surround changes were added to the 10-minute delay, although the context changes alone did elicit significant errors.

Recollection-dependent memory for event duration in large-scale spatial navigation

PubMed Central

Barense, Morgan D.

2017-01-01

Time and space represent two key aspects of episodic memories, forming the spatiotemporal context of events in a sequence. Little is known, however, about how temporal information, such as the duration and the order of particular events, are encoded into memory, and if it matters whether the memory representation is based on recollection or familiarity. To investigate this issue, we used a real world virtual reality navigation paradigm where periods of navigation were interspersed with pauses of different durations. Crucially, participants were able to reliably distinguish the durations of events that were subjectively “reexperienced” (i.e., recollected), but not of those that were familiar. This effect was not found in temporal order (ordinal) judgments. We also show that the active experience of the passage of time (holding down a key while waiting) moderately enhanced duration memory accuracy. Memory for event duration, therefore, appears to rely on the hippocampally supported ability to recollect or reexperience an event enabling the reinstatement of both its duration and its spatial context, to distinguish it from other events in a sequence. In contrast, ordinal memory appears to rely on familiarity and recollection to a similar extent. PMID:28202714

Does virtual reality have a future for the study of episodic memory in aging?

PubMed

Abichou, Kouloud; La Corte, Valentina; Piolino, Pascale

2017-03-01

Episodic memory is the memory of personally lived events located in time and space, it shapes our identity and allows us to project ourselves into the past and the future. This form of memory is vulnerable to the effects of age and its alteration, hindering the autonomy of the subjects, can predict the evolution towards neurodegenerative disorders. Hence, a better understanding of this type of memory is a priority in the field of public health. Actually, traditional neuropsychological tools are often decontextualized, using simplistic situations that did not require the mobilization of all the characteristics of episodic memory, thus they just offer a partial measure of this complex mnemonic capacity. Nowadays, the virtual reality (VR) is a tool allowing the immersion of subjects in simulations of real situations, rich in spatial and temporal naturalistic contexts. Due to its many characteristics, the VR allows to solve several limitations of the traditional tests. The purpose of this review is to expose studies that investigated episodic memory in normal and Alzheimer's disease using VR in order to address its relevance as a new tool in the future practice of neuropsychology of aging.

High Storage Efficiency and Large Fractional Delay of EIT-Based Memory

NASA Astrophysics Data System (ADS)

Chen, Yi-Hsin; Lee, Meng-Jung; Wang, I.-Chung; Du, Shengwang; Chen, Yong-Fan; Chen, Ying-Cheng; Yu, Ite

2013-05-01

In long-distance quantum communication and optical quantum computation, an efficient and long-lived quantum memory is an important component. We first experimentally demonstrated that a time-space-reversing method plus the optimum pulse shape can improve the storage efficiency (SE) of light pulses to 78% in cold media based on the effect of electromagnetically induced transparency (EIT). We obtain a large fractional delay of 74 at 50% SE, which is the best record so far. The measured classical fidelity of the recalled pulse is higher than 90% and nearly independent of the storage time, implying that the optical memory maintains excellent phase coherence. Our results suggest the current result may be readily applied to single-photon quantum states due to quantum nature of the EIT light-matter inference. This study advances the EIT-based quantum memory in practical quantum information applications.

The time course of protecting a visual memory representation from perceptual interference

PubMed Central

van Moorselaar, Dirk; Gunseli, Eren; Theeuwes, Jan; N. L. Olivers, Christian

2015-01-01

Cueing a remembered item during the delay of a visual memory task leads to enhanced recall of the cued item compared to when an item is not cued. This cueing benefit has been proposed to reflect attention within visual memory being shifted from a distributed mode to a focused mode, thus protecting the cued item against perceptual interference. Here we investigated the dynamics of building up this mnemonic protection against visual interference by systematically varying the stimulus onset asynchrony (SOA) between cue onset and a subsequent visual mask in an orientation memory task. Experiment 1 showed that a cue counteracted the deteriorating effect of pattern masks. Experiment 2 demonstrated that building up this protection is a continuous process that is completed in approximately half a second after cue onset. The similarities between shifting attention in perceptual and remembered space are discussed. PMID:25628555

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sypek, John T.; Yu, Hang; Dusoe, Keith J.

Shape memory materials have the ability to recover their original shape after a significant amount of deformation when they are subjected to certain stimuli, for instance, heat or magnetic fields. But, their performance is often limited by the energetics and geometry of the martensitic-austenitic phase transformation. We report a unique shape memory behavior in CaFe 2As 2, which exhibits superelasticity with over 13% recoverable strain, over 3 GPa yield strength, repeatable stress–strain response even at the micrometer scale, and cryogenic linear shape memory effects near 50 K. These properties are acheived through a reversible uni-axial phase transformation mechanism, the tetragonal/orthorhombic-to-collapsed-tetragonalmore » phase transformation. These results offer the possibility of developing cryogenic linear actuation technologies with a high precision and high actuation power per unit volume for deep space exploration, and more broadly, suggest a mechanistic path to a class of shape memory materials, ThCr 2Si 2-structured intermetallic compounds.« less

Memory matters: influence from a cognitive map on animal space use.

PubMed

Gautestad, Arild O

2011-10-21

A vertebrate individual's cognitive map provides a capacity for site fidelity and long-distance returns to favorable patches. Fractal-geometrical analysis of individual space use based on collection of telemetry fixes makes it possible to verify the influence of a cognitive map on the spatial scatter of habitat use and also to what extent space use has been of a scale-specific versus a scale-free kind. This approach rests on a statistical mechanical level of system abstraction, where micro-scale details of behavioral interactions are coarse-grained to macro-scale observables like the fractal dimension of space use. In this manner, the magnitude of the fractal dimension becomes a proxy variable for distinguishing between main classes of habitat exploration and site fidelity, like memory-less (Markovian) Brownian motion and Levy walk and memory-enhanced space use like Multi-scaled Random Walk (MRW). In this paper previous analyses are extended by exploring MRW simulations under three scenarios: (1) central place foraging, (2) behavioral adaptation to resource depletion (avoidance of latest visited locations) and (3) transition from MRW towards Levy walk by narrowing memory capacity to a trailing time window. A generalized statistical-mechanical theory with the power to model cognitive map influence on individual space use will be important for statistical analyses of animal habitat preferences and the mechanics behind site fidelity and home ranges. Copyright © 2011 Elsevier Ltd. All rights reserved.

Aerial view of the Kennedy Space Center Visitor Center

NASA Technical Reports Server (NTRS)

1998-01-01

The Kennedy Space Center Visitor Center, shown in this aerial view looking south, sprawls across 70 acres on Florida's Space Coast , and is located off State Road 405, NASA Parkway, six miles inside the Space Center entrance. SR 405 can be seen at the bottom of the photo. Just above the roadway, from left can be seen the Shuttle/Gantry mockup; the Post Show Dome; the Astronaut Memorial; and to the far right, the Center for Space Education. Behind the Memorial are a cluster of buildings that include the Theater Complex, Cafeteria, Space Flight Exhibit Building, Souvenir Sales Building, Spaceport Central, and Ticket Pavilion. At the upper right are various rockets that have played a significant role in the growth of the space program.

Three list scheduling temporal partitioning algorithm of time space characteristic analysis and compare for dynamic reconfigurable computing

NASA Astrophysics Data System (ADS)

Chen, Naijin

2013-03-01

Level Based Partitioning (LBP) algorithm, Cluster Based Partitioning (CBP) algorithm and Enhance Static List (ESL) temporal partitioning algorithm based on adjacent matrix and adjacent table are designed and implemented in this paper. Also partitioning time and memory occupation based on three algorithms are compared. Experiment results show LBP partitioning algorithm possesses the least partitioning time and better parallel character, as far as memory occupation and partitioning time are concerned, algorithms based on adjacent table have less partitioning time and less space memory occupation.

A Screen Space GPGPU Surface LIC Algorithm for Distributed Memory Data Parallel Sort Last Rendering Infrastructures

NASA Astrophysics Data System (ADS)

Loring, B.; Karimabadi, H.; Rortershteyn, V.

2015-10-01

The surface line integral convolution(LIC) visualization technique produces dense visualization of vector fields on arbitrary surfaces. We present a screen space surface LIC algorithm for use in distributed memory data parallel sort last rendering infrastructures. The motivations for our work are to support analysis of datasets that are too large to fit in the main memory of a single computer and compatibility with prevalent parallel scientific visualization tools such as ParaView and VisIt. By working in screen space using OpenGL we can leverage the computational power of GPUs when they are available and run without them when they are not. We address efficiency and performance issues that arise from the transformation of data from physical to screen space by selecting an alternate screen space domain decomposition. We analyze the algorithm's scaling behavior with and without GPUs on two high performance computing systems using data from turbulent plasma simulations.

A Screen Space GPGPU Surface LIC Algorithm for Distributed Memory Data Parallel Sort Last Rendering Infrastructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loring, Burlen; Karimabadi, Homa; Rortershteyn, Vadim

2014-07-01

The surface line integral convolution(LIC) visualization technique produces dense visualization of vector fields on arbitrary surfaces. We present a screen space surface LIC algorithm for use in distributed memory data parallel sort last rendering infrastructures. The motivations for our work are to support analysis of datasets that are too large to fit in the main memory of a single computer and compatibility with prevalent parallel scientific visualization tools such as ParaView and VisIt. By working in screen space using OpenGL we can leverage the computational power of GPUs when they are available and run without them when they are not.more » We address efficiency and performance issues that arise from the transformation of data from physical to screen space by selecting an alternate screen space domain decomposition. We analyze the algorithm's scaling behavior with and without GPUs on two high performance computing systems using data from turbulent plasma simulations.« less

Adrenergic Transmission Facilitates Extinction of Conditional Fear in Mice

ERIC Educational Resources Information Center

Barad, Mark; Cain, Christopher K.; Blouin, Ashley M.

2004-01-01

Extinction of classically conditioned fear, like its acquisition, is active learning, but little is known about its molecular mechanisms. We recently reported that temporal massing of conditional stimulus (CS) presentations improves extinction memory acquisition, and suggested that temporal spacing was less effective because individual CS…

Monotonic and Nonmonotonic Lag Effects in Paired-Associate and Recognition Memory Paradigms

ERIC Educational Resources Information Center

Glenberg, Arthur M.

1976-01-01

Three experiments are reported investigating the relationship between response recall and the spacing of repetitions as a function of the retention interval. The results of the experiments support the theory which emphasizes the nature of the cues available for retrieval. (Author/RM)

Dr. Wernher Von Braun Memorial Dinner

NASA Image and Video Library

2017-10-26

The annual Dr. Wernher Von Braun Memorial Dinner was held at the U.S. Space and Rocket Center's Davidson Center on October 26, 2017 with Keynote speaker General John Hyten, Commander of U.S. Strategic Command. Emcee was Mark Larson of Mark Larson Media Services, Inc. Dr. Wernher Von Braun Memorial Scholarships were presented to 8 college students by the National Space Club. Educator of the Year was awarded to Tammy Thorpe; Community Service award was presented to Huntsville, Al. Mayor Tommy Battle. The Communications Award was presented to retired astronaut Dr. Mike Massimino. The Distinguished Science Award was presented to Dr. Martin Weisskopf. The Astronautics Engineer Award was presented to Douglas R. Cooke. The Dr. Wernher Von Braun Space Flight Trophy was presented to Robert Lightfoot.

Ultra-High Density Holographic Memory Module with Solid-State Architecture

NASA Technical Reports Server (NTRS)

Markov, Vladimir B.

2000-01-01

NASA's terrestrial. space, and deep-space missions require technology that allows storing. retrieving, and processing a large volume of information. Holographic memory offers high-density data storage with parallel access and high throughput. Several methods exist for data multiplexing based on the fundamental principles of volume hologram selectivity. We recently demonstrated that a spatial (amplitude-phase) encoding of the reference wave (SERW) looks promising as a way to increase the storage density. The SERW hologram offers a method other than traditional methods of selectivity, such as spatial de-correlation between recorded and reconstruction fields, In this report we present the experimental results of the SERW-hologram memory module with solid-state architecture, which is of particular interest for space operations.

Recollection-Dependent Memory for Event Duration in Large-Scale Spatial Navigation

ERIC Educational Resources Information Center

Brunec, Iva K.; Ozubko, Jason D.; Barense, Morgan D.; Moscovitch, Morris

2017-01-01

Time and space represent two key aspects of episodic memories, forming the spatiotemporal context of events in a sequence. Little is known, however, about how temporal information, such as the duration and the order of particular events, are encoded into memory, and if it matters whether the memory representation is based on recollection or…

Memory, Literacy, and Invention: Reimagining the Canon of Memory for the Writing Classroom

ERIC Educational Resources Information Center

Ryan, Kathleen J.

2004-01-01

This article challenges the assumption that the canon of memory means memorization and transcription, and, as a result, has little relevance for the writing classroom. An examination of the canon's historical legacy and its relationships to literacy and invention open a space for redefining the canon of memory as "rememoried knowing." In brief,…

Intelligent Memory Module Overcomes Harsh Environments

NASA Technical Reports Server (NTRS)

2008-01-01

Solar cells, integrated circuits, and sensors are essential to manned and unmanned space flight and exploration, but such systems are highly susceptible to damage from radiation. Especially problematic, the Van Allen radiation belts encircle Earth in concentric radioactive tori at distances from about 6,300 to 38,000 km, though the inner radiation belt can dip as low as 700 km, posing a severe hazard to craft and humans leaving Earth s atmosphere. To avoid this radiation, the International Space Station and space shuttles orbit at altitudes between 275 and 460 km, below the belts range, and Apollo astronauts skirted the edge of the belts to minimize exposure, passing swiftly through thinner sections of the belts and thereby avoiding significant side effects. This radiation can, however, prove detrimental to improperly protected electronics on satellites that spend the majority of their service life in the harsh environment of the belts. Compact, high-performance electronics that can withstand extreme environmental and radiation stress are thus critical to future space missions. Increasing miniaturization of electronics addresses the need for lighter weight in launch payloads, as launch costs put weight at a premium. Likewise, improved memory technologies have reduced size, cost, mass, power demand, and system complexity, and improved high-bandwidth communication to meet the data volume needs of the next-generation high-resolution sensors. This very miniaturization, however, has exacerbated system susceptibility to radiation, as the charge of ions may meet or exceed that of circuitry, overwhelming the circuit and disrupting operation of a satellite. The Hubble Space Telescope, for example, must turn off its sensors when passing through intense radiation to maintain reliable operation. To address the need for improved data quality, additional capacity for raw and processed data, ever-increasing resolution, and radiation tolerance, NASA spurred the development of the Radiation Tolerant Intelligent Memory Stack (RTIMS).

The Optimization of In-Memory Space Partitioning Trees for Cache Utilization

NASA Astrophysics Data System (ADS)

Yeo, Myung Ho; Min, Young Soo; Bok, Kyoung Soo; Yoo, Jae Soo

In this paper, a novel cache conscious indexing technique based on space partitioning trees is proposed. Many researchers investigated efficient cache conscious indexing techniques which improve retrieval performance of in-memory database management system recently. However, most studies considered data partitioning and targeted fast information retrieval. Existing data partitioning-based index structures significantly degrade performance due to the redundant accesses of overlapped spaces. Specially, R-tree-based index structures suffer from the propagation of MBR (Minimum Bounding Rectangle) information by updating data frequently. In this paper, we propose an in-memory space partitioning index structure for optimal cache utilization. The proposed index structure is compared with the existing index structures in terms of update performance, insertion performance and cache-utilization rate in a variety of environments. The results demonstrate that the proposed index structure offers better performance than existing index structures.

Making long-term memories in minutes: a spaced learning pattern from memory research in education

PubMed Central

Kelley, Paul; Whatson, Terry

2013-01-01

Memory systems select from environmental stimuli those to encode permanently. Repeated stimuli separated by timed spaces without stimuli can initiate Long-Term Potentiation (LTP) and long-term memory (LTM) encoding. These processes occur in time scales of minutes, and have been demonstrated in many species. This study reports on using a specific timed pattern of three repeated stimuli separated by 10 min spaces drawn from both behavioral and laboratory studies of LTP and LTM encoding. A technique was developed based on this pattern to test whether encoding complex information into LTM in students was possible using the pattern within a very short time scale. In an educational context, stimuli were periods of highly compressed instruction, and spaces were created through 10 min distractor activities. Spaced Learning in this form was used as the only means of instruction for a national curriculum Biology course, and led to very rapid LTM encoding as measured by the high-stakes test for the course. Remarkably, learning at a greatly increased speed and in a pattern that included deliberate distraction produced significantly higher scores than random answers (p < 0.00001) and scores were not significantly different for experimental groups (one hour spaced learning) and control groups (four months teaching). Thus learning per hour of instruction, as measured by the test, was significantly higher for the spaced learning groups (p < 0.00001). In a third condition, spaced learning was used to replace the end of course review for one of two examinations. Results showed significantly higher outcomes for the course using spaced learning (p < 0.0005). The implications of these findings and further areas for research are briefly considered. PMID:24093012

Long-Term Memory: A State-Space Approach

ERIC Educational Resources Information Center

Kiss, George R.

1972-01-01

Some salient concepts derived from the information sciences and currently used in theories of human memory are critically reviewed. The application of automata theory is proposed as a new approach in this field. The approach is illustrated by applying it to verbal memory. (Author)

The intermixed-blocked effect in human perceptual learning is not the consequence of trial spacing.

PubMed

Mitchell, Chris; Nash, Scott; Hall, Geoffrey

2008-01-01

A robust finding in humans and animals is that intermixed exposure to 2 similar stimuli (AX/BX) results in better discriminability of those stimuli on test than does exposure to 2 equally similar stimuli in 2 separate blocks (CX_DX)--the intermixed-blocked effect. This intermixed-blocked effect may be an example of the superiority of spaced over massed practice; in the intermixed, but not the blocked exposure regime, each presentation of a given stimulus (e.g., AX) is separated from the next by the presentation of its partner (BX). Two experiments with human participants replicated the intermixed-blocked effect and showed that the effect was not due to the spacing of exposure trials. A mechanism for the intermixed-blocked effect is proposed, which combines theories from associative learning and memory. PsycINFO Database Record (c) 2008 APA, all rights reserved.

Space electric field concentrated effect for Zr:SiO2 RRAM devices using porous SiO2 buffer layer

PubMed Central

2013-01-01

To improve the operation current lowing of the Zr:SiO2 RRAM devices, a space electric field concentrated effect established by the porous SiO2 buffer layer was investigated and found in this study. The resistive switching properties of the low-resistance state (LRS) and high-resistance state (HRS) in resistive random access memory (RRAM) devices for the single-layer Zr:SiO2 and bilayer Zr:SiO2/porous SiO2 thin films were analyzed and discussed. In addition, the original space charge limited current (SCLC) conduction mechanism in LRS and HRS of the RRAM devices using bilayer Zr:SiO2/porous SiO2 thin films was found. Finally, a space electric field concentrated effect in the bilayer Zr:SiO2/porous SiO2 RRAM devices was also explained and verified by the COMSOL Multiphysics simulation model. PMID:24330524

Brain regions involved in subprocesses of small-space episodic object-location memory: a systematic review of lesion and functional neuroimaging studies.

PubMed

Zimmermann, Kathrin; Eschen, Anne

2017-04-01

Object-location memory (OLM) enables us to keep track of the locations of objects in our environment. The neurocognitive model of OLM (Postma, A., Kessels, R. P. C., & Van Asselen, M. (2004). The neuropsychology of object-location memory. In G. L. Allen (Ed.), Human spatial memory: Remembering where (pp. 143-160). Mahwah, NJ: Lawrence Erlbaum, Postma, A., Kessels, R. P. C., & Van Asselen, M. (2008). How the brain remembers and forgets where things are: The neurocognition of object-location memory. Neuroscience & Biobehavioral Reviews, 32, 1339-1345. doi: 10.1016/j.neubiorev.2008.05.001 ) proposes that distinct brain regions are specialised for different subprocesses of OLM (object processing, location processing, and object-location binding; categorical and coordinate OLM; egocentric and allocentric OLM). It was based mainly on findings from lesion studies. However, recent episodic memory studies point to a contribution of additional or different brain regions to object and location processing within episodic OLM. To evaluate and update the neurocognitive model of OLM, we therefore conducted a systematic literature search for lesion as well as functional neuroimaging studies contrasting small-space episodic OLM with object memory or location memory. We identified 10 relevant lesion studies and 8 relevant functional neuroimaging studies. We could confirm some of the proposals of the neurocognitive model of OLM, but also differing hypotheses from episodic memory research, about which brain regions are involved in the different subprocesses of small-space episodic OLM. In addition, we were able to identify new brain regions as well as important research gaps.

Day of Remembrance

NASA Image and Video Library

2018-01-25

Mike Oldak, Resnik Family member, left, Chuck Resnik, brother of the late space shuttle Challenger astronaut Judy Resnik, Amy Resnik, sister-in-law of the late Judy Resnik and acting NASA Administrator Robert Lightfoot, right, are seen after laying a wreath at the Space Shuttle Columbia Memorial as part of NASA's Day of Remembrance, Thursday, Jan. 25, 2018, Arlington National Cemetery in Arlington, Virginia. Wreaths were laid in memory of those men and women who lost their lives in the quest for space exploration. Photo Credit: (NASA/Bill Ingalls)

The impact of subjective memory complaints on quality of life in community-dwelling older adults.

PubMed

Maki, Yohko; Yamaguchi, Tomoharu; Yamagami, Tetsuya; Murai, Tatsuhiko; Hachisuka, Kenji; Miyamae, Fumiko; Ito, Kae; Awata, Shuichi; Ura, Chiaki; Takahashi, Ryutaro; Yamaguchi, Haruyasu

2014-09-01

The aim of this study was to evaluate the impact of memory complaints on quality of life (QOL) in elderly community dwellers with or without mild cognitive impairment (MCI). Participants included 120 normal controls (NC) and 37 with MCI aged 65 and over. QOL was measured using the Japanese version of Satisfaction in Daily Life, and memory complaints were measured using a questionnaire consisting of four items. The relevance of QOL was evaluated with psychological factors of personality traits, sense of self-efficacy, depressive mood, self-evaluation of daily functioning, range of social activities (Life-Space Assessment), social network size, and cognitive functions including memory. The predictors of QOL were analyzed by multiple linear regression analysis. QOL was not significantly different between the NC and MCI groups. In both groups, QOL was positively correlated with self-efficacy, daily functioning, social network size, Life-Space Assessment, and the personality traits of extraversion and agreeableness; QOL was negatively correlated with memory complaints, depressive mood, and the personality trait of neuroticism. In regression analysis, memory complaints were a negative predictor of QOL in the MCI group, but not in the NC group. The partial correlation coefficient between QOL and memory complaints was -0.623 (P < 0.05), after scores of depressive mood and self-efficacy were controlled. Depressive mood was a common negative predictor in both groups. Positive predictors were Life-Space Assessment in the NC group and sense of self-efficacy in the MCI group. Memory complaints exerted a negative impact on self-rated QOL in the MCI group, whereas a negative correlation was weak in the NC group. Memory training has been widely practised in individuals with MCI to prevent the development of dementia. However, such approaches inevitably identify their memory deficits and could aggravate their awareness of memory decline. Thus, it is critical to give sufficient consideration not to reduce QOL in the intervention for those with MCI. © 2014 The Authors. Psychogeriatrics © 2014 Japanese Psychogeriatric Society.

Navigating Monogamy: Nonapeptide Sensitivity in a Memory Neural Circuit May Shape Social Behavior and Mating Decisions

PubMed Central

Ophir, Alexander G.

2017-01-01

The role of memory in mating systems is often neglected despite the fact that most mating systems are defined in part by how animals use space. Monogamy, for example, is usually characterized by affiliative (e.g., pairbonding) and defensive (e.g., mate guarding) behaviors, but a high degree of spatial overlap in home range use is the easiest defining feature of monogamous animals in the wild. The nonapeptides vasopressin and oxytocin have been the focus of much attention for their importance in modulating social behavior, however this work has largely overshadowed their roles in learning and memory. To date, the understanding of memory systems and mechanisms governing social behavior have progressed relatively independently. Bridging these two areas will provide a deeper appreciation for understanding behavior, and in particular the mechanisms that mediate reproductive decision-making. Here, I argue that the ability to mate effectively as monogamous individuals is linked to the ability to track conspecifics in space. I discuss the connectivity across some well-known social and spatial memory nuclei, and propose that the nonapeptide receptors within these structures form a putative “socio-spatial memory neural circuit.” This purported circuit may function to integrate social and spatial information to shape mating decisions in a context-dependent fashion. The lateral septum and/or the nucleus accumbens, and neuromodulation therein, may act as an intermediary to relate socio-spatial information with social behavior. Identifying mechanisms responsible for relating information about the social world with mechanisms mediating mating tactics is crucial to fully appreciate the suite of factors driving reproductive decisions and social decision-making. PMID:28744194

KSC-2012-1127

NASA Image and Video Library

2012-01-26

CAPE CANAVERAL, Fla. -- A blue sky is reflected in the massive granite Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida where a large wreath was placed during Kennedy Space Center’s NASA Day of Remembrance. The Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the astronaut crews of Apollo 1 and space shuttles Challenger and Columbia. Kennedy civil service and contractor employees, along with the general public, paid their respects throughout the day. The visitor complex provided flowers for visitors to place at the memorial. Photo credit: NASA/Kim Shiflett

KSC-2012-1121

NASA Image and Video Library

2012-01-26

CAPE CANAVERAL, Fla. -- An American flag flies at half staff near the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida during Kennedy Space Center’s NASA Day of Remembrance. The Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the astronaut crews of Apollo 1 and space shuttles Challenger and Columbia. Kennedy civil service and contractor employees, along with the general public, paid their respects throughout the day. The visitor complex provided flowers for visitors to place at the memorial. Photo credit: NASA/Kim Shiflett

PMMA interlayer-modulated memory effects by space charge polarization in resistive switching based on CuSCN-nanopyramids/ZnO-nanorods p-n heterojunction

PubMed Central

Cheng, Baochang; Zhao, Jie; Xiao, Li; Cai, Qiangsheng; Guo, Rui; Xiao, Yanhe; Lei, Shuijin

2015-01-01

Resistive switching (RS) devices are commonly believed as a promising candidate for next generation nonvolatile resistance random access memory. Here, polymethylmethacrylate (PMMA) interlayer was introduced at the heterointerface of p-CuSCN hollow nanopyramid arrays and n-ZnO nanorod arrays, resulting in a typical bipolar RS behavior. We propose the mechanism of nanostructure trap-induced space charge polarization modulated by PMMA interlayer. At low reverse bias, PMMA insulator can block charges through the heterointerface, and and trapped states are respectively created on both sides of PMMA, resulting in a high resistance state (HRS) due to wider depletion region. At high reverse bias, however, electrons and holes can cross PMMA interlayer by Fowler-Nordeim tunneling due to a massive tilt of energy band, and then inject into the traps of ZnO and CuSCN, respectively. and trapped states are created, resulting in the formation of degenerate semiconductors on both sides of PMMA. Therefore, quantum tunneling and space charge polarization lead to a low resistance state (LRS). At relatively high forward bias, subsequently, the trapped states of and are recreated due to the opposite injection of charges, resulting in a recovery of HRS. The introduction of insulating interlayer at heterointerface, point a way to develop next-generation nonvolatile memories. PMID:26648249

The Cognitive Underpinnings of Incremental Rehearsal

ERIC Educational Resources Information Center

Varma, Sashank; Schleisman, Katrina B.

2014-01-01

Incremental rehearsal (IR) is a flashcard technique that has been developed and evaluated by school psychologists. We discuss potential learning and memory effects from cognitive psychology that may explain the observed superiority of IR over other flashcard techniques. First, we propose that IR is a form of "spaced practice" that…

Space-Bounded Church-Turing Thesis and Computational Tractability of Closed Systems.

PubMed

Braverman, Mark; Schneider, Jonathan; Rojas, Cristóbal

2015-08-28

We report a new limitation on the ability of physical systems to perform computation-one that is based on generalizing the notion of memory, or storage space, available to the system to perform the computation. Roughly, we define memory as the maximal amount of information that the evolving system can carry from one instant to the next. We show that memory is a limiting factor in computation even in lieu of any time limitations on the evolving system-such as when considering its equilibrium regime. We call this limitation the space-bounded Church-Turing thesis (SBCT). The SBCT is supported by a simulation assertion (SA), which states that predicting the long-term behavior of bounded-memory systems is computationally tractable. In particular, one corollary of SA is an explicit bound on the computational hardness of the long-term behavior of a discrete-time finite-dimensional dynamical system that is affected by noise. We prove such a bound explicitly.

Space-Bounded Church-Turing Thesis and Computational Tractability of Closed Systems

NASA Astrophysics Data System (ADS)

Braverman, Mark; Schneider, Jonathan; Rojas, Cristóbal

2015-08-01

We report a new limitation on the ability of physical systems to perform computation—one that is based on generalizing the notion of memory, or storage space, available to the system to perform the computation. Roughly, we define memory as the maximal amount of information that the evolving system can carry from one instant to the next. We show that memory is a limiting factor in computation even in lieu of any time limitations on the evolving system—such as when considering its equilibrium regime. We call this limitation the space-bounded Church-Turing thesis (SBCT). The SBCT is supported by a simulation assertion (SA), which states that predicting the long-term behavior of bounded-memory systems is computationally tractable. In particular, one corollary of SA is an explicit bound on the computational hardness of the long-term behavior of a discrete-time finite-dimensional dynamical system that is affected by noise. We prove such a bound explicitly.

Accuracy of saccades to remembered targets as a function of body orientation in space

NASA Technical Reports Server (NTRS)

Vogelstein, Joshua T.; Snyder, Lawrence H.; Angelaki, Dora E.

2003-01-01

A vertical asymmetry in memory-guided saccadic eye movements has been previously demonstrated in humans and in rhesus monkeys. In the upright orientation, saccades generally land several degrees above the target. The origin of this asymmetry has remained unknown. In this study, we investigated whether the asymmetry in memory saccades is dependent on body orientation in space. Thus animals performed memory saccades in four different body orientations: upright, left-side-down (LSD), right-side-down (RSD), and supine. Data in all three rhesus monkeys confirm previous observations regarding a significant upward vertical asymmetry. Saccade errors made from LSD and RSD postures were partitioned into components made along the axis of gravity and along the vertical body axis. Up/down asymmetry persisted only in body coordinates but not in gravity coordinates. However, this asymmetry was generally reduced in tilted positions. Therefore the upward bias seen in memory saccades is egocentric although orientation in space might play a modulatory role.

Space-charge Effect on Electroresistance in Metal-Ferroelectric-Metal capacitors

PubMed Central

Tian, Bo Bo; Liu, Yang; Chen, Liu Fang; Wang, Jian Lu; Sun, Shuo; Shen, Hong; Sun, Jing Lan; Yuan, Guo Liang; Fusil, Stéphane; Garcia, Vincent; Dkhil, Brahim; Meng, Xiang Jian; Chu, Jun Hao

2015-01-01

Resistive switching through electroresistance (ER) effect in metal-ferroelectric-metal (MFM) capacitors has attracted increasing interest due to its potential applications as memories and logic devices. However, the detailed electronic mechanisms resulting in large ER when polarisation switching occurs in the ferroelectric barrier are still not well understood. Here, ER effect up to 1000% at room temperature is demonstrated in C-MOS compatible MFM nanocapacitors with a 8.8 nm-thick poly(vinylidene fluoride) (PVDF) homopolymer ferroelectric, which is very promising for silicon industry integration. Most remarkably, using theory developed for metal-semiconductor rectifying contacts, we derive an analytical expression for the variation of interfacial barrier heights due to space-charge effect that can interpret the observed ER response. We extend this space-charge model, related to the release of trapped charges by defects, to MFM structures made of ferroelectric oxides. This space-charge model provides a simple and straightforward tool to understand recent unusual reports. Finally, this work suggests that defect-engineering could be an original and efficient route for tuning the space-charge effect and thus the ER performances in future electronic devices. PMID:26670138

Space-charge Effect on Electroresistance in Metal-Ferroelectric-Metal capacitors

NASA Astrophysics Data System (ADS)

Tian, Bo Bo; Liu, Yang; Chen, Liu Fang; Wang, Jian Lu; Sun, Shuo; Shen, Hong; Sun, Jing Lan; Yuan, Guo Liang; Fusil, Stéphane; Garcia, Vincent; Dkhil, Brahim; Meng, Xiang Jian; Chu, Jun Hao

2015-12-01

Resistive switching through electroresistance (ER) effect in metal-ferroelectric-metal (MFM) capacitors has attracted increasing interest due to its potential applications as memories and logic devices. However, the detailed electronic mechanisms resulting in large ER when polarisation switching occurs in the ferroelectric barrier are still not well understood. Here, ER effect up to 1000% at room temperature is demonstrated in C-MOS compatible MFM nanocapacitors with a 8.8 nm-thick poly(vinylidene fluoride) (PVDF) homopolymer ferroelectric, which is very promising for silicon industry integration. Most remarkably, using theory developed for metal-semiconductor rectifying contacts, we derive an analytical expression for the variation of interfacial barrier heights due to space-charge effect that can interpret the observed ER response. We extend this space-charge model, related to the release of trapped charges by defects, to MFM structures made of ferroelectric oxides. This space-charge model provides a simple and straightforward tool to understand recent unusual reports. Finally, this work suggests that defect-engineering could be an original and efficient route for tuning the space-charge effect and thus the ER performances in future electronic devices.

Memories and NASA Spacecraft: A Description of Memories, Radiation Failure Modes, and System Design Considerations

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Ladbury, Ray; Oldhamm, Timothy

2010-01-01

As NASA has evolved it's usage of spaceflight computing, memory applications have followed as well. In this slide presentation, the history of NASA's memories from magnetic core and tape recorders to current semiconductor approaches is discussed. There is a brief description of current functional memory usage in NASA space systems followed by a description of potential radiation-induced failure modes along with considerations for reliable system design.

Expressions of Private Mourning in Public Space: The Evolving Structure of Spontaneous and Permanent Roadside Memorials in the Netherlands

ERIC Educational Resources Information Center

Klaassens, Mirjam; Groote, Peter D.; Vanclay, Frank M.

2013-01-01

A visual content analysis of photos of 216 roadside memorials in the Netherlands was undertaken together with 24 interviews with the people who constructed them to understand how they deal with traumatic death. Friends urgently need to memorialize the deceased and establish spontaneous memorials. They place meaningful objects at the place of…

Community-based memorials to September 11, 2001: environmental stewardship as memory work

Treesearch

Erika S. Svendsen; Lindsay K. Campbell

2014-01-01

This chapter investigates how people use trees, parks, gardens, and other natural resources as raw materials in and settings for memorials to September 11, 2001. In particular, we focus on 'found space living memorials', which we define as sites that are community-managed, re-appropriated from their prior use, often carved out of the public right-of-way, and...

Memory Overview - Technologies and Needs

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.

2010-01-01

As NASA has evolved it's usage of spaceflight computing, memory applications have followed as well. In this talk, we will discuss the history of NASA's memories from magnetic core and tape recorders to current semiconductor approaches. We will briefly describe current functional memory usage in NASA space systems followed by a description of potential radiation-induced failure modes along with considerations for reliable system design.

KSC-98PC-1041

NASA Image and Video Library

1998-08-06

The Kennedy Space Center Visitor Center, shown in this aerial view looking south, sprawls across 70 acres on Florida's Space Coast , and is located off State Road 405, NASA Parkway, six miles inside the Space Center entrance. SR 405 can be seen at the bottom of the photo. Just above the roadway, from left can be seen the Shuttle/Gantry mockup; the Post Show Dome; the Astronaut Memorial; and to the far right, the Center for Space Education. Behind the Memorial are a cluster of buildings that include the Theater Complex, Cafeteria, Space Flight Exhibit Building, Souvenir Sales Building, Spaceport Central, and Ticket Pavilion. At the upper right are various rockets that have played a significant role in the growth of the space program.

Dynamic Organization of Hierarchical Memories

PubMed Central

Kurikawa, Tomoki; Kaneko, Kunihiko

2016-01-01

In the brain, external objects are categorized in a hierarchical way. Although it is widely accepted that objects are represented as static attractors in neural state space, this view does not take account interaction between intrinsic neural dynamics and external input, which is essential to understand how neural system responds to inputs. Indeed, structured spontaneous neural activity without external inputs is known to exist, and its relationship with evoked activities is discussed. Then, how categorical representation is embedded into the spontaneous and evoked activities has to be uncovered. To address this question, we studied bifurcation process with increasing input after hierarchically clustered associative memories are learned. We found a “dynamic categorization”; neural activity without input wanders globally over the state space including all memories. Then with the increase of input strength, diffuse representation of higher category exhibits transitions to focused ones specific to each object. The hierarchy of memories is embedded in the transition probability from one memory to another during the spontaneous dynamics. With increased input strength, neural activity wanders over a narrower state space including a smaller set of memories, showing more specific category or memory corresponding to the applied input. Moreover, such coarse-to-fine transitions are also observed temporally during transient process under constant input, which agrees with experimental findings in the temporal cortex. These results suggest the hierarchy emerging through interaction with an external input underlies hierarchy during transient process, as well as in the spontaneous activity. PMID:27618549

Everyday memory impairment in patients with temporal lobe epilepsy caused by hippocampal sclerosis.

PubMed

Rzezak, Patrícia; Lima, Ellen Marise; Gargaro, Ana Carolina; Coimbra, Erica; de Vincentiis, Silvia; Velasco, Tonicarlo Rodrigues; Leite, João Pereira; Busatto, Geraldo F; Valente, Kette D

2017-04-01

Patients with temporal lobe epilepsy caused by hippocampal sclerosis (TLE-HS) have episodic memory impairment. Memory has rarely been evaluated using an ecologic measure, even though performance on these tests is more related to patients' memory complaints. We aimed to measure everyday memory of patients with TLE-HS to age- and gender-matched controls. We evaluated 31 patients with TLE-HS and 34 healthy controls, without epilepsy and psychiatric disorders, using the Rivermead Behavioral Memory Test (RBMT), Visual Reproduction (WMS-III) and Logical Memory (WMS-III). We evaluated the impact of clinical variables such as the age of onset, epilepsy duration, AED use, history of status epilepticus, and seizure frequency on everyday memory. Statistical analyses were performed using MANCOVA with years of education as a confounding factor. Patients showed worse performance than controls on traditional memory tests and in the overall score of RBMT. Patients had more difficulties to recall names, a hidden belonging, to deliver a message, object recognition, to remember a story full of details, a previously presented short route, and in time and space orientation. Clinical epilepsy variables were not associated with RBMT performance. Memory span and working memory were correlated with worse performance on RBMT. Patients with TLE-HS demonstrated deficits in everyday memory functions. A standard neuropsychological battery, designed to assess episodic memory, would not evaluate these impairments. Impairment in recalling names, routes, stories, messages, and space/time disorientation can adversely impact social adaptation, and we must consider these ecologic measures with greater attention in the neuropsychological evaluation of patients with memory complaints. Copyright © 2017 Elsevier Inc. All rights reserved.

UPC++ Programmer’s Guide (v1.0 2017.9)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bachan, J.; Baden, S.; Bonachea, D.

UPC++ is a C++11 library that provides Asynchronous Partitioned Global Address Space (APGAS) programming. It is designed for writing parallel programs that run efficiently and scale well on distributed-memory parallel computers. The APGAS model is single program, multiple-data (SPMD), with each separate thread of execution (referred to as a rank, a term borrowed from MPI) having access to local memory as it would in C++. However, APGAS also provides access to a global address space, which is allocated in shared segments that are distributed over the ranks. UPC++ provides numerous methods for accessing and using global memory. In UPC++, allmore » operations that access remote memory are explicit, which encourages programmers to be aware of the cost of communication and data movement. Moreover, all remote-memory access operations are by default asynchronous, to enable programmers to write code that scales well even on hundreds of thousands of cores.« less

UPC++ Programmer’s Guide, v1.0-2018.3.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bachan, J.; Baden, S.; Bonachea, Dan

UPC++ is a C++11 library that provides Partitioned Global Address Space (PGAS) programming. It is designed for writing parallel programs that run efficiently and scale well on distributed-memory parallel computers. The PGAS model is single program, multiple-data (SPMD), with each separate thread of execution (referred to as a rank, a term borrowed from MPI) having access to local memory as it would in C++. However, PGAS also provides access to a global address space, which is allocated in shared segments that are distributed over the ranks. UPC++ provides numerous methods for accessing and using global memory. In UPC++, all operationsmore » that access remote memory are explicit, which encourages programmers to be aware of the cost of communication and data movement. Moreover, all remote-memory access operations are by default asynchronous, to enable programmers to write code that scales well even on hundreds of thousands of cores.« less

Saturation: An efficient iteration strategy for symbolic state-space generation

NASA Technical Reports Server (NTRS)

Ciardo, Gianfranco; Luettgen, Gerald; Siminiceanu, Radu; Bushnell, Dennis M. (Technical Monitor)

2001-01-01

This paper presents a novel algorithm for generating state spaces of asynchronous systems using Multi-valued Decision Diagrams. In contrast to related work, the next-state function of a system is not encoded as a single Boolean function, but as cross-products of integer functions. This permits the application of various iteration strategies to build a system's state space. In particular, this paper introduces a new elegant strategy, called saturation, and implements it in the tool SMART. On top of usually performing several orders of magnitude faster than existing BDD-based state-space generators, the algorithm's required peak memory is often close to the nal memory needed for storing the overall state spaces.

KSC-2012-1123

NASA Image and Video Library

2012-01-26

CAPE CANAVERAL, Fla. -- Kennedy Space Center Deputy Director Janet Petro, at left, Kennedy Center Director Robert Cabana, and United Space Alliance’s Vice President for Aerospace Services/Florida Site Director Mark Nappi, place a wreath at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex during Kennedy’s NASA Day of Remembrance. The Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the astronaut crews of Apollo 1 and space shuttles Challenger and Columbia. Kennedy civil service and contractor employees, along with the general public, paid their respects throughout the day. The visitor complex provided flowers for visitors to place at the memorial. Photo credit: NASA/Kim Shiflett

KSC-2012-1119

NASA Image and Video Library

2012-01-26

CAPE CANAVERAL, Fla. -- Kennedy Space Center Director Robert Cabana, Deputy Director Janet Petro, and United Space Alliance’s Vice President for Aerospace Services/Florida Site Director Mark Nappi place a wreath at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida during Kennedy’s NASA Day of Remembrance. The Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the astronaut crews of Apollo 1 and space shuttles Challenger and Columbia. Kennedy civil service and contractor employees, along with the general public, paid their respects throughout the day. The visitor complex provided flowers for visitors to place at the memorial. Photo credit: NASA/Kim Shiflett

KSC-2012-1124

NASA Image and Video Library

2012-01-26

CAPE CANAVERAL, Fla. -- Kennedy Space Center Director Robert Cabana, at left, Deputy Director Janet Petro, and United Space Alliance’s Vice President for Aerospace Services/Florida Site Director Mark Nappi, place a wreath at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in Florida during Kennedy’s NASA Day of Remembrance. The Day of Remembrance honors members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the astronaut crews of Apollo 1 and space shuttles Challenger and Columbia. Kennedy civil service and contractor employees, along with the general public, paid their respects throughout the day. The visitor complex provided flowers for visitors to place at the memorial. Photo credit: NASA/Kim Shiflett

Lack of spacing effects during piano learning.

PubMed

Wiseheart, Melody; D'Souza, Annalise A; Chae, Jacey

2017-01-01

Spacing effects during retention of verbal information are easily obtained, and the effect size is large. Relatively little evidence exists on whether motor skill retention benefits from distributed practice, with even less evidence on complex motor skills. We taught a 17-note musical sequence on a piano to individuals without prior formal training. There were five lags between learning episodes: 0-, 1-, 5-, 10-, and 15-min. After a 5-min retention interval, participants' performance was measured using three criteria: accuracy of note playing, consistency in pressure applied to the keys, and consistency in timing. No spacing effect was found, suggesting that the effect may not always be demonstrable for complex motor skills or non-verbal abilities (timing and motor skills). Additionally, we taught short phrases from five songs, using the same set of lags and retention interval, and did not find any spacing effect for accuracy of song reproduction. Our findings indicate that although the spacing effect is one of the most robust phenomena in the memory literature (as demonstrated by verbal learning studies), the effect may vary when considered in the novel realm of complex motor skills such as piano performance.

Lack of spacing effects during piano learning

PubMed Central

D’Souza, Annalise A.; Chae, Jacey

2017-01-01

Spacing effects during retention of verbal information are easily obtained, and the effect size is large. Relatively little evidence exists on whether motor skill retention benefits from distributed practice, with even less evidence on complex motor skills. We taught a 17-note musical sequence on a piano to individuals without prior formal training. There were five lags between learning episodes: 0-, 1-, 5-, 10-, and 15-min. After a 5-min retention interval, participants’ performance was measured using three criteria: accuracy of note playing, consistency in pressure applied to the keys, and consistency in timing. No spacing effect was found, suggesting that the effect may not always be demonstrable for complex motor skills or non-verbal abilities (timing and motor skills). Additionally, we taught short phrases from five songs, using the same set of lags and retention interval, and did not find any spacing effect for accuracy of song reproduction. Our findings indicate that although the spacing effect is one of the most robust phenomena in the memory literature (as demonstrated by verbal learning studies), the effect may vary when considered in the novel realm of complex motor skills such as piano performance. PMID:28800631

Optoelectronic Inner-Product Neural Associative Memory

NASA Technical Reports Server (NTRS)

Liu, Hua-Kuang

1993-01-01

Optoelectronic apparatus acts as artificial neural network performing associative recall of binary images. Recall process is iterative one involving optical computation of inner products between binary input vector and one or more reference binary vectors in memory. Inner-product method requires far less memory space than matrix-vector method.

Temporal Context Memory in High-Functioning Autism

ERIC Educational Resources Information Center

Gras-Vincendon, Agnes; Mottron, Laurent; Salame, Pierre; Bursztejn, Claude; Danion, Jean-Marie

2007-01-01

Episodic memory, i.e. memory for specific episodes situated in space and time, seems impaired in individuals with autism. According to weak central coherence theory, individuals with autism have general difficulty connecting contextual and item information which then impairs their capacity to memorize information in context. This study…

KSC-04PD-0122

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Some of the dancers from the Shoshone- Bannock Junior-Senior High School, Fort Hall, Idaho, hold a flag commemorating the orbiter Columbia and her crew. The dancers performed a healing ceremony during the memorial service held at the Space Memorial Mirror for the crew of Columbia. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

KSC-04PD-0129

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. A member of the Shoshone-Bannock Native American community from Fort Hall, Idaho, displays a handmade item with the STS-107 logo. Dancers from Shoshone- Bannock Junior-Senior High School performed a healing ceremony during the memorial held at the Space Memorial Mirror, in the KSC Visitor Complex. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

Efficacy of the Ubiquitous Spaced Retrieval-based Memory Advancement and Rehabilitation Training (USMART) program among patients with mild cognitive impairment: a randomized controlled crossover trial.

PubMed

Han, Ji Won; Son, Kyung Lak; Byun, Hye Jin; Ko, Ji Won; Kim, Kayoung; Hong, Jong Woo; Kim, Tae Hyun; Kim, Ki Woong

2017-06-06

Spaced retrieval training (SRT) is a nonpharmacological intervention for mild cognitive impairment (MCI) and dementia that trains the learning and retention of target information by recalling it over increasingly long intervals. We recently developed the Ubiquitous Spaced Retrieval-based Memory Advancement and Rehabilitation Training (USMART) program as a convenient, self-administered tablet-based SRT program. We also demonstrated the utility of USMART for improving memory in individuals with MCI through an open-label uncontrolled trial. This study had an open-label, single-blind, randomized, controlled, two-period crossover design. Fifty patients with MCI were randomized into USMART-usual care and usual care-USMART treatment sequences. USMART was completed or usual care was provided biweekly over a 4-week treatment period with a 2-week washout period between treatment periods. Primary outcome measures included the Word List Memory Test, Word List Recall Test (WLRT), and Word List Recognition Test. Outcomes were measured at baseline, week 5, and week 11 by raters who were blinded to intervention type. An intention-to-treat analysis and linear mixed modeling were used. Of 50 randomized participants, 41 completed the study (18% dropout rate). The USMART group had larger improvements in WLRT score (effect size = 0.49, p = 0.031) than the usual care group. There were no significant differences in other primary or secondary measures between the USMART and usual care groups. Moreover, no USMART-related adverse events were reported. The 4-week USMART modestly improved information retrieval in older people with MCI, and was well accepted with minimal technical support. ClinicalTrials.gov NCT01688128 . Registered 12 September 2012.

Memory impairment, oxidative damage and apoptosis induced by space radiation: ameliorative potential of alpha-lipoic acid.

PubMed

Manda, Kailash; Ueno, Megumi; Anzai, Kazunori

2008-03-05

Exposure to high-energy particle radiation (HZE) may cause oxidative stress and cognitive impairment in the same manner that seen in aged mice. This phenomenon has raised the concerns about the safety of an extended manned mission into deep space where a significant portion of the radiation burden would come from HZE particle radiation. The present study aimed at investigating the role of alpha-lipoic acid against space radiation-induced oxidative stress and antioxidant status in cerebellum and its correlation with cognitive dysfunction. We observed spontaneous motor activities and spatial memory task of mice using pyroelectric infrared sensor and programmed video tracking system, respectively. Whole body irradiation of mice with high-LET (56)Fe beams (500 MeV/nucleon, 1.5 Gy) substantially impaired the reference memory at 30 day post-irradiation; however, no significant effect was observed on motor activities of mice. Acute intraperitoneal treatment of mice with alpha-lipoic acid prior to irradiation significantly attenuated such memory dysfunction. Radiation-induced apoptotic damage in cerebellum was examined using a neuronal-specific terminal deoxynucleotidyl transferase-mediated nick end-labeling method (NeuroTACS). Radiation-induced apoptotic and necrotic cell death of granule cells and Purkinje cells were inhibited significantly by alpha-lipoic acid pretreatment. Alpha-lipoic acid pretreatment exerted a very high magnitude of protection against radiation-induced augmentation of DNA damage (comet tail movement and serum 8-OHdG), lipid proxidation products (MDA+HAE) and protein carbonyls in mice cerebellum. Further, radiation-induced decline of non-protein sulfhydryl (NP-SH) contents of cerebellum and plasma ferric reducing power (FRAP) was also inhibited by alpha-lipoic acid pre-treatment. Results clearly indicate that alpha-lipoic acid is a potent neuroprotective antioxidant. Moreover, present finding also support the idea suggesting the cerebellar involvement in cognition.

Switching from reaching to navigation: differential cognitive strategies for spatial memory in children and adults.

PubMed

Belmonti, Vittorio; Cioni, Giovanni; Berthoz, Alain

2015-07-01

Navigational and reaching spaces are known to involve different cognitive strategies and brain networks, whose development in humans is still debated. In fact, high-level spatial processing, including allocentric location encoding, is already available to very young children, but navigational strategies are not mature until late childhood. The Magic Carpet (MC) is a new electronic device translating the traditional Corsi Block-tapping Test (CBT) to navigational space. In this study, the MC and the CBT were used to assess spatial memory for navigation and for reaching, respectively. Our hypothesis was that school-age children would not treat MC stimuli as navigational paths, assimilating them to reaching sequences. Ninety-one healthy children aged 6 to 11 years and 18 adults were enrolled. Overall short-term memory performance (span) on both tests, effects of sequence geometry, and error patterns according to a new classification were studied. Span increased with age on both tests, but relatively more in navigational than in reaching space, particularly in males. Sequence geometry specifically influenced navigation, not reaching. The number of body rotations along the path affected MC performance in children more than in adults, and in women more than in men. Error patterns indicated that navigational sequences were increasingly retained as global paths across development, in contrast to separately stored reaching locations. A sequence of spatial locations can be coded as a navigational path only if a cognitive switch from a reaching mode to a navigation mode occurs. This implies the integration of egocentric and allocentric reference frames, of visual and idiothetic cues, and access to long-term memory. This switch is not yet fulfilled at school age due to immature executive functions. © 2014 John Wiley & Sons Ltd.

Large-scale hydropower system optimization using dynamic programming and object-oriented programming: the case of the Northeast China Power Grid.

PubMed

Li, Ji-Qing; Zhang, Yu-Shan; Ji, Chang-Ming; Wang, Ai-Jing; Lund, Jay R

2013-01-01

This paper examines long-term optimal operation using dynamic programming for a large hydropower system of 10 reservoirs in Northeast China. Besides considering flow and hydraulic head, the optimization explicitly includes time-varying electricity market prices to maximize benefit. Two techniques are used to reduce the 'curse of dimensionality' of dynamic programming with many reservoirs. Discrete differential dynamic programming (DDDP) reduces the search space and computer memory needed. Object-oriented programming (OOP) and the ability to dynamically allocate and release memory with the C++ language greatly reduces the cumulative effect of computer memory for solving multi-dimensional dynamic programming models. The case study shows that the model can reduce the 'curse of dimensionality' and achieve satisfactory results.

A Nonlinear Functional Differential Equation in Banach Space with Applications to Materials with Fading Memory.

DTIC Science & Technology

1982-08-01

memory can be interpreted * mathematically as a smoothness requirement for Y. Following Coleman and Noll [ 4,5 ], we introduce an influence function , intended...to characterize the rate at which memory fades, and construct an LP-type space of admissible strain histories, using the influence function as a...that f h(s)fw(s)I ds < c, 0 equipped with the norm* given by (1.8) IwIl h = w(o)l + f h(s)w(s) 2d 0 We refer to h as an influence function and to the

KSC-07pd0181

NASA Image and Video Library

2007-01-27

KENNEDY SPACE CENTER, FLA. -- The Space Mirror Memorial, seen in profile, is reflected in the nearby lake at the KSC Visitor Complex. The memorial is the scene of a ceremony being held in remembrance of the astronauts lost in the Apollo 1 fire: Virgil "Gus" Grissom, Edward H. White II and Roger B. Chaffee. The mirror was designated as a national memorial by Congress and President George Bush in 1991 to honor fallen astronauts. Their names are emblazoned on the monument's 42-1/2-foot-high by 50-foot-wide black granite surface as if to be projected into the heavens. Photo credit:NASA/George Shelton

Face-name association learning in early Alzheimer's disease: a comparison of learning methods and their underlying mechanisms.

PubMed

Bier, Nathalie; Van Der Linden, Martial; Gagnon, Lise; Desrosiers, Johanne; Adam, Stephane; Louveaux, Stephanie; Saint-Mleux, Julie

2008-06-01

This study compared the efficacy of five learning methods in the acquisition of face-name associations in early dementia of Alzheimer type (AD). The contribution of error production and implicit memory to the efficacy of each method was also examined. Fifteen participants with early AD and 15 matched controls were exposed to five learning methods: spaced retrieval, vanishing cues, errorless, and two trial-and-error methods, one with explicit and one with implicit memory task instructions. Under each method, participants had to learn a list of five face-name associations, followed by free recall, cued recall and recognition. Delayed recall was also assessed. For AD, results showed that all methods were efficient but there were no significant differences between them. The number of errors produced during the learning phases varied between the five methods but did not influence learning. There were no significant differences between implicit and explicit memory task instructions on test performances. For the control group, there were no differences between the five methods. Finally, no significant correlations were found between the performance of the AD participants in free recall and their cognitive profile, but generally, the best performers had better remaining episodic memory. Also, case study analyses showed that spaced retrieval was the method for which the greatest number of participants (four) obtained results as good as the controls. This study suggests that the five methods are effective for new learning of face-name associations in AD. It appears that early AD patients can learn, even in the context of error production and explicit memory conditions.

Modeling Age-Related Differences in Immediate Memory Using SIMPLE

ERIC Educational Resources Information Center

Surprenant, Aimee M.; Neath, Ian; Brown, Gordon D. A.

2006-01-01

In the SIMPLE model (Scale Invariant Memory and Perceptual Learning), performance on memory tasks is determined by the locations of items in multidimensional space, and better performance is associated with having fewer close neighbors. Unlike most previous simulations with SIMPLE, the ones reported here used measured, rather than assumed,…

Optimal Foraging in Semantic Memory

ERIC Educational Resources Information Center

Hills, Thomas T.; Jones, Michael N.; Todd, Peter M.

2012-01-01

Do humans search in memory using dynamic local-to-global search strategies similar to those that animals use to forage between patches in space? If so, do their dynamic memory search policies correspond to optimal foraging strategies seen for spatial foraging? Results from a number of fields suggest these possibilities, including the shared…

On the Clash of Martyrological Memories

ERIC Educational Resources Information Center

Jansen, Jonathan D.

2009-01-01

What happens when students holding rival though indirect memories of past conflicts confront each other in the same classroom? What are the kinds of political and pedagogical approaches necessary for mediating such "clashes of martyrological memories" in the same educational space? And why is critical theory inept at offering resolutions…

NASA's 3D Flight Computer for Space Applications

NASA Technical Reports Server (NTRS)

Alkalai, Leon

2000-01-01

The New Millennium Program (NMP) Integrated Product Development Team (IPDT) for Microelectronics Systems was planning to validate a newly developed 3D Flight Computer system on its first deep-space flight, DS1, launched in October 1998. This computer, developed in the 1995-97 time frame, contains many new computer technologies previously never used in deep-space systems. They include: advanced 3D packaging architecture for future low-mass and low-volume avionics systems; high-density 3D packaged chip-stacks for both volatile and non-volatile mass memory: 400 Mbytes of local DRAM memory, and 128 Mbytes of Flash memory; high-bandwidth Peripheral Component Interface (Per) local-bus with a bridge to VME; high-bandwidth (20 Mbps) fiber-optic serial bus; and other attributes, such as standard support for Design for Testability (DFT). Even though this computer system did not complete on time for delivery to the DS1 project, it was an important development along a technology roadmap towards highly integrated and highly miniaturized avionics systems for deep-space applications. This continued technology development is now being performed by NASA's Deep Space System Development Program (also known as X2000) and within JPL's Center for Integrated Space Microsystems (CISM).

Library API for Z-Order Memory Layout

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bethel, E. Wes

This library provides a simple-to-use API for implementing an altnerative to traditional row-major order in-memory layout, one based on a Morton- order space filling curve (SFC) , specifically, a Z-order variant of the Morton order curve. The library enables programmers to, after a simple initialization step, to convert a multidimensional array from row-major to Z- order layouts, then use a single, generic API call to access data from any arbitrary (i,j,k) location from within the array, whether it it be stored in row- major or z-order format. The motivation for using a SFC in-memory layout is for improved spatial locality,more » which results in increased use of local high speed cache memory. The basic idea is that with row-major order layouts, a data access to some location that is nearby in index space is likely far away in physical memory, resulting in poor spatial locality and slow runtime. On the other hand, with a SFC-based layout, accesses that are nearby in index space are much more likely to also be nearby in physical memory, resulting in much better spatial locality, and better runtime performance. Numerous studies over the years have shown significant runtime performance gains are realized by using a SFC-based memory layout compared to a row-major layout, sometimes by as much as 50%, which result from the better use of the memory and cache hierarchy that are attendant with a SFC-based layout (see, for example, [Beth2012]). This library implementation is intended for use with codes that work with structured, array-based data in 2 or 3 dimensions. It is not appropriate for use with unstructured or point-based data.« less

Nonlinear reflection and refraction of ultrashort light pulses at the surfaces of resonant media and phase memory effects

NASA Astrophysics Data System (ADS)

Vlasov, R. A.; Gadomskii, O. H.; Gadomskaia, I. V.; Samartsev, V. V.

1986-06-01

The method of integrodifferential equations related to the optical Bloch equations is used to study the nonlinear reflection (or refraction) of a scanning laser beam at the surface of a resonant medium excited by traveling and standing surface electromagnetic waves at resonant frequency. The effect of the phase memory of surface atoms on the pulsed action of fields with space-time resolution is taken into account. The reversal of the scanning beam from the excited surface with phase conjugation of the wave front is considered. In addition, the spectrum of the nonlinear surface polaritons is analyzed as a function of the area of the exciting pulse and the penetration depth of polaritons in the resonant optical medium.

[Application of spaced retrieval training on patients with dementia].

PubMed

Wu, Hua-Shan; Lin, Li-Chan

2012-10-01

Dementia causes semantic and episodic memory impairments that limit patients' activities of daily living (ADL) and increase caregiver burden. Spaced retrieval training uses repetitive retrieval to strengthen cognitive and motor skills intuitively in mild / moderate dementia patients who retain preserved implicit / non-declarative memory. This article describes and discusses the operative mechanism, influencing variables, and practical applications of spaced retrieval training. We hope this article increases professional understanding and application of this training approach to improve dementia patient ADL and improve quality of life for both caregivers and patients.

Results from On-Orbit Testing of the Fram Memory Test Experiment on the Fastsat Micro-Satellite

NASA Technical Reports Server (NTRS)

MacLeod, Todd C.; Sims, W. Herb; Varnavas, Kosta A.; Ho, Fat D.

2011-01-01

NASA is planning on going beyond Low Earth orbit with manned exploration missions. The radiation environment for most Low Earth orbit missions is harsher than at the Earth's surface but much less harsh than deep space. Development of new electronics is needed to meet the requirements of high performance, radiation tolerance, and reliability. The need for both Volatile and Non-volatile memory has been identified. Emerging Non-volatile memory technologies (FRAM, C-RAM,M-RAM, R-RAM, Radiation Tolerant FLASH, SONOS, etc.) need to be investigated for use in Space missions. An opportunity arose to fly a small memory experiment on a high inclination satellite (FASTSAT). An off-the-shelf 512K Ramtron FRAM was chosen to be tested in the experiment.

Aerial view of the Kennedy Space Center Visitor Center

NASA Technical Reports Server (NTRS)

1998-01-01

The Kennedy Space Center Visitor Complex, shown in this aerial view looking south, sprawls across 70 acres on Florida's Space Coast. It is located off State Road 405, NASA Parkway, six miles inside the Space Center entrance. SR 405 can be seen at the bottom of the photo. Just above the roadway, from left, can be seen the Shuttle/Gantry mockup, the Post Show Dome, the Astronaut Memorial, and to the far right, the Center for Space Education. Behind the Memorial are a cluster of buildings that include the Theater Complex, Cafeteria, Space Flight Exhibit Building, Souvenir Sales Building, Spaceport Central, and Ticket Pavilion. At the upper right of the site is a display of rockets that have played a significant role in the growth of the space program. Parking lots span the width of the complex on the south side.

Annual Conference on Nuclear and Space Radiation Effects, 15th, University of New Mexico, Albuquerque, N. Mex., July 18-21, 1978, Proceedings

NASA Technical Reports Server (NTRS)

Simons, M.

1978-01-01

Radiation effects in MOS devices and circuits are considered along with radiation effects in materials, space radiation effects and spacecraft charging, SGEMP, IEMP, EMP, fabrication of radiation-hardened devices, radiation effects in bipolar devices and circuits, simulation, energy deposition, and dosimetry. Attention is given to the rapid anneal of radiation-induced silicon-sapphire interface charge trapping, cosmic ray induced errors in MOS memory cells, a simple model for predicting radiation effects in MOS devices, the response of MNOS capacitors to ionizing radiation at 80 K, trapping effects in irradiated and avalanche-injected MOS capacitors, inelastic interactions of electrons with polystyrene, the photoelectron spectral yields generated by monochromatic soft X radiation, and electron transport in reactor materials.

Towards a Theory of Learning for Naming Rehabilitation: Retrieval Practice and Spacing Effects

ERIC Educational Resources Information Center

Middleton, Erica L.; Schwarts, Myrna F.; Rawson, Katherine A.; Traut, Hilary; Verkuilen, Jay

2016-01-01

Purpose: The purpose of this article was to examine how different types of learning experiences affect naming impairment in aphasia. Methods: In 4 people with aphasia with naming impairment, we compared the benefits of naming treatment that emphasized "retrieval practice" (practice retrieving target names from long-term memory) with…

76 FR 16737 - Notice of Availability of the Draft Environmental Impact Statement for the Proposed South Coast...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-25

..., visual effects, noise, vibration, cultural resources, air quality, open space, farmland, hazardous... is also available to review at the following locations: 1. State Transportation Library of Massachusetts 10 Park Plaza, 2nd Floor, Boston, MA. 2. Russell Memorial Library, 88 Main Street, Acushnet, MA. 3...

The Impact of Verbal Working Memory on Number-Space Associations

ERIC Educational Resources Information Center

Ginsburg, Véronique; van Dijck, Jean-Philippe; Previtali, Paola; Fias, Wim; Gevers, Wim

2014-01-01

Spatial-numerical associations are observed when participants perform number categorization tasks. One such observation is the spatial numerical associations of response codes (SNARC) effect, showing an association between small numbers and the left-hand side and between large numbers and the right-hand side. It has long been argued that this…

Including Memory Friction in Single- and Two-State Quantum Dynamics Simulations.

PubMed

Brown, Paul A; Messina, Michael

2016-03-03

We present a simple computational algorithm that allows for the inclusion of memory friction in a quantum dynamics simulation of a small, quantum, primary system coupled to many atoms in the surroundings. We show how including a memory friction operator, F̂, in the primary quantum system's Hamiltonian operator builds memory friction into the dynamics of the primary quantum system. We show that, in the harmonic, semi-classical limit, this friction operator causes the classical phase-space centers of a wavepacket to evolve exactly as if it were a classical particle experiencing memory friction. We also show that this friction operator can be used to include memory friction in the quantum dynamics of an anharmonic primary system. We then generalize the algorithm so that it can be used to treat a primary quantum system that is evolving, non-adiabatically on two coupled potential energy surfaces, i.e., a model that can be used to model H atom transfer, for example. We demonstrate this approach's computational ease and flexibility by showing numerical results for both harmonic and anharmonic primary quantum systems in the single surface case. Finally, we present numerical results for a model of non-adiabatic H atom transfer between a reactant and product state that includes memory friction on one or both of the non-adiabatic potential energy surfaces and uncover some interesting dynamical effects of non-memory friction on the H atom transfer process.

"Space Challenge '88" Summit Meeting on Space. Proceedings Report of the National Space Symposium (4th, April 12-15, 1988).

ERIC Educational Resources Information Center

Kinsley, Allison P., Ed.; And Others

Forum topics included discussions on: (1) "Provocative Perceptions: Space Achievement and Challenge"; (2) "International Cooperation and Competition"; (3) "International Space Programs"; (4) "Astronauts Memorial Foundation"; (5) "Prospects for U.S. Commerical Space Transportation"; (6)…

Asymmetric Spatial Processing Under Cognitive Load

PubMed Central

Naert, Lien; Bonato, Mario; Fias, Wim

2018-01-01

Spatial attention allows us to selectively process information within a certain location in space. Despite the vast literature on spatial attention, the effect of cognitive load on spatial processing is still not fully understood. In this study we added cognitive load to a spatial processing task, so as to see whether it would differentially impact upon the processing of visual information in the left versus the right hemispace. The main paradigm consisted of a detection task that was performed during the maintenance interval of a verbal working memory task. We found that increasing cognitive working memory load had a more negative impact on detecting targets presented on the left side compared to those on the right side. The strength of the load effect correlated with the strength of the interaction on an individual level. The implications of an asymmetric attentional bias with a relative disadvantage for the left (vs the right) hemispace under high verbal working memory (WM) load are discussed. PMID:29740371

[Effects of chrysalis oil on learning, memory and oxidative stress in D-galactose-induced ageing model of mice].

PubMed

Chen, Weiping; Yang, Qiongjie; Wei, Xing

2013-11-01

To investigate the effects of chrysalis oil on learning, memory and oxidative stress in D-galactose-induced ageing model of mice. Mice were injected intraperitoneally with D-galactose daily and received chrysalis oil intragastrically simultaneously for 30 d. Then mice underwent space navigation test and spatial probe test, superoxide dismutase (SOD), glutathione peroxidase (GSH-PX) activity and malondialdehyde (MDA) contents in mouse brain were measured. Compared to model group, escape latency in mice treated with 6 ml/kg*d chrysalis oil was significantly shorter (P<0.05), crossing times in 12 ml/kg*d group and 6 ml/kg*d group treated with chrysalis oil were significantly increased (P<0.05). Chrysalis oil treatment (12ml/kg*d) significantly increased SOD and GSH-PX activity and reduced MDA contents in brain of D-galactose-induced aging mice. Chrysalis oil can improve the ability of learning and memory in D-galactose-induced aging mice, and inhibit peroxidation in brain tissue.

Memory access in shared virtual memory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berrendorf, R.

1992-01-01

Shared virtual memory (SVM) is a virtual memory layer with a single address space on top of a distributed real memory on parallel computers. We examine the behavior and performance of SVM running a parallel program with medium-grained, loop-level parallelism on top of it. A simulator for the underlying parallel architecture can be used to examine the behavior of SVM more deeply. The influence of several parameters, such as the number of processors, page size, cold or warm start, and restricted page replication, is studied.

Memory access in shared virtual memory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berrendorf, R.

1992-09-01

Shared virtual memory (SVM) is a virtual memory layer with a single address space on top of a distributed real memory on parallel computers. We examine the behavior and performance of SVM running a parallel program with medium-grained, loop-level parallelism on top of it. A simulator for the underlying parallel architecture can be used to examine the behavior of SVM more deeply. The influence of several parameters, such as the number of processors, page size, cold or warm start, and restricted page replication, is studied.

Rambrain - a library for virtually extending physical memory

NASA Astrophysics Data System (ADS)

Imgrund, Maximilian; Arth, Alexander

2017-08-01

We introduce Rambrain, a user space library that manages memory consumption of your code. Using Rambrain you can overcommit memory over the size of physical memory present in the system. Rambrain takes care of temporarily swapping out data to disk and can handle multiples of the physical memory size present. Rambrain is thread-safe, OpenMP and MPI compatible and supports Asynchronous IO. The library was designed to require minimal changes to existing programs and to be easy to use.

KSC-04PD-0121

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Astronaut John Herrington speaks to the visitors at the memorial service held at the Space Memorial Mirror for the crew of Columbia. Herrington, who is a Chickasaw from Oklahoma, introduced the Shoshone-Bannock Junior-Senior High School dancers, from the Native American community at Fort Hall, Idaho, who performed a healing ceremony. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

KSC-04PD-0124

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. Astronaut John Herrington (right) holds part of a flag presented by dancers from the Shoshone- Bannock Junior-Senior High School, Fort Hall, Idaho, commemorating the orbiter Columbia and her crew. The dancers performed a healing ceremony during the memorial service held at the Space Memorial Mirror for the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

BAE Systems Radiation Hardened SpaceWire ASIC and Roadmap

NASA Technical Reports Server (NTRS)

Berger, Richard; Milliser, Myrna; Kapcio, Paul; Stanley, Dan; Moser, David; Koehler, Jennifer; Rakow, Glenn; Schnurr, Richard

2006-01-01

An Application Specific Integrated Circuit (ASIC) that implements the SpaceWire protocol has been developed in a radiation hardened 0.25 micron CMOS, technology. This effort began in March 2003 as a joint development between the NASA Goddard Space Flight Center (GSFC) and BAE Systems. The BAE Systems SpaceWire ASlC is comprised entirely of reusable core elements, many of which are already flight-proven. It incorporates a 4-port SpaceWire router with two local ports, dual PC1 bus interfaces, a microcontroller, 32KB of internal memory, -and a memory controller for additional external memory use. The SpaceWire ASlC is planned for use on both the Geostationary Operational Environmental Satellites (GOES)-R and the Lunar Reconnaissance Orbiter (LRO). Engineering parts have already been delivered to both programs. This paper discusses the SpaceWire protocol and those elements of it that have been built into the current SpaceWire reusable core. There are features within the core that go beyond the current standard that can be enabled or disabled by the user and these will be described. The adaptation of SpaceWire to BAE Systems' On Chip Bus (OCB) for compatibility with the other reusable cores will be discussed. Optional configurations within user systems will be shown. The physical imp!ementation of the design will be described and test results from the hardware will be discussed. Finally, the BAE Systems roadmap for SpaceWire developments will be discussed, including some products already in design as well as longer term plans.

Recognition Memory for Realistic Synthetic Faces

PubMed Central

Yotsumoto, Yuko; Kahana, Michael J.; Wilson, Hugh R.; Sekuler, Robert

2006-01-01

A series of experiments examined short-term recognition memory for trios of briefly-presented, synthetic human faces derived from three real human faces. The stimuli were graded series of faces, which differed by varying known amounts from the face of the average female. Faces based on each of the three real faces were transformed so as to lie along orthogonal axes in a 3-D face space. Experiment 1 showed that the synthetic faces' perceptual similarity stucture strongly influenced recognition memory. Results were fit by NEMo, a noisy exemplar model of perceptual recognition memory. The fits revealed that recognition memory was influenced both by the similarity of the probe to series items, and by the similarities among the series items themselves. Non-metric multi-dimensional scaling (MDS) showed that faces' perceptual representations largely preserved the 3-D space in which the face stimuli were arrayed. NEMo gave a better account of the results when similarity was defined as perceptual, MDS similarity rather than physical proximity of one face to another. Experiment 2 confirmed the importance of within-list homogeneity directly, without mediation of a model. We discuss the affinities and differences between visual memory for synthetic faces and memory for simpler stimuli. PMID:17948069

GPU color space conversion

NASA Astrophysics Data System (ADS)

Chase, Patrick; Vondran, Gary

2011-01-01

Tetrahedral interpolation is commonly used to implement continuous color space conversions from sparse 3D and 4D lookup tables. We investigate the implementation and optimization of tetrahedral interpolation algorithms for GPUs, and compare to the best known CPU implementations as well as to a well known GPU-based trilinear implementation. We show that a 500 NVIDIA GTX-580 GPU is 3x faster than a 1000 Intel Core i7 980X CPU for 3D interpolation, and 9x faster for 4D interpolation. Performance-relevant GPU attributes are explored including thread scheduling, local memory characteristics, global memory hierarchy, and cache behaviors. We consider existing tetrahedral interpolation algorithms and tune based on the structure and branching capabilities of current GPUs. Global memory performance is improved by reordering and expanding the lookup table to ensure optimal access behaviors. Per multiprocessor local memory is exploited to implement optimally coalesced global memory accesses, and local memory addressing is optimized to minimize bank conflicts. We explore the impacts of lookup table density upon computation and memory access costs. Also presented are CPU-based 3D and 4D interpolators, using SSE vector operations that are faster than any previously published solution.

Institutional Memory and the US Air Force

DTIC Science & Technology

2016-01-01

38 | Air & Space Power Journal Institutional Memory and the US Air Force Lt Col Daniel J. Brown, USAF Disclaimer: The views and opinions expressed...national defense. After each ad- vance is tested in combat, a new round of intellectual sparring commences regarding Summer 2016 | 39 Institutional Memory ...the service’s institutional memory of how it fights and what it fights with—the ways and means of war fighting. Critical to maintaining its

Configurable test bed design for nanosats to qualify commercial and customized integrated circuits

NASA Astrophysics Data System (ADS)

Guareschi, W.; Azambuja, J.; Kastensmidt, F.; Reis, R.; Durao, O.; Schuch, N.; Dessbesel, G.

The use of small satellites has increased substantially in recent years due to the reduced cost of their development and launch, as well to the flexibility offered by commercial components. The test bed is a platform that allows components to be evaluated and tested in space. It is a flexible platform, which can be adjusted to a wide quantity of components and interfaces. This work proposes the design and implementation of a test bed suitable for test and evaluation of commercial circuits used in nanosatellites. The development of such a platform allows developers to reduce the efforts in the integration of components and therefore speed up the overall system development time. The proposed test bed is a configurable platform implemented using a Field Programmable Gate Array (FPGA) that controls the communication protocols and connections to the devices under test. The Flash-based ProASIC3E FPGA from Microsemi is used as a control system. This adaptive system enables the control of new payloads and softcores for test and validation in space. Thus, the integration can be easily performed through configuration parameters. It is intended for modularity. Each component connected to the test bed can have a specific interface programmed using a hardware description language (HDL). The data of each component is stored in embedded memories. Each component has its own memory space. The size of the allocated memory can be also configured. The data transfer priority can be set and packaging can be added to the logic, when needed. Communication with peripheral devices and with the Onboard Computer (OBC) is done through the pre-implemented protocols, such as I2C (Inter-Integrated Circuit), SPI (Serial Peripheral Interface) and external memory control. In loco primary tests demonstrated the control system's functionality. The commercial ProASIC3E FPGA family is not space-flight qualified, but tests have been made under Total Ionizing Dose (TID) showing its robustness up to 25 kr- ds (Si). When considering proton and heavy ions, flash-based FPGAs provide immunity to configuration loss and low bit-flips susceptibility in flash memory. In this first version of the test bed two components are connected to the controller FPGA: a commercial magnetometer and a hardened test chip. The embedded FPGA implements a Single Event Effects (SEE) hardened microprocessor and few other soft-cores to be used in space. This test bed will be used in the NanoSatC-BR1, the first Brazilian Cubesat scheduled to be launched in mid-2013.

Cost-effective, transfer-free, flexible resistive random access memory using laser-scribed reduced graphene oxide patterning technology.

PubMed

Tian, He; Chen, Hong-Yu; Ren, Tian-Ling; Li, Cheng; Xue, Qing-Tang; Mohammad, Mohammad Ali; Wu, Can; Yang, Yi; Wong, H-S Philip

2014-06-11

Laser scribing is an attractive reduced graphene oxide (rGO) growth and patterning technology because the process is low-cost, time-efficient, transfer-free, and flexible. Various laser-scribed rGO (LSG) components such as capacitors, gas sensors, and strain sensors have been demonstrated. However, obstacles remain toward practical application of the technology where all the components of a system are fabricated using laser scribing. Memory components, if developed, will substantially broaden the application space of low-cost, flexible electronic systems. For the first time, a low-cost approach to fabricate resistive random access memory (ReRAM) using laser-scribed rGO as the bottom electrode is experimentally demonstrated. The one-step laser scribing technology allows transfer-free rGO synthesis directly on flexible substrates or non-flat substrates. Using this time-efficient laser-scribing technology, the patterning of a memory-array area up to 100 cm(2) can be completed in 25 min. Without requiring the photoresist coating for lithography, the surface of patterned rGO remains as clean as its pristine state. Ag/HfOx/LSG ReRAM using laser-scribing technology is fabricated in this work. Comprehensive electrical characteristics are presented including forming-free behavior, stable switching, reasonable reliability performance and potential for 2-bit storage per memory cell. The results suggest that laser-scribing technology can potentially produce more cost-effective and time-effective rGO-based circuits and systems for practical applications.

Functional Performances of CuZnAl Shape Memory Alloy Open-Cell Foams

NASA Astrophysics Data System (ADS)

Biffi, C. A.; Casati, R.; Bassani, P.; Tuissi, A.

2018-01-01

Shape memory alloys (SMAs) with cellular structure offer a unique mixture of thermo-physical-mechanical properties. These characteristics can be tuned by changing the pore size and make the shape memory metallic foams very attractive for developing new devices for structural and functional applications. In this work, CuZnAl SMA foams were produced through the liquid infiltration of space holder method. In comparison, a conventional CuZn brass alloy was foamed trough the same method. Functional performances were studied on both bulk and foamed SMA specimens. Calorimetric response shows similar martensitic transformation (MT) below 0 °C. Compressive response of CuZnAl revealed that mechanical behavior is strongly affected by sample morphology and that damping capacity of metallic foam is increased above the MT temperatures. The shape memory effect was detected in the CuZnAl foams. The conventional brass shows a compressive response similar to that of the martensitic CuZnAl, in which plastic deformation accumulation occurs up to the cellular structure densification after few thermal cycles.

Effect of oxide insertion layer on resistance switching properties of copper phthalocyanine

NASA Astrophysics Data System (ADS)

Joshi, Nikhil G.; Pandya, Nirav C.; Joshi, U. S.

2013-02-01

Organic memory device showing resistance switching properties is a next-generation of the electrical memory unit. We have investigated the bistable resistance switching in current-voltage (I-V) characteristics of organic diode based on copper phthalocyanine (CuPc) film sandwiched between aluminum (Al) electrodes. Pronounced hysteresis in the I-V curves revealed a resistance switching with on-off ratio of the order of 85%. In order to control the charge injection in the CuPc, nanoscale indium oxide buffer layer was inserted to form Al/CuPc/In2O3/Al device. Analysis of I-V measurements revealed space charge limited switching conduction at the Al/CuPc interface. The traps in the organic layer and charge blocking by oxide insertion layer have been used to explain the absence of resistance switching in the oxide buffer layered memory device cell. Present study offer potential applications for CuPc organic semiconductor in low power non volatile resistive switching memory and logic circuits.

What Is It Like to Be a Child? Childhood Subjectivity and Teacher Memories as Heterotopia

ERIC Educational Resources Information Center

Chang-Kredl, Sandra; Wilkie, Gala

2016-01-01

Foucault's notion of heterotopia offers a novel way to understand teachers' conceptualizations of childhood, in juxtaposing adult memories of childhood with their present context of teaching children. Memory writing prompts were given to 41 early childhood teachers, and the resulting written narratives were analyzed as heterotopic spaces. The…

Semantic Memory and Verbal Working Memory Correlates of N400 to Subordinate Homographs

ERIC Educational Resources Information Center

Salisbury, Dean F.

2004-01-01

N400 is an event-related brain potential that indexes operations in semantic memory conceptual space, whether elicited by language or some other representation (e.g., drawings). Language models typically propose three stages: lexical access or orthographic- and phonological-level analysis; lexical selection or word-level meaning and associate…

Accessibility versus Accuracy in Retrieving Spatial Memory: Evidence for Suboptimal Assumed Headings

ERIC Educational Resources Information Center

Yerramsetti, Ashok; Marchette, Steven A.; Shelton, Amy L.

2013-01-01

Orientation dependence in spatial memory has often been interpreted in terms of accessibility: Object locations are encoded relative to a reference orientation that affords the most accurate access to spatial memory. An open question, however, is whether people naturally use this "preferred" orientation whenever recalling the space. We…

Remembering "A Great Fag": Visualizing Public Memory and the Construction of Queer Space

ERIC Educational Resources Information Center

Dunn, Thomas R.

2011-01-01

This essay examines how public memory is visualized in the statue to Canada's "gay pioneer," Alexander Wood. By analyzing three viewing positions of the statue--the official democratic memory, traditionalist countermemory, and camp countermemory--I argue each position enacts a distinct form of remembering Wood with implications for both…

Optical Associative Processors For Visual Perception"

NASA Astrophysics Data System (ADS)

Casasent, David; Telfer, Brian

1988-05-01

We consider various associative processor modifications required to allow these systems to be used for visual perception, scene analysis, and object recognition. For these applications, decisions on the class of the objects present in the input image are required and thus heteroassociative memories are necessary (rather than the autoassociative memories that have been given most attention). We analyze the performance of both associative processors and note that there is considerable difference between heteroassociative and autoassociative memories. We describe associative processors suitable for realizing functions such as: distortion invariance (using linear discriminant function memory synthesis techniques), noise and image processing performance (using autoassociative memories in cascade with with a heteroassociative processor and with a finite number of autoassociative memory iterations employed), shift invariance (achieved through the use of associative processors operating on feature space data), and the analysis of multiple objects in high noise (which is achieved using associative processing of the output from symbolic correlators). We detail and provide initial demonstrations of the use of associative processors operating on iconic, feature space and symbolic data, as well as adaptive associative processors.

Major Robert Lawrence Memorial Tribute

NASA Image and Video Library

2017-12-08

During an Astronauts Memorial Foundation tribute honoring U.S. Air Foce Maj. Robert Lawrence, vocalist Marva King sings with the Winston Scott “Cosmic Jazz Ensemble.” Selected in 1967 for the Manned Orbiting Laboratory Program, Lawrence was the first African-American astronaut. He lost his life in a training accident 50 years ago. The ceremony took place in the Center for Space Education at the Kennedy Space Center Visitor Complex.

2017 A Day of Remembrance

NASA Image and Video Library

2017-01-26

Following the Kennedy Space Center's NASA Day of Remembrance ceremony, Family members of fallen astronauts placed a wreath at the Space Mirror Memorial. From the left, are Kathie Scobee Flugham, daughter of 51-L Challenger astronaut Dick Scobee, June Scobee Rodgers, Scobee's widow and State Rep. Thad Altman, president and chief executive officer of the Astronauts Memorial Foundation. They are standing in front of the memorial includes the names of the fallen astronauts from Apollo 1, Challenger and Columbia, as well as the astronauts who perished in training and commercial airplane accidents are emblazoned on the monument's 45-foot-high-by-50-foot-wide polished black granite surface.

Attitudes and learning difficulties in middle school science in South Korea

NASA Astrophysics Data System (ADS)

Jung, Eun Sook

The purpose of this study is to investigate the relationship between cognitive and attitudinal aspects of learning science, concentrating mainly on the influence of cognitive understanding and learning difficulty on attitudes to science. This theme is selected, in particular, because it is reported that Korean students at secondary level do not enjoy studying science and have not enough confidence, although their achievements are high. Johnstone's information processing model (1993) is used to account for cognitive aspects of science education. Learning processes are understood in terms of student's own knowledge construction through the operation of perception filters, processing in working memory space and storing in long term memory. In particular, the overload of student's working memory space is considered as the main factor causing learning difficulty and, in consequence, learning failure. The research took place in one middle school located in Seoul, the capital city in South Korea. 364 students aged 13 and 350 aged 15 participated. In order to try to find relationships between cognitive and affective factors of science learning, individual student's working memory space was measured and a questionnaire designed to gather information about students' attitudes was prepared and given to all students. To determine the working memory space capacity of the students, the Figural Intersection Test (F.I.T), designed by Pascual-Leone, was used. Two kinds of analysis, comparison and correlation, were performed with data from the Figural Intersection Test and the questionnaire applied to students. For the comparison of attitudes between age 13 and 15, the distributions of frequencies of responses were analyzed for each particular statement in a question. The Chi-square (?[2]) test was applied to judge the statistically significant differences in responses of the two groups. The levels of significance used were 0.05, 0.01 and 0.001. In order to see whether there is difference of opinions related to various aspects of learning science between age 13 and 15, and between high and middle and low working memory capacity groups, students responses were compared by just looking at the distribution of percentages without doing more statistics. Correlation coefficients were calculated to see if student's working memory capacity is linked with attitudes. As a result of data analyses from the working memory test and the questionnaire, it is seen that working memory space is related to some student attitudes towards science and their way of studying. Compared to students with high working memory capacity, students who have low working memory capacity are likely to lose their interest in science, feel science is difficult, and have low confidence about studying science. In addition, they tend to depend on memorization when they study science, consider science as a future career less, and are less motivated to study science by attitudinal factors such as "I really enjoy studying science", "Science is useful in my life". This exploratory study has suggested some important issues which need addressed in developing positive attitudes as well as encouraging meaningful learning.

The ninth Dr. Albert Plesman memorial lecture: The Future of Space Flight

NASA Technical Reports Server (NTRS)

Moore, J. W.

1984-01-01

The history of space flight is reviewed and major NASA programs (Mercury, Gemini, Apollo, Skylab, Apollo-Soyuz, Science and Applications, Space Shuttle, Space Station) are summarized. Developments into the early 21st century are predicted.

A simple modern correctness condition for a space-based high-performance multiprocessor

NASA Technical Reports Server (NTRS)

Probst, David K.; Li, Hon F.

1992-01-01

A number of U.S. national programs, including space-based detection of ballistic missile launches, envisage putting significant computing power into space. Given sufficient progress in low-power VLSI, multichip-module packaging and liquid-cooling technologies, we will see design of high-performance multiprocessors for individual satellites. In very high speed implementations, performance depends critically on tolerating large latencies in interprocessor communication; without latency tolerance, performance is limited by the vastly differing time scales in processor and data-memory modules, including interconnect times. The modern approach to tolerating remote-communication cost in scalable, shared-memory multiprocessors is to use a multithreaded architecture, and alter the semantics of shared memory slightly, at the price of forcing the programmer either to reason about program correctness in a relaxed consistency model or to agree to program in a constrained style. The literature on multiprocessor correctness conditions has become increasingly complex, and sometimes confusing, which may hinder its practical application. We propose a simple modern correctness condition for a high-performance, shared-memory multiprocessor; the correctness condition is based on a simple interface between the multiprocessor architecture and a high-performance, shared-memory multiprocessor; the correctness condition is based on a simple interface between the multiprocessor architecture and the parallel programming system.

KENNEDY SPACE CENTER, FLA. -- Family members of the STS-107 astronauts and other dignitaries watch NASA T-38 jets fly over the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in a Missing Man Formation. During this dedication ceremony, the names of the STS-107 astronauts who lost their lives during the Columbia accident -- Rick Husband, Willie McCool, Laurel Clark, Michael Anderson, David Brown, Kalpana Chawla, and Ilan Ramon -- join the names of 17 other space heroes who gave their lives for the U.S. space program.

NASA Image and Video Library

2003-10-28

KENNEDY SPACE CENTER, FLA. -- Family members of the STS-107 astronauts and other dignitaries watch NASA T-38 jets fly over the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in a Missing Man Formation. During this dedication ceremony, the names of the STS-107 astronauts who lost their lives during the Columbia accident -- Rick Husband, Willie McCool, Laurel Clark, Michael Anderson, David Brown, Kalpana Chawla, and Ilan Ramon -- join the names of 17 other space heroes who gave their lives for the U.S. space program.

Radiation Hardened DDR2 SDRAM Solution

NASA Astrophysics Data System (ADS)

Wang, Pierre-Xiao; Sellier, Charles

2016-08-01

The Radiation Hardened (RH) DDR2 SDRAM Solution is a User's Friendly, Plug-and-Play and Radiation Hardened DDR2 solution, which includes the radiation tolerant stacking DDR2 modules and a radiation intelligent memory controller (RIMC) IP core. It provides a high speed radiation hardened by design DRAM solution suitable for all space applications such as commercial or scientific geo-stationary missions, earth observation, navigation, manned space vehicles and deep space scientific exploration. The DDR2 module has been guaranteed with SEL immune and TID > 100Krad(Si), on the other hand the RIMC IP core provides a full protection against the DDR2 radiation effects such as SEFI and SEU.

Immunological memory is associative

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, D.J.; Forrest, S.; Perelson, A.S.

1996-12-31

The purpose of this paper is to show that immunological memory is an associative and robust memory that belongs to the class of sparse distributed memories. This class of memories derives its associative and robust nature by sparsely sampling the input space and distributing the data among many independent agents. Other members of this class include a model of the cerebellar cortex and Sparse Distributed Memory (SDM). First we present a simplified account of the immune response and immunological memory. Next we present SDM, and then we show the correlations between immunological memory and SDM. Finally, we show how associativemore » recall in the immune response can be both beneficial and detrimental to the fitness of an individual.« less

Analysis of space radiation data of semiconductor memories

NASA Technical Reports Server (NTRS)

Stassinopoulos, E. G.; Brucker, G. J.; Stauffer, C. A.

1996-01-01

This article presents an analysis of radiation effects for several select device types and technologies aboard the Combined Release and Radiation Effects Satellite (CRRES) satellite. These space-flight measurements covered a period of about 14 months of mission lifetime. Single Event Upset (SEU) data of the investigated devices from the Microelectronics Package (MEP) were processed and analyzed. Valid upset measurements were determined by correcting for invalid readings, hard failures, missing data tapes (thus voids in data), and periods over which devices were disabled from interrogation. The basic resolution time of the measurement system was confirmed to be 2 s. Lessons learned, important findings, and recommendations are presented.

Radiation and Reliability Concerns for Modern Nonvolatile Memory Technology

NASA Technical Reports Server (NTRS)

Oldham, Timothy R.; Friendlich, Mark R.; Kim, Hak S.; Berg, Melanie D.; LaBel, Kenneth A.; Buchner, S. P.; McMorrow, D.; Mavis, D. G.; Eaton, P. H.; Castillo, J.

2011-01-01

Commercial nonvolatile memory technology is attractive for space applications, but radiation issues are serious concerns. In addition, we discuss combined radiation/reliability concerns which are only beginning to be addressed.

Distributed Saturation

NASA Technical Reports Server (NTRS)

Chung, Ming-Ying; Ciardo, Gianfranco; Siminiceanu, Radu I.

2007-01-01

The Saturation algorithm for symbolic state-space generation, has been a recent break-through in the exhaustive veri cation of complex systems, in particular globally-asyn- chronous/locally-synchronous systems. The algorithm uses a very compact Multiway Decision Diagram (MDD) encoding for states and the fastest symbolic exploration algo- rithm to date. The distributed version of Saturation uses the overall memory available on a network of workstations (NOW) to efficiently spread the memory load during the highly irregular exploration. A crucial factor in limiting the memory consumption during the symbolic state-space generation is the ability to perform garbage collection to free up the memory occupied by dead nodes. However, garbage collection over a NOW requires a nontrivial communication overhead. In addition, operation cache policies become critical while analyzing large-scale systems using the symbolic approach. In this technical report, we develop a garbage collection scheme and several operation cache policies to help on solving extremely complex systems. Experiments show that our schemes improve the performance of the original distributed implementation, SmArTNow, in terms of time and memory efficiency.

Fault-tolerant NAND-flash memory module for next-generation scientific instruments

NASA Astrophysics Data System (ADS)

Lange, Tobias; Michel, Holger; Fiethe, Björn; Michalik, Harald; Walter, Dietmar

2015-10-01

Remote sensing instruments on today's space missions deliver a high amount of data which is typically evaluated on ground. Especially for deep space missions the telemetry downlink is very limited which creates the need for the scientific evaluation and thereby a reduction of data volume already on-board the spacecraft. A demanding example is the Polarimetric and Helioseismic Imager (PHI) instrument on Solar Orbiter. To enable on-board offline processing for data reduction, the instrument has to be equipped with a high capacity memory module. The module is based on non-volatile NAND-Flash technology, which requires more advanced operation than volatile DRAM. Unlike classical mass memories, the module is integrated into the instrument and allows readback of data for processing. The architecture and safe operation of such kind of memory module is described in the following paper.

MSuPDA: A Memory Efficient Algorithm for Sequence Alignment.

PubMed

Khan, Mohammad Ibrahim; Kamal, Md Sarwar; Chowdhury, Linkon

2016-03-01

Space complexity is a million dollar question in DNA sequence alignments. In this regard, memory saving under pushdown automata can help to reduce the occupied spaces in computer memory. Our proposed process is that anchor seed (AS) will be selected from given data set of nucleotide base pairs for local sequence alignment. Quick splitting techniques will separate the AS from all the DNA genome segments. Selected AS will be placed to pushdown automata's (PDA) input unit. Whole DNA genome segments will be placed into PDA's stack. AS from input unit will be matched with the DNA genome segments from stack of PDA. Match, mismatch and indel of nucleotides will be popped from the stack under the control unit of pushdown automata. During the POP operation on stack, it will free the memory cell occupied by the nucleotide base pair.

"Just another pretty face": a multidimensional scaling approach to face attractiveness and variability.

PubMed

Potter, Timothy; Corneille, Olivier; Ruys, Kirsten I; Rhodes, Ginwan

2007-04-01

Findings on both attractiveness and memory for faces suggest that people should perceive more similarity among attractive than among unattractive faces. A multidimensional scaling approach was used to test this hypothesis in two studies. In Study 1, we derived a psychological face space from similarity ratings of attractive and unattractive Caucasian female faces. In Study 2, we derived a face space for attractive and unattractive male faces of Caucasians and non-Caucasians. Both studies confirm that attractive faces are indeed more tightly clustered than unattractive faces in people's psychological face spaces. These studies provide direct and original support for theoretical assumptions previously made in the face space and face memory literatures.

KSC-98PC-1058

NASA Image and Video Library

1998-08-06

The Kennedy Space Center Visitor Complex, shown in this aerial view looking south, sprawls across 70 acres on Florida's Space Coast. It is located off State Road 405, NASA Parkway, six miles inside the Space Center entrance. SR 405 can be seen at the bottom of the photo. Just above the roadway, from left, can be seen the Shuttle/Gantry mockup, the Post Show Dome, the Astronaut Memorial, and to the far right, the Center for Space Education. Behind the Memorial are a cluster of buildings that include the Theater Complex, Cafeteria, Space Flight Exhibit Building, Souvenir Sales Building, Spaceport Central, and Ticket Pavilion. At the upper right of the site is a display of rockets that have played a significant role in the growth of the space program. Parking lots span the width of the complex on the south side.

Feasibility of Shape-Memory Ni/Ti Alloy Wire Containing Tube Elevators for Transcrestal Detaching Maxillary Sinus Mucosa: Ex Vivo Study.

PubMed

Li, Yanfeng; Wang, Fuli; Hu, Pin; Fan, Jiadong; Han, Yishi; Liu, Bin; Liu, Tao; Yang, Chunhao; Gu, Xiangmin

2016-01-01

Osteotome sinus floor elevation is a less invasive approach to augment an insufficient alveolar bone at the posterior maxilla for dental implantation. However, this approach has some limitations due to the lack of sinus lift tools available for clinical use and the small transcrestal access to the maxillary sinus floor. We recently invented shape-memory Ni/Ti alloy wire containing tube elevators for transcrestal detaching maxillary sinus mucosa, and developed goat ex vivo models for direct visualizing the effectiveness of detaching sinus mucosa in real time during transcrestal maxillary sinus floor elevation. We evaluated our invented elevators, namely elevator 012 and elevator 014, for their effectiveness for transcrestal detaching maxillary sinus mucosa using the goat ex vivo models. We measured the length of sinus mucosa detached in mesial and distal directions or buccal and palatal directions, and the space volume created by detaching maxillary sinus mucosa in mesial, distal, buccal and palatal directions using the invented elevators. Elevator 012 had a shape-memory Ni/Ti alloy wire with a diameter of 0.012 inch, while elevator 014 had its shape-memory Ni/Ti alloy wire with a diameter of 0.014 inch. Elevator 012 could detach the goat maxillary sinus mucosa in the mesial or distal direction for 12.1±4.3 mm, while in the buccal or palatal direction for 12.5±6.7 mm. The elevator 014 could detach the goat maxillary sinus mucosa for 23.0±4.9 mm in the mesial or distal direction, and for 19.0±8.1 mm in the buccal or palatal direction. An average space volume of 1.7936±0.2079 ml was created after detaching the goat maxillay sinus mucosa in both mesial/distal direction and buccal/palatal direction using elevator 012; while the average space volume created using elevator 014 was 1.8764±0.2366 ml. Both two newly invented tube elevators could effectively detach the maxillary sinus mucosa on the goat ex vivo sinus models. Moreover, elevator 014 has advantages over the elevator 012 for the capability to detach sinus mucosa. © 2016 The Author(s) Published by S. Karger AG, Basel.

SEU hardened memory cells for a CCSDS Reed Solomon encoder

DOE Office of Scientific and Technical Information (OSTI.GOV)

Whitaker, S.; Canaris, J.; Liu, K.

This paper reports on design technique to harden CMOS memory circuits against Single Event Upset (SEU) in the space environment. The design technique provides a recovery mechanism which is independent of the shape of the upsetting event. A RAM cell and Flip Flop design are presented to demonstrate the method. The Flip Flop was used in the control circuitry for a Reed Solomon encoder designed for the Space Station and Explorer platforms.

Land-markings: 12 Journeys through 9/11 Living Memorials

Treesearch

Erika S. Svendsen; Lindsay K. Campbell

2006-01-01

Living memorials are spaces created, used, or reappropriated by people as they employ the landscape to memorialize individuals, places, and events. Ranging from single tree plantings, to the creation of new parks, to the rededication of existing forests, hundreds of groups across the country created a vast network of sites that continues to grow. "Land-markings:...

Memory Practices in History Education about the 1947 British India Partition: Opportunities and Challenges to Breaching Hegemonic Remembering

ERIC Educational Resources Information Center

Chhabra, Meenakshi

2015-01-01

This article is an epistemological reflection on memory practices in the construction, deconstruction, and reconstruction of collective memories of a historical event involving collective violence and conflict in formal and informal spaces of education. It focuses on the 1947 British India Partition of Punjab. The article engages with multiple…

Keeping Timbre in Mind: Working Memory for Complex Sounds that Can't Be Verbalized

ERIC Educational Resources Information Center

Golubock, Jason L.; Janata, Petr

2013-01-01

Properties of auditory working memory for sounds that lack strong semantic associations and are not readily verbalized or sung are poorly understood. We investigated auditory working memory capacity for lists containing 2-6 easily discriminable abstract sounds synthesized within a constrained timbral space, at delays of 1-6 s (Experiment 1), and…

Living memorials project: year 1 social and site assessment

Treesearch

Erika S. Svendsen; Lindsay K. Campbell

2005-01-01

The Living Memorials Project (LMP) social and site assessment identified more than 200 public open spaces created, used, or enhanced in memory of the tragic events of September 11, 2001 (9-11). A national registry of these sites is available for viewing and updating online. Researchers interviewed 100 community groups using social ecology methods of observation,...

Spatial Working Memory Capacity Predicts Bias in Estimates of Location

ERIC Educational Resources Information Center

Crawford, L. Elizabeth; Landy, David; Salthouse, Timothy A.

2016-01-01

Spatial memory research has attributed systematic bias in location estimates to a combination of a noisy memory trace with a prior structure that people impose on the space. Little is known about intraindividual stability and interindividual variation in these patterns of bias. In the current work, we align recent empirical and theoretical work on…

A Time and Place for Everything: Developmental Differences in the Building Blocks of Episodic Memory

ERIC Educational Resources Information Center

Lee, Joshua K.; Wendelken, Carter; Bunge, Silvia A.; Ghetti, Simona

2016-01-01

This research investigated whether episodic memory development can be explained by improvements in relational binding processes, involved in forming novel associations between events and the context in which they occurred. Memory for item-space, item-time, and item-item relations was assessed in an ethnically diverse sample of 151 children aged…

KSC-07pd0175

NASA Image and Video Library

2007-01-27

KENNEDY SPACE CENTER, FLA. -- Guests and attendees salute the U.S. flag during a ceremony at the KSC Visitor Complex held in remembrance of the astronauts lost in the Apollo 1 fire: Virgil "Gus" Grissom, Edward H. White II and Roger B. Chaffee. Among those gathered on stage are (from left) Faith Johnson, daughter of Theodore Freeman and Martha Chaffee, daughter of Roger Chaffee, Associate Administrator for Space Operations William Gerstenmaier and KSC Director Bill Parsons, plus former astronaut John Young and Lowell Grissom, brother of Gus Grissom (far right). At the podium is Stephen Feldman, president of the Astronauts Memorial Foundation. Behind the stage is the Space Mirror Memorial, designated as a national memorial by Congress and President George Bush in 1991 to honor fallen astronauts. Their names are emblazoned on the monument’s 42-½-foot-high by 50-foot-wide black granite surface as if to be projected into the heavens. Photo credit:NASA/Kim Shiflett

KSC-07pd0182

NASA Image and Video Library

2007-01-27

KENNEDY SPACE CENTER, FLA. -- Guests are gathered on stage during a ceremony at the KSC Visitor Complex held in remembrance of the astronauts lost in the Apollo 1 fire: Virgil "Gus" Grissom, Edward H. White II and Roger B. Chaffee. Among those gathered on stage are (from left) Faith Johnson, daughter of Theodore Freeman and Martha Chaffee, daughter of Roger Chaffee, Associate Administrator for Space Operations William Gerstenmaier and KSC Director Bill Parsons, plus former astronaut John Young (second from right). Members of the astronauts' families were guests at the ceremony. At the podium is Stephen Feldman, president of the Astronauts Memorial Foundation. Behind the stage is the Space Mirror Memorial, designated as a national memorial by Congress and President George Bush in 1991 to honor fallen astronauts. Their names are emblazoned on the monument’s 42-1/2-foot-high by 50-foot-wide black granite surface as if to be projected into the heavens. Photo credit:NASA/George Shelton

KSC-04PD-0128

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. A member of the Shoshone-Bannock Native American community from Fort Hall, Idaho, reads a tribute to the crew of Columbia while another displays a handmade item with the STS-107 logo. Dancers from Shoshone-Bannock Junior- Senior High School performed a healing ceremony during the memorial held at the Space Memorial Mirror, in the KSC Visitor Complex. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

KSC-04PD-0126

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. A student from Shoshone-Bannock Junior-Senior High School, Fort Hall, Idaho, holds part of a flag presented by dancers from the Shoshone-Bannock Native American community, Fort Hall, Idaho, commemorating the orbiter Columbia and her crew. The dancers performed a healing ceremony during the memorial service held at the Space Memorial Mirror for the crew of Columbia. Feb. 1 is the one-year anniversary of the loss of the crew and orbiter Columbia in a tragic accident as the ship returned to Earth following mission STS-107. Students and staff of the Shoshone-Bannock Nation had an experiment on board Columbia. The public was invited to the memorial service, held in the KSC Visitor Complex, which included comments by Center Director Jim Kennedy and Executive Director of Florida Space Authority Winston Scott. Scott is a former astronaut who flew on Columbia in 1997.

Project Golden Gate: towards real-time Java in space missions

NASA Technical Reports Server (NTRS)

Dvorak, Daniel; Bollella, Greg; Canham, Tim; Carson, Vanessa; Champlin, Virgil; Giovannoni, Brian; Indictor, Mark; Meyer, Kenny; Murray, Alex; Reinholtz, Kirk

2004-01-01

This paper describes the problem domain and our experimentation with the first commercial implementation of the Real Time Specification for Java. The two main issues explored in this report are: (1) the effect of RTSJ's non-heap memory on the programming model, and (2) performance benchmarking of RTSJ/Linux relative to C++/VxWorks.

Non Volatile Flash Memory Radiation Tests

NASA Technical Reports Server (NTRS)

Irom, Farokh; Nguyen, Duc N.; Allen, Greg

2012-01-01

Commercial flash memory industry has experienced a fast growth in the recent years, because of their wide spread usage in cell phones, mp3 players and digital cameras. On the other hand, there has been increased interest in the use of high density commercial nonvolatile flash memories in space because of ever increasing data requirements and strict power requirements. Because of flash memories complex structure; they cannot be treated as just simple memories in regards to testing and analysis. It becomes quite challenging to determine how they will respond in radiation environments.

Electrical Stimulation in Hippocampus and Entorhinal Cortex Impairs Spatial and Temporal Memory.

PubMed

Goyal, Abhinav; Miller, Jonathan; Watrous, Andrew J; Lee, Sang Ah; Coffey, Tom; Sperling, Michael R; Sharan, Ashwini; Worrell, Gregory; Berry, Brent; Lega, Bradley; Jobst, Barbara C; Davis, Kathryn A; Inman, Cory; Sheth, Sameer A; Wanda, Paul A; Ezzyat, Youssef; Das, Sandhitsu R; Stein, Joel; Gorniak, Richard; Jacobs, Joshua

2018-05-09

The medial temporal lobe (MTL) is widely implicated in supporting episodic memory and navigation, but its precise functional role in organizing memory across time and space remains elusive. Here we examine the specific cognitive processes implemented by MTL structures (hippocampus and entorhinal cortex) to organize memory by using electrical brain stimulation, leveraging its ability to establish causal links between brain regions and features of behavior. We studied neurosurgical patients of both sexes who performed spatial-navigation and verbal-episodic memory tasks while brain stimulation was applied in various regions during learning. During the verbal memory task, stimulation in the MTL disrupted the temporal organization of encoded memories such that items learned with stimulation tended to be recalled in a more randomized order. During the spatial task, MTL stimulation impaired subjects' abilities to remember items located far away from boundaries. These stimulation effects were specific to the MTL. Our findings thus provide the first causal demonstration in humans of the specific memory processes that are performed by the MTL to encode when and where events occurred. SIGNIFICANCE STATEMENT Numerous studies have implicated the medial temporal lobe (MTL) in encoding spatial and temporal memories, but they have not been able to causally demonstrate the nature of the cognitive processes by which this occurs in real-time. Electrical brain stimulation is able to demonstrate causal links between a brain region and a given function with high temporal precision. By examining behavior in a memory task as subjects received MTL stimulation, we provide the first causal evidence demonstrating the role of the MTL in organizing the spatial and temporal aspects of episodic memory. Copyright © 2018 the authors 0270-6474/18/384471-11$15.00/0.

A One Chip Hardened Solution for High Speed SpaceWire System Implementations. Session: Components

NASA Technical Reports Server (NTRS)

Marshall, Joseph R.; Berger, Richard W.; Rakow, Glenn P.

2007-01-01

An Application Specific Integrated Circuit (ASIC) that implements the SpaceWire protocol has been developed in a radiation hardened 0.25 micron CMOS technology. This effort began in March 2003 as a joint development between the NASA Goddard Space Flight Center (GSFC) and BAE Systems. The BAE Systems SpaceWire ASIC is comprised entirely of reusable core elements, many of which are already flight-proven. It incorporates a router with 4 SpaceWire ports and two local ports, dual PC1 bus interfaces, a microcontroller, 32KB of internal memory, and a memory controller for additional external memory use. The SpaceWire cores are also reused in other ASICs under development. The SpaceWire ASIC is planned for use on the Geostationary Operational Environmental Satellites (GOES)-R, the Lunar Reconnaissance Orbiter (LRO) and other missions. Engineering and flight parts have been delivered to programs and users. This paper reviews the SpaceWire protocol and those elements of it that have been built into the current and next SpaceWire reusable cores and features within the core that go beyond the current standard and can be enabled or disabled by the user. The adaptation of SpaceWire to BAE Systems' On Chip Bus (OCB) for compatibility with the other reusable cores will be reviewed and highlighted. Optional configurations within user systems and test boards will be shown. The physical implementation of the design will be described and test results from the hardware will be discussed. Application of this ASIC and other ASICs containing the SpaceWire cores and embedded microcontroller to Plug and Play and reconfigurable implementations will be described. Finally, the BAE Systems roadmap for SpaceWire developments will be updated, including some products already in design as well as longer term plans.

Neural correlates of the spacing effect in explicit verbal semantic encoding support the deficient-processing theory.

PubMed

Callan, Daniel E; Schweighofer, Nicolas

2010-04-01

Spaced presentations of to-be-learned items during encoding leads to superior long-term retention over massed presentations. Despite over a century of research, the psychological and neural basis of this spacing effect however is still under investigation. To test the hypotheses that the spacing effect results either from reduction in encoding-related verbal maintenance rehearsal in massed relative to spaced presentations (deficient processing hypothesis) or from greater encoding-related elaborative rehearsal of relational information in spaced relative to massed presentations (encoding variability hypothesis), we designed a vocabulary learning experiment in which subjects encoded paired-associates, each composed of a known word paired with a novel word, in both spaced and massed conditions during functional magnetic resonance imaging. As expected, recall performance in delayed cued-recall tests was significantly better for spaced over massed conditions. Analysis of brain activity during encoding revealed that the left frontal operculum, known to be involved in encoding via verbal maintenance rehearsal, was associated with greater performance-related increased activity in the spaced relative to massed condition. Consistent with the deficient processing hypothesis, a significant decrease in activity with subsequent episodes of presentation was found in the frontal operculum for the massed but not the spaced condition. Our results suggest that the spacing effect is mediated by activity in the frontal operculum, presumably by encoding-related increased verbal maintenance rehearsal, which facilitates binding of phonological and word level verbal information for transfer into long-term memory. Copyright 2009 Wiley-Liss, Inc.

CoNNeCT Baseband Processor Module

NASA Technical Reports Server (NTRS)

Yamamoto, Clifford K; Jedrey, Thomas C.; Gutrich, Daniel G.; Goodpasture, Richard L.

2011-01-01

A document describes the CoNNeCT Baseband Processor Module (BPM) based on an updated processor, memory technology, and field-programmable gate arrays (FPGAs). The BPM was developed from a requirement to provide sufficient computing power and memory storage to conduct experiments for a Software Defined Radio (SDR) to be implemented. The flight SDR uses the AT697 SPARC processor with on-chip data and instruction cache. The non-volatile memory has been increased from a 20-Mbit EEPROM (electrically erasable programmable read only memory) to a 4-Gbit Flash, managed by the RTAX2000 Housekeeper, allowing more programs and FPGA bit-files to be stored. The volatile memory has been increased from a 20-Mbit SRAM (static random access memory) to a 1.25-Gbit SDRAM (synchronous dynamic random access memory), providing additional memory space for more complex operating systems and programs to be executed on the SPARC. All memory is EDAC (error detection and correction) protected, while the SPARC processor implements fault protection via TMR (triple modular redundancy) architecture. Further capability over prior BPM designs includes the addition of a second FPGA to implement features beyond the resources of a single FPGA. Both FPGAs are implemented with Xilinx Virtex-II and are interconnected by a 96-bit bus to facilitate data exchange. Dedicated 1.25- Gbit SDRAMs are wired to each Xilinx FPGA to accommodate high rate data buffering for SDR applications as well as independent SpaceWire interfaces. The RTAX2000 manages scrub and configuration of each Xilinx.

Effects of the time dimension and presentation on incidental memory.

PubMed

Toyota, Hiroshi

2009-08-01

Undergraduates were presented targets on two occasions, and each time they were asked to choose one of two alternatives (past or future) associated with the targets in the orienting task, followed by an unexpected free recall. For the pleasant targets, the spaced presentation led to a better recall than the massed presentation for both past and future time. However, for unpleasant targets, the spacing effect was found in recall of targets associated with the past but the effect was not observed in recall of targets associated with the future. These results were interpreted as indicating that the quantity and the quality of the episodes associated with the targets were processed differently as a function of emotional attribute and time dimension.

Monuments in the Structure of an Urban Environment: The Source of Social Memory and the Marker of the Urban Space

NASA Astrophysics Data System (ADS)

Antonova, N.; Grunt, E.; Merenkov, A.

2017-10-01

The major research objective was to analyze the role of monuments in the formation of local residents’ and guests’ representations about the city, its history and traditions. The authors consider the system of monuments’ location in the urban space as a way of its social construction, as the system of influence on citizens’ aesthetic feelings, as the formation of their attitudes towards maintaining of continuity in the activities of different generations for the improvement of the territory of their permanent residence. Methodology. An urban monument is considered in two ways: as a transfer of historical memory and as a social memory transfer, which includes the experience of previous generations. One of the main provisions of the study is the idea that monuments can lose their former social value, transforming into “simple” objects of a public place. The study was conducted in the city of Yekaterinburg, one of the largest, cultural, scientific and industrial Russian megalopolises in 2015. The primary data was collected using standardized interviews. Four hundred and twenty respondents at the age of and above 18 were questioned on the basis of quota sampling. Interviews with respondents were conducted in order to identify key problems involved and reasons for shaping respondents’ representations of monuments in the urban environment typical for the population of Russian megalopolises. The standardized interview guide included 15 questions. Findings and discussion. Our investigation has revealed that different monuments fulfil various functions in an urban environment (ideological, aesthetic, transferring, valuable, etc.). The study has unequivocally confirmed that objects in the urban space have a different emotional colour background: people paint them in accordance with the feelings that arise in their perception. Hence, some monuments effectively fulfil the functions of social memory transfer: they are remembered, they tell us about the events to which they point. Other monuments in the physical space remain in citizens’ consciousness only as a point on the map of the city. It has been found that “old” and “new” monuments as semantic points of the urban space have an ambiguous perception and a significance for the citizen: some monuments are inscribed in mental maps, while others are ignored or their appearance is condemned.

Cellular dynamical mechanisms for encoding the time and place of events along spatiotemporal trajectories in episodic memory.

PubMed

Hasselmo, Michael E; Giocomo, Lisa M; Brandon, Mark P; Yoshida, Motoharu

2010-12-31

Understanding the mechanisms of episodic memory requires linking behavioral data and lesion effects to data on the dynamics of cellular membrane potentials and population interactions within brain regions. Linking behavior to specific membrane channels and neurochemicals has implications for therapeutic applications. Lesions of the hippocampus, entorhinal cortex and subcortical nuclei impair episodic memory function in humans and animals, and unit recording data from these regions in behaving animals indicate episodic memory processes. Intracellular recording in these regions demonstrates specific cellular properties including resonance, membrane potential oscillations and bistable persistent spiking that could underlie the encoding and retrieval of episodic trajectories. A model presented here shows how intrinsic dynamical properties of neurons could mediate the encoding of episodic memories as complex spatiotemporal trajectories. The dynamics of neurons allow encoding and retrieval of unique episodic trajectories in multiple continuous dimensions including temporal intervals, personal location, the spatial coordinates and sensory features of perceived objects and generated actions, and associations between these elements. The model also addresses how cellular dynamics could underlie unit firing data suggesting mechanisms for coding continuous dimensions of space, time, sensation and action. Copyright © 2010 Elsevier B.V. All rights reserved.

Cellular dynamical mechanisms for encoding the time and place of events along spatiotemporal trajectories in episodic memory

PubMed Central

Hasselmo, Michael E.; Giocomo, Lisa M.; Yoshida, Motoharu

2010-01-01

Understanding the mechanisms of episodic memory requires linking behavioural data and lesion effects to data on the dynamics of cellular membrane potentials and population interactions within these brain regions. Linking behavior to specific membrane channels and neurochemicals has implications for therapeutic applications. Lesions of the hippocampus, entorhinal cortex and subcortical nuclei impair episodic memory function in humans and animals, and unit recording data from these regions in behaving animals indicate episodic memory processes. Intracellular recording in these regions demonstrates specific cellular properties including resonance, membrane potential oscillations and bistable persistent spiking that could underlie the encoding and retrieval of episodic trajectories. A model presented here shows how intrinsic dynamical properties of neurons could mediate the encoding of episodic memories as complex spatiotemporal trajectories. The dynamics of neurons allow encoding and retrieval of unique episodic trajectories in multiple continuous dimensions including temporal intervals, personal location, the spatial coordinates and sensory features of perceived objects and generated actions, and associations between these elements. The model also addresses how cellular dynamics could underlie unit firing data suggesting mechanisms for coding continuous dimensions of space, time, sensation and action. PMID:20018213

Brain signaling and behavioral responses induced by exposure to (56)Fe-particle radiation

NASA Technical Reports Server (NTRS)

Denisova, N. A.; Shukitt-Hale, B.; Rabin, B. M.; Joseph, J. A.

2002-01-01

Previous experiments have demonstrated that exposure to 56Fe-particle irradiation (1.5 Gy, 1 GeV) produced aging-like accelerations in neuronal and behavioral deficits. Astronauts on long-term space flights will be exposed to similar heavy-particle radiations that might have similar deleterious effects on neuronal signaling and cognitive behavior. Therefore, the present study evaluated whether radiation-induced spatial learning and memory behavioral deficits are associated with region-specific brain signaling deficits by measuring signaling molecules previously found to be essential for behavior [pre-synaptic vesicle proteins, synaptobrevin and synaptophysin, and protein kinases, calcium-dependent PRKCs (also known as PKCs) and PRKA (PRKA RIIbeta)]. The results demonstrated a significant radiation-induced increase in reference memory errors. The increases in reference memory errors were significantly negatively correlated with striatal synaptobrevin and frontal cortical synaptophysin expression. Both synaptophysin and synaptobrevin are synaptic vesicle proteins that are important in cognition. Striatal PRKA, a memory signaling molecule, was also significantly negatively correlated with reference memory errors. Overall, our findings suggest that radiation-induced pre-synaptic facilitation may contribute to some previously reported radiation-induced decrease in striatal dopamine release and for the disruption of the central dopaminergic system integrity and dopamine-mediated behavior.

Brain signaling and behavioral responses induced by exposure to (56)Fe-particle radiation.

PubMed

Denisova, N A; Shukitt-Hale, B; Rabin, B M; Joseph, J A

2002-12-01

Previous experiments have demonstrated that exposure to 56Fe-particle irradiation (1.5 Gy, 1 GeV) produced aging-like accelerations in neuronal and behavioral deficits. Astronauts on long-term space flights will be exposed to similar heavy-particle radiations that might have similar deleterious effects on neuronal signaling and cognitive behavior. Therefore, the present study evaluated whether radiation-induced spatial learning and memory behavioral deficits are associated with region-specific brain signaling deficits by measuring signaling molecules previously found to be essential for behavior [pre-synaptic vesicle proteins, synaptobrevin and synaptophysin, and protein kinases, calcium-dependent PRKCs (also known as PKCs) and PRKA (PRKA RIIbeta)]. The results demonstrated a significant radiation-induced increase in reference memory errors. The increases in reference memory errors were significantly negatively correlated with striatal synaptobrevin and frontal cortical synaptophysin expression. Both synaptophysin and synaptobrevin are synaptic vesicle proteins that are important in cognition. Striatal PRKA, a memory signaling molecule, was also significantly negatively correlated with reference memory errors. Overall, our findings suggest that radiation-induced pre-synaptic facilitation may contribute to some previously reported radiation-induced decrease in striatal dopamine release and for the disruption of the central dopaminergic system integrity and dopamine-mediated behavior.

MSuPDA: A memory efficient algorithm for sequence alignment.

PubMed

Khan, Mohammad Ibrahim; Kamal, Md Sarwar; Chowdhury, Linkon

2015-01-16

Space complexity is a million dollar question in DNA sequence alignments. In this regards, MSuPDA (Memory Saving under Pushdown Automata) can help to reduce the occupied spaces in computer memory. Our proposed process is that Anchor Seed (AS) will be selected from given data set of Nucleotides base pairs for local sequence alignment. Quick Splitting (QS) techniques will separate the Anchor Seed from all the DNA genome segments. Selected Anchor Seed will be placed to pushdown Automata's (PDA) input unit. Whole DNA genome segments will be placed into PDA's stack. Anchor Seed from input unit will be matched with the DNA genome segments from stack of PDA. Whatever matches, mismatches or Indel, of Nucleotides will be POP from the stack under the control of control unit of Pushdown Automata. During the POP operation on stack it will free the memory cell occupied by the Nucleotide base pair.

Sex- and dose-dependent effects of calcium ion irradiation on behavioral performance of B6D2F1 mice during contextual fear conditioning training.

PubMed

Raber, Jacob; Weber, Sydney J; Kronenberg, Amy; Turker, Mitchell S

2016-06-01

The space radiation environment includes energetic charged particles that may impact behavioral and cognitive performance. The relationship between the dose and the ionization density of the various types of charged particles (expressed as linear energy transfer or LET), and cognitive performance is complex. In our earlier work, whole body exposure to (28)Si ions (263 MeV/n, LET=78keV/μm; 1.6 Gy) affected contextual fear memory in C57BL/6J × DBA2/J F1 (B6D2F1) mice three months following irradiation but this was not the case following exposure to (48)Ti ions (1 GeV/n, LET=107keV/μm; 0.2 or 0.4 Gy). As an increased understanding of the impact of charged particle exposures is critical for assessment of risk to the CNS of astronauts during and following missions, in this study we used (40)Ca ion beams (942 MeV/n, LET=90keV/μm) to determine the behavioral and cognitive effects for the LET region between that of Si ions and Ti ions. (40)Ca ion exposure reduced baseline activity in a novel environment in a dose-dependent manner, which suggests reduced motivation to explore and/or a diminished level of curiosity in a novel environment. In addition, exposure to (40)Ca ions had sex-dependent effects on response to shock. (40)Ca ion irradiation reduced the response to shock in female, but not male, mice. In contrast, (40)Ca ion irradiation did not affect fear learning, memory, or extinction of fear memory for either gender at the doses employed in this study. Thus (40)Ca ion irradiation affected behavioral, but not cognitive, performance. The effects of (40)Ca ion irradiation on behavioral performance are relevant, as a combination of novelty and aversive environmental stimuli is pertinent to conditions experienced by astronauts during and following space missions. Copyright © 2016 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

How memory of direct animal interactions can lead to territorial pattern formation.

PubMed

Potts, Jonathan R; Lewis, Mark A

2016-05-01

Mechanistic home range analysis (MHRA) is a highly effective tool for understanding spacing patterns of animal populations. It has hitherto focused on populations where animals defend their territories by communicating indirectly, e.g. via scent marks. However, many animal populations defend their territories using direct interactions, such as ritualized aggression. To enable application of MHRA to such populations, we construct a model of direct territorial interactions, using linear stability analysis and energy methods to understand when territorial patterns may form. We show that spatial memory of past interactions is vital for pattern formation, as is memory of 'safe' places, where the animal has visited but not suffered recent territorial encounters. Additionally, the spatial range over which animals make decisions to move is key to understanding the size and shape of their resulting territories. Analysis using energy methods, on a simplified version of our system, shows that stability in the nonlinear system corresponds well to predictions of linear analysis. We also uncover a hysteresis in the process of territory formation, so that formation may depend crucially on initial space-use. Our analysis, in one dimension and two dimensions, provides mathematical groundwork required for extending MHRA to situations where territories are defended by direct encounters. © 2016 The Author(s).

Multiple Roles for Time in Short-Term Memory: Evidence from Serial Recall of Order and Timing

ERIC Educational Resources Information Center

Farrell, Simon

2008-01-01

Three experiments are reported that examine the relationship between short-term memory for time and order information, and the more specific claim that order memory is driven by a timing signal. Participants were presented with digits spaced irregularly in time and postcued (Experiments 1 and 2) or precued (Experiment 3) to recall the order or…

Parametric State Space Structuring

NASA Technical Reports Server (NTRS)

Ciardo, Gianfranco; Tilgner, Marco

1997-01-01

Structured approaches based on Kronecker operators for the description and solution of the infinitesimal generator of a continuous-time Markov chains are receiving increasing interest. However, their main advantage, a substantial reduction in the memory requirements during the numerical solution, comes at a price. Methods based on the "potential state space" allocate a probability vector that might be much larger than actually needed. Methods based on the "actual state space", instead, have an additional logarithmic overhead. We present an approach that realizes the advantages of both methods with none of their disadvantages, by partitioning the local state spaces of each submodel. We apply our results to a model of software rendezvous, and show how they reduce memory requirements while, at the same time, improving the efficiency of the computation.

Poster Session

NASA Technical Reports Server (NTRS)

1997-01-01

In this session, Poster Session, the discussion focuses on the following topics: Development of correlative measures for the assessment of attention and memory; Biodynamical Responses of the Crewmember Head/Neck System During Emergence Ejection; Fecundation in the Sky, a Ten Years Old Experiment in Microgravity; A Modified Botex Incubator as a Transport System For Developing Crickets into Space; Chromosomal Aberrations in Peripheral Lymphocytes of Cosmonauts and Astronauts after Space Flights; Method for Establishing Long term Bone Marrow; Cultures Under Microgravity Conditions Reproduction Under Simulated Weightlessness --Mammalian in vivo Experiments Under Suspension; Towards Human Movement Analysis Without the Use of Markers; Habitability Requirements For a Cogent Mars Mission; The Saucer Concept for Space Habitats; New Way In Modeling the Growth of the Organism; The Fractionation of Hydrogen and Oxygen Stable Isotopes By Life Support Systems of Space Station "MIR"; and Effect of Space Flight on Neutrophil Function.

Towards Low-Cost Effective and Homogeneous Thermal Activation of Shape Memory Polymers

PubMed Central

Lantada, Andrés Díaz; Rebollo, María Ángeles Santamaría

2013-01-01

A typical limitation of intelligent devices based on the use of shape-memory polymers as actuators is linked to the widespread use of distributed heating resistors, via Joule effect, as activation method, which involves several relevant issues needing attention, such as: (a) Final device size is importantly increased due to the additional space required for the resistances; (b) the use of resistances limits materials’ strength and the obtained devices are normally weaker; (c) the activation process through heating resistances is not homogeneous, thus leading to important temperature differences among the polymeric structure and to undesirable thermal gradients and stresses, also limiting the application fields of shape-memory polymers. In our present work we describe interesting activation alternatives, based on coating shape-memory polymers with different kinds of conductive materials, including textiles, conductive threads and conductive paint, which stand out for their easy, rapid and very cheap implementation. Distributed heating and homogeneous activation can be achieved in several of the alternatives studied and the technical results are comparable to those obtained by using advanced shape-memory nanocomposites, which have to deal with complex synthesis, processing and security aspects. Different combinations of shape memory epoxy resin with several coating electrotextiles, conductive films and paints are prepared, simulated with the help of thermal finite element method based resources and characterized using infrared thermography for validating the simulations and overall design process. A final application linked to an active catheter pincer is detailed and the advantages of using distributed heating instead of conventional resistors are discussed. PMID:28788401

Surface Control of Cold Hibernated Elastic Memory Self-Deployable Structure

NASA Technical Reports Server (NTRS)

Sokolowski, Witold M.; Ghaffarian, Reza

2006-01-01

A new class of simple, reliable, lightweight, low packaging volume and cost, self-deployable structures has been developed for use in space and commercial applications. This technology called 'cold hibernated elastic memory' (CHEM) utilizes shape memory polymers (SMP)in open cellular (foam) structure or sandwich structures made of shape memory polymer foam cores and polymeric composite skins. Some of many potential CHEM space applications require a high precision deployment and surface accuracy during operation. However, a CHEM structure could be slightly distorted by the thermo-mechanical processing as well as by thermal space environment Therefore, the sensor system is desirable to monitor and correct the potential surface imperfection. During these studies, the surface control of CHEM smart structures was demonstrated using a Macro-Fiber Composite (MFC) actuator developed by the NASA LaRC and US Army ARL. The test results indicate that the MFC actuator performed well before and after processing cycles. It reduced some residue compressive strain that in turn corrected very small shape distortion after each processing cycle. The integrated precision strain gages were detecting only a small flat shape imperfection indicating a good recoverability of original shape of the CHEM test structure.

Memory and Space: Towards an Understanding of the Cognitive Map.

PubMed

Schiller, Daniela; Eichenbaum, Howard; Buffalo, Elizabeth A; Davachi, Lila; Foster, David J; Leutgeb, Stefan; Ranganath, Charan

2015-10-14

More than 50 years of research have led to the general agreement that the hippocampus contributes to memory, but there has been a major schism among theories of hippocampal function over this time. Some researchers argue that the hippocampus plays a broad role in episodic and declarative memory, whereas others argue for a specific role in the creation of spatial cognitive maps and navigation. Although both views have merit, neither provides a complete account of hippocampal function. Guided by recent reviews that attempt to bridge between these views, here we suggest that reconciliation can be accomplished by exploring hippocampal function from the perspective of Tolman's (1948) original conception of a cognitive map as organizing experience and guiding behavior across all domains of cognition. We emphasize recent studies in animals and humans showing that hippocampal networks support a broad range of domains of cognitive maps, that these networks organize specific experiences within the contextually relevant map, and that network activity patterns reflect behavior guided through cognitive maps. These results are consistent with a framework that bridges theories of hippocampal function by conceptualizing the hippocampus as organizing incoming information within the context of a multidimensional cognitive map of spatial, temporal, and associational context. Research of hippocampal function is dominated by two major views. The spatial view argues that the hippocampus tracks routes through space, whereas the memory view suggests a broad role in declarative memory. Both views rely on considerable evidence, but neither provides a complete account of hippocampal function. Here we review evidence that, in addition to spatial context, the hippocampus encodes a wide variety of information about temporal and situational context, about the systematic organization of events in abstract space, and about routes through maps of cognition and space. We argue that these findings cross the boundaries of the memory and spatial views and offer new insights into hippocampal function as a system supporting a broad range of cognitive maps. Copyright © 2015 the authors 0270-6474/15/3513904-08$15.00/0.

High-Performance, Radiation-Hardened Electronics for Space Environments

NASA Technical Reports Server (NTRS)

Keys, Andrew S.; Watson, Michael D.; Frazier, Donald O.; Adams, James H.; Johnson, Michael A.; Kolawa, Elizabeth A.

2007-01-01

The Radiation Hardened Electronics for Space Environments (RHESE) project endeavors to advance the current state-of-the-art in high-performance, radiation-hardened electronics and processors, ensuring successful performance of space systems required to operate within extreme radiation and temperature environments. Because RHESE is a project within the Exploration Technology Development Program (ETDP), RHESE's primary customers will be the human and robotic missions being developed by NASA's Exploration Systems Mission Directorate (ESMD) in partial fulfillment of the Vision for Space Exploration. Benefits are also anticipated for NASA's science missions to planetary and deep-space destinations. As a technology development effort, RHESE provides a broad-scoped, full spectrum of approaches to environmentally harden space electronics, including new materials, advanced design processes, reconfigurable hardware techniques, and software modeling of the radiation environment. The RHESE sub-project tasks are: SelfReconfigurable Electronics for Extreme Environments, Radiation Effects Predictive Modeling, Radiation Hardened Memory, Single Event Effects (SEE) Immune Reconfigurable Field Programmable Gate Array (FPGA) (SIRF), Radiation Hardening by Software, Radiation Hardened High Performance Processors (HPP), Reconfigurable Computing, Low Temperature Tolerant MEMS by Design, and Silicon-Germanium (SiGe) Integrated Electronics for Extreme Environments. These nine sub-project tasks are managed by technical leads as located across five different NASA field centers, including Ames Research Center, Goddard Space Flight Center, the Jet Propulsion Laboratory, Langley Research Center, and Marshall Space Flight Center. The overall RHESE integrated project management responsibility resides with NASA's Marshall Space Flight Center (MSFC). Initial technology development emphasis within RHESE focuses on the hardening of Field Programmable Gate Arrays (FPGA)s and Field Programmable Analog Arrays (FPAA)s for use in reconfigurable architectures. As these component/chip level technologies mature, the RHESE project emphasis shifts to focus on efforts encompassing total processor hardening techniques and board-level electronic reconfiguration techniques featuring spare and interface modularity. This phased approach to distributing emphasis between technology developments provides hardened FPGA/FPAAs for early mission infusion, then migrates to hardened, board-level, high speed processors with associated memory elements and high density storage for the longer duration missions encountered for Lunar Outpost and Mars Exploration occurring later in the Constellation schedule.

Evidence for an Evolutionarily Conserved Memory Coding Scheme in the Mammalian Hippocampus

PubMed Central

Thome, Alexander; Lisanby, Sarah H.; McNaughton, Bruce L.

2017-01-01

Decades of research identify the hippocampal formation as central to memory storage and recall. Events are stored via distributed population codes, the parameters of which (e.g., sparsity and overlap) determine both storage capacity and fidelity. However, it remains unclear whether the parameters governing information storage are similar between species. Because episodic memories are rooted in the space in which they are experienced, the hippocampal response to navigation is often used as a proxy to study memory. Critically, recent studies in rodents that mimic the conditions typical of navigation studies in humans and nonhuman primates (i.e., virtual reality) show that reduced sensory input alters hippocampal representations of space. The goal of this study was to quantify this effect and determine whether there are commonalities in information storage across species. Using functional molecular imaging, we observe that navigation in virtual environments elicits activity in fewer CA1 neurons relative to real-world conditions. Conversely, comparable neuronal activity is observed in hippocampus region CA3 and the dentate gyrus under both conditions. Surprisingly, we also find evidence that the absolute number of neurons used to represent an experience is relatively stable between nonhuman primates and rodents. We propose that this convergence reflects an optimal ensemble size for episodic memories. SIGNIFICANCE STATEMENT One primary factor constraining memory capacity is the sparsity of the engram, the proportion of neurons that encode a single experience. Investigating sparsity in humans is hampered by the lack of single-cell resolution and differences in behavioral protocols. Sparsity can be quantified in freely moving rodents, but extrapolating these data to humans assumes that information storage is comparable across species and is robust to restraint-induced reduction in sensory input. Here, we test these assumptions and show that species differences in brain size build memory capacity without altering the structure of the data being stored. Furthermore, sparsity in most of the hippocampus is resilient to reduced sensory information. This information is vital to integrating animal data with human imaging navigation studies. PMID:28174334

2017 A Day of Remembrance

NASA Image and Video Library

2017-01-26

Following Kennedy Space Center's Day of Remembrance ceremony in the Center for Space Education at the Kennedy visitor complex, guests gathered to place flowers at the Space Mirror Memorial. Many of those in attendance were family members of the fallen astronauts.

Pulaski Award Ceremony

NASA Image and Video Library

2017-11-01

A presentation of colors opened a ceremony Nov. 1 on the Merritt Island National Wildlife Refuge in Florida. During the joint ceremony, the Spaceport Integration Team and its partners were presented with the prestigious 2017 Pulaski Award and a new memorial marker was dedicated. The multi-agency team includes representatives from NASA's Kennedy Space Center, Cape Canaveral Air Force Station's 45th Space Wing, the Merritt Island National Wildlife Refuge, as well as the Florida Forest Service and Brevard County Fire Rescue. The memorial marker honors two fallen firefighters, Scott Maness and Beau Sauselein, who died fighting a wildfire on space center property in 1981. Held outdoors, the ceremony was attended by 140 guests.

Performance and scalability evaluation of "Big Memory" on Blue Gene Linux.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoshii, K.; Iskra, K.; Naik, H.

2011-05-01

We address memory performance issues observed in Blue Gene Linux and discuss the design and implementation of 'Big Memory' - an alternative, transparent memory space introduced to eliminate the memory performance issues. We evaluate the performance of Big Memory using custom memory benchmarks, NAS Parallel Benchmarks, and the Parallel Ocean Program, at a scale of up to 4,096 nodes. We find that Big Memory successfully resolves the performance issues normally encountered in Blue Gene Linux. For the ocean simulation program, we even find that Linux with Big Memory provides better scalability than does the lightweight compute node kernel designed solelymore » for high-performance applications. Originally intended exclusively for compute node tasks, our new memory subsystem dramatically improves the performance of certain I/O node applications as well. We demonstrate this performance using the central processor of the LOw Frequency ARray radio telescope as an example.« less

Origin of negative resistance in anion migration controlled resistive memory

NASA Astrophysics Data System (ADS)

Banerjee, Writam; Wu, Facai; Hu, Yuan; Wu, Quantan; Wu, Zuheng; Liu, Qi; Liu, Ming

2018-03-01

Resistive random access memory (RRAM) is one of the most promising emerging nonvolatile technologies for the futuristic memory devices. Resistive switching behavior often shows negative resistance (NR), either voltage controlled or current controlled. In this work, the origin of a current compliance dependent voltage controlled NR effect during the resetting of anion migration based RRAM devices is discussed. The N-type voltage controlled NR is a high field driven phenomena. The current conduction within the range of a certain negative voltage is mostly dominated by space charge limited current. But with the higher negative voltage, a field induced tunneling effect is generated in the NR region. The voltage controlled NR is strongly dependent on the compliance current. The area independent behavior indicates the filamentary switching. The peak to valley ratio (PVR) is > 5. The variation of PVR as a function of the conduction band offset is achieved. Compared to other reported works, based on the PVR, it is possible to distinguish the RRAM types. Generally, due to the higher electric field effect on the metallic bridge during RESET, the electrochemical metallization type RRAM shows much higher PVR than the valance change type RRAM.

Neurochemical differences in learning and memory paradigms among rats supplemented with anthocyanin-rich blueberry diets and exposed to acute doses of 56Fe particles

USDA-ARS?s Scientific Manuscript database

The protective effects of anthocyanin-rich blueberries (BB) on brain health are well documented and are particularly important under conditions of high oxidative stress, which can lead to “accelerated aging.” One such scenario is exposure to space radiation, consisting of high-energy and -charge par...

Fault tolerance issues in nanoelectronics

NASA Astrophysics Data System (ADS)

Spagocci, S. M.

The astonishing success story of microelectronics cannot go on indefinitely. In fact, once devices reach the few-atom scale (nanoelectronics), transient quantum effects are expected to impair their behaviour. Fault tolerant techniques will then be required. The aim of this thesis is to investigate the problem of transient errors in nanoelectronic devices. Transient error rates for a selection of nanoelectronic gates, based upon quantum cellular automata and single electron devices, in which the electrostatic interaction between electrons is used to create Boolean circuits, are estimated. On the bases of such results, various fault tolerant solutions are proposed, for both logic and memory nanochips. As for logic chips, traditional techniques are found to be unsuitable. A new technique, in which the voting approach of triple modular redundancy (TMR) is extended by cascading TMR units composed of nanogate clusters, is proposed and generalised to other voting approaches. For memory chips, an error correcting code approach is found to be suitable. Various codes are considered and a lookup table approach is proposed for encoding and decoding. We are then able to give estimations for the redundancy level to be provided on nanochips, so as to make their mean time between failures acceptable. It is found that, for logic chips, space redundancies up to a few tens are required, if mean times between failures have to be of the order of a few years. Space redundancy can also be traded for time redundancy. As for memory chips, mean times between failures of the order of a few years are found to imply both space and time redundancies of the order of ten.

Dry etch challenges for CD shrinkage in memory process

NASA Astrophysics Data System (ADS)

Matsushita, Takaya; Matsumoto, Takanori; Mukai, Hidefumi; Kyoh, Suigen; Hashimoto, Kohji

2015-03-01

Line pattern collapse attracts attention as a new problem of the L&S formation in sub-20nm H.P feature. Line pattern collapse that occurs in a slight non-uniformity of adjacent CD (Critical dimension) space using double patterning process has been studied with focus on micro-loading effect in Si etching. Bias RF pulsing plasma etching process using low duty cycle helped increase of selectivity Si to SiO2. In addition to the effect of Bias RF pulsing process, the thin mask obtained from improvement of selectivity has greatly suppressed micro-loading in Si etching. However it was found that micro-loading effect worsen again in sub-20nm space width. It has been confirmed that by using cycle etch process to remove deposition with CFx based etching micro-loading effect could be suppressed. Finally, Si etching process condition using combination of results above could provide finer line and space without "line pattern collapse" in sub-20nm.

The rates of protein synthesis and degradation account for the differential response of neurons to spaced and massed training protocols.

PubMed

Naqib, Faisal; Farah, Carole A; Pack, Christopher C; Sossin, Wayne S

2011-12-01

The sensory-motor neuron synapse of Aplysia is an excellent model system for investigating the biochemical changes underlying memory formation. In this system, training that is separated by rest periods (spaced training) leads to persistent changes in synaptic strength that depend on biochemical pathways that are different from those that occur when the training lacks rest periods (massed training). Recently, we have shown that in isolated sensory neurons, applications of serotonin, the neurotransmitter implicated in inducing these synaptic changes during memory formation, lead to desensitization of the PKC Apl II response, in a manner that depends on the method of application (spaced versus massed). Here, we develop a mathematical model of this response in order to gain insight into how neurons sense these different training protocols. The model was developed incrementally, and each component was experimentally validated, leading to two novel findings: First, the increased desensitization due to PKA-mediated heterologous desensitization is coupled to a faster recovery than the homologous desensitization that occurs in the absence of PKA activity. Second, the model suggests that increased spacing leads to greater desensitization due to the short half-life of a hypothetical protein, whose production prevents homologous desensitization. Thus, we predict that the effects of differential spacing are largely driven by the rates of production and degradation of proteins. This prediction suggests a powerful mechanism by which information about time is incorporated into neuronal processing.

Corporate Memory and Spacecraft Course Development

NASA Technical Reports Server (NTRS)

1999-01-01

The Florida Space Grant Consortium (FSGC) entered into a cooperative agreement with NASA's Kennedy Space Center (KSC) to manage two programs, (1) Corporate Memory and (2) Spacecraft Course Development. The FSGC, with its central office at the University of Florida, administered these programs. In conjunction with KSC, the FGSC was responsible for the release of the Request for Proposals (RFP's) and its distribution to all its affiliates. FSGC received the applications, forwarded them to KSC for evaluations, and awarded grants to the institutions chosen by KSC.

Hidden long evolutionary memory in a model biochemical network

NASA Astrophysics Data System (ADS)

Ali, Md. Zulfikar; Wingreen, Ned S.; Mukhopadhyay, Ranjan

2018-04-01

We introduce a minimal model for the evolution of functional protein-interaction networks using a sequence-based mutational algorithm, and apply the model to study neutral drift in networks that yield oscillatory dynamics. Starting with a functional core module, random evolutionary drift increases network complexity even in the absence of specific selective pressures. Surprisingly, we uncover a hidden order in sequence space that gives rise to long-term evolutionary memory, implying strong constraints on network evolution due to the topology of accessible sequence space.

DSPACE hardware architecture for on-board real-time image/video processing in European space missions

NASA Astrophysics Data System (ADS)

Saponara, Sergio; Donati, Massimiliano; Fanucci, Luca; Odendahl, Maximilian; Leupers, Reiner; Errico, Walter

2013-02-01

The on-board data processing is a vital task for any satellite and spacecraft due to the importance of elaborate the sensing data before sending them to the Earth, in order to exploit effectively the bandwidth to the ground station. In the last years the amount of sensing data collected by scientific and commercial space missions has increased significantly, while the available downlink bandwidth is comparatively stable. The increasing demand of on-board real-time processing capabilities represents one of the critical issues in forthcoming European missions. Faster and faster signal and image processing algorithms are required to accomplish planetary observation, surveillance, Synthetic Aperture Radar imaging and telecommunications. The only available space-qualified Digital Signal Processor (DSP) free of International Traffic in Arms Regulations (ITAR) restrictions faces inadequate performance, thus the development of a next generation European DSP is well known to the space community. The DSPACE space-qualified DSP architecture fills the gap between the computational requirements and the available devices. It leverages a pipelined and massively parallel core based on the Very Long Instruction Word (VLIW) paradigm, with 64 registers and 8 operational units, along with cache memories, memory controllers and SpaceWire interfaces. Both the synthesizable VHDL and the software development tools are generated from the LISA high-level model. A Xilinx-XC7K325T FPGA is chosen to realize a compact PCI demonstrator board. Finally first synthesis results on CMOS standard cell technology (ASIC 180 nm) show an area of around 380 kgates and a peak performance of 1000 MIPS and 750 MFLOPS at 125MHz.

The relationship between cognitive function and life space: the potential role of personal control beliefs.

PubMed

Sartori, Andrea C; Wadley, Virginia G; Clay, Olivio J; Parisi, Jeanine M; Rebok, George W; Crowe, Michael

2012-06-01

We examined the relationship of cognitive and functional measures with life space (a measure of spatial mobility examining extent of movement within a person's environment) in older adults, and investigated the potential moderating role of personal control beliefs. Internal control beliefs reflect feelings of competence and personal agency, while attributions of external control imply a more dependent or passive point of view. Participants were 2,737 adults from the ACTIVE study, with a mean age of 74 years. Females comprised 76% of the sample, with good minority representation (27% African American). In multiple regression models controlling for demographic factors, cognitive domains of memory, reasoning, and processing speed were significantly associated with life space (p < .001 for each), and reasoning ability appeared most predictive (B = .117). Measures of everyday function also showed significant associations with life space, independent from the traditional cognitive measures. Interactions between cognitive function and control beliefs were tested, and external control beliefs moderated the relationship between memory and life space, with the combination of high objective memory and low external control beliefs yielding the highest life space (t = -2.07; p = .039). In conclusion, older adults with better cognitive function have a larger overall life space. Performance-based measures of everyday function may also be useful in assessing the functional outcome of life space. Additionally, subjective external control beliefs may moderate the relationship between objective cognitive function and life space. Future studies examining the relationships between these factors longitudinally appear worthwhile to further elucidate the interrelationships of cognitive function, control beliefs, and life space. PsycINFO Database Record (c) 2012 APA, all rights reserved

Single event upsets in semiconductor devices induced by highly ionising particles.

PubMed

Sannikov, A V

2004-01-01

A new model of single event upsets (SEUs), created in memory cells by heavy ions and high energy hadrons, has been developed. The model takes into account the spatial distribution of charge collection efficiency over the cell area not considered in previous approaches. Three-dimensional calculations made by the HADRON code have shown good agreement with experimental data for the energy dependence of proton SEU cross sections, sensitive depths and other SEU observables. The model is promising for prediction of SEU rates for memory chips exposed in space and in high-energy experiments as well as for the development of a high-energy neutron dosemeter based on the SEU effect.

A sparse matrix algorithm on the Boolean vector machine

NASA Technical Reports Server (NTRS)

Wagner, Robert A.; Patrick, Merrell L.

1988-01-01

VLSI technology is being used to implement a prototype Boolean Vector Machine (BVM), which is a large network of very small processors with equally small memories that operate in SIMD mode; these use bit-serial arithmetic, and communicate via cube-connected cycles network. The BVM's bit-serial arithmetic and the small memories of individual processors are noted to compromise the system's effectiveness in large numerical problem applications. Attention is presently given to the implementation of a basic matrix-vector iteration algorithm for space matrices of the BVM, in order to generate over 1 billion useful floating-point operations/sec for this iteration algorithm. The algorithm is expressed in a novel language designated 'BVM'.

Space - New opportunities for international ventures; Proceedings of the Seventeenth Goddard Memorial Symposium, Washington, D.C., March 28-30, 1979

NASA Technical Reports Server (NTRS)

Hayes, W. C., Jr.

1980-01-01

Consideration is given to such topics as new opportunities for international ventures in space, the Tracking and Data Relay Satellite System, the commercial potential for the Space Shuttle, and approaches to the financing of space ventures. Also considered are Japanese space activities and the European role in the Space Transportation System.

Planning a new type of cultural community space in Goyang City, Korea

NASA Astrophysics Data System (ADS)

Kim, Jeonghye; Kim, Saehoon

2017-12-01

Between March and June 2017, Seoul National University Graduate School of Environment Studies and Goyang City organized a course titled ‘Environment Design and Planning’. At the beginning stage of the project, even though the Unified Korean Silicon Vally Project was initiated, our team members in the class decide to reconsider whether a large redevelopment project aimed at attracting tourists is actually a desirable goal for the residents or not. What would be truly needed for space users living in the area? How should we preserve and maintain the existing meaningful space? Meanwhile, we come up with the Gyeongui Railroad, which passes through Goyang and Ilsan. It was a railway line that shared memories of the past, the daily lives of the residents, and the joys and sorrows of them. Among the railways, ‘Baek-Ma Station’ was the place which was filled with the memories of the people who spent their youth in the city in the 1980s. The station is currently not in use, because this place is abandoned and empty. We wished to make this space more accessible for the residents and also to create a place that would give an opportunity to the resident's social comeback. The space could be activated again with the revival of local cultural activities. And we hope the residents will be able to create new memories of 2017 in this space.

KENNEDY SPACE CENTER, FLA. - A ceremonial wreath is placed at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex. During this dedication ceremony, the names of the STS-107 astronauts who lost their lives during the Columbia accident -- Rick Husband, Willie McCool, Laurel Clark, Michael Anderson, David Brown, Kalpana Chawla, and Ilan Ramon -- join the names of 17 other space heroes who gave their lives for the U.S. space program. The "Space Mirror," 42 1/2 feet high by 50 feet wide, illuminates the names of the fallen astronauts cut through the monument's black granite surface.

NASA Image and Video Library

2003-10-28

KENNEDY SPACE CENTER, FLA. - A ceremonial wreath is placed at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex. During this dedication ceremony, the names of the STS-107 astronauts who lost their lives during the Columbia accident -- Rick Husband, Willie McCool, Laurel Clark, Michael Anderson, David Brown, Kalpana Chawla, and Ilan Ramon -- join the names of 17 other space heroes who gave their lives for the U.S. space program. The "Space Mirror," 42 1/2 feet high by 50 feet wide, illuminates the names of the fallen astronauts cut through the monument's black granite surface.

KENNEDY SPACE CENTER, FLA. - NASA T-38 jets fly over the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in the Missing Man Formation. During this dedication ceremony, the names of the STS-107 astronauts who lost their lives during the Columbia accident -- Rick Husband, Willie McCool, Laurel Clark, Michael Anderson, David Brown, Kalpana Chawla, and Ilan Ramon -- join the names of 17 other space heroes who gave their lives for the U.S. space program. The "Space Mirror," 42 1/2 feet high by 50 feet wide, illuminates the names of the fallen astronauts cut through the monument's black granite surface.

NASA Image and Video Library

2003-10-28

KENNEDY SPACE CENTER, FLA. - NASA T-38 jets fly over the Space Mirror Memorial at the Kennedy Space Center Visitor Complex in the Missing Man Formation. During this dedication ceremony, the names of the STS-107 astronauts who lost their lives during the Columbia accident -- Rick Husband, Willie McCool, Laurel Clark, Michael Anderson, David Brown, Kalpana Chawla, and Ilan Ramon -- join the names of 17 other space heroes who gave their lives for the U.S. space program. The "Space Mirror," 42 1/2 feet high by 50 feet wide, illuminates the names of the fallen astronauts cut through the monument's black granite surface.

Fault tolerant onboard packet switch architecture for communication satellites: Shared memory per beam approach

NASA Technical Reports Server (NTRS)

Shalkhauser, Mary JO; Quintana, Jorge A.; Soni, Nitin J.

1994-01-01

The NASA Lewis Research Center is developing a multichannel communication signal processing satellite (MCSPS) system which will provide low data rate, direct to user, commercial communications services. The focus of current space segment developments is a flexible, high-throughput, fault tolerant onboard information switching processor. This information switching processor (ISP) is a destination-directed packet switch which performs both space and time switching to route user information among numerous user ground terminals. Through both industry study contracts and in-house investigations, several packet switching architectures were examined. A contention-free approach, the shared memory per beam architecture, was selected for implementation. The shared memory per beam architecture, fault tolerance insertion, implementation, and demonstration plans are described.

Multiple core computer processor with globally-accessible local memories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shalf, John; Donofrio, David; Oliker, Leonid

A multi-core computer processor including a plurality of processor cores interconnected in a Network-on-Chip (NoC) architecture, a plurality of caches, each of the plurality of caches being associated with one and only one of the plurality of processor cores, and a plurality of memories, each of the plurality of memories being associated with a different set of at least one of the plurality of processor cores and each of the plurality of memories being configured to be visible in a global memory address space such that the plurality of memories are visible to two or more of the plurality ofmore » processor cores.« less

Exposure to radiation accelerates normal brain aging and produces deficits in spatial learning and memory

NASA Astrophysics Data System (ADS)

Shukitt-Hale, B.; Casadesus, G.; Carey, A.; Rabin, B. M.; Joseph, J. A.

Previous studies have shown that radiation exposure, particularly to particles of high energy and charge (HZE particles), produces deficits in spatial learning and memory. These adverse behavioral effects are similar to those seen in aged animals. It is possible that these shared effects may be produced by the same mechanism; oxidative stress damage to the central nervous system caused by an increased release of reactive oxygen species is likely responsible for the deficits seen in aging and following irradiation. Both aged and irradiated rats display cognitive impairment in tests of spatial learning and memory such as the Morris water maze and the radial arm maze. These rats have decrements in the ability to build spatial representations of the environment and they utilize non-spatial strategies to solve tasks. Furthermore, they show a lack of spatial preference, due to a decline in the ability to process or retain place (position of a goal with reference to a "map" provided by the configuration of numerous cues in the environment) information. These declines in spatial memory occur in measures dependent on both reference and working memory, and in the flexibility to reset mental images. These results show that irradiation with high-energy particles produces age-like decrements in cognitive behavior that may impair the ability of astronauts to perform critical tasks during long-term space travel beyond the magnetosphere. Supported by NASA Grants NAG9-1190 and NAG9-1529

Advanced Health Management System for the Space Shuttle Main Engine

NASA Technical Reports Server (NTRS)

Davidson, Matt; Stephens, John; Rodela, Chris

2006-01-01

Pratt & Whitney Rocketdyne, Inc., in cooperation with NASA-Marshall Space Flight Center (MSFC), has developed a new Advanced Health Management System (AHMS) controller for the Space Shuttle Main Engine (SSME) that will increase the probability of successfully placing the shuttle into the intended orbit and increase the safety of the Space Transportation System (STS) launches. The AHMS is an upgrade o the current Block II engine controller whose primary component is an improved vibration monitoring system called the Real-Time Vibration Monitoring System (RTVMS) that can effectively and reliably monitor the state of the high pressure turbomachinery and provide engine protection through a new synchronous vibration redline which enables engine shutdown if the vibration exceeds predetermined thresholds. The introduction of this system required improvements and modification to the Block II controller such as redesigning the Digital Computer Unit (DCU) memory and the Flight Accelerometer Safety Cut-Off System (FASCOS) circuitry, eliminating the existing memory retention batteries, installation of the Digital Signal Processor (DSP) technology, and installation of a High Speed Serial Interface (HSSI) with accompanying outside world connectors. Test stand hot-fire testing along with lab testing have verified successful implementation and is expected to reduce the probability of catastrophic engine failures during the shuttle ascent phase and improve safely by about 23% according to the Quantitative Risk Assessment System (QRAS), leading to a safer and more reliable SSME.

The Impact on Space Radiation Requirements and Effects on ASIMS

NASA Technical Reports Server (NTRS)

Barnes, C.; Johnston, A.; Swift, G.

1995-01-01

The evolution of highly miniaturized electronic and mechanical systems will be accompanied by new problems and issues regarding the radiation response of these systems in the space environment. In this paper we discuss some of the more prominent radiation problems brought about by miniaturization. For example, autonomous micro-spacecraft will require large amounts of high density memory, most likely in the form of stacked, multichip modules of DRAM's, that must tolerate the radiation environment. However, advanced DRAM's (16 to 256 Mbit) are quite susceptible to radiation, particularly single event effects, and even exhibit new radiation phenomena that were not a problem for older, less dense memory chips. Another important trend in micro-spacecraft electronics is toward the use of low-voltage microelectronic systems that consume less power. However, the reduction in operating voltage also caries with it an increased susceptibility to radiation. In the case of application specific integrated microcircuits (ASIM's), advanced devices of this type, such as high density field programmable gate arrays (FPGA's) exhibit new single event effects (SEE), such as single particle reprogramming of anti-fuse links. New advanced bipolar circuits have been shown recently to degrade more rapidly in the low dose rate space environment than in the typical laboratory total dose radiation test used to qualify such devices. Thus total dose testing of these parts is no longer an appropriately conservative measure to be used for hardness assurance. We also note that the functionality of micromechanical Si-based devices may be altered due to the radiation-induced deposition of charge in the oxide passivation layers.

A multi-hypothesis tracker for clicking whales.

PubMed

Baggenstoss, Paul M

2015-05-01

This paper describes a tracker specially designed to track clicking beaked whales using widely spaced bottom-mounted hydrophones, although it can be adapted to different species and sensors. The input to the tracker is a sequence of static localization solutions obtained using time difference of arrival information at widely spaced hydrophones. To effectively handle input localizations with high ambiguity, the tracker is based on multi-hypothesis tracker concepts, so it considers all potential association hypotheses and keeps a large number of potential tracks in memory. The method is demonstrated on actual data and shown to successfully track multiple beaked whales at depth.

Robust holographic storage system design.

PubMed

Watanabe, Takahiro; Watanabe, Minoru

2011-11-21

Demand is increasing daily for large data storage systems that are useful for applications in spacecraft, space satellites, and space robots, which are all exposed to radiation-rich space environment. As candidates for use in space embedded systems, holographic storage systems are promising because they can easily provided the demanded large-storage capability. Particularly, holographic storage systems, which have no rotation mechanism, are demanded because they are virtually maintenance-free. Although a holographic memory itself is an extremely robust device even in a space radiation environment, its associated lasers and drive circuit devices are vulnerable. Such vulnerabilities sometimes engendered severe problems that prevent reading of all contents of the holographic memory, which is a turn-off failure mode of a laser array. This paper therefore presents a proposal for a recovery method for the turn-off failure mode of a laser array on a holographic storage system, and describes results of an experimental demonstration. © 2011 Optical Society of America

Paying attention to working memory: Similarities in the spatial distribution of attention in mental and physical space.

PubMed

Sahan, Muhammet Ikbal; Verguts, Tom; Boehler, Carsten Nicolas; Pourtois, Gilles; Fias, Wim

2016-08-01

Selective attention is not limited to information that is physically present in the external world, but can also operate on mental representations in the internal world. However, it is not known whether the mechanisms of attentional selection operate in similar fashions in physical and mental space. We studied the spatial distributions of attention for items in physical and mental space by comparing how successfully distractors were rejected at varying distances from the attended location. The results indicated very similar distribution characteristics of spatial attention in physical and mental space. Specifically, we found that performance monotonically improved with increasing distractor distance relative to the attended location, suggesting that distractor confusability is particularly pronounced for nearby distractors, relative to distractors farther away. The present findings suggest that mental representations preserve their spatial configuration in working memory, and that similar mechanistic principles underlie selective attention in physical and in mental space.

Pulaski Award Ceremony

NASA Image and Video Library

2017-11-01

From left, Col. Z. Walter Jackim, vice commander, 45th Space Wing, Cape Canaveral Air Force Station; Michael Good, assistant fire management officer, Merritt Island National Wildlife Refuge; John Fish, chief, Florida Forest Service; Mark Schollmeyer, chief, Brevard County Fire Rescue; and Kelvin Manning, associate director, NASA's Kennedy Space Center, pose for a portrait following a ceremony Nov. 1 on the Merritt Island National Wildlife Refuge in Florida. During the joint ceremony, the Spaceport Integration Team and its partners were presented with the prestigious 2017 Pulaski Award and a new memorial marker was dedicated. The multi-agency team includes representatives from NASA's Kennedy Space Center, Cape Canaveral Air Force Station's 45th Space Wing, the Merritt Island National Wildlife Refuge, as well as the Florida Forest Service and Brevard County Fire Rescue. The memorial marker honors two fallen firefighters, Scott Maness and Beau Sauselein, who died fighting a wildfire on space center property in 1981. Held outdoors, the ceremony was attended by 140 guests.

Evidence for a retinal velocity memory underlying the direction of anticipatory smooth pursuit eye movements.

PubMed

Murdison, T Scott; Paré-Bingley, Chanel A; Blohm, Gunnar

2013-08-01

To compute spatially correct smooth pursuit eye movements, the brain uses both retinal motion and extraretinal signals about the eyes and head in space (Blohm and Lefèvre 2010). However, when smooth eye movements rely solely on memorized target velocity, such as during anticipatory pursuit, it is unknown if this velocity memory also accounts for extraretinal information, such as head roll and ocular torsion. To answer this question, we used a novel behavioral updating paradigm in which participants pursued a repetitive, spatially constant fixation-gap-ramp stimulus in series of five trials. During the first four trials, participants' heads were rolled toward one shoulder, inducing ocular counterroll (OCR). With each repetition, participants increased their anticipatory pursuit gain, indicating a robust encoding of velocity memory. On the fifth trial, they rolled their heads to the opposite shoulder before pursuit, also inducing changes in ocular torsion. Consequently, for spatially accurate anticipatory pursuit, the velocity memory had to be updated across changes in head roll and ocular torsion. We tested how the velocity memory accounted for head roll and OCR by observing the effects of changes to these signals on anticipatory trajectories of the memory decoding (fifth) trials. We found that anticipatory pursuit was updated for changes in head roll; however, we observed no evidence of compensation for OCR, representing the absence of ocular torsion signals within the velocity memory. This indicated that the directional component of the memory must be coded retinally and updated to account for changes in head roll, but not OCR.

Efficient Graph Based Assembly of Short-Read Sequences on Hybrid Core Architecture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sczyrba, Alex; Pratap, Abhishek; Canon, Shane

2011-03-22

Advanced architectures can deliver dramatically increased throughput for genomics and proteomics applications, reducing time-to-completion in some cases from days to minutes. One such architecture, hybrid-core computing, marries a traditional x86 environment with a reconfigurable coprocessor, based on field programmable gate array (FPGA) technology. In addition to higher throughput, increased performance can fundamentally improve research quality by allowing more accurate, previously impractical approaches. We will discuss the approach used by Convey?s de Bruijn graph constructor for short-read, de-novo assembly. Bioinformatics applications that have random access patterns to large memory spaces, such as graph-based algorithms, experience memory performance limitations on cache-based x86more » servers. Convey?s highly parallel memory subsystem allows application-specific logic to simultaneously access 8192 individual words in memory, significantly increasing effective memory bandwidth over cache-based memory systems. Many algorithms, such as Velvet and other de Bruijn graph based, short-read, de-novo assemblers, can greatly benefit from this type of memory architecture. Furthermore, small data type operations (four nucleotides can be represented in two bits) make more efficient use of logic gates than the data types dictated by conventional programming models.JGI is comparing the performance of Convey?s graph constructor and Velvet on both synthetic and real data. We will present preliminary results on memory usage and run time metrics for various data sets with different sizes, from small microbial and fungal genomes to very large cow rumen metagenome. For genomes with references we will also present assembly quality comparisons between the two assemblers.« less

k(+)-buffer: An Efficient, Memory-Friendly and Dynamic k-buffer Framework.

PubMed

Vasilakis, Andreas-Alexandros; Papaioannou, Georgios; Fudos, Ioannis

2015-06-01

Depth-sorted fragment determination is fundamental for a host of image-based techniques which simulates complex rendering effects. It is also a challenging task in terms of time and space required when rasterizing scenes with high depth complexity. When low graphics memory requirements are of utmost importance, k-buffer can objectively be considered as the most preferred framework which advantageously ensures the correct depth order on a subset of all generated fragments. Although various alternatives have been introduced to partially or completely alleviate the noticeable quality artifacts produced by the initial k-buffer algorithm in the expense of memory increase or performance downgrade, appropriate tools to automatically and dynamically compute the most suitable value of k are still missing. To this end, we introduce k(+)-buffer, a fast framework that accurately simulates the behavior of k-buffer in a single rendering pass. Two memory-bounded data structures: (i) the max-array and (ii) the max-heap are developed on the GPU to concurrently maintain the k-foremost fragments per pixel by exploring pixel synchronization and fragment culling. Memory-friendly strategies are further introduced to dynamically (a) lessen the wasteful memory allocation of individual pixels with low depth complexity frequencies, (b) minimize the allocated size of k-buffer according to different application goals and hardware limitations via a straightforward depth histogram analysis and (c) manage local GPU cache with a fixed-memory depth-sorting mechanism. Finally, an extensive experimental evaluation is provided demonstrating the advantages of our work over all prior k-buffer variants in terms of memory usage, performance cost and image quality.

Radiation effects in reconfigurable FPGAs

NASA Astrophysics Data System (ADS)

Quinn, Heather

2017-04-01

Field-programmable gate arrays (FPGAs) are co-processing hardware used in image and signal processing. FPGA are programmed with custom implementations of an algorithm. These algorithms are highly parallel hardware designs that are faster than software implementations. This flexibility and speed has made FPGAs attractive for many space programs that need in situ, high-speed signal processing for data categorization and data compression. Most commercial FPGAs are affected by the space radiation environment, though. Problems with TID has restricted the use of flash-based FPGAs. Static random access memory based FPGAs must be mitigated to suppress errors from single-event upsets. This paper provides a review of radiation effects issues in reconfigurable FPGAs and discusses methods for mitigating these problems. With careful design it is possible to use these components effectively and resiliently.

A class Hierarchical, object-oriented approach to virtual memory management

NASA Technical Reports Server (NTRS)

Russo, Vincent F.; Campbell, Roy H.; Johnston, Gary M.

1989-01-01

The Choices family of operating systems exploits class hierarchies and object-oriented programming to facilitate the construction of customized operating systems for shared memory and networked multiprocessors. The software is being used in the Tapestry laboratory to study the performance of algorithms, mechanisms, and policies for parallel systems. Described here are the architectural design and class hierarchy of the Choices virtual memory management system. The software and hardware mechanisms and policies of a virtual memory system implement a memory hierarchy that exploits the trade-off between response times and storage capacities. In Choices, the notion of a memory hierarchy is captured by abstract classes. Concrete subclasses of those abstractions implement a virtual address space, segmentation, paging, physical memory management, secondary storage, and remote (that is, networked) storage. Captured in the notion of a memory hierarchy are classes that represent memory objects. These classes provide a storage mechanism that contains encapsulated data and have methods to read or write the memory object. Each of these classes provides specializations to represent the memory hierarchy.

Intermediate memory devices

NASA Technical Reports Server (NTRS)

Basalayev, G. V.; Kmet, A. B.; Rakov, M. A.; Tarasevich, V. A.

1974-01-01

Several methods of transfer and processing of data whose practical implementation requires operational memory devices are described. Devices incorporating multistable elements are proposed and their main parameters are given. The possibility of using the proposed devices for storing information for transmission in space radio communications channels is examined.

Facilitating the use of implicit memory and learning in the physical therapy management of individuals with Alzheimer disease: a case series.

PubMed

White, Laura; Ford, Matthew P; Brown, Cynthia J; Peel, Claire; Triebel, Kristen L

2014-01-01

Physical rehabilitation of individuals with Alzheimer disease (AD) is often complicated by impairments in explicit memory and learning. Rehabilitation strategies that facilitate the use of the preserved implicit memory system may be effective in treating patients with AD. The purpose of this case series is to describe the application of these strategies, including high-repetition practice, errorless learning (EL), and spaced retrieval, to the physical therapy management of individuals with moderate AD. Three women aged 89 to 95 years with moderate AD who resided in an assisted living facility participated in physical therapy to address their mobility limitations. Twelve physical therapy sessions were scheduled over a period of 4 weeks. Interventions were individually designed to address the mobility needs of each patient, and rehabilitation strategies based on implicit learning principles were integrated into the interventions. All patients participated in at least 10 of the 12 physical therapy sessions. Improvements in performance of objective measures of balance were observed in all patients, although only 1 patient's balance score exceeded the minimal detectable change. No significant clinical change was observed in any patients on the Timed Up and Go Test or self-selected gait speed. Principles of implicit learning were integrated into the interventions for these patients with moderate AD. However, the feasibility of applying the EL paradigm was limited. Further research on the effectiveness of EL, spaced retrieval, and other rehabilitation strategies that facilitate implicit learning of mobility skills in patients with AD is needed to promote optimal physical therapy outcomes in this patient population.

Space physiology II: adaptation of the central nervous system to space flight--past, current, and future studies.

PubMed

Clément, Gilles; Ngo-Anh, Jennifer Thu

2013-07-01

Experiments performed in orbit on the central nervous system have focused on the control of posture, eye movements, spatial orientation, as well as cognitive processes, such as three-dimensional visual perception and mental representation of space. Brain activity has also been recorded during and immediately after space flight for evaluating the changes in brain structure activation during tasks involving perception, attention, memory, decision, and action. Recent ground-based studies brought evidence that the inputs from the neurovestibular system also participate in orthostatic intolerance. It is, therefore, important to revisit the flight data of neuroscience studies in the light of new models of integrative physiology. The outcomes of this exercise will increase our knowledge on the adaptation of body functions to changing gravitational environment, vestibular disorders, aging, and our approach towards more effective countermeasures during human space flight and planetary exploration.

Biological and psychosocial effects of space travel: A case study

NASA Astrophysics Data System (ADS)

Hsia, Robert Edward Tien Ming

This dissertation interviewed a single astronaut to explore psychosocial issues relevant to long-duration space travel and how these issues relate to the astronaut's training. It examined the psychological impact of isolation, crew interaction, and the experience of microgravity with the goal of increasing understanding of how to foster crew survivability and positive small group interactions in space (Santy, 1994). It also focused on how to develop possible treatments for crews when they transition back to Earth from the extreme environment of space missions. The astronaut's responses agreed with the literature and the predictions for long-duration space missions except the participant reported no temporary or permanent cognitive or memory deficits due to microgravity exposure. The dissertation identified five frequently endorsed themes including communication, environmental stressors, personal strengths, un-researched problems, and other. The agreement found between the literature and astronaut's responses offer a strong foundation of questions and data that needs to be further studied before conducting research in space or long-duration space missions.

KENNEDY SPACE CENTER, FLA. - NASA's Associate Administrator for Space Flight William Readdy and Evelyn Husband, widow of astronaut Rick Husband, place a ceremonial wreath at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex. During this dedication ceremony, the names of the STS-107 astronauts who lost their lives during the Columbia accident -- Rick Husband, Willie McCool, Laurel Clark, Michael Anderson, David Brown, Kalpana Chawla, and Ilan Ramon -- join the names of 17 other space heroes who gave their lives for the U.S. space program. The "Space Mirror," 42 1/2 feet high by 50 feet wide, illuminates the names of the fallen astronauts cut through the monument's black granite surface.

NASA Image and Video Library

2003-10-28

KENNEDY SPACE CENTER, FLA. - NASA's Associate Administrator for Space Flight William Readdy and Evelyn Husband, widow of astronaut Rick Husband, place a ceremonial wreath at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex. During this dedication ceremony, the names of the STS-107 astronauts who lost their lives during the Columbia accident -- Rick Husband, Willie McCool, Laurel Clark, Michael Anderson, David Brown, Kalpana Chawla, and Ilan Ramon -- join the names of 17 other space heroes who gave their lives for the U.S. space program. The "Space Mirror," 42 1/2 feet high by 50 feet wide, illuminates the names of the fallen astronauts cut through the monument's black granite surface.

The Neural Representations Underlying Human Episodic Memory.

PubMed

Xue, Gui

2018-06-01

A fundamental question of human episodic memory concerns the cognitive and neural representations and processes that give rise to the neural signals of memory. By integrating behavioral tests, formal computational models, and neural measures of brain activity patterns, recent studies suggest that memory signals not only depend on the neural processes and representations during encoding and retrieval, but also on the interaction between encoding and retrieval (e.g., transfer-appropriate processing), as well as on the interaction between the tested events and all other events in the episodic memory space (e.g., global matching). In addition, memory signals are also influenced by the compatibility of the event with the existing long-term knowledge (e.g., schema matching). These studies highlight the interactive nature of human episodic memory. Copyright © 2018 Elsevier Ltd. All rights reserved.

Hierarchically clustered adaptive quantization CMAC and its learning convergence.

PubMed

Teddy, S D; Lai, E M K; Quek, C

2007-11-01

The cerebellar model articulation controller (CMAC) neural network (NN) is a well-established computational model of the human cerebellum. Nevertheless, there are two major drawbacks associated with the uniform quantization scheme of the CMAC network. They are the following: (1) a constant output resolution associated with the entire input space and (2) the generalization-accuracy dilemma. Moreover, the size of the CMAC network is an exponential function of the number of inputs. Depending on the characteristics of the training data, only a small percentage of the entire set of CMAC memory cells is utilized. Therefore, the efficient utilization of the CMAC memory is a crucial issue. One approach is to quantize the input space nonuniformly. For existing nonuniformly quantized CMAC systems, there is a tradeoff between memory efficiency and computational complexity. Inspired by the underlying organizational mechanism of the human brain, this paper presents a novel CMAC architecture named hierarchically clustered adaptive quantization CMAC (HCAQ-CMAC). HCAQ-CMAC employs hierarchical clustering for the nonuniform quantization of the input space to identify significant input segments and subsequently allocating more memory cells to these regions. The stability of the HCAQ-CMAC network is theoretically guaranteed by the proof of its learning convergence. The performance of the proposed network is subsequently benchmarked against the original CMAC network, as well as two other existing CMAC variants on two real-life applications, namely, automated control of car maneuver and modeling of the human blood glucose dynamics. The experimental results have demonstrated that the HCAQ-CMAC network offers an efficient memory allocation scheme and improves the generalization and accuracy of the network output to achieve better or comparable performances with smaller memory usages. Index Terms-Cerebellar model articulation controller (CMAC), hierarchical clustering, hierarchically clustered adaptive quantization CMAC (HCAQ-CMAC), learning convergence, nonuniform quantization.

Rating Training Continuum: Development Procedures

DTIC Science & Technology

1992-01-01

During the workshop, the SMEs will need to review technical documents to refresh their memory and resolve any technical issues. It is important that a...endorsement. 7 additional memory space was very useful. The computers with the 80-megabyte hard disk drive were used to collect all final PPPs and TLAs...description, general, and documentation). If you reed to refresh your memory , refer to Figure 3-5 for the definitions associated with the indirectly

Parametric and genetic analysis of Drosophila appetitive long-term memory and sugar motivation.

PubMed

Colomb, J; Kaiser, L; Chabaud, M-A; Preat, T

2009-06-01

Distinct forms of memory can be highlighted using different training protocols. In Drosophila olfactory aversive learning, one conditioning session triggers memory formation independently of protein synthesis, while five spaced conditioning sessions lead to the formation of long-term memory (LTM), a long-lasting memory dependent on de novo protein synthesis. In contrast, one session of odour-sugar association appeared sufficient for the fly to form LTM. We designed and tuned an apparatus that facilitates repeated discriminative conditioning by alternate presentations of two odours, one being associated with sugar, as well as a new paradigm to test sugar responsiveness (SR). Our results show that both SR and short-term memory (STM) scores increase with starvation length before conditioning. The protein dependency of appetitive LTM is independent of the repetition and the spacing of training sessions, on the starvation duration and on the strength of the unconditioned stimulus. In contrast to a recent report, our test measures an abnormal SR of radish mutant flies, which might initiate their STM and LTM phenotypes. In addition, our work shows that crammer and tequila mutants, which are deficient for aversive LTM, present both an SR and an appetitive STM defect. Using the MB247-P[switch] system, we further show that tequila is required in the adult mushroom bodies for normal sugar motivation.

Exploring the Structure of Spatial Representations

PubMed Central

Madl, Tamas; Franklin, Stan; Chen, Ke; Trappl, Robert; Montaldi, Daniela

2016-01-01

It has been suggested that the map-like representations that support human spatial memory are fragmented into sub-maps with local reference frames, rather than being unitary and global. However, the principles underlying the structure of these ‘cognitive maps’ are not well understood. We propose that the structure of the representations of navigation space arises from clustering within individual psychological spaces, i.e. from a process that groups together objects that are close in these spaces. Building on the ideas of representational geometry and similarity-based representations in cognitive science, we formulate methods for learning dissimilarity functions (metrics) characterizing participants’ psychological spaces. We show that these learned metrics, together with a probabilistic model of clustering based on the Bayesian cognition paradigm, allow prediction of participants’ cognitive map structures in advance. Apart from insights into spatial representation learning in human cognition, these methods could facilitate novel computational tools capable of using human-like spatial concepts. We also compare several features influencing spatial memory structure, including spatial distance, visual similarity and functional similarity, and report strong correlations between these dimensions and the grouping probability in participants’ spatial representations, providing further support for clustering in spatial memory. PMID:27347681

Sptrace

NASA Technical Reports Server (NTRS)

Burleigh, Scott C.

2011-01-01

Sptrace is a general-purpose space utilization tracing system that is conceptually similar to the commercial Purify product used to detect leaks and other memory usage errors. It is designed to monitor space utilization in any sort of heap, i.e., a region of data storage on some device (nominally memory; possibly shared and possibly persistent) with a flat address space. This software can trace usage of shared and/or non-volatile storage in addition to private RAM (random access memory). Sptrace is implemented as a set of C function calls that are invoked from within the software that is being examined. The function calls fall into two broad classes: (1) functions that are embedded within the heap management software [e.g., JPL's SDR (Simple Data Recorder) and PSM (Personal Space Management) systems] to enable heap usage analysis by populating a virtual time-sequenced log of usage activity, and (2) reporting functions that are embedded within the application program whose behavior is suspect. For ease of use, these functions may be wrapped privately inside public functions offered by the heap management software. Sptrace can be used for VxWorks or RTEMS realtime systems as easily as for Linux or OS/X systems.

zorder-lib: Library API for Z-Order Memory Layout

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nowell, Lucy; Edward W. Bethel

2015-04-01

This document describes the motivation for, elements of, and use of the zorder-lib, a library API that implements organization of and access to data in memory using either a-order (also known as "row-major" order) or z-order memory layouts. The primary motivation for this work is to improve the performance of many types of data- intensive codes by increasing both spatial and temporal locality of memory accesses. The basic idea is that the cost associated with accessing a datum is less when it is nearby in either space or time.

2014-1288

NASA Image and Video Library

2014-01-31

CAPE CANAVERAL, Fla. -- Kennedy Space Center Employees and guests placed flowers at the Space Mirror Memorial at the spaceport's Visitor Complex during NASA's Day of Remembrance. A brief ceremony honored the astronauts of Apollo 1, who were lost in 1967, the shuttle Challenger crew, who perished in 1986, the space shuttle Columbia astronauts who were lost in 2003, as well as other astronauts who gave their lives while furthering the cause of exploration and discovery. Dedicated in 1991, the names of fallen astronauts are emblazoned the monument's 4.5-foot-high-by-50-foot-wide polished black granite surface which reflects the sky and has been designated by Congress as a National Memorial. Photo credit: NASA/Dimitri Gerondidakis

Pulaski Award Ceremony

NASA Image and Video Library

2017-11-01

A presentation of colors by the U.S. Fish and Wildlife Service honor guard opened a ceremony Nov. 1 on the Merritt Island National Wildlife Refuge in Florida. During the joint ceremony, the Spaceport Integration Team and its partners were presented with the prestigious 2017 Pulaski Award and the new memorial marker was dedicated. The multi-agency team includes representatives from NASA's Kennedy Space Center, Cape Canaveral Air Force Station's 45th Space Wing, the Merritt Island National Wildlife Refuge, as well as the Florida Forest Service and Brevard County Fire Rescue. The memorial marker honors two fallen firefighters, Scott Maness and Beau Sauselein, who died fighting a wildfire on space center property in 1981. Held outdoors, the ceremony was attended by 140 guests.

KSC-05PD-0565

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. In the Vehicle Assembly Building at NASAs Kennedy Space Center, a digital still camera has been mounted in the External Tank (ET) umbilical well on the aft end of Space Shuttle Discovery. The camera is being used to obtain and downlink high-resolution images of the disconnect point on the ET following ET separation from the orbiter after launch. The Kodak camera will record 24 images, at one frame per 1.5 seconds, on a flash memory card. After orbital insertion, the crew will transfer the images from the memory card to a laptop computer. The files will then be downloaded through the Ku-band system to the Mission Control Center in Houston for analysis.

KSC-05PD-0562

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. In the Vehicle Assembly Building at NASAs Kennedy Space Center, workers check the digital still camera they will mount in the External Tank (ET) umbilical well on the aft end of Space Shuttle Discovery. The camera is being used to obtain and downlink high-resolution images of the disconnect point on the ET following the tank's separation from the orbiter after launch. The Kodak camera will record 24 images, at one frame per 1.5 seconds, on a flash memory card. After orbital insertion, the crew will transfer the images from the memory card to a laptop computer. The files will then be downloaded through the Ku-band system to the Mission Control Center in Houston for analysis.

KSC-05PD-0564

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. In the Vehicle Assembly Building at NASAs Kennedy Space Center, a worker mounts a digital still camera in the External Tank (ET) umbilical well on the aft end of Space Shuttle Discovery. The camera is being used to obtain and downlink high-resolution images of the disconnect point on the ET following the ET separation from the orbiter after launch. The Kodak camera will record 24 images, at one frame per 1.5 seconds, on a flash memory card. After orbital insertion, the crew will transfer the images from the memory card to a laptop computer. The files will then be downloaded through the Ku-band system to the Mission Control Center in Houston for analysis.

KSC-05PD-0561

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. In the Vehicle Assembly Building at NASAs Kennedy Space Center, workers prepare a digital still camera they will mount in the External Tank (ET) umbilical well on the aft end of Space Shuttle Discovery. The camera is being used to obtain and downlink high-resolution images of the disconnect point on the ET following its separation from the orbiter after launch. The Kodak camera will record 24 images, at one frame per 1.5 seconds, on a flash memory card. After orbital insertion, the crew will transfer the images from the memory card to a laptop computer. The files will then be downloaded through the Ku-band system to the Mission Control Center in Houston for analysis.

KSC-05PD-0563

NASA Technical Reports Server (NTRS)

2005-01-01

KENNEDY SPACE CENTER, FLA. In the Vehicle Assembly Building at NASAs Kennedy Space Center, workers prepare a digital still camera they will mount in the External Tank (ET) umbilical well on the aft end of Space Shuttle Discovery. The camera is being used to obtain and downlink high-resolution images of the disconnect point on the ET following the ET separation from the orbiter after launch. The Kodak camera will record 24 images, at one frame per 1.5 seconds, on a flash memory card. After orbital insertion, the crew will transfer the images from the memory card to a laptop computer. The files will then be downloaded through the Ku-band system to the Mission Control Center in Houston for analysis.

Pulaski Award Ceremony

NASA Image and Video Library

2017-11-01

Layne Hamilton, manager of the Merritt Island National Wildlife Refuge, welcomes guests to a ceremony held Nov. 1 on the refuge in Florida. During the joint ceremony, the Spaceport Integration Team and its partners were presented with the prestigious 2017 Pulaski Award and a new memorial marker was dedicated. The multi-agency team includes representatives from NASA's Kennedy Space Center, Cape Canaveral Air Force Station's 45th Space Wing, the Merritt Island National Wildlife Refuge, as well as the Florida Forest Service and Brevard County Fire Rescue. The memorial marker honors two fallen firefighters, Scott Maness and Beau Sauselein, who died fighting a wildfire on space center property in 1981. Held outdoors, the ceremony was attended by 140 guests.

KSC-03pd0267

NASA Image and Video Library

2003-02-05

KENNEDY SPACE CENTER, FLA. - Employees at KSC reveal emotion as they watch the memorial service for the fallen seven astronauts of Columbia being held at Johnson Space Center, Houston, and broadcast on NASA television. .

KSC-03PD-0267

NASA Technical Reports Server (NTRS)

2003-01-01

KENNEDY SPACE CENTER, FLA. - Employees at KSC reveal emotion as they watch the memorial service for the fallen seven astronauts of Columbia being held at Johnson Space Center, Houston, and broadcast on NASA television. .

From "Double Vision" to Panorama: Using History of Memory to Bridge "Event Space" When Exploring Interpretations of Nazi Popularity with Year 13

ERIC Educational Resources Information Center

Carroll, James Edward

2017-01-01

Jim Carroll relished the opportunity, in the new A-level specification he was teaching, to find an effective way of teaching his students to analyse interpretations in their coursework essays. Reflecting on the difficulties he had faced as a trainee teacher teaching younger pupils about interpretations, and dissatisfied with examination board…

The effects of background noise on cognitive performance during a 70 hour simulation of conditions aboard the International Space Station.

PubMed

Smith, D G; Baranski, J V; Thompson, M M; Abel, S M

2003-01-01

A total of twenty-five subjects were cloistered for a period of 70 hours, five at a time, in a hyperbaric chamber modified to simulate the conditions aboard the International Space Station (ISS). A recording of 72 dBA background noise from the ISS service module was used to simulate noise conditions on the ISS. Two groups experienced the background noise throughout the experiment, two other groups experienced the noise only during the day, and one control group was cloistered in a quiet environment. All subjects completed a battery of cognitive tests nine times throughout the experiment. The data showed little or no effect of noise on reasoning, perceptual decision-making, memory, vigilance, mood, or subjective indices of fatigue. Our results suggest that the level of noise on the space station should not affect cognitive performance, at least over a period of several days.

2018 NASA Day of Remembrance

NASA Image and Video Library

2018-01-25

A memorial wreath stands in the Center for Space Education during this year's Day of Remembrance ceremony at the Kennedy Space Center Visitor Complex. Each year spaceport employees and guests join others throughout NASA honoring the contributions of astronauts who have perished in the conquest of space.

Retrieval practice as an effective memory strategy in children and adolescents with traumatic brain injury.

PubMed

Coyne, Julia H; Borg, Jacquelyn M; DeLuca, John; Glass, Leslie; Sumowski, James F

2015-04-01

To investigate whether retrieval practice (RP) is a more effective memory strategy than restudy in children and adolescents with traumatic brain injury (TBI). Three × two within-subjects experiment: 3 (learning condition: massed restudy [MR], spaced restudy [SR], retrieval practice [RP]) × 2 (stimulus type: verbal paired associates [VPAs] and face-name pairs [FNPs]). The dependent measure was delayed recall of VPAs and FNPs. Subacute pediatric neurorehabilitation center. Pediatric survivors of TBI (N=15) aged 8 to 16 years with below-average memory. During RP, participants were quizzed on to-be-learned information (VPAs and FNPs) shortly after it was presented, such that they practiced retrieval during the learning phase. MR consisted of repeated restudy (tantamount to cramming). SR consisted of restudy trials separated in time (ie, distributed learning). Delayed recall of 24 VPAs and 24 FNPs after a 25-minute delay. VPAs and FNPs were equally divided across 3 learning conditions (16 per condition). There was a large main effect of learning condition on delayed recall (P<.001; ηp(2)=.84), with better mean recall of VPAs and FNPs studied through RP (6.23±1.39) relative to MR (3.60±1.53; P<.001) and SR (4.77±1.39; P<.001). Moreover, RP was the single best learning strategy for every participant. Memory problems and related academic learning difficulties are common after pediatric TBI. Herein, we identify RP as a promising and simple strategy to support learning and improve memory in children and adolescents with TBI. Our experimental findings were quite robust and set the stage for subsequent randomized controlled trials of RP in pediatric TBI. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Grain size of recall practice for lengthy text material: fragile and mysterious effects on memory.

PubMed

Wissman, Kathryn T; Rawson, Katherine A

2015-03-01

The current research evaluated the extent to which the grain size of recall practice for lengthy text material affects recall during practice and subsequent memory. The grain size hypothesis states that a smaller vs. larger grain size will increase retrieval success during practice that in turn will enhance subsequent memory for lengthy text material. Participants were prompted to recall directly after studying each section (section recall) or after all sections had been studied (whole-text recall) during practice, and then all participants completed a final test after a delay. Results across 7 experiments (including 587 participants and 1,394 recall protocols) partially disconfirmed the predictions of the grain size hypothesis: Although the smaller grain size produced sizable recall advantages during practice as expected (ds from 1.02 to 1.87 across experiments), the advantage was substantially or completely attenuated across a delay. Experiments 2-7 falsified several plausible methodological and theoretical explanations for the fragility of the effect, indicating that it was not due to particular text materials, retrieval from working memory during practice, the length of the retention interval, the spacing between study and practice recall, a disproportionate increase in recall of unimportant details, or a deficit in integration of ideas across text sections. In sum, results conclusively establish an initially sizable but mysteriously fragile effect of grain size, for which an explanation remains elusive. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Memory assisted free space quantum communication

NASA Astrophysics Data System (ADS)

Jordaan, Bertus; Namazi, Mehdi; Goham, Connor; Shahrokhshahi, Reihaneh; Vallone, Giuseppe; Villoresi, Paolo; Figueroa, Eden

2016-05-01

A quantum memory assisted node between different quantum channels has the capability to modify and synchronize its output, allowing for easy connectivity, and advanced cryptography protocols. We present the experimental progress towards the storage of single photon level pulses carrying random polarization qubits into a dual rail room temperature quantum memory (RTQM) after ~ 20m of free space propagation. The RTQM coherently stores the input pulses through electromagnetically induced transparency (EIT) of a warm 87 Rb vapor and filters the output by polarization elements and temperature-controlled etalon resonators. This allows the characterization of error rates for each polarization basis and the testing of the synchronization ability of the quantum memory. This work presents a steppingstone towards quantum key distribution and quantum repeater networks. The work was supported by the US-Navy Office of Naval Research, Grant Number N00141410801 and the Simons Foundation, Grant Number SBF241180.B. J. acknowledges financial assistance of the National Research Foundation (NRF) of South Africa.

Analytical Solutions, Moments, and Their Asymptotic Behaviors for the Time-Space Fractional Cable Equation

NASA Astrophysics Data System (ADS)

Li, Can; Deng, Wei-Hua

2014-07-01

Following the fractional cable equation established in the letter [B.I. Henry, T.A.M. Langlands, and S.L. Wearne, Phys. Rev. Lett. 100 (2008) 128103], we present the time-space fractional cable equation which describes the anomalous transport of electrodiffusion in nerve cells. The derivation is based on the generalized fractional Ohm's law; and the temporal memory effects and spatial-nonlocality are involved in the time-space fractional model. With the help of integral transform method we derive the analytical solutions expressed by the Green's function; the corresponding fractional moments are calculated; and their asymptotic behaviors are discussed. In addition, the explicit solutions of the considered model with two different external current injections are also presented.

The role of spatial memory and frames of reference in the precision of angular path integration.

PubMed

Arthur, Joeanna C; Philbeck, John W; Kleene, Nicholas J; Chichka, David

2012-09-01

Angular path integration refers to the ability to maintain an estimate of self-location after a rotational displacement by integrating internally-generated (idiothetic) self-motion signals over time. Previous work has found that non-sensory inputs, namely spatial memory, can play a powerful role in angular path integration (Arthur et al., 2007, 2009). Here we investigated the conditions under which spatial memory facilitates angular path integration. We hypothesized that the benefit of spatial memory is particularly likely in spatial updating tasks in which one's self-location estimate is referenced to external space. To test this idea, we administered passive, non-visual body rotations (ranging 40°-140°) about the yaw axis and asked participants to use verbal reports or open-loop manual pointing to indicate the magnitude of the rotation. Prior to some trials, previews of the surrounding environment were given. We found that when participants adopted an egocentric frame of reference, the previously-observed benefit of previews on within-subject response precision was not manifested, regardless of whether remembered spatial frameworks were derived from vision or spatial language. We conclude that the powerful effect of spatial memory is dependent on one's frame of reference during self-motion updating. Copyright © 2012 Elsevier B.V. All rights reserved.

Memory and the Korsakoff syndrome: not remembering what is remembered.

PubMed

d'Ydewalle, Géry; Van Damme, Ilse

2007-03-14

Following the distinction between involuntary unconscious memory, involuntary conscious memory, and intentional retrieval, the focus of the present paper is whether there is an impairment of involuntary conscious memory among Korsakoff patients. At study, participants generated associations versus counted the number of letters with enclosed spaces or the number of vowels in the target words (semantic versus perceptual processing). In the Direct tests, stems were to be used to retrieve the targets with either guessing or no guessing allowed; in the Opposition tests, the stems were to be completed with the first word that came to mind but using another word if that first word was a target word; and in the Indirect tests, no reference was made to the target words from the study phase. In the Direct tests, the performance of Korsakoff patients was not necessarily worse than the one of healthy controls, provided guessing was allowed. More critical for the Korsakoff patients was the deficient involuntary conscious memory. The deficiency explained the suppression failures in the Opposition tests, the absence of performance differences between the Indirect and Opposition tests, the absence of a beneficial effect in providing information about the status of the stem, the performance boost when allowed to guess, and the very low rate of "Know"/"Remember" responses.

Statistical quantifiers of memory for an analysis of human brain and neuro-system diseases

NASA Astrophysics Data System (ADS)

Demin, S. A.; Yulmetyev, R. M.; Panischev, O. Yu.; Hänggi, Peter

2008-03-01

On the basis of a memory function formalism for correlation functions of time series we investigate statistical memory effects by the use of appropriate spectral and relaxation parameters of measured stochastic data for neuro-system diseases. In particular, we study the dynamics of the walk of a patient who suffers from Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS), and compare against the data of healthy people (CO - control group). We employ an analytical method which is able to characterize the stochastic properties of stride-to-stride variations of gait cycle timing. Our results allow us to estimate quantitatively a few human locomotion function abnormalities occurring in the human brain and in the central nervous system (CNS). Particularly, the patient's gait dynamics are characterized by an increased memory behavior together with sizable fluctuations as compared with the locomotion dynamics of healthy patients. Moreover, we complement our findings with peculiar features as detected in phase-space portraits and spectral characteristics for the different data sets (PD, HD, ALS and healthy people). The evaluation of statistical quantifiers of the memory function is shown to provide a useful toolkit which can be put to work to identify various abnormalities of locomotion dynamics. Moreover, it allows one to diagnose qualitatively and quantitatively serious brain and central nervous system diseases.

Position, scale, and rotation invariant holographic associative memory

NASA Astrophysics Data System (ADS)

Fielding, Kenneth H.; Rogers, Steven K.; Kabrisky, Matthew; Mills, James P.

1989-08-01

This paper describes the development and characterization of a holographic associative memory (HAM) system that is able to recall stored objects whose inputs were changed in position, scale, and rotation. The HAM is based on the single iteration model described by Owechko et al. (1987); however, the system described uses a self-pumped BaTiO3 phase conjugate mirror, rather than a degenerate four-wave mixing proposed by Owechko and his coworkers. The HAM system can store objects in a position, scale, and rotation invariant feature space. The angularly multiplexed diffuse Fourier transform holograms of the HAM feature space are characterized as the memory unit; distorted input objects are correlated with the hologram, and the nonlinear phase conjugate mirror reduces cross-correlation noise and provides object discrimination. Applications of the HAM system are presented.

Advanced Compact Holographic Data Storage System

NASA Technical Reports Server (NTRS)

Chao, Tien-Hsin; Zhou, Hanying; Reyes, George

2000-01-01

JPL, under current sponsorship from NASA Space Science and Earth Science Programs, is developing a high-density, nonvolatile and rad-hard Advanced Holographic Memory (AHM) system to enable large-capacity, high-speed, low power consumption, and read/write of data in a space environment. The entire read/write operation will be controlled with electro-optic mechanism without any moving parts. This CHDS will consist of laser diodes, photorefractive crystal, spatial light modulator, photodetector array, and I/O electronic interface. In operation, pages of information would be recorded and retrieved with random access and highspeed. The nonvolatile, rad-hard characteristics of the holographic memory will provide a revolutionary memory technology to enhance mission capabilities for all NASA's Earth Science Mission. In this paper, recent technology progress in developing this CHDS at JPL will be presented.

Mary J. "Niki" Werkheiser presented Space Technology Award

NASA Image and Video Library

2017-10-26

Mary J. "Niki" Werkheiser is presented the 2016 Space Technology Award during proceedings at the 10th annual Dr. Wernher von Braun Memorial Symposium at the University of Alabama, Huntsville, Alabama.

Methods for Effective Virtual Screening and Scaffold-Hopping in Chemical Compounds

DTIC Science & Technology

2007-04-04

contains color images. 14. ABSTRACT 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 12 19a...Opterons with 4 GB of memory . We used the descriptor- spaces GF, ECZ3, and ErG (described in Section 4) for the evaluating the methods introduced in...screening: Use of data fusion and machine learning to enchance the effectiveness of sim- ilarity searching. J. Chem. Info. Model., (46):462–470, 2006. [18] J

Major Robert Lawrence Memorial Tribute

NASA Image and Video Library

2017-12-08

During an Astronauts Memorial Foundation tribute honoring U.S. Air Foce Maj. Robert Lawrence, The Winston Scott “Cosmic Jazz Ensemble” performed. Participants are, from the left, former NASA astronaut Winston Scott playing trumpet, Al Dodds on bass, Stan Soloko playing drums, vocalist Shyrl “Lady Tandy” Johnson, and Ron Teixeira playing piano. Selected in 1967 for the Manned Orbiting Laboratory Program, Lawrence was the first African-American astronaut. He lost his life in a training accident 50 years ago. The ceremony took place in the Center for Space Education at the Kennedy Space Center Visitor Complex.

Flexible Kernel Memory

PubMed Central

Nowicki, Dimitri; Siegelmann, Hava

2010-01-01

This paper introduces a new model of associative memory, capable of both binary and continuous-valued inputs. Based on kernel theory, the memory model is on one hand a generalization of Radial Basis Function networks and, on the other, is in feature space, analogous to a Hopfield network. Attractors can be added, deleted, and updated on-line simply, without harming existing memories, and the number of attractors is independent of input dimension. Input vectors do not have to adhere to a fixed or bounded dimensionality; they can increase and decrease it without relearning previous memories. A memory consolidation process enables the network to generalize concepts and form clusters of input data, which outperforms many unsupervised clustering techniques; this process is demonstrated on handwritten digits from MNIST. Another process, reminiscent of memory reconsolidation is introduced, in which existing memories are refreshed and tuned with new inputs; this process is demonstrated on series of morphed faces. PMID:20552013

Precision of working memory for speech sounds.

PubMed

Joseph, Sabine; Iverson, Paul; Manohar, Sanjay; Fox, Zoe; Scott, Sophie K; Husain, Masud

2015-01-01

Memory for speech sounds is a key component of models of verbal working memory (WM). But how good is verbal WM? Most investigations assess this using binary report measures to derive a fixed number of items that can be stored. However, recent findings in visual WM have challenged such "quantized" views by employing measures of recall precision with an analogue response scale. WM for speech sounds might rely on both continuous and categorical storage mechanisms. Using a novel speech matching paradigm, we measured WM recall precision for phonemes. Vowel qualities were sampled from a formant space continuum. A probe vowel had to be adjusted to match the vowel quality of a target on a continuous, analogue response scale. Crucially, this provided an index of the variability of a memory representation around its true value and thus allowed us to estimate how memories were distorted from the original sounds. Memory load affected the quality of speech sound recall in two ways. First, there was a gradual decline in recall precision with increasing number of items, consistent with the view that WM representations of speech sounds become noisier with an increase in the number of items held in memory, just as for vision. Based on multidimensional scaling (MDS), the level of noise appeared to be reflected in distortions of the formant space. Second, as memory load increased, there was evidence of greater clustering of participants' responses around particular vowels. A mixture model captured both continuous and categorical responses, demonstrating a shift from continuous to categorical memory with increasing WM load. This suggests that direct acoustic storage can be used for single items, but when more items must be stored, categorical representations must be used.

2017 A Day of Remembrance

NASA Image and Video Library

2017-01-26

Following Kennedy Space Center's Day of Remembrance ceremony in the Center for Space Education at the Kennedy visitor complex, guests including astronauts Tom Stafford, left, and Buzz Aldrin, center, gathered to place flowers at the Space Mirror Memorial. Many of those in attendance were family members of the fallen astronauts.

KENNEDY SPACE CENTER, FLA. - Family members of the STS-107 astronauts and other dignitaries attend a dedication ceremony at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex. During this solemn event, the names of the STS-107 astronauts who lost their lives during the Columbia accident -- Rick Husband, Willie McCool, Laurel Clark, Michael Anderson, David Brown, Kalpana Chawla, and Ilan Ramon -- join the names of 17 other space heroes who gave their lives for the U.S. space program. The "Space Mirror," 42 1/2 feet high by 50 feet wide, illuminates the names of the fallen astronauts cut through the monument's black granite surface.

NASA Image and Video Library

2003-10-28

KENNEDY SPACE CENTER, FLA. - Family members of the STS-107 astronauts and other dignitaries attend a dedication ceremony at the Space Mirror Memorial at the Kennedy Space Center Visitor Complex. During this solemn event, the names of the STS-107 astronauts who lost their lives during the Columbia accident -- Rick Husband, Willie McCool, Laurel Clark, Michael Anderson, David Brown, Kalpana Chawla, and Ilan Ramon -- join the names of 17 other space heroes who gave their lives for the U.S. space program. The "Space Mirror," 42 1/2 feet high by 50 feet wide, illuminates the names of the fallen astronauts cut through the monument's black granite surface.

Discrete-time Quantum Walks via Interchange Framework and Memory in Quantum Evolution

NASA Astrophysics Data System (ADS)

Dimcovic, Zlatko

One of the newer and rapidly developing approaches in quantum computing is based on "quantum walks," which are quantum processes on discrete space that evolve in either discrete or continuous time and are characterized by mixing of components at each step. The idea emerged in analogy with the classical random walks and stochastic techniques, but these unitary processes are very different even as they have intriguing similarities. This thesis is concerned with study of discrete-time quantum walks. The original motivation from classical Markov chains required for discrete-time quantum walks that one adds an auxiliary Hilbert space, unrelated to the one in which the system evolves, in order to be able to mix components in that space and then take the evolution steps accordingly (based on the state in that space). This additional, "coin," space is very often an internal degree of freedom like spin. We have introduced a general framework for construction of discrete-time quantum walks in a close analogy with the classical random walks with memory that is rather different from the standard "coin" approach. In this method there is no need to bring in a different degree of freedom, while the full state of the system is still described in the direct product of spaces (of states). The state can be thought of as an arrow pointing from the previous to the current site in the evolution, representing the one-step memory. The next step is then controlled by a single local operator assigned to each site in the space, acting quite like a scattering operator. This allows us to probe and solve some problems of interest that have not had successful approaches with "coined" walks. We construct and solve a walk on the binary tree, a structure of great interest but until our result without an explicit discrete time quantum walk, due to difficulties in managing coin spaces necessary in the standard approach. Beyond algorithmic interests, the model based on memory allows one to explore effects of history on the quantum evolution and the subtle emergence of classical features as "memory" is explicitly kept for additional steps. We construct and solve a walk with an additional correlation step, finding interesting new features. On the other hand, the fact that the evolution is driven entirely by a local operator, not involving additional spaces, enables us to choose the Fourier transform as an operator completely controlling the evolution. This in turn allows us to combine the quantum walk approach with Fourier transform based techniques, something decidedly not possible in classical computational physics. We are developing a formalism for building networks manageable by walks constructed with this framework, based on the surprising efficiency of our framework in discovering internals of a simple network that we so far solved. Finally, in line with our expectation that the field of quantum walks can take cues from the rich history of development of the classical stochastic techniques, we establish starting points for the work on non-Abelian quantum walks, with a particular quantum-walk analog of the classical "card shuffling," the walk on the permutation group. In summary, this thesis presents a new framework for construction of discrete time quantum walks, employing and exploring memoried nature of unitary evolution. It is applied to fully solving the problems of: A walk on the binary tree and exploration of the quantum-to-classical transition with increased correlation length (history). It is then used for simple network discovery, and to lay the groundwork for analysis of complex networks, based on combined power of efficient exploration of the Hilbert space (as a walk mixing components) and Fourier transformation (since we can choose this for the evolution operator). We hope to establish this as a general technique as its power would be unmatched by any approaches available in the classical computing. We also looked at the promising and challenging prospect of walks on non-Abelian structures by setting up the problem of "quantum card shuffling," a quantum walk on the permutation group. Relation to other work is thoroughly discussed throughout, along with examination of the context of our work and overviews of our current and future work.

The road to virtual: the Sauls Memorial Virtual Library journey.

PubMed

Waddell, Stacie; Harkness, Amy; Cohen, Mark L

2014-01-01

The Sauls Memorial Virtual Library closed its physical space in 2012. This article outlines the reasons for this change and how the library staff and hospital leadership planned and executed the enormous undertaking. Outcomes of the change and lessons learned from the process are discussed.