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Sample records for memory gijutsu energy

  1. Memory device for two-dimensional radiant energy array computers

    NASA Technical Reports Server (NTRS)

    Schaefer, D. H.; Strong, J. P., III (Inventor)

    1977-01-01

    A memory device for two dimensional radiant energy array computers was developed, in which the memory device stores digital information in an input array of radiant energy digital signals that are characterized by ordered rows and columns. The memory device contains a radiant energy logic storing device having a pair of input surface locations for receiving a pair of separate radiant energy digital signal arrays and an output surface location adapted to transmit a radiant energy digital signal array. A regenerative feedback device that couples one of the input surface locations to the output surface location in a manner for causing regenerative feedback is also included

  2. Aging, memory, and nonhierarchical energy landscape of spin jam.

    PubMed

    Samarakoon, Anjana; Sato, Taku J; Chen, Tianran; Chern, Gai-Wei; Yang, Junjie; Klich, Israel; Sinclair, Ryan; Zhou, Haidong; Lee, Seung-Hun

    2016-10-18

    The notion of complex energy landscape underpins the intriguing dynamical behaviors in many complex systems ranging from polymers, to brain activity, to social networks and glass transitions. The spin glass state found in dilute magnetic alloys has been an exceptionally convenient laboratory frame for studying complex dynamics resulting from a hierarchical energy landscape with rugged funnels. Here, we show, by a bulk susceptibility and Monte Carlo simulation study, that densely populated frustrated magnets in a spin jam state exhibit much weaker memory effects than spin glasses, and the characteristic properties can be reproduced by a nonhierarchical landscape with a wide and nearly flat but rough bottom. Our results illustrate that the memory effects can be used to probe different slow dynamics of glassy materials, hence opening a window to explore their distinct energy landscapes.

  3. Aging, memory, and nonhierarchical energy landscape of spin jam

    PubMed Central

    Samarakoon, Anjana; Sato, Taku J.; Chen, Tianran; Chern, Gai-Wei; Yang, Junjie; Klich, Israel; Sinclair, Ryan; Zhou, Haidong; Lee, Seung-Hun

    2016-01-01

    The notion of complex energy landscape underpins the intriguing dynamical behaviors in many complex systems ranging from polymers, to brain activity, to social networks and glass transitions. The spin glass state found in dilute magnetic alloys has been an exceptionally convenient laboratory frame for studying complex dynamics resulting from a hierarchical energy landscape with rugged funnels. Here, we show, by a bulk susceptibility and Monte Carlo simulation study, that densely populated frustrated magnets in a spin jam state exhibit much weaker memory effects than spin glasses, and the characteristic properties can be reproduced by a nonhierarchical landscape with a wide and nearly flat but rough bottom. Our results illustrate that the memory effects can be used to probe different slow dynamics of glassy materials, hence opening a window to explore their distinct energy landscapes. PMID:27698141

  4. Aging, memory, and nonhierarchical energy landscape of spin jam

    NASA Astrophysics Data System (ADS)

    Samarakoon, Anjana; Sato, Taku J.; Chen, Tianran; Chern, Gai-Wei; Yang, Junjie; Klich, Israel; Sinclair, Ryan; Zhou, Haidong; Lee, Seung-Hun

    2016-10-01

    The notion of complex energy landscape underpins the intriguing dynamical behaviors in many complex systems ranging from polymers, to brain activity, to social networks and glass transitions. The spin glass state found in dilute magnetic alloys has been an exceptionally convenient laboratory frame for studying complex dynamics resulting from a hierarchical energy landscape with rugged funnels. Here, we show, by a bulk susceptibility and Monte Carlo simulation study, that densely populated frustrated magnets in a spin jam state exhibit much weaker memory effects than spin glasses, and the characteristic properties can be reproduced by a nonhierarchical landscape with a wide and nearly flat but rough bottom. Our results illustrate that the memory effects can be used to probe different slow dynamics of glassy materials, hence opening a window to explore their distinct energy landscapes.

  5. Shape memory alloy heat engines and energy harvesting systems

    SciTech Connect

    Browne, Alan L; Johnson, Nancy L; Keefe, Andrew C; Alexander, Paul W; Sarosi, Peter Maxwell; Herrera, Guillermo A; Yates, James Ryan

    2013-12-17

    A heat engine includes a first rotatable pulley and a second rotatable pulled spaced from the first rotatable pulley. A shape memory alloy (SMA) element is disposed about respective portions of the pulleys at an SMA pulley ratio. The SMA element includes first spring coil and a first fiber core within the first spring coil. A timing cable is disposed about disposed about respective portions of the pulleys at a timing pulley ratio, which is different than the SMA pulley ratio. The SMA element converts a thermal energy gradient between the hot region and the cold region into mechanical energy.

  6. Thermal energy conversion by coupled shape memory and piezoelectric effects

    NASA Astrophysics Data System (ADS)

    Zakharov, Dmitry; Lebedev, Gor; Cugat, Orphee; Delamare, Jerome; Viala, Bernard; Lafont, Thomas; Gimeno, Leticia; Shelyakov, Alexander

    2012-09-01

    This work gives experimental evidence of a promising method of thermal-to-electric energy conversion by coupling shape memory effect (SME) and direct piezoelectric effect (DPE) for harvesting quasi-static ambient temperature variations. Two original prototypes of thermal energy harvesters have been fabricated and tested experimentally. The first is a hybrid laminated composite consisting of TiNiCu shape memory alloy (SMA) and macro fiber composite piezoelectric. This composite comprises 0.1 cm3 of active materials and harvests 75 µJ of energy for each temperature variation of 60 °C. The second prototype is a SME/DPE ‘machine’ which uses the thermally induced linear strains of the SMA to bend a bulk PZT ceramic plate through a specially designed mechanical structure. The SME/DPE ‘machine’ with 0.2 cm3 of active material harvests 90 µJ over a temperature increase of 35 °C (60 µJ when cooling). In contrast to pyroelectric materials, such harvesters are also compatible with both small and slow temperature variations.

  7. Low-energy phase change memory with graphene confined layer

    NASA Astrophysics Data System (ADS)

    Zhu, Chengqiu; Ma, Jun; Ge, Xiaoming; Rao, Feng; Ding, Keyuan; Lv, Shilong; Wu, Liangcai; Song, Zhitang

    2016-06-01

    How to reduce the Reset operation energy is the key scientific and technological problem in the field of phase change memory (PCM). Here, we show in the Ge2Sb2Te5 based PCM cell, inserting an additional graphene monolayer in the Ge2Sb2Te5 layer can remarkably decrease both the Reset current and energy. Because of the small out-of-plane electrical and thermal conductivities of such monolayer graphene, the Set resistance and the heat dissipation towards top TiN electrode of the modified PCM cell are significantly increased and decreased, respectively. The mushroom-typed larger active phase transition volume thus can be confined inside the underlying thinner GST layer, resulting in the lower power consumption.

  8. Shape memory alloy heat engines and energy harvesting systems

    DOEpatents

    Browne, Alan L; Johnson, Nancy L; Shaw, John Andrew; Churchill, Christopher Burton; Keefe, Andrew C; McKnight, Geoffrey P; Alexander, Paul W; Herrera, Guillermo A; Yates, James Ryan; Brown, Jeffrey W

    2014-09-30

    A heat engine includes a first rotatable pulley and a second rotatable pulley spaced from the first rotatable pulley. A shape memory alloy (SMA) element is disposed about respective portions of the pulleys at an SMA pulley ratio. The SMA element includes a first wire, a second wire, and a matrix joining the first wire and the second wire. The first wire and the second wire are in contact with the pulleys, but the matrix is not in contact with the pulleys. A timing cable is disposed about respective portions of the pulleys at a timing pulley ratio, which is different than the SMA pulley ratio. The SMA element converts a thermal energy gradient between the hot region and the cold region into mechanical energy.

  9. Frequency-dependent energy harvesting via magnetic shape memory alloys

    NASA Astrophysics Data System (ADS)

    Sayyaadi, Hassan; Askari Farsangi, Mohammad Amin

    2015-11-01

    This paper is focused on presenting an accurate framework to describe frequency-dependent energy harvesting via magnetic shape memory alloys (MSMAs). Modeling strategy incorporates the phenomenological constitutive model developed formerly together with the magnetic diffusion equation. A hyperbolic hardening function is employed to define reorientation-induced strain hardening in the material, and the diffusion equation is used to add dynamic effects to the model. The MSMA prismatic specimen is surrounded by a pickup coil, and the induced voltage during martensite-variant reorientation is investigated with the help of Faraday’s law of magnetic field induction. It has been shown that, in order to harvest the maximum RMS voltage in the MSMA-based energy harvester, an optimum value of bias magnetic field exists, which is the corresponding magnetic field for the start of pseudoelasticity behavior. In addition, to achieve a more compact energy harvester with higher energy density, a specimen with a lower aspect ratio can be chosen. As the main novelty of the paper, it is found that the dynamic effects play a major role in determining the harvested voltage and power, especially for high excitation frequency or specimen thickness.

  10. A novel inertial energy harvester using magnetic shape memory alloy

    NASA Astrophysics Data System (ADS)

    Askari Farsangi, Mohammad Amin; Sayyaadi, Hassan; Zakerzadeh, Mohammad Reza

    2016-10-01

    This paper studies the output voltage from a novel inertial energy harvester using magnetic shape memory alloys (MSMAs). The MSMA elements are attached to the root of a cantilever beam by means of two steps. In order to get electrical voltage, two coils are wound around the MSMAs and a shock load is applied to a tip mass at the end of the beam to have vibration in it. The beam vibration causes strain in the MSMAs along their longitudinal directions and as a result the magnetic flux alters in the coils. The change of magnetic flux in the surrounding coil produces an AC voltage. In order to predict the output voltage, the nonlinear governing equations of beam motion based on Euler-Bernoulli model and von Kármán theory are derived. A thermodynamics-based constitutive model is used to predict the nonlinear strain and magnetization response of the MSMAs. Also, the induced voltage during martensite variant reorientation in MSMAs is investigated with the help of Faraday’s law of induction. Finally, the effect of different parameters including bias magnetic field, pre-strain and number of MSMA elements are investigated in details. The results show that this novel energy harvester has the capability of using as an alternative to the current piezoelectric and magnetostrictive ones for harvesting energy from ambient vibration.

  11. Energy-band engineering for tunable memory characteristics through controlled doping of reduced graphene oxide.

    PubMed

    Han, Su-Ting; Zhou, Ye; Yang, Qing Dan; Zhou, Li; Huang, Long-Biao; Yan, Yan; Lee, Chun-Sing; Roy, Vellaisamy A L

    2014-02-25

    Tunable memory characteristics are used in multioperational mode circuits where memory cells with various functionalities are needed in one combined device. It is always a challenge to obtain control over threshold voltage for multimode operation. On this regard, we use a strategy of shifting the work function of reduced graphene oxide (rGO) in a controlled manner through doping gold chloride (AuCl3) and obtained a gradient increase of rGO work function. By inserting doped rGO as floating gate, a controlled threshold voltage (Vth) shift has been achieved in both p- and n-type low voltage flexible memory devices with large memory window (up to 4 times for p-type and 8 times for n-type memory devices) in comparison with pristine rGO floating gate memory devices. By proper energy band engineering, we demonstrated a flexible floating gate memory device with larger memory window and controlled threshold voltage shifts.

  12. Upregulated energy metabolism in the Drosophila mushroom body is the trigger for long-term memory

    PubMed Central

    Plaçais, Pierre-Yves; de Tredern, Éloïse; Scheunemann, Lisa; Trannoy, Séverine; Goguel, Valérie; Han, Kyung-An; Isabel, Guillaume; Preat, Thomas

    2017-01-01

    Efficient energy use has constrained the evolution of nervous systems. However, it is unresolved whether energy metabolism may resultantly regulate major brain functions. Our observation that Drosophila flies double their sucrose intake at an early stage of long-term memory formation initiated the investigation of how energy metabolism intervenes in this process. Cellular-resolution imaging of energy metabolism reveals a concurrent elevation of energy consumption in neurons of the mushroom body, the fly's major memory centre. Strikingly, upregulation of mushroom body energy flux is both necessary and sufficient to drive long-term memory formation. This effect is triggered by a specific pair of dopaminergic neurons afferent to the mushroom bodies, via the D5-like DAMB dopamine receptor. Hence, dopamine signalling mediates an energy switch in the mushroom body that controls long-term memory encoding. Our data thus point to an instructional role for energy flux in the execution of demanding higher brain functions. PMID:28580949

  13. Memory

    MedlinePlus

    ... it has to decide what is worth remembering. Memory is the process of storing and then remembering this information. There are different types of memory. Short-term memory stores information for a few ...

  14. Energy harvesting from structural vibrations of magnetic shape memory alloys

    NASA Astrophysics Data System (ADS)

    Farsangi, Mohammad Amin Askari; Cottone, Francesco; Sayyaadi, Hassan; Zakerzadeh, Mohammad Reza; Orfei, Francesco; Gammaitoni, Luca

    2017-03-01

    This letter presents the idea of scavenging energy from vibrating structures through magnetic shape memory alloy (MSMA). To this end, a MSMA specimen made of Ni50Mn28Ga22 is coupled to a cantilever beam through a step. Two permanent magnets installed at the top and bottom of the beam create a bias field perpendicular to the magnetization axis of the specimen. When vibrating the device, a longitudinal axial load applies on the MSMA, which in turn changes the magnetization, due to the martensitic variant reorientation mechanism. A pick-up coil wounded around the MSMA converts this variation into voltage according to the Faraday's law. Experimental test confirms the possibility of generating voltage in a vibrating MSMA. In particular, 15 μW power is harvested for acceleration of 0.3 g RMS at a frequency of 19.1 Hz, which is comparable with piezoelectric energy harvesters. It is also found that the optimum bias magnetic field for maximum voltage is lower than the starting field of pseudo elastic behavior.

  15. Memory.

    ERIC Educational Resources Information Center

    McKean, Kevin

    1983-01-01

    Discusses current research (including that involving amnesiacs and snails) into the nature of the memory process, differentiating between and providing examples of "fact" memory and "skill" memory. Suggests that three brain parts (thalamus, fornix, mammilary body) are involved in the memory process. (JN)

  16. Memory.

    ERIC Educational Resources Information Center

    McKean, Kevin

    1983-01-01

    Discusses current research (including that involving amnesiacs and snails) into the nature of the memory process, differentiating between and providing examples of "fact" memory and "skill" memory. Suggests that three brain parts (thalamus, fornix, mammilary body) are involved in the memory process. (JN)

  17. Moore-Gibson-Thompson equation with memory, part I: exponential decay of energy

    NASA Astrophysics Data System (ADS)

    Lasiecka, Irena; Wang, Xiaojun

    2016-04-01

    We are interested in the Moore-Gibson-Thompson equation with memory τ{u}_{ttt}+ α u_{tt}+c2Au+bAu_t -int_0tg(t-s)A w(s){d}s=0. This model arises in high-frequency ultrasound applications accounting for thermal flux and molecular relaxation times. According to revisited extended irreversible thermodynamics, thermal flux relaxation leads to the third-order derivative in time while molecular relaxation leads to non-local effects governed by memory terms. The resulting model is of hyperbolic type with viscous effects. We first classify the memory into three types. Then, we study how a memory term creates damping mechanism and how the memory causes energy decay even in the cases when the original memoryless system is unstable.

  18. 1Protein Energy Malnutrition Impairs Homeostatic Proliferation of Memory CD8 T cells

    PubMed Central

    Iyer, Smita S.; Chatraw, Janel Hart; Tan, Wendy G.; Wherry, E. John; Becker, Todd C.; Ahmed, Rafi; Kapasi, Zoher F.

    2011-01-01

    Nutrition is a critical but poorly understood determinant of immunity. There is abundant epidemiological evidence linking protein malnutrition to impaired vaccine efficacy and increased susceptibility to infections; yet, the role of dietary protein in immune memory homeostasis remains poorly understood. Here we show that protein energy malnutrition (PEM) induced in mice by low-protein (LP) feeding has a detrimental impact on CD8 memory. Relative to adequate-protein (AP) fed controls, LP feeding in lymphocytic choriomeningitis virus (LCMV) immune mice resulted in a 2-fold decrease in LCMV-specific CD8 memory T cells. Adoptive transfer of memory cells, labeled with a division tracking dye, from AP mice into naive LP or AP mice demonstrated that PEM caused profound defects in homeostatic proliferation. Remarkably, this defect occurred despite the lymphopenic environment in LP hosts. While antigen-specific memory cells in LP and AP hosts were phenotypically similar, memory cells in LP hosts were markedly less-responsive to poly(I:C)-induced acute proliferative signals. Furthermore, upon recall, memory cells in LP hosts displayed reduced proliferation and protection from challenge with LCMV-clone 13 resulting in impaired viral clearance in the liver. The findings show a metabolic requirement of dietary protein in sustaining functional CD8 memory and suggest that interventions to optimize dietary protein intake may improve vaccine efficacy in malnourished individuals. PMID:22116826

  19. Energy-aware Thread and Data Management in Heterogeneous Multi-core, Multi-memory Systems

    SciTech Connect

    Su, Chun-Yi

    2014-12-16

    By 2004, microprocessor design focused on multicore scaling—increasing the number of cores per die in each generation—as the primary strategy for improving performance. These multicore processors typically equip multiple memory subsystems to improve data throughput. In addition, these systems employ heterogeneous processors such as GPUs and heterogeneous memories like non-volatile memory to improve performance, capacity, and energy efficiency. With the increasing volume of hardware resources and system complexity caused by heterogeneity, future systems will require intelligent ways to manage hardware resources. Early research to improve performance and energy efficiency on heterogeneous, multi-core, multi-memory systems focused on tuning a single primitive or at best a few primitives in the systems. The key limitation of past efforts is their lack of a holistic approach to resource management that balances the tradeoff between performance and energy consumption. In addition, the shift from simple, homogeneous systems to these heterogeneous, multicore, multi-memory systems requires in-depth understanding of efficient resource management for scalable execution, including new models that capture the interchange between performance and energy, smarter resource management strategies, and novel low-level performance/energy tuning primitives and runtime systems. Tuning an application to control available resources efficiently has become a daunting challenge; managing resources in automation is still a dark art since the tradeoffs among programming, energy, and performance remain insufficiently understood. In this dissertation, I have developed theories, models, and resource management techniques to enable energy-efficient execution of parallel applications through thread and data management in these heterogeneous multi-core, multi-memory systems. I study the effect of dynamic concurrent throttling on the performance and energy of multi-core, non-uniform memory access

  20. Energy-Efficient Phase-Change Memory with Graphene as a Thermal Barrier

    DTIC Science & Technology

    2015-09-02

    Energy-Efficient Phase-Change Memory with Graphene as a Thermal Barrier Chiyui Ahn,*,† Scott W. Fong,† Yongsung Kim,‡ Seunghyun Lee,† Aditya Sood...Samsung Advanced Institute of Technology (SAIT), Suwon, 443-803, South Korea *S Supporting Information ABSTRACT: Phase-change memory (PCM) is an important...cycles, and the graphene could further enhance the PCM endurance by limiting atomic migration or material segregation at the bottom electrode interface

  1. Association between energy intake and viewing television, distractibility, and memory for advertisements.

    PubMed

    Martin, Corby K; Coulon, Sandra M; Markward, Nathan; Greenway, Frank L; Anton, Stephen D

    2009-01-01

    The effect of television viewing (TVV) with and without advertisements (ads) on energy intake is unclear. The objectives were to test 1) the effect of TVV, with and without ads, on energy intake compared with a control and reading condition and 2) the association of distractibility and memory for ads with energy intake and body weight. Forty-eight (26 female) adults (age: 19-54 y) with a body mass index (in kg/m(2)) of 20-35 completed this laboratory-based study. All participants completed 4 buffet-style meals in random order in the following conditions: 1) control, 2) while reading, 3) while watching TV with food and nonfood ads (TV-ads), and 4) while watching TV with no ads (TV-no ads). Energy intake was quantified by weighing foods. Distractibility and memory for ads in the TV-ads condition were quantified with a norm-referenced test and recognition task, respectively. Repeated-measures analysis of variance indicated that energy and macronutrient intake did not differ significantly among the 4 conditions (P > 0.65). Controlling for sex, memory for ads was associated with body weight (r = 0.36, P < 0.05) and energy intake but only when viewing TV (r = 0.39, P < 0.05 during the TV-no ads condition, and r = 0.29, P = 0.06 during the TV-ads condition). Controlling for sex, distractibility was associated with body weight (r = 0.36, P < 0.05) but not energy intake. Distractibility, however, accounted for 13% of the variance in men's energy intake (P = 0.11). TVV did not affect energy intake, but individual characteristics (memory for ads) were associated with body weight and energy intake in certain conditions. These characteristics should be considered in food intake and intervention studies.

  2. High energy diets prevent the enhancing effects of emotional arousal on memory.

    PubMed

    Ross, Amy P; Darling, Jenna N; Parent, Marise B

    2013-10-01

    Over the past five decades, per capita caloric intake has increased by approximately 28% in the United States. Excessive intake of calories from fats and sugars (high energy diets; HEDs) negatively impacts hippocampal-dependent memory. These deleterious effects of HEDs on hippocampal function involve HED-induced decreases in neuronal growth factors, neurogenesis, and synaptic plasticity. Given that HEDs also alter responses to emotional arousal, the present experiment determined whether the effects of HEDs on memory depend on the emotional arousal produced by the memory task during encoding. Rats were fed a high fat/sugar cafeteria-style diet for 4 weeks and then tested in a low or high emotional arousal version of a spatial object place recognition task. The results demonstrated that the HED prevented the memory-enhancing effects of emotional arousal. Thus, altered responses to emotional arousal likely contribute to HED-induced memory impairments, particularly in stressful memory tasks such as the spatial water maze. 2013 APA, all rights reserved

  3. Memories.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    1998-01-01

    This theme issue of the journal "Exploring" covers the topic of "memories" and describes an exhibition at San Francisco's Exploratorium that ran from May 22, 1998 through January 1999 and that contained over 40 hands-on exhibits, demonstrations, artworks, images, sounds, smells, and tastes that demonstrated and depicted the biological,…

  4. Memories.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    1998-01-01

    This theme issue of the journal "Exploring" covers the topic of "memories" and describes an exhibition at San Francisco's Exploratorium that ran from May 22, 1998 through January 1999 and that contained over 40 hands-on exhibits, demonstrations, artworks, images, sounds, smells, and tastes that demonstrated and depicted the biological,…

  5. Discrete Fluctuations in Memory Erasure without Energy Cost

    NASA Astrophysics Data System (ADS)

    Croucher, Toshio; Bedkihal, Salil; Vaccaro, Joan A.

    2017-02-01

    According to Landauer's principle, erasing one bit of information incurs a minimum energy cost. Recently, Vaccaro and Barnett (VB) explored information erasure within the context of generalized Gibbs ensembles and demonstrated that for energy-degenerate spin reservoirs the cost of erasure can be solely in terms of a minimum amount of spin angular momentum and no energy. As opposed to the Landauer case, the cost of erasure in this case is associated with an intrinsically discrete degree of freedom. Here we study the discrete fluctuations in this cost and the probability of violation of the VB bound. We also obtain a Jarzynski-like equality for the VB erasure protocol. We find that the fluctuations below the VB bound are exponentially suppressed at a far greater rate and more tightly than for an equivalent Jarzynski expression for VB erasure. We expose a trade-off between the size of the fluctuations and the cost of erasure. We find that the discrete nature of the fluctuations is pronounced in the regime where reservoir spins are maximally polarized. We also state the first laws of thermodynamics corresponding to the conservation of spin angular momentum for this particular erasure protocol. Our work will be important for novel heat engines based on information erasure schemes that do not incur an energy cost.

  6. Discrete Fluctuations in Memory Erasure without Energy Cost.

    PubMed

    Croucher, Toshio; Bedkihal, Salil; Vaccaro, Joan A

    2017-02-10

    According to Landauer's principle, erasing one bit of information incurs a minimum energy cost. Recently, Vaccaro and Barnett (VB) explored information erasure within the context of generalized Gibbs ensembles and demonstrated that for energy-degenerate spin reservoirs the cost of erasure can be solely in terms of a minimum amount of spin angular momentum and no energy. As opposed to the Landauer case, the cost of erasure in this case is associated with an intrinsically discrete degree of freedom. Here we study the discrete fluctuations in this cost and the probability of violation of the VB bound. We also obtain a Jarzynski-like equality for the VB erasure protocol. We find that the fluctuations below the VB bound are exponentially suppressed at a far greater rate and more tightly than for an equivalent Jarzynski expression for VB erasure. We expose a trade-off between the size of the fluctuations and the cost of erasure. We find that the discrete nature of the fluctuations is pronounced in the regime where reservoir spins are maximally polarized. We also state the first laws of thermodynamics corresponding to the conservation of spin angular momentum for this particular erasure protocol. Our work will be important for novel heat engines based on information erasure schemes that do not incur an energy cost.

  7. Energy production from waste heat by means of elastomers or memory metals

    NASA Astrophysics Data System (ADS)

    Ljung, L.

    1980-05-01

    Calculation of the energy of an ideal heat engine for a flow between waste water and cooling water was made. Also the Brayton, Carnot and Rankine cycles were computed as well as the processes with nitinol or elastomers as converters. It was shown that half the energy can be recovered by a nitinol heat engine which is comparable to or has better efficiency than the Rankine cycle. The memory metal makes better use of the temperature difference than the Rankine cycle. Elastomers or Gadolinium may be used to utilize energy at low waste heat temperatures.

  8. Minimum energy surface required by quantum memory devices.

    PubMed

    van Dam, Wim; Nguyen, Hieu D

    2013-06-21

    We address the question of what physical resources are required and sufficient to store classical information. While there is no lower bound on the required energy or space to store information, we find that there is a nonzero lower bound for the product P = of these two resources. Specifically, we prove that any physical system of mass m and d degrees of freedom that stores S bits of information will have a lower bound on the product P that is proportional to d2/m(exp(S/d) - 1)2. This result is obtained in a nonrelativistic, quantum mechanical setting, and it is independent of earlier thermodynamical results such as the Bekenstein bound on the entropy of black holes.

  9. Airfoil-based piezoelectric energy harvesting by exploiting the pseudoelastic hysteresis of shape memory alloy springs

    NASA Astrophysics Data System (ADS)

    de Sousa, Vagner Candido; De Marqui Junior, Carlos

    2015-12-01

    The modeling and analysis of an electromechanically coupled typical aeroelastic section with shape memory alloy springs for wind energy harvesting is addressed in this paper. An airfoil with two-degrees-of-freedom, namely pitch and plunge, is considered and piezoelectric coupling is added to the plunge degree-of-freedom. A load resistance is assumed in the electrical domain of the problem in order to estimate the electrical power output. Shape memory alloy coil springs are modeled in the pitch degree-of-freedom of the typical section. A nickel-titanium alloy that exhibits pseudoelasticity at room temperature is assumed. The constitutive model for the shape memory alloy is based on classical phenomenological models. The unsteady aerodynamic loads are obtained by Jones’ approximation to Wagner’s indicial function. The resulting nonlinear electroaeroelastic model is cast into a state-space representation and solved with a Runge-Kutta method. The effects of preload values of the shape memory springs and resistive power generation on the aeroelastic behavior of the wind energy harvester are investigated at the flutter boundary and in a post-flutter regime. The nonlinear kinetics of the austenite-to-martensite phase transformation changes the typical linear flutter behavior to stable limit-cycle oscillations over a range of airflow speeds. Such nonlinear aeroelastic behavior introduced by the hysteretic behavior of the SMA springs provides an important source of persistent electrical power.

  10. Delayed dopamine signaling of energy level builds appetitive long-term memory in Drosophila.

    PubMed

    Musso, Pierre-Yves; Tchenio, Paul; Preat, Thomas

    2015-02-24

    Sensory cues relevant to a food source, such as odors, can be associated with post-ingestion signals related either to food energetic value or toxicity. Despite numerous behavioral studies, a global understanding of the mechanisms underlying these long delay associations remains out of reach. Here, we demonstrate in Drosophila that the long-term association between an odor and a nutritious sugar depends on delayed post-ingestion signaling of energy level. We show at the neural circuit level that the activity of two pairs of dopaminergic neurons is necessary and sufficient to signal energy level to the olfactory memory center. Accordingly, we have identified in these dopaminergic neurons a delayed calcium trace that correlates with appetitive long-term memory formation. Altogether, these findings demonstrate that the Drosophila brain remembers food quality through a two-step mechanism that consists of the integration of olfactory and gustatory sensory information and then post-ingestion energetic value.

  11. Energy drinks and their component modulate attention, memory, and antioxidant defences in rats.

    PubMed

    Valle, M T Costa; Couto-Pereira, N S; Lampert, C; Arcego, D M; Toniazzo, A P; Limberger, R P; Dallegrave, E; Dalmaz, C; Arbo, M D; Leal, M B

    2017-08-12

    This study aimed to evaluate the effects of the subchronic consumption of energy drinks and their constituents (caffeine and taurine) in male Wistar rats using behavioural and oxidative measures. Energy drinks (ED 5, 7.5, and 10 mL/kg) or their constituents, caffeine (3.2 mg/kg) and taurine (40 mg/kg), either separately or in combination, were administered orally to animals for 28 days. Attention was measured though the ox-maze apparatus and the object recognition memory test. Following behavioural analyses, markers of oxidative stress, including SOD, CAT, GPx, thiol content, and free radicals, were measured in the prefrontal cortex, hippocampus, and striatum. The latency time to find the first reward was lower in animals that received caffeine, taurine, or a combination of both (P = 0.003; ANOVA/Bonferroni). In addition, these animals took less time to complete the ox-maze task (P = 0.0001; ANOVA/Bonferroni), and had better short-term memory (P < 0.01, Kruskal-Wallis). The ED 10 group showed improvement in the attention task, but did not differ on other measures. In addition, there was an imbalance in enzymatic markers of oxidative stress in the prefrontal cortex, the hippocampus, and the striatum. In the group that received both caffeine and taurine, there was a significant increase in the production of free radicals in the prefrontal cortex and in the hippocampus (P < 0.0001; ANOVA/Bonferroni). Exposure to a combination of caffeine and taurine improved memory and attention, and led to an imbalance in the antioxidant defence system. These results differed from those of the group that was exposed to the energy drink. This might be related to other components contained in the energy drink, such as vitamins and minerals, which may have altered the ability of caffeine and taurine to modulate memory and attention.

  12. Protein Folding and Structure Prediction from the Ground Up: The Atomistic Associative Memory, Water Mediated, Structure and Energy Model.

    PubMed

    Chen, Mingchen; Lin, Xingcheng; Zheng, Weihua; Onuchic, José N; Wolynes, Peter G

    2016-08-25

    The associative memory, water mediated, structure and energy model (AWSEM) is a coarse-grained force field with transferable tertiary interactions that incorporates local in sequence energetic biases using bioinformatically derived structural information about peptide fragments with locally similar sequences that we call memories. The memory information from the protein data bank (PDB) database guides proper protein folding. The structural information about available sequences in the database varies in quality and can sometimes lead to frustrated free energy landscapes locally. One way out of this difficulty is to construct the input fragment memory information from all-atom simulations of portions of the complete polypeptide chain. In this paper, we investigate this approach first put forward by Kwac and Wolynes in a more complete way by studying the structure prediction capabilities of this approach for six α-helical proteins. This scheme which we call the atomistic associative memory, water mediated, structure and energy model (AAWSEM) amounts to an ab initio protein structure prediction method that starts from the ground up without using bioinformatic input. The free energy profiles from AAWSEM show that atomistic fragment memories are sufficient to guide the correct folding when tertiary forces are included. AAWSEM combines the efficiency of coarse-grained simulations on the full protein level with the local structural accuracy achievable from all-atom simulations of only parts of a large protein. The results suggest that a hybrid use of atomistic fragment memory and database memory in structural predictions may well be optimal for many practical applications.

  13. Quantum memories with zero-energy Majorana modes and experimental constraints

    NASA Astrophysics Data System (ADS)

    Ippoliti, Matteo; Rizzi, Matteo; Giovannetti, Vittorio; Mazza, Leonardo

    2016-06-01

    In this work we address the problem of realizing a reliable quantum memory based on zero-energy Majorana modes in the presence of experimental constraints on the operations aimed at recovering the information. In particular, we characterize the best recovery operation acting only on the zero-energy Majorana modes and the memory fidelity that can be therewith achieved. In order to understand the effect of such restriction, we discuss two examples of noise models acting on the topological system and compare the amount of information that can be recovered by accessing either the whole system, or the zero modes only, with particular attention to the scaling with the size of the system and the energy gap. We explicitly discuss the case of a thermal bosonic environment inducing a parity-preserving Markovian dynamics in which the memory fidelity achievable via a read-out of the zero modes decays exponentially in time, independent from system size. We argue, however, that even in the presence of said experimental limitations, the Hamiltonian gap is still beneficial to the storage of information.

  14. Analyzing the Energy and Power Consumption of Remote Memory Accesses in the OpenSHMEM Model

    SciTech Connect

    Jana, Siddhartha; Hernandez, Oscar R; Poole, Stephen W; Hsu, Chung-Hsing; Chapman, Barbara

    2014-01-01

    PGAS models like OpenSHMEM provide interfaces to explicitly initiate one-sided remote memory accesses among processes. In addition, the model also provides synchronizing barriers to ensure a consistent view of the distributed memory at different phases of an application. The incorrect use of such interfaces affects the scalability achievable while using a parallel programming model. This study aims at understanding the effects of these constructs on the energy and power consumption behavior of OpenSHMEM applications. Our experiments show that cost incurred in terms of the total energy and power consumed depends on multiple factors across the software and hardware stack. We conclude that there is a significant impact on the power consumed by the CPU and DRAM due to multiple factors including the design of the data transfer patterns within an application, the design of the communication protocols within a middleware, the architectural constraints laid by the interconnect solutions, and also the levels of memory hierarchy within a compute node. This work motivates treating energy and power consumption as important factors while designing compute solutions for current and future distributed systems.

  15. Energy-efficient writing scheme for magnetic domain-wall motion memory

    NASA Astrophysics Data System (ADS)

    Kim, Kab-Jin; Yoshimura, Yoko; Ham, Woo Seung; Ernst, Rick; Hirata, Yuushou; Li, Tian; Kim, Sanghoon; Moriyama, Takahiro; Nakatani, Yoshinobu; Ono, Teruo

    2017-04-01

    We present an energy-efficient magnetic domain-writing scheme for domain wall (DW) motion-based memory devices. A cross-shaped nanowire is employed to inject a domain into the nanowire through current-induced DW propagation. The energy required for injecting the magnetic domain is more than one order of magnitude lower than that for the conventional field-based writing scheme. The proposed scheme is beneficial for device miniaturization because the threshold current for DW propagation scales with the device size, which cannot be achieved in the conventional field-based technique.

  16. The ecological relevance of sleep: the trade-off between sleep, memory and energy conservation.

    PubMed

    Roth, Timothy C; Rattenborg, Niels C; Pravosudov, Vladimir V

    2010-03-27

    All animals in which sleep has been studied express signs of sleep-like behaviour, suggesting that sleep must have some fundamental functions that are sustained by natural selection. Those functions, however, are still not clear. Here, we examine the ecological relevance of sleep from the perspective of behavioural trade-offs that might affect fitness. Specifically, we highlight the advantage of using food-caching animals as a system in which a conflict might occur between engaging in sleep for memory/learning and hypothermia/torpor to conserve energy. We briefly review the evidence for the importance of sleep for memory, the importance of memory for food-caching animals and the conflicts that might occur between sleep and energy conservation in these animals. We suggest that the food-caching paradigm represents a naturalistic and experimentally practical system that provides the opportunity for a new direction in sleep research that will expand our understanding of sleep, especially within the context of ecological and evolutionary processes.

  17. Memory and energy optimization strategies for multithreaded operating system on the resource-constrained wireless sensor node.

    PubMed

    Liu, Xing; Hou, Kun Mean; de Vaulx, Christophe; Xu, Jun; Yang, Jianfeng; Zhou, Haiying; Shi, Hongling; Zhou, Peng

    2014-12-23

    Memory and energy optimization strategies are essential for the resource-constrained wireless sensor network (WSN) nodes. In this article, a new memory-optimized and energy-optimized multithreaded WSN operating system (OS) LiveOS is designed and implemented. Memory cost of LiveOS is optimized by using the stack-shifting hybrid scheduling approach. Different from the traditional multithreaded OS in which thread stacks are allocated statically by the pre-reservation, thread stacks in LiveOS are allocated dynamically by using the stack-shifting technique. As a result, memory waste problems caused by the static pre-reservation can be avoided. In addition to the stack-shifting dynamic allocation approach, the hybrid scheduling mechanism which can decrease both the thread scheduling overhead and the thread stack number is also implemented in LiveOS. With these mechanisms, the stack memory cost of LiveOS can be reduced more than 50% if compared to that of a traditional multithreaded OS. Not is memory cost optimized, but also the energy cost is optimized in LiveOS, and this is achieved by using the multi-core "context aware" and multi-core "power-off/wakeup" energy conservation approaches. By using these approaches, energy cost of LiveOS can be reduced more than 30% when compared to the single-core WSN system. Memory and energy optimization strategies in LiveOS not only prolong the lifetime of WSN nodes, but also make the multithreaded OS feasible to run on the memory-constrained WSN nodes.

  18. Memory and Energy Optimization Strategies for Multithreaded Operating System on the Resource-Constrained Wireless Sensor Node

    PubMed Central

    Liu, Xing; Hou, Kun Mean; de Vaulx, Christophe; Xu, Jun; Yang, Jianfeng; Zhou, Haiying; Shi, Hongling; Zhou, Peng

    2015-01-01

    Memory and energy optimization strategies are essential for the resource-constrained wireless sensor network (WSN) nodes. In this article, a new memory-optimized and energy-optimized multithreaded WSN operating system (OS) LiveOS is designed and implemented. Memory cost of LiveOS is optimized by using the stack-shifting hybrid scheduling approach. Different from the traditional multithreaded OS in which thread stacks are allocated statically by the pre-reservation, thread stacks in LiveOS are allocated dynamically by using the stack-shifting technique. As a result, memory waste problems caused by the static pre-reservation can be avoided. In addition to the stack-shifting dynamic allocation approach, the hybrid scheduling mechanism which can decrease both the thread scheduling overhead and the thread stack number is also implemented in LiveOS. With these mechanisms, the stack memory cost of LiveOS can be reduced more than 50% if compared to that of a traditional multithreaded OS. Not is memory cost optimized, but also the energy cost is optimized in LiveOS, and this is achieved by using the multi-core “context aware” and multi-core “power-off/wakeup” energy conservation approaches. By using these approaches, energy cost of LiveOS can be reduced more than 30% when compared to the single-core WSN system. Memory and energy optimization strategies in LiveOS not only prolong the lifetime of WSN nodes, but also make the multithreaded OS feasible to run on the memory-constrained WSN nodes. PMID:25545264

  19. Energy-based fatigue model for shape memory alloys including thermomechanical coupling

    NASA Astrophysics Data System (ADS)

    Zhang, Yahui; Zhu, Jihong; Moumni, Ziad; Van Herpen, Alain; Zhang, Weihong

    2016-03-01

    This paper is aimed at developing a low cycle fatigue criterion for pseudoelastic shape memory alloys to take into account thermomechanical coupling. To this end, fatigue tests are carried out at different loading rates under strain control at room temperature using NiTi wires. Temperature distribution on the specimen is measured using a high speed thermal camera. Specimens are tested to failure and fatigue lifetimes of specimens are measured. Test results show that the fatigue lifetime is greatly influenced by the loading rate: as the strain rate increases, the fatigue lifetime decreases. Furthermore, it is shown that the fatigue cracks initiate when the stored energy inside the material reaches a critical value. An energy-based fatigue criterion is thus proposed as a function of the irreversible hysteresis energy of the stabilized cycle and the loading rate. Fatigue life is calculated using the proposed model. The experimental and computational results compare well.

  20. Energy scaling advantages of resistive memory crossbar based computation and its application to sparse coding

    SciTech Connect

    Agarwal, Sapan; Quach, Tu -Thach; Parekh, Ojas; DeBenedictis, Erik P.; James, Conrad D.; Marinella, Matthew J.; Aimone, James B.

    2016-01-06

    In this study, the exponential increase in data over the last decade presents a significant challenge to analytics efforts that seek to process and interpret such data for various applications. Neural-inspired computing approaches are being developed in order to leverage the computational properties of the analog, low-power data processing observed in biological systems. Analog resistive memory crossbars can perform a parallel read or a vector-matrix multiplication as well as a parallel write or a rank-1 update with high computational efficiency. For an N × N crossbar, these two kernels can be O(N) more energy efficient than a conventional digital memory-based architecture. If the read operation is noise limited, the energy to read a column can be independent of the crossbar size (O(1)). These two kernels form the basis of many neuromorphic algorithms such as image, text, and speech recognition. For instance, these kernels can be applied to a neural sparse coding algorithm to give an O(N) reduction in energy for the entire algorithm when run with finite precision. Sparse coding is a rich problem with a host of applications including computer vision, object tracking, and more generally unsupervised learning.

  1. Energy scaling advantages of resistive memory crossbar based computation and its application to sparse coding

    DOE PAGES

    Agarwal, Sapan; Quach, Tu -Thach; Parekh, Ojas; ...

    2016-01-06

    In this study, the exponential increase in data over the last decade presents a significant challenge to analytics efforts that seek to process and interpret such data for various applications. Neural-inspired computing approaches are being developed in order to leverage the computational properties of the analog, low-power data processing observed in biological systems. Analog resistive memory crossbars can perform a parallel read or a vector-matrix multiplication as well as a parallel write or a rank-1 update with high computational efficiency. For an N × N crossbar, these two kernels can be O(N) more energy efficient than a conventional digital memory-basedmore » architecture. If the read operation is noise limited, the energy to read a column can be independent of the crossbar size (O(1)). These two kernels form the basis of many neuromorphic algorithms such as image, text, and speech recognition. For instance, these kernels can be applied to a neural sparse coding algorithm to give an O(N) reduction in energy for the entire algorithm when run with finite precision. Sparse coding is a rich problem with a host of applications including computer vision, object tracking, and more generally unsupervised learning.« less

  2. Energy Scaling Advantages of Resistive Memory Crossbar Based Computation and Its Application to Sparse Coding

    PubMed Central

    Agarwal, Sapan; Quach, Tu-Thach; Parekh, Ojas; Hsia, Alexander H.; DeBenedictis, Erik P.; James, Conrad D.; Marinella, Matthew J.; Aimone, James B.

    2016-01-01

    The exponential increase in data over the last decade presents a significant challenge to analytics efforts that seek to process and interpret such data for various applications. Neural-inspired computing approaches are being developed in order to leverage the computational properties of the analog, low-power data processing observed in biological systems. Analog resistive memory crossbars can perform a parallel read or a vector-matrix multiplication as well as a parallel write or a rank-1 update with high computational efficiency. For an N × N crossbar, these two kernels can be O(N) more energy efficient than a conventional digital memory-based architecture. If the read operation is noise limited, the energy to read a column can be independent of the crossbar size (O(1)). These two kernels form the basis of many neuromorphic algorithms such as image, text, and speech recognition. For instance, these kernels can be applied to a neural sparse coding algorithm to give an O(N) reduction in energy for the entire algorithm when run with finite precision. Sparse coding is a rich problem with a host of applications including computer vision, object tracking, and more generally unsupervised learning. PMID:26778946

  3. Protein Folding and Structure Prediction from the Ground Up: The Atomistic Associative Memory, Water Mediated, Structure and Energy Model

    PubMed Central

    Chen, Mingchen; Lin, Xingcheng; Zheng, Weihua; Onuchic, José N.; Wolynes, Peter G.

    2016-01-01

    The associative memory, water mediated, structure and energy model (AWSEM) is a coarse-grained force field with transferable tertiary interactions that incorporates local in sequence energetic biases using bioinformatically derived structural information about peptide fragments with locally similar sequence that we call memories. The memory information from the protein data bank (PDB) database guides proper protein folding. The structural information about available sequences in the database varies in quality and can sometimes lead to frustrated free energy landscapes locally. One way out of this difficulty is to construct the input fragment memory information from all-atom simulations of portions of the complete polypeptide chain. In this paper, we investigate this approach first put forward by Kwac and Wolynes in a more complete way by studying the structure prediction capabilities of this approach for six alpha-helical proteins. This scheme which we call the atomistic associative memory, water mediated, structure and energy model (AAWSEM) amounts to an ab initio protein structure prediction method that starts from the ground-up without using bioinformatic input. The free energy profiles from AAWSEM show that atomistic fragment memories are sufficient to guide the correct folding when tertiary forces are included. AAWSEM combines the efficiency of coarse-grained simulations on the full protein level with the local structural accuracy achievable from all-atom simulations of only parts of a large protein. The results suggest that a hybrid use of atomistic fragment memory and database memory in structural predictions may well be optimal for many practical applications. PMID:27148634

  4. A comprehensive energy approach to predict fatigue life in CuAlBe shape memory alloy

    NASA Astrophysics Data System (ADS)

    Sameallah, S.; Legrand, V.; Saint-Sulpice, L.; Kadkhodaei, M.; Arbab Chirani, S.

    2015-02-01

    Stabilized dissipated energy is an effective parameter on the fatigue life of shape memory alloys (SMAs). In this study, a formula is proposed to directly evaluate the stabilized dissipated energy for different values of the maximum and minimum applied stresses, as well as the loading frequency, under cyclic tensile loadings. To this aim, a one-dimensional fully coupled thermomechanical constitutive model and a cycle-dependent phase diagram are employed to predict the uniaxial stress-strain response of an SMA in a specified cycle, including the stabilized one, with no need of obtaining the responses of the previous cycles. An enhanced phase diagram in which different slopes are defined for the start and finish of a backward transformation strip is also proposed to enable the capture of gradual transformations in a CuAlBe shape memory alloy. It is shown that the present approach is capable of reproducing the experimental responses of CuAlBe specimens under cyclic tensile loadings. An explicit formula is further presented to predict the fatigue life of CuAlBe as a function of the maximum and minimum applied stresses as well as the loading frequency. Fatigue tests are also carried out, and this formula is verified against the empirically predicted number of cycles for failure.

  5. Energy-Efficient Phase-Change Memory with Graphene as a Thermal Barrier.

    PubMed

    Ahn, Chiyui; Fong, Scott W; Kim, Yongsung; Lee, Seunghyun; Sood, Aditya; Neumann, Christopher M; Asheghi, Mehdi; Goodson, Kenneth E; Pop, Eric; Wong, H-S Philip

    2015-10-14

    Phase-change memory (PCM) is an important class of data storage, yet lowering the programming current of individual devices is known to be a significant challenge. Here we improve the energy-efficiency of PCM by placing a graphene layer at the interface between the phase-change material, Ge2Sb2Te5 (GST), and the bottom electrode (W) heater. Graphene-PCM (G-PCM) devices have ∼40% lower RESET current compared to control devices without the graphene. This is attributed to the graphene as an added interfacial thermal resistance which helps confine the generated heat inside the active PCM volume. The G-PCM achieves programming up to 10(5) cycles, and the graphene could further enhance the PCM endurance by limiting atomic migration or material segregation at the bottom electrode interface.

  6. Event parallelism: Distributed memory parallel computing for high energy physics experiments

    SciTech Connect

    Nash, T.

    1989-05-01

    This paper describes the present and expected future development of distributed memory parallel computers for high energy physics experiments. It covers the use of event parallel microprocessor farms, particularly at Fermilab, including both ACP multiprocessors and farms of MicroVAXES. These systems have proven very cost effective in the past. A case is made for moving to the more open environment of UNIX and RISC processors. The 2nd Generation ACP Multiprocessor System, which is based on powerful RISC systems, is described. Given the promise of still more extraordinary increases in processor performance, a new emphasis on point to point, rather than bussed, communication will be required. Developments in this direction are described. 6 figs.

  7. Improvement of brain energy metabolism and cholinergic functions contributes to the beneficial effects of silibinin against streptozotocin induced memory impairment.

    PubMed

    Tota, Santoshkumar; Kamat, Pradeep Kumar; Shukla, Rakesh; Nath, Chandishwar

    2011-08-01

    Recently, silibinin, a clinically used hepatoprotectant, has been reported to prevent amyloid beta induced memory impairment by reducing oxidative stress and inflammation in mice brain. However, the exact mechanism of neuroprotective effect of silibinin has not been properly studied especially in context of brain energy metabolism and cholinergic functions, the essential factors that undergo impairment in Alzheimer's disease. Therefore, the present study investigated the effect of silibinin on impairment in memory, brain energy metabolism and cholinergic function following intracerebral (IC) streptozotocin (STZ) administration in mice. STZ (0.5mg/kg), administered twice at an interval of 48h, caused significant memory impairment tested by Morris water maze. Further, STZ significantly decreased ATP and increased synaptosomal calcium level in mice brain. Increased oxidative and nitrosative stress was also observed in IC STZ injected mice brain. STZ IC induced memory impairment is associated with increased activity and mRNA expression of acetylcholinesterase (AChE) and decreased α-7 nicotinic acetylcholine receptor (α-7-nAChR) mRNA expression in mice brain. Pretreatment with silibinin (100 and 200mg/kg, po) attenuated STZ induced memory impairment by reducing oxidative and nitrosative stress and synaptosomal calcium ion level. Further, silibinin dose dependently restored ATP level indicating improvement in brain energy metabolism. The activity and mRNA expression of AChE was restored by silibinin. Moreover, α-7-nAChR mRNA expression was significantly increased by silibinin in STZ treated mice brain. The present study clearly demonstrates that beneficial effects of silibinin in STZ induced memory impairment in mice is due to improvement in brain energy metabolism and cholinergic function. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. A Grey NGM(1,1, k) Self-Memory Coupling Prediction Model for Energy Consumption Prediction

    PubMed Central

    Guo, Xiaojun; Liu, Sifeng; Wu, Lifeng; Tang, Lingling

    2014-01-01

    Energy consumption prediction is an important issue for governments, energy sector investors, and other related corporations. Although there are several prediction techniques, selection of the most appropriate technique is of vital importance. As for the approximate nonhomogeneous exponential data sequence often emerging in the energy system, a novel grey NGM(1,1, k) self-memory coupling prediction model is put forward in order to promote the predictive performance. It achieves organic integration of the self-memory principle of dynamic system and grey NGM(1,1, k) model. The traditional grey model's weakness as being sensitive to initial value can be overcome by the self-memory principle. In this study, total energy, coal, and electricity consumption of China is adopted for demonstration by using the proposed coupling prediction technique. The results show the superiority of NGM(1,1, k) self-memory coupling prediction model when compared with the results from the literature. Its excellent prediction performance lies in that the proposed coupling model can take full advantage of the systematic multitime historical data and catch the stochastic fluctuation tendency. This work also makes a significant contribution to the enrichment of grey prediction theory and the extension of its application span. PMID:25054174

  9. A grey NGM(1,1, k) self-memory coupling prediction model for energy consumption prediction.

    PubMed

    Guo, Xiaojun; Liu, Sifeng; Wu, Lifeng; Tang, Lingling

    2014-01-01

    Energy consumption prediction is an important issue for governments, energy sector investors, and other related corporations. Although there are several prediction techniques, selection of the most appropriate technique is of vital importance. As for the approximate nonhomogeneous exponential data sequence often emerging in the energy system, a novel grey NGM(1,1, k) self-memory coupling prediction model is put forward in order to promote the predictive performance. It achieves organic integration of the self-memory principle of dynamic system and grey NGM(1,1, k) model. The traditional grey model's weakness as being sensitive to initial value can be overcome by the self-memory principle. In this study, total energy, coal, and electricity consumption of China is adopted for demonstration by using the proposed coupling prediction technique. The results show the superiority of NGM(1,1, k) self-memory coupling prediction model when compared with the results from the literature. Its excellent prediction performance lies in that the proposed coupling model can take full advantage of the systematic multitime historical data and catch the stochastic fluctuation tendency. This work also makes a significant contribution to the enrichment of grey prediction theory and the extension of its application span.

  10. Energy efficient low power shared-memory Fast Fourier Transform (FFT) processor with dynamic voltage scaling

    NASA Astrophysics Data System (ADS)

    Fitrio, D.; Singh, J.; Stojcevski, A.

    2005-12-01

    Reduction of power dissipations in CMOS circuits needs to be addressed for portable battery devices. Selection of appropriate transistor library to minimise leakage current, implementation of low power design architectures, power management implementation, and the choice of chip packaging, all have impact on power dissipation and are important considerations in design and implementation of integrated circuits for low power applications. Energy-efficient architecture is highly desirable for battery operated systems, which operates in a wide variation of operating scenarios. Energy-efficient design aims to reconfigure its own architectures to scale down energy consumption depending upon the throughput and quality requirement. An energy efficient system should be able to decide its minimum power requirements by dynamically scaling its own operating frequency, supply voltage or the threshold voltage according to a variety of operating scenarios. The increasing product demand for application specific integrated circuit or processor for independent portable devices has influenced designers to implement dedicated processors with ultra low power requirements. One of these dedicated processors is a Fast Fourier Transform (FFT) processor, which is widely used in signal processing for numerous applications such as, wireless telecommunication and biomedical applications where the demand for extended battery life is extremely high. This paper presents the design and performance analysis of a low power shared memory FFT processor incorporating dynamic voltage scaling. Dynamic voltage scaling enables power supply scaling into various supply voltage levels. The concept behind the proposed solution is that if the speed of the main logic core can be adjusted according to input load or amount of processor's computation "just enough" to meet the requirement. The design was implemented using 0.12 μm ST-Microelectronic 6-metal layer CMOS dual- process technology in Cadence Analogue

  11. Energy-efficient miniature-scale heat pumping based on shape memory alloys

    NASA Astrophysics Data System (ADS)

    Ossmer, Hinnerk; Wendler, Frank; Gueltig, Marcel; Lambrecht, Franziska; Miyazaki, Shuichi; Kohl, Manfred

    2016-08-01

    Cooling and thermal management comprise a major part of global energy consumption. The by far most widespread cooling technology today is vapor compression, reaching rather high efficiencies, but promoting global warming due to the use of environmentally harmful refrigerants. For widespread emerging applications using microelectronics and micro-electro-mechanical systems, thermoelectrics is the most advanced technology, which however hardly reaches coefficients of performance (COP) above 2.0. Here, we introduce a new approach for energy-efficient heat pumping using the elastocaloric effect in shape memory alloys. This development is mainly targeted at applications on miniature scales, while larger scales are envisioned by massive parallelization. Base materials are cold-rolled textured Ti49.1Ni50.5Fe0.4 foils of 30 μm thickness showing an adiabatic temperature change of +20/-16 K upon superelastic loading/unloading. Different demonstrator layouts consisting of mechanically coupled bridge structures with large surface-to-volume ratios are developed allowing for control by a single actuator as well as work recovery. Heat transfer times are in the order of 1 s, being orders of magnitude faster than for bulk geometries. Thus, first demonstrators achieve values of specific heating and cooling power of 4.5 and 2.9 W g-1, respectively. A maximum temperature difference of 9.4 K between heat source and sink is reached within 2 min. Corresponding COP on the device level are 4.9 (heating) and 3.1 (cooling).

  12. Shape-memory transformations of NiTi: Minimum-energy pathways between austenite, martensites, and kinetically limited intermediate states

    SciTech Connect

    Zarkevich, N. A.; Johnson, D. D.

    2014-12-24

    NiTi is the most used shape-memory alloy, nonetheless, a lack of understanding remains regarding the associated structures and transitions, including their barriers. Using a generalized solid-state nudge elastic band (GSSNEB) method implemented via density-functional theory, we detail the structural transformations in NiTi relevant to shape memory: those between body-centered orthorhombic (BCO) groundstate and a newly identified stable austenite (“glassy” B2-like) structure, including energy barriers (hysteresis) and intermediate structures (observed as a kinetically limited R-phase), and between martensite variants (BCO orientations). All results are in good agreement with available experiment. We contrast the austenite results to those from the often-assumed, but unstable B2. Furthermore, these high- and low-temperature structures and structural transformations provide much needed atomic-scale detail for transitions responsible for NiTi shape-memory effects.

  13. Shape-memory transformations of NiTi: minimum-energy pathways between austenite, martensites, and kinetically limited intermediate states.

    PubMed

    Zarkevich, N A; Johnson, D D

    2014-12-31

    NiTi is the most used shape-memory alloy; nonetheless, a lack of understanding remains regarding the associated structures and transitions, including their barriers. Using a generalized solid-state nudged elastic band method implemented via density-functional theory, we detail the structural transformations in NiTi relevant to shape memory: those between a body-centered orthorhombic (bco) ground state and a newly identified stable austenite ("glassy" B2-like) structure, including energy barriers (hysteresis) and intermediate structures (observed as a kinetically limited R phase), and between martensite variants (bco orientations). All results are in good agreement with available experiment. We contrast the austenite results to those from the often-assumed, but unstable B2. These high- and low-temperature structures and structural transformations provide much needed atomic-scale detail for transitions responsible for NiTi shape-memory effects.

  14. Shape-memory transformations of NiTi: Minimum-energy pathways between austenite, martensites, and kinetically limited intermediate states

    DOE PAGES

    Zarkevich, N. A.; Johnson, D. D.

    2014-12-24

    NiTi is the most used shape-memory alloy, nonetheless, a lack of understanding remains regarding the associated structures and transitions, including their barriers. Using a generalized solid-state nudge elastic band (GSSNEB) method implemented via density-functional theory, we detail the structural transformations in NiTi relevant to shape memory: those between body-centered orthorhombic (BCO) groundstate and a newly identified stable austenite (“glassy” B2-like) structure, including energy barriers (hysteresis) and intermediate structures (observed as a kinetically limited R-phase), and between martensite variants (BCO orientations). All results are in good agreement with available experiment. We contrast the austenite results to those from the often-assumed, butmore » unstable B2. Furthermore, these high- and low-temperature structures and structural transformations provide much needed atomic-scale detail for transitions responsible for NiTi shape-memory effects.« less

  15. Locating Temporal Functional Dynamics of Visual Short-Term Memory Binding using Graph Modular Dirichlet Energy

    NASA Astrophysics Data System (ADS)

    Smith, Keith; Ricaud, Benjamin; Shahid, Nauman; Rhodes, Stephen; Starr, John M.; Ibáñez, Augustin; Parra, Mario A.; Escudero, Javier; Vandergheynst, Pierre

    2017-02-01

    Visual short-term memory binding tasks are a promising early marker for Alzheimer’s disease (AD). To uncover functional deficits of AD in these tasks it is meaningful to first study unimpaired brain function. Electroencephalogram recordings were obtained from encoding and maintenance periods of tasks performed by healthy young volunteers. We probe the task’s transient physiological underpinnings by contrasting shape only (Shape) and shape-colour binding (Bind) conditions, displayed in the left and right sides of the screen, separately. Particularly, we introduce and implement a novel technique named Modular Dirichlet Energy (MDE) which allows robust and flexible analysis of the functional network with unprecedented temporal precision. We find that connectivity in the Bind condition is less integrated with the global network than in the Shape condition in occipital and frontal modules during the encoding period of the right screen condition. Using MDE we are able to discern driving effects in the occipital module between 100–140 ms, coinciding with the P100 visually evoked potential, followed by a driving effect in the frontal module between 140–180 ms, suggesting that the differences found constitute an information processing difference between these modules. This provides temporally precise information over a heterogeneous population in promising tasks for the detection of AD.

  16. Facile 3D Metal Electrode Fabrication for Energy Applications via Inkjet Printing and Shape Memory Polymer

    NASA Astrophysics Data System (ADS)

    Roberts, R. C.; Wu, J.; Hau, N. Y.; Chang, Y. H.; Feng, S. P.; Li, D. C.

    2014-11-01

    This paper reports on a simple 3D metal electrode fabrication technique via inkjet printing onto a thermally contracting shape memory polymer (SMP) substrate. Inkjet printing allows for the direct patterning of structures from metal nanoparticle bearing liquid inks. After deposition, these inks require thermal curing steps to render a stable conductive film. By printing onto a SMP substrate, the metal nanoparticle ink can be cured and substrate shrunk simultaneously to create 3D metal microstructures, forming a large surface area topology well suited for energy applications. Polystyrene SMP shrinkage was characterized in a laboratory oven from 150-240°C, resulting in a size reduction of 1.97-2.58. Silver nanoparticle ink was patterned into electrodes, shrunk, and the topology characterized using scanning electron microscopy. Zinc-Silver Oxide microbatteries were fabricated to demonstrate the 3D electrodes compared to planar references. Characterization was performed using 10M potassium hydroxide electrolyte solution doped with zinc oxide (57g/L). After a 300s oxidation at 3Vdc, the 3D electrode battery demonstrated a 125% increased capacity over the reference cell. Reference cells degraded with longer oxidations, but the 3D electrodes were fully oxidized for 4 hours, and exhibited a capacity of 5.5mA-hr/cm2 with stable metal performance.

  17. Locating Temporal Functional Dynamics of Visual Short-Term Memory Binding using Graph Modular Dirichlet Energy

    PubMed Central

    Smith, Keith; Ricaud, Benjamin; Shahid, Nauman; Rhodes, Stephen; Starr, John M.; Ibáñez, Augustin; Parra, Mario A.; Escudero, Javier; Vandergheynst, Pierre

    2017-01-01

    Visual short-term memory binding tasks are a promising early marker for Alzheimer’s disease (AD). To uncover functional deficits of AD in these tasks it is meaningful to first study unimpaired brain function. Electroencephalogram recordings were obtained from encoding and maintenance periods of tasks performed by healthy young volunteers. We probe the task’s transient physiological underpinnings by contrasting shape only (Shape) and shape-colour binding (Bind) conditions, displayed in the left and right sides of the screen, separately. Particularly, we introduce and implement a novel technique named Modular Dirichlet Energy (MDE) which allows robust and flexible analysis of the functional network with unprecedented temporal precision. We find that connectivity in the Bind condition is less integrated with the global network than in the Shape condition in occipital and frontal modules during the encoding period of the right screen condition. Using MDE we are able to discern driving effects in the occipital module between 100–140 ms, coinciding with the P100 visually evoked potential, followed by a driving effect in the frontal module between 140–180 ms, suggesting that the differences found constitute an information processing difference between these modules. This provides temporally precise information over a heterogeneous population in promising tasks for the detection of AD. PMID:28186173

  18. Locating Temporal Functional Dynamics of Visual Short-Term Memory Binding using Graph Modular Dirichlet Energy.

    PubMed

    Smith, Keith; Ricaud, Benjamin; Shahid, Nauman; Rhodes, Stephen; Starr, John M; Ibáñez, Augustin; Parra, Mario A; Escudero, Javier; Vandergheynst, Pierre

    2017-02-10

    Visual short-term memory binding tasks are a promising early marker for Alzheimer's disease (AD). To uncover functional deficits of AD in these tasks it is meaningful to first study unimpaired brain function. Electroencephalogram recordings were obtained from encoding and maintenance periods of tasks performed by healthy young volunteers. We probe the task's transient physiological underpinnings by contrasting shape only (Shape) and shape-colour binding (Bind) conditions, displayed in the left and right sides of the screen, separately. Particularly, we introduce and implement a novel technique named Modular Dirichlet Energy (MDE) which allows robust and flexible analysis of the functional network with unprecedented temporal precision. We find that connectivity in the Bind condition is less integrated with the global network than in the Shape condition in occipital and frontal modules during the encoding period of the right screen condition. Using MDE we are able to discern driving effects in the occipital module between 100-140 ms, coinciding with the P100 visually evoked potential, followed by a driving effect in the frontal module between 140-180 ms, suggesting that the differences found constitute an information processing difference between these modules. This provides temporally precise information over a heterogeneous population in promising tasks for the detection of AD.

  19. Ordered arrays of a defect-modified ferroelectric polymer for non-volatile memory with minimized energy consumption

    NASA Astrophysics Data System (ADS)

    Chen, Xiang-Zhong; Chen, Xin; Guo, Xu; Cui, Yu-Shuang; Shen, Qun-Dong; Ge, Hai-Xiong

    2014-10-01

    Ferroelectric polymers are among the most promising materials for flexible electronic devices. Highly ordered arrays of the defect-modified ferroelectric polymer P(VDF-TrFE-CFE) (poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene)) are fabricated by nanoimprint lithography for nonvolatile memory application. The defective CFE units reduce the coercive field to one-fifth of that of the un-modified P(VDF-TrFE), which can help minimize the energy consumption and extend the lifespan of the device. The nanoimprint process leads to preferable orientation of polymer chains and delicately controlled distribution of the defects, and thus a bi-stable polarization that makes the memory nonvolatile, as revealed by the pulsed polarization experiment.Ferroelectric polymers are among the most promising materials for flexible electronic devices. Highly ordered arrays of the defect-modified ferroelectric polymer P(VDF-TrFE-CFE) (poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene)) are fabricated by nanoimprint lithography for nonvolatile memory application. The defective CFE units reduce the coercive field to one-fifth of that of the un-modified P(VDF-TrFE), which can help minimize the energy consumption and extend the lifespan of the device. The nanoimprint process leads to preferable orientation of polymer chains and delicately controlled distribution of the defects, and thus a bi-stable polarization that makes the memory nonvolatile, as revealed by the pulsed polarization experiment. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr03866e

  20. A new variable-resolution associative memory for high energy physics

    SciTech Connect

    Annovi, A.; Amerio, S.; Beretta, M.; Bossini, E.; Crescioli, F.; Dell'Orso, M.; Giannetti, P.; Hoff, J.; Liu, T.; Magalotti, D.; Piendibene, M.; Sacco, I.; Schoening, A.; Soltveit, H. K.; Stabile, A.; Tripiccione, R.; Liberali, V.; Vitillo, R.; Volpi, G.

    2011-07-01

    We describe an important advancement for the Associative Memory device (AM). The AM is a VLSI processor for pattern recognition based on Content Addressable Memory (CAM) architecture. The AM is optimized for on-line track finding in high-energy physics experiments. Pattern matching is carried out by finding track candidates in coarse resolution 'roads'. A large AM bank stores all trajectories of interest, called 'patterns', for a given detector resolution. The AM extracts roads compatible with a given event during detector read-out. Two important variables characterize the quality of the AM bank: its 'coverage' and the level of fake roads. The coverage, which describes the geometric efficiency of a bank, is defined as the fraction of tracks that match at least one pattern in the bank. Given a certain road size, the coverage of the bank can be increased just adding patterns to the bank, while the number of fakes unfortunately is roughly proportional to the number of patterns in the bank. Moreover, as the luminosity increases, the fake rate increases rapidly because of the increased silicon occupancy. To counter that, we must reduce the width of our roads. If we decrease the road width using the current technology, the system will become very large and extremely expensive. We propose an elegant solution to this problem: the 'variable resolution patterns'. Each pattern and each detector layer within a pattern will be able to use the optimal width, but we will use a 'don't care' feature (inspired from ternary CAMs) to increase the width when that is more appropriate. In other words we can use patterns of variable shape. As a result we reduce the number of fake roads, while keeping the efficiency high and avoiding excessive bank size due to the reduced width. We describe the idea, the implementation in the new AM design and the implementation of the algorithm in the simulation. Finally we show the effectiveness of the 'variable resolution patterns' idea using simulated

  1. Calculation of energy-barrier lowering by incoherent switching in spin-transfer torque magnetoresistive random-access memory

    NASA Astrophysics Data System (ADS)

    Munira, Kamaram; Visscher, P. B.

    2015-05-01

    To make a useful spin-transfer torque magnetoresistive random-access memory (STT-MRAM) device, it is necessary to be able to calculate switching rates, which determine the error rates of the device. In a single-macrospin model, one can use a Fokker-Planck equation to obtain a low-current thermally activated rate ∝exp(-Ee f f/kBT ) . Here, the effective energy barrier Eeff scales with the single-macrospin energy barrier KV, where K is the effective anisotropy energy density and V the volume. A long-standing paradox in this field is that the actual energy barrier appears to be much smaller than this. It has been suggested that incoherent motions may lower the barrier, but this has proved difficult to quantify. In the present paper, we show that the coherent precession has a magnetostatic instability, which allows quantitative estimation of the energy barrier and may resolve the paradox.

  2. Data-driven Techniques to Estimate Parameters in the Homogenized Energy Model for Shape Memory Alloys

    DTIC Science & Technology

    2011-11-01

    sensor. volume 79781K. Proceedings of the SPIE 7978, 2011. [9] D.J. Hartl, D.C. Lagoudas, F.T. Calkins , and J.H. Mabe. Use of a ni60ti shape memory...D.C. Lagoudas, F.T. Calkins , and J.H. Mabe. Use of a ni60ti shape memory alloy for active jet engine chevron application: II. experimentally validated

  3. Atom redistribution and multilayer structure in NiTi shape memory alloy induced by high energy proton irradiation

    NASA Astrophysics Data System (ADS)

    Wang, Haizhen; Yi, Xiaoyang; Zhu, Yingying; Yin, Yongkui; Gao, Yuan; Cai, Wei; Gao, Zhiyong

    2017-10-01

    The element distribution and surface microstructure in NiTi shape memory alloys exposed to 3 MeV proton irradiation were investigated. Redistribution of the alloying element and a clearly visible multilayer structure consisting of three layers were observed on the surface of NiTi shape memory alloys after proton irradiation. The outermost layer consists primarily of a columnar-like TiH2 phase with a tetragonal structure, and the internal layer is primarily comprised of a bcc austenite phase. In addition, the Ti2Ni phase, with an fcc structure, serves as the transition layer between the outermost and internal layer. The above-mentioned phenomenon is attributed to the preferential sputtering of high energy protons and segregation induced by irradiation.

  4. Tunable bandgap energy of fluorinated nanocrystals for flash memory applications produced by low-damage plasma treatment.

    PubMed

    Huang, Chi-Hsien; Lin, Chih-Ting; Wang, Jer-Chyi; Chou, Chien; Ye, Yu-Ren; Cheng, Bing-Ming; Lai, Chao-Sung

    2012-11-30

    A plasma system with a complementary filter to shield samples from damage during tetrafluoromethane (CF(4)) plasma treatment was proposed in order to incorporate fluorine atoms into gadolinium oxide nanocrystals (Gd(2)O(3)-NCs) for flash memory applications. X-ray photoelectron spectroscopy confirmed that fluorine atoms were successfully introduced into the Gd(2)O(3)-NCs despite the use of a filter in the plasma-enhanced chemical vapour deposition system to shield against several potentially damaging species. The number of incorporated fluorine atoms can be controlled by varying the treatment time. The optimized memory window of the resulting flash memory devices was twice that of devices treated by a filterless system because more fluorine atoms were incorporated into the Gd(2)O(3)-NCs film with very little damage. This enlarged the bandgap energy from 5.48 to 6.83 eV, as observed by ultraviolet absorption measurements. This bandgap expansion can provide a large built-in electric field that allows more charges to be stored in the Gd(2)O(3)-NCs. The maximum improvement in the retention characteristic was >60%. Because plasma damage during treatment is minimal, maximum fluorination can be achieved. The concept of simply adding a filter to a plasma system to prevent plasma damage exhibits great promise for functionalization or modification of nanomaterials for advanced nanoelectronics while introducing minimal defects.

  5. Tunable bandgap energy of fluorinated nanocrystals for flash memory applications produced by low-damage plasma treatment

    NASA Astrophysics Data System (ADS)

    Huang, Chi-Hsien; Lin, Chih-Ting; Wang, Jer-Chyi; Chou, Chien; Ye, Yu-Ren; Cheng, Bing-Ming; Lai, Chao-Sung

    2012-11-01

    A plasma system with a complementary filter to shield samples from damage during tetrafluoromethane (CF4) plasma treatment was proposed in order to incorporate fluorine atoms into gadolinium oxide nanocrystals (Gd2O3-NCs) for flash memory applications. X-ray photoelectron spectroscopy confirmed that fluorine atoms were successfully introduced into the Gd2O3-NCs despite the use of a filter in the plasma-enhanced chemical vapour deposition system to shield against several potentially damaging species. The number of incorporated fluorine atoms can be controlled by varying the treatment time. The optimized memory window of the resulting flash memory devices was twice that of devices treated by a filterless system because more fluorine atoms were incorporated into the Gd2O3-NCs film with very little damage. This enlarged the bandgap energy from 5.48 to 6.83 eV, as observed by ultraviolet absorption measurements. This bandgap expansion can provide a large built-in electric field that allows more charges to be stored in the Gd2O3-NCs. The maximum improvement in the retention characteristic was >60%. Because plasma damage during treatment is minimal, maximum fluorination can be achieved. The concept of simply adding a filter to a plasma system to prevent plasma damage exhibits great promise for functionalization or modification of nanomaterials for advanced nanoelectronics while introducing minimal defects.

  6. An energy-efficient SIMD DSP with multiple VLIW configurations and an advanced memory access unit for LTE-A modem LSIs

    NASA Astrophysics Data System (ADS)

    Tomono, Mitsuru; Ito, Makiko; Nomura, Yoshitaka; Mouri, Makoto; Hirose, Yoshio

    2015-12-01

    Energy efficiency is the most important factor in the design of wireless modem LSIs for mobile handset systems. We have developed an energy-efficient SIMD DSP for LTE-A modem LSIs. Our DSP has mainly two hardware features in order to reduce energy consumption. The first one is multiple VLIW configurations to minimize accesses to instruction memories. The second one is an advanced memory access unit to realize complex memory accesses required for wireless baseband processing. With these features, performance of our DSP is about 1.7 times faster than a base DSP on average for standard LTE-A Libraries. Our DSP achieves about 20% improvement in energy efficiency compared to a base DSP for LTE-A modem LSIs.

  7. Calculation of energy-barrier lowering by incoherent switching in spin-transfer torque magnetoresistive random-access memory

    SciTech Connect

    Munira, Kamaram; Visscher, P. B.

    2015-05-07

    To make a useful spin-transfer torque magnetoresistive random-access memory (STT-MRAM) device, it is necessary to be able to calculate switching rates, which determine the error rates of the device. In a single-macrospin model, one can use a Fokker-Planck equation to obtain a low-current thermally activated rate ∝exp(−E{sub eff}/k{sub B}T). Here, the effective energy barrier E{sub eff} scales with the single-macrospin energy barrier KV, where K is the effective anisotropy energy density and V the volume. A long-standing paradox in this field is that the actual energy barrier appears to be much smaller than this. It has been suggested that incoherent motions may lower the barrier, but this has proved difficult to quantify. In the present paper, we show that the coherent precession has a magnetostatic instability, which allows quantitative estimation of the energy barrier and may resolve the paradox.

  8. Energy problem in Einstein's theory of gravitation (Dedicated to the memory of V. A. Fock)

    SciTech Connect

    Faddeev, L.D.

    1982-03-01

    The review is devoted to a discussion of the definition and properties of energy in Einstein's theory of gravitation. Asymptotically flat space-time is defined in terms of admissible asymptotically Cartesian coordinates and a corresponding group of coordinate transformations. A Lagrange function is introduced on such a space-time, and a generalized Hamiltonian formulation of the theory of gravitation is constructed in accordance with Dirac's method. The energy is defined as the generator of displacement with respect to the asymptotic time. It is shown that the total energy of the gravitational field and the matter fields with normal energy-momentum tensor is positive and vanishes only in the absence of matter fields and gravitational waves. The proof follows Witten's proof but contains a number of corrections and improvements. Various standard criticisms of the energy concept in general relativity are discussed and shown to be without substance.

  9. Low-energy Resistive Random Access Memory Devices with No Need for a Compliance Current

    PubMed Central

    Xu, Zedong; Yu, Lina; Wu, Yong; Dong, Chang; Deng, Ning; Xu, Xiaoguang; Miao, J.; Jiang, Yong

    2015-01-01

    A novel resistive random access memory device is designed with SrTiO3/ La2/3Sr1/3MnO3 (LSMO)/MgAl2O4 (MAO)/Cu structure, in which metallic epitaxial LSMO is employed as the bottom electrode rather than traditional metal materials. In this device, the critical external compliance current is no longer necessary due to the high self-resistance of LSMO. The LMSO bottom electrode can act as a series resistor to offer a compliance current during the set process. Besides, the device also has excellent switching features which are originated in the formation of Cu filaments under external voltage. Therefore it provides the possibility of reducing power consumption and accelerating the commercialization of resistive switching devices. PMID:25982101

  10. Calibration and Finite Element Implementation of an Energy-Based Material Model for Shape Memory Alloys

    NASA Astrophysics Data System (ADS)

    Junker, Philipp; Hackl, Klaus

    2016-09-01

    Numerical simulations are a powerful tool to analyze the complex thermo-mechanically coupled material behavior of shape memory alloys during product engineering. The benefit of the simulations strongly depends on the quality of the underlying material model. In this contribution, we discuss a variational approach which is based solely on energetic considerations and demonstrate that unique calibration of such a model is sufficient to predict the material behavior at varying ambient temperature. In the beginning, we recall the necessary equations of the material model and explain the fundamental idea. Afterwards, we focus on the numerical implementation and provide all information that is needed for programing. Then, we show two different ways to calibrate the model and discuss the results. Furthermore, we show how this model is used during real-life industrial product engineering.

  11. Soft-error tolerance and energy consumption evaluation of embedded computer with magnetic random access memory in practical systems using computer simulations

    NASA Astrophysics Data System (ADS)

    Nebashi, Ryusuke; Sakimura, Noboru; Sugibayashi, Tadahiko

    2017-08-01

    We evaluated the soft-error tolerance and energy consumption of an embedded computer with magnetic random access memory (MRAM) using two computer simulators. One is a central processing unit (CPU) simulator of a typical embedded computer system. We simulated the radiation-induced single-event-upset (SEU) probability in a spin-transfer-torque MRAM cell and also the failure rate of a typical embedded computer due to its main memory SEU error. The other is a delay tolerant network (DTN) system simulator. It simulates the power dissipation of wireless sensor network nodes of the system using a revised CPU simulator and a network simulator. We demonstrated that the SEU effect on the embedded computer with 1 Gbit MRAM-based working memory is less than 1 failure in time (FIT). We also demonstrated that the energy consumption of the DTN sensor node with MRAM-based working memory can be reduced to 1/11. These results indicate that MRAM-based working memory enhances the disaster tolerance of embedded computers.

  12. Structures with Superelastic Shape Memory Alloy Stiffeners for Maximuj Damping and Energy Dissipation

    DTIC Science & Technology

    2010-02-15

    suggested by Ungar and Kerwin (1962) as: fpw ffppww UUU UηUηUη η ++ ++ = (22) where pη is the loss factor of the plate and wU and pU are the...New York. Ungar , E.E. and Kerwin, E.M, Jr., 1962. “Loss Factors of Viscoelastic Systems in Terms of Strain Energy,” Journal of the Acoustical

  13. Encoding Random Hot Spots of a Volume Gold Nanorod Assembly for Ultralow Energy Memory.

    PubMed

    Dai, Qiaofeng; Ouyang, Min; Yuan, Weiguang; Li, Jinxiang; Guo, Banghong; Lan, Sheng; Liu, Songhao; Zhang, Qiming; Lu, Guang; Tie, Shaolong; Deng, Haidong; Xu, Yi; Gu, Min

    2017-09-01

    Data storage with ultrahigh density, ultralow energy, high security, and long lifetime is highly desirable in the 21st century and optical data storage is considered as the most promising way to meet the challenge of storing big data. Plasmonic coupling in regularly arranged metallic nanoparticles has demonstrated its superior properties in various applications due to the generation of hot spots. Here, the discovery of the polarization and spectrum sensitivity of random hot spots generated in a volume gold nanorod assembly is reported. It is demonstrated that the two-photon-induced absorption and two-photon-induced luminescence of the gold nanorods adjacent to such hot spots are enhanced significantly because of plasmonic coupling. The polarization, wavelength, and spatial multiplexing of the hot spots can be realized by using an ultralow energy of only a few picojoule per pulse, which is two orders of magnitude lower than the value in the state-of-the-art technology that utilizes isolated gold nanorods. The ultralow recording energy reduces the cross-talk between different recording channels and makes it possible to realize rewriting function, improving significantly both the quality and capacity of optical data storage. It is anticipated that the demonstrated technology can facilitate the development of multidimensional optical data storage for a greener future. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Four-electron model for singlet and triplet excitation energy transfers with inclusion of coherence memory, inelastic tunneling and nuclear quantum effects

    NASA Astrophysics Data System (ADS)

    Suzuki, Yosuke; Ebina, Kuniyoshi; Tanaka, Shigenori

    2016-08-01

    A computational scheme to describe the coherent dynamics of excitation energy transfer (EET) in molecular systems is proposed on the basis of generalized master equations with memory kernels. This formalism takes into account those physical effects in electron-bath coupling system such as the spin symmetry of excitons, the inelastic electron tunneling and the quantum features of nuclear motions, thus providing a theoretical framework to perform an ab initio description of EET through molecular simulations for evaluating the spectral density and the temporal correlation function of electronic coupling. Some test calculations have then been carried out to investigate the dependence of exciton population dynamics on coherence memory, inelastic tunneling correlation time, magnitude of electronic coupling, quantum correction to temporal correlation function, reorganization energy and energy gap.

  15. Real-time changes in hippocampal energy demands during a spatial working memory task.

    PubMed

    Kealy, John; Bennett, Rachel; Woods, Barbara; Lowry, John P

    2017-02-27

    Activity-dependent changes in hippocampal energy consumption have largely been determined using microdialysis. However, real-time recordings of brain energy consumption can be more accurately achieved using amperometric sensors, allowing for sensitive real-time monitoring of concentration changes. Here, we test the theory that systemic pre-treatment with glucose in rats prevents activity-dependent decreases in hippocampal glucose levels and thus enhances their performance in a spontaneous alternation task. Male Sprague Dawley rats were implanted into the hippocampus with either: 1) microdialysis probe; or 2) an oxygen sensor and glucose biosensor co-implanted together. Animals were pre-treated with either saline or glucose (250mg/kg) 30min prior to performing a single 20-min spontaneous alternation task in a +-maze. There were no significant differences found between either treatment group in terms of spontaneous alternation performance. Additionally, there was a significant difference found between treatment groups on hippocampal glucose levels measured using microdialysis (a decrease associated with glucose pre-treatment in control animals) but not amperometry. There were significant increases in hippocampal oxygen during +-maze exploration. Combining the findings from both methods, it appears that hippocampal activity in the spontaneous alternation task does not cause an increase in glucose consumption, despite an increase in regional cerebral blood flow (using oxygen supply as an index of blood flow) and, as such, pre-treatment with glucose does not enhance spontaneous alternation performance.

  16. Inhibition of central angiotensin converting enzyme ameliorates scopolamine induced memory impairment in mice: role of cholinergic neurotransmission, cerebral blood flow and brain energy metabolism.

    PubMed

    Tota, Santoshkumar; Nath, Chandishwar; Najmi, Abul Kalam; Shukla, Rakesh; Hanif, Kashif

    2012-06-15

    Evidences indicate that inhibition of central Renin angiotensin system (RAS) ameliorates memory impairment in animals and humans. Earlier we have reported involvement of central angiotensin converting enzyme (ACE) in streptozotocin induced neurodegeneration and memory impairment. The present study investigated the role of central ACE in cholinergic neurotransmission, brain energy metabolism and cerebral blood flow (CBF) in model of memory impairment induced by injection of scopolamine in mice. Perindopril (0.05 and 0.1 mg/kg, PO) was given orally for one week before administration of scopolamine (3mg/kg, IP). Then, memory function was evaluated by Morris water maze and passive avoidance tests. CBF was measured by laser Doppler flowmetry. Biochemical and molecular parameters were estimated after the completion of behavioral studies. Scopolamine caused impairment in memory which was associated with reduced CBF, acetylcholine (ACh) level and elevated acetylcholinesterase (AChE) activity and malondialdehyde (MDA) level. Perindopril ameliorated scopolamine induced amnesia in both the behavioral paradigms. Further, perindopril prevented elevation of AChE and MDA level in mice brain. There was a significant increase in CBF and ACh level in perindopril treated mice. However, scopolamine had no significant effect on ATP level and mRNA expression of angiotensin receptors and ACE in cortex and hippocampus. But, perindopril significantly decreased ACE activity in brain without affecting its mRNA expression. The study clearly showed the interaction between ACE and cholinergic neurotransmission and beneficial effect of perindopril can be attributed to improvement in central cholinergic neurotransmission and CBF.

  17. Dawn of High Energy Spin Physics — In Memory of Michel Borghini

    NASA Astrophysics Data System (ADS)

    Masaike, Akira

    2016-02-01

    High energy spin physics with the polarized proton target in 1960s is shown. The dynamic polarization in which the electronic polarization is transferred to protons in paramagnetic material by means of magnetic coupling was proposed at the beginning of 1960s. The first N-N experiment using a polarized proton target was performed with the crystal of La2Mg3 (NO3)1224H2O at CEN-Saclay and Berkeley in 1962, followed by π-p experiments in several laboratories. Protons in organic materials were found to be polarized up to 80% in 3He cryostats in 1969. It was helpful for large background experiments. High proton polarization was interpreted in the spin temperature theory. Spin frozen targets were constructed in early 1970s and used for experiments which require wide access angle. Michel Borghini was a main player for almost all the above works.

  18. Interannual Variability of Deep-Layer Hydrologic Memory and Mechanisms of Its Influence on Surface Energy Fluxes.

    NASA Astrophysics Data System (ADS)

    Amenu, Geremew G.; Kumar, Praveen; Liang, Xin-Zhong

    2005-12-01

    The characteristics of deep-layer terrestrial memory are explored using observed soil moisture data and simulated soil temperature from the Illinois Climate Network stations. Both soil moisture and soil temperature are characterized by exponential decay in amplitude, linear lag in phase, and increasing persistence with depth. Using spectral analysis, four dominant low-frequency modes are identified in the soil moisture variability. These signals have periods of about 12, 17, 34, and 60 months, which correspond to annual cycle, (4/3) ENSO, quasi-biennial (QB) ENSO, and quasi-quadrennial (QQ) ENSO signals, respectively. For deep layers, the interannual modes are dominant over the annual cycle, and vice versa for the near-surface layer. There are inherently two mechanisms by which deep-layer moisture impacts the surface fluxes. First, its temporal variability sets the lower boundary condition for the transfer of moisture and heat fluxes from the surface. Second, this temporal variability influences the uptake of moisture by plant roots, resulting in the variability of the transpiration and, therefore, the entire energy balance. Initial results suggest that this second mechanism may be more predominant.

  19. Sweet taste signaling and the formation of memories of energy sources.

    PubMed

    de Araujo, Ivan E

    2011-01-01

    The last decade witnessed remarkable advances in our knowledge of the gustatory system. Application of molecular biology techniques not only determined the identity of the membrane receptors and downstream effectors that mediate sweetness, but also uncovered the overall logic of gustatory coding in the periphery. However, while the ability to taste sweet may offer the obvious advantage of eliciting rapid and robust intake of sugars, a number of recent studies demonstrate that sweetness is neither necessary nor sufficient for the formation of long-lasting preferences for stimuli associated with sugar intake. Furthermore, uncoupling sweet taste from ensuing energy utilization may disrupt body weight control. This minireview examines recent experiments performed in both rodents and Drosophila revealing the taste-independent rewarding properties of metabolizable sugars. Taken together, these experiments demonstrate the reinforcing actions of sugars in the absence of sweet taste signaling and point to a critical role played by dopamine systems in translating metabolic sensing into behavioral action. From a mechanistic viewpoint, current evidence favors the concept that gastrointestinal and post-absorptive signals contribute in parallel to sweet-independent sugar acceptance and dopamine release.

  20. [Energy and memory efficient calculation of the accommodation demand in the artificial accommodation system].

    PubMed

    Nagel, J A; Beck, C; Harms, H; Stiller, P; Guth, H; Stachs, O; Bretthauer, G

    2010-12-01

    Presbyopia and cataract are gaining more and more importance in the ageing society. Both age-related complaints are accompanied with a loss of the eye's ability to accommodate. A new approach to restore accommodation is the Artificial Accommodation System, an autonomous micro system, which will be implanted into the capsular bag instead of a rigid intraocular lens. The Artificial Accommodation System will, depending on the actual demand for accommodation, autonomously adapt the refractive power of its integrated optical element. One possibility to measure the demand for accommodation non-intrusively is to analyse eye movements. We present an efficient algorithm, based on the CORDIC technique, to calculate the demand for accommodation from magnetic field sensor data. It can be shown that specialised algorithms significantly shorten calculation time without violating precision requirements. Additionally, a communication strategy for the wireless exchange of sensor data between the implants of the left and right eye is introduced. The strategy allows for a one-sided calculation of the demand for accommodation, resulting in an overall reduction of calculation time by 50 %. The presented methods enable autonomous microsystems, such as the Artificial Accommodation System, to save significant amounts of energy, leading to extended autonomous run-times.

  1. Mechanical memory

    DOEpatents

    Gilkey, Jeffrey C.; Duesterhaus, Michelle A.; Peter, Frank J.; Renn, Rosemarie A.; Baker, Michael S.

    2006-05-16

    A first-in-first-out (FIFO) microelectromechanical memory apparatus (also termed a mechanical memory) is disclosed. The mechanical memory utilizes a plurality of memory cells, with each memory cell having a beam which can be bowed in either of two directions of curvature to indicate two different logic states for that memory cell. The memory cells can be arranged around a wheel which operates as a clocking actuator to serially shift data from one memory cell to the next. The mechanical memory can be formed using conventional surface micromachining, and can be formed as either a nonvolatile memory or as a volatile memory.

  2. Mechanical memory

    DOEpatents

    Gilkey, Jeffrey C.; Duesterhaus, Michelle A.; Peter, Frank J.; Renn, Rosemarie A.; Baker, Michael S.

    2006-08-15

    A first-in-first-out (FIFO) microelectromechanical memory apparatus (also termed a mechanical memory) is disclosed. The mechanical memory utilizes a plurality of memory cells, with each memory cell having a beam which can be bowed in either of two directions of curvature to indicate two different logic states for that memory cell. The memory cells can be arranged around a wheel which operates as a clocking actuator to serially shift data from one memory cell to the next. The mechanical memory can be formed using conventional surface micromachining, and can be formed as either a nonvolatile memory or as a volatile memory.

  3. Energy-dispersive neutron imaging and diffraction of magnetically driven twins in a Ni2MnGa single crystal magnetic shape memory alloy

    NASA Astrophysics Data System (ADS)

    Kabra, Saurabh; Kelleher, Joe; Kockelmann, Winfried; Gutmann, Matthias; Tremsin, Anton

    2016-09-01

    Single crystals of a partially twinned magnetic shape memory alloy, Ni2MnGa, were imaged using neutron diffraction and energy-resolved imaging techniques at the ISIS spallation neutron source. Single crystal neutron diffraction showed that the crystal produces two twin variants with a specific crystallographic relationship. Transmission images were captured using a time of flight MCP/Timepix neutron counting detector. The twinned and untwinned regions were clearly distinguishable in images corresponding to narrow-energy transmission images. Further, the spatially-resolved transmission spectra were used to elucidate the orientations of the crystallites in the different volumes of the crystal.

  4. Active Flash: Performance-Energy Tradeoffs for Out-of-Core Processing on Non-Volatile Memory Devices

    SciTech Connect

    Boboila, Simona; Kim, Youngjae; Vazhkudai, Sudharshan S; Desnoyers, Peter; Shipman, Galen M

    2012-01-01

    In this abstract, we study the performance and energy tradeoffs involved in migrating data analysis into the flash device, a process we refer to as Active Flash. The Active Flash paradigm is similar to 'active disks', which has received considerable attention. Active Flash allows us to move processing closer to data, thereby minimizing data movement costs and reducing power consumption. It enables true out-of-core computation. The conventional definition of out-of-core solvers refers to an approach to process data that is too large to fit in the main memory and, consequently, requires access to disk. However, in Active Flash, processing outside the host CPU literally frees the core and achieves real 'out-of-core' analysis. Moving analysis to data has long been desirable, not just at this level, but at all levels of the system hierarchy. However, this requires a detailed study on the tradeoffs involved in achieving analysis turnaround under an acceptable energy envelope. To this end, we first need to evaluate if there is enough computing power on the flash device to warrant such an exploration. Flash processors require decent computing power to run the internal logic pertaining to the Flash Translation Layer (FTL), which is responsible for operations such as address translation, garbage collection (GC) and wear-leveling. Modern SSDs are composed of multiple packages and several flash chips within a package. The packages are connected using multiple I/O channels to offer high I/O bandwidth. SSD computing power is also expected to be high enough to exploit such inherent internal parallelism within the drive to increase the bandwidth and to handle fast I/O requests. More recently, SSD devices are being equipped with powerful processing units and are even embedded with multicore CPUs (e.g. ARM Cortex-A9 embedded processor is advertised to reach 2GHz frequency and deliver 5000 DMIPS; OCZ RevoDrive X2 SSD has 4 SandForce controllers, each with 780MHz max frequency

  5. Asymmetric underlap optimization of sub-10nm finfets for realizing energy-efficient logic and robust memories

    NASA Astrophysics Data System (ADS)

    Akkala, Arun Goud

    Leakage currents in CMOS transistors have risen dramatically with technology scaling leading to significant increase in standby power consumption. Among the various transistor candidates, the excellent short channel immunity of Silicon double gate FinFETs have made them the best contender for successful scaling to sub-10nm nodes. For sub-10nm FinFETs, new quantum mechanical leakage mechanisms such as direct source to drain tunneling (DSDT) of charge carriers through channel potential energy barrier arising due to proximity of source/drain regions coupled with the high transport direction electric field is expected to dominate overall leakage. To counter the effects of DSDT and worsening short channel effects and to maintain Ion/ Ioff, performance and power consumption at reasonable values, device optimization techniques are necessary for deeply scaled transistors. In this work, source/drain underlapping of FinFETs has been explored using quantum mechanical device simulations as a potentially promising method to lower DSDT while maintaining the Ion/ Ioff ratio at acceptable levels. By adopting a device/circuit/system level co-design approach, it is shown that asymmetric underlapping, where the drain side underlap is longer than the source side underlap, results in optimal energy efficiency for logic circuits in near-threshold as well as standard, super-threshold operating regimes. In addition, read/write conflict in 6T SRAMs and the degradation in cell noise margins due to the low supply voltage can be mitigated by using optimized asymmetric underlapped n-FinFETs for the access transistor, thereby leading to robust cache memories. When gate-workfunction tuning is possible, using asymmetric underlapped n-FinFETs for both access and pull-down devices in an SRAM bit cell can lead to high-speed and low-leakage caches. Further, it is shown that threshold voltage degradation in the presence of Hot Carrier Injection (HCI) is less severe in asymmetric underlap n-FinFETs. A

  6. In situ TEM and energy dispersion spectrometer analysis of chemical composition change in ZnO nanowire resistive memories.

    PubMed

    Huang, Yu-Ting; Yu, Shih-Ying; Hsin, Cheng-Lun; Huang, Chun-Wei; Kang, Chen-Fang; Chu, Fu-Hsuan; Chen, Jui-Yuan; Hu, Jung-Chih; Chen, Lien-Tai; He, Jr-Hau; Wu, Wen-Wei

    2013-04-16

    Resistive random-access memory (ReRAM) has been of wide interest for its potential to replace flash memory in the next-generation nonvolatile memory roadmap. In this study, we have fabricated the Au/ZnO-nanowire/Au nanomemory device by electron beam lithography and, subsequently, utilized in situ transmission electron microscopy (TEM) to observe the atomic structure evolution from the initial state to the low-resistance state (LRS) in the ZnO nanowire. The element mapping of LRS showing that the nanowire was zinc dominant indicating that the oxygen vacancies were introduced after resistance switching. The results provided direct evidence, suggesting that the resistance change resulted from oxygen migration.

  7. New gravitational memories

    NASA Astrophysics Data System (ADS)

    Pasterski, Sabrina; Strominger, Andrew; Zhiboedov, Alexander

    2016-12-01

    The conventional gravitational memory effect is a relative displacement in the position of two detectors induced by radiative energy flux. We find a new type of gravitational `spin memory' in which beams on clockwise and counterclockwise orbits acquire a relative delay induced by radiative angular momentum flux. It has recently been shown that the displacement memory formula is a Fourier transform in time of Weinberg's soft graviton theorem. Here we see that the spin memory formula is a Fourier transform in time of the recently-discovered subleading soft graviton theorem.

  8. Memory bistable mechanisms of organic memory devices

    NASA Astrophysics Data System (ADS)

    Lee, Ching-Ting; Yu, Li-Zhen; Chen, Hung-Chun

    2010-07-01

    To investigate the memory bistable mechanisms of organic memory devices, the structure of [top Au anode/9,10-di(2-naphthyl)anthracene (ADN) active layer/bottom Au cathode] was deposited using a thermal deposition system. The Au atoms migrated into the ADN active layer was observed from the secondary ion mass spectrometry. The density of 9.6×1016 cm-3 and energy level of 0.553 eV of the induced trapping centers caused by the migrated Au atoms in the ADN active layer were calculated. The induced trapping centers did not influence the carrier injection barrier height between Au and ADN active layer. Therefore, the memory bistable behaviors of the organic memory devices were attributed to the induced trapping centers. The energy diagram was established to verify the mechanisms.

  9. Reversible strain-induced magnetization switching in FeGa nanomagnets: Pathway to a rewritable, non-volatile, non-toggle, extremely low energy straintronic memory

    NASA Astrophysics Data System (ADS)

    Ahmad, Hasnain; Atulasimha, Jayasimha; Bandyopadhyay, Supriyo

    2015-12-01

    We report reversible strain-induced magnetization switching between two stable/metastable states in ~300 nm sized FeGa nanomagnets delineated on a piezoelectric PMN-PT substrate. Voltage of one polarity applied across the substrate generates compressive strain in a nanomagnet and switches its magnetization to one state, while voltage of the opposite polarity generates tensile strain and switches the magnetization back to the original state. The two states can encode the two binary bits, and, using the right voltage polarity, one can write either bit deterministically. This portends an ultra-energy-efficient non-volatile “non-toggle” memory.

  10. Distributed memory parallel implementation of energies and gradients for second-order Møller-Plesset perturbation theory with the resolution-of-the-identity approximation.

    PubMed

    Hättig, Christof; Hellweg, Arnim; Köhn, Andreas

    2006-03-14

    We present a parallel implementation of second-order Møller-Plesset perturbation theory with the resolution-of-the-identity approximation (RI-MP2). The implementation is based on a recent improved sequential implementation of RI-MP2 within the Turbomole program package and employs the message passing interface (MPI) standard for communication between distributed memory nodes. The parallel implementation extends the applicability of canonical MP2 to considerably larger systems. Examples are presented for full geometry optimizations with up to 60 atoms and 3300 basis functions and MP2 energy calculations with more than 200 atoms and 7000 basis functions.

  11. Reversible strain-induced magnetization switching in FeGa nanomagnets: Pathway to a rewritable, non-volatile, non-toggle, extremely low energy straintronic memory

    PubMed Central

    Ahmad, Hasnain; Atulasimha, Jayasimha; Bandyopadhyay, Supriyo

    2015-01-01

    We report reversible strain-induced magnetization switching between two stable/metastable states in ~300 nm sized FeGa nanomagnets delineated on a piezoelectric PMN-PT substrate. Voltage of one polarity applied across the substrate generates compressive strain in a nanomagnet and switches its magnetization to one state, while voltage of the opposite polarity generates tensile strain and switches the magnetization back to the original state. The two states can encode the two binary bits, and, using the right voltage polarity, one can write either bit deterministically. This portends an ultra-energy-efficient non-volatile “non-toggle” memory. PMID:26657829

  12. Acoustically assisted spin-transfer-torque switching of nanomagnets: An energy-efficient hybrid writing scheme for non-volatile memory

    SciTech Connect

    Biswas, Ayan K.; Bandyopadhyay, Supriyo; Atulasimha, Jayasimha

    2013-12-02

    We show that the energy dissipated to write bits in spin-transfer-torque random access memory can be reduced by an order of magnitude if a surface acoustic wave (SAW) is launched underneath the magneto-tunneling junctions (MTJs) storing the bits. The SAW-generated strain rotates the magnetization of every MTJs' soft magnet from the easy towards the hard axis, whereupon passage of a small spin-polarized current through a target MTJ selectively switches it to the desired state with > 99.99% probability at room temperature, thereby writing the bit. The other MTJs return to their original states at the completion of the SAW cycle.

  13. MEMORY MODULATION

    PubMed Central

    Roozendaal, Benno; McGaugh, James L.

    2011-01-01

    Our memories are not all created equally strong: Some experiences are well remembered while others are remembered poorly, if at all. Research on memory modulation investigates the neurobiological processes and systems that contribute to such differences in the strength of our memories. Extensive evidence from both animal and human research indicates that emotionally significant experiences activate hormonal and brain systems that regulate the consolidation of newly acquired memories. These effects are integrated through noradrenergic activation of the basolateral amygdala which regulates memory consolidation via interactions with many other brain regions involved in consolidating memories of recent experiences. Modulatory systems not only influence neurobiological processes underlying the consolidation of new information, but also affect other mnemonic processes, including memory extinction, memory recall and working memory. In contrast to their enhancing effects on consolidation, adrenal stress hormones impair memory retrieval and working memory. Such effects, as with memory consolidation, require noradrenergic activation of the basolateral amygdala and interactions with other brain regions. PMID:22122145

  14. Memory Matters

    MedlinePlus

    ... different parts. Some of them are important for memory. The hippocampus (say: hih-puh-KAM-pus) is one of the more important parts of the brain that processes memories. Old information and new information, or memories, are ...

  15. Shape memory polymer medical device

    DOEpatents

    Maitland, Duncan; Benett, William J.; Bearinger, Jane P.; Wilson, Thomas S.; Small, IV, Ward; Schumann, Daniel L.; Jensen, Wayne A.; Ortega, Jason M.; Marion, III, John E.; Loge, Jeffrey M.

    2010-06-29

    A system for removing matter from a conduit. The system includes the steps of passing a transport vehicle and a shape memory polymer material through the conduit, transmitting energy to the shape memory polymer material for moving the shape memory polymer material from a first shape to a second and different shape, and withdrawing the transport vehicle and the shape memory polymer material through the conduit carrying the matter.

  16. 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.

  17. Memory Palaces

    ERIC Educational Resources Information Center

    Wood, Marianne

    2007-01-01

    This article presents a lesson called Memory Palaces. A memory palace is a memory tool used to remember information, usually as visual images, in a sequence that is logical to the person remembering it. In his book, "In the Palaces of Memory", George Johnson calls them "...structure(s) for arranging knowledge. Lots of connections to language arts,…

  18. About lamination upper and convexification lower bounds on the free energy of monoclinic shape memory alloys in the context of T 3-configurations and R-phase formation

    NASA Astrophysics Data System (ADS)

    Fechte-Heinen, R.; Schlömerkemper, A.

    2016-11-01

    This work is concerned with different estimates of the quasiconvexification of multi-well energy landscapes of NiTi shape memory alloys, which models the overall behavior of the material. Within the setting of the geometrically linear theory of elasticity, we consider a formula of the quasiconvexification which involves the so-called energy of mixing.We are interested in lower and upper bounds on the energy of mixing in order to get a better understanding of the quasiconvexification. The lower bound on the energy of mixing is obtained by convexification; it is also called Sachs or Reuß lower bound. The upper bound on the energy of mixing is based on second-order lamination. In particular, we are interested in the difference between the lower and upper bounds. Our numerical simulations show that the difference is in fact of the order of 1% and less in martensitic NiTi, even though both bounds on the energy of mixing were rather expected to differ more significantly. Hence, in various circumstances it may be justified to simply work with the convexification of the multi-well energy, which is relatively easy to deal with, or with the lamination upper bound, which always corresponds to a physically realistic microstructure, as an estimate of the quasiconvexification. In order to obtain a potentially large difference between upper and lower bound, we consider the bounds along paths in strain space which involve incompatible strains. In monoclinic shape memory alloys, three-tuples of pairwise incompatible strains play a special role since they form so-called T 3-configurations, originally discussed in a stress-free setting. In this work, we therefore consider in particular numerical simulations along paths in strain space which are related to these T 3-configurations. Interestingly, we observe that the second-order lamination upper bound along such paths is related to the geometry of the T 3-configurations. In addition to the purely martensitic regime, we also consider

  19. The effect of memory in the stochastic master equation analyzed using the stochastic Liouville equation of motion. Electronic energy migration transfer between reorienting donor-donor, donor-acceptor chromophores.

    PubMed

    Håkansson, Pär; Westlund, Per-Olof

    2005-01-01

    This paper discusses the process of energy migration transfer within reorientating chromophores using the stochastic master equation (SME) and the stochastic Liouville equation (SLE) of motion. We have found that the SME over-estimates the rate of the energy migration compared to the SLE solution for a case of weakly interacting chromophores. This discrepancy between SME and SLE is caused by a memory effect occurring when fluctuations in the dipole-dipole Hamiltonian (H(t)) are on the same timescale as the intrinsic fast transverse relaxation rate characterized by (1/T(2)). Thus the timescale critical for energy-transfer experiments is T(2) approximately 10(-13) s. An extended SME is constructed, accounting for the memory effect of the dipole-dipole Hamiltonian dynamics. The influence of memory on the interpretation of experiments is discussed.

  20. Central acylated ghrelin improves memory function and hippocampal AMPK activation and partly reverses the impairment of energy and glucose metabolism in rats infused with β-amyloid.

    PubMed

    Kang, Suna; Moon, Na Rang; Kim, Da Sol; Kim, Sung Hoon; Park, Sunmin

    2015-09-01

    Ghrelin is a gastric hormone released during the fasting state that targets the hypothalamus where it induces hunger; however, emerging evidence suggests it may also affect memory function. We examined the effect of central acylated-ghrelin and DES-acetylated ghrelin (native ghrelin) on memory function and glucose metabolism in an experimentally induced Alzheimer's disease (AD) rat model. AD rats were divided into 3 groups and Non-AD rats were used as a normal-control group. Each rat in the AD groups had intracerebroventricular (ICV) infusion of β-amyloid (25-35; 16.8nmol/day) into the lateral ventricle for 3 days, and then the pumps were changed to infuse either acylated-ghrelin (0.2nmol/h; AD-G), DES-acylated ghrelin (0.2nmol/h; AD-DES-G), or saline (control; AD-C) for 3 weeks. The Non-AD group had ICV infusion of β-amyloid (35-25) which does not deposit in the hippocampus. During the next 3 weeks memory function, food intake, body weight gain, body fat composition, and glucose metabolism were measured. AD-C exhibited greater β-amyloid deposition compared to Non-AD-C, and AD-G suppressed the increased β-amyloid deposition and potentiated the phosphorylation AMPK. In addition, AD-G increased the phosphorylation GSK and decreased the phosphorylation of Tau in comparison to AD-C and AD-DES-G. Cognitive function, measured by passive avoidance and water maze tests, was much lower in AD-C than Non-AD-C whereas AD-G but not AD-DES-G prevented the decrease (p<0.021). Body weight gain was lower in AD-C group than Non-AD-C group without changing epididymal fat mass. AD-G reversed the decrease in body weight which was due to increased energy intake and decreased energy expenditure. The AD-G group exhibited a decrease in the second part of serum glucose levels during an oral glucose tolerance test (OGTT) compared to the AD-C and AD-DES-G group (p<0.009). However, area under the curve of insulin during the first part of OGTT was higher in AD-DES-G than other groups

  1. Energy efficient and fast reversal of a fixed skyrmion two-terminal memory with spin current assisted by voltage controlled magnetic anisotropy

    NASA Astrophysics Data System (ADS)

    Bhattacharya, Dhritiman; Mamun Al-Rashid, Md; Atulasimha, Jayasimha

    2017-10-01

    Recent work (P-H Jang et al 2015 Appl. Phys. Lett. 107 202401, J. Sampaio et al 2016 Appl. Phys. Lett. 108 112403) suggests that ferromagnetic reversal with spin transfer torque (STT) requires more current in a system in the presence of Dzyaloshinskii-Moriya interaction (DMI) than switching a typical ferromagnet of the same dimensions and perpendicular magnetic anisotropy (PMA). However, DMI promotes the stabilization of skyrmions and we report that when perpendicular anisotropy is modulated (reduced) for both the skyrmion and ferromagnet, it takes a much smaller current to reverse the fixed skyrmion than to reverse the ferromagnet in the same amount of time, or the skyrmion reverses much faster than the ferromagnet at similar levels of current. We show with rigorous micromagnetic simulations that skyrmion switching proceeds along a different path at very low PMA, which results in a significant reduction in the spin current or time required for reversal. This can offer potential for memory applications where a relatively simple modification of the standard STT-RAM (to include a heavy metal adjacent to the soft magnetic layer and with appropriate design of the tunnel barrier) can lead to an energy efficient and fast magnetic memory device based on the reversal of fixed skyrmions.

  2. Giant voltage manipulation of MgO-based magnetic tunnel junctions via localized anisotropic strain: A potential pathway to ultra-energy-efficient memory technology

    NASA Astrophysics Data System (ADS)

    Zhao, Zhengyang; Jamali, Mahdi; D'Souza, Noel; Zhang, Delin; Bandyopadhyay, Supriyo; Atulasimha, Jayasimha; Wang, Jian-Ping

    2016-08-01

    Voltage control of magnetization via strain in piezoelectric/magnetostrictive systems is a promising mechanism to implement energy-efficient straintronic memory devices. Here, we demonstrate giant voltage manipulation of MgO magnetic tunnel junctions (MTJ) on a Pb(Mg1/3Nb2/3)0.7Ti0.3O3 piezoelectric substrate with (001) orientation. It is found that the magnetic easy axis, switching field, and the tunnel magnetoresistance (TMR) of the MTJ can be efficiently controlled by strain from the underlying piezoelectric layer upon the application of a gate voltage. Repeatable voltage controlled MTJ toggling between high/low-resistance states is demonstrated. More importantly, instead of relying on the intrinsic anisotropy of the piezoelectric substrate to generate the required strain, we utilize anisotropic strain produced using a local gating scheme, which is scalable and amenable to practical memory applications. Additionally, the adoption of crystalline MgO-based MTJ on piezoelectric layer lends itself to high TMR in the strain-mediated MRAM devices.

  3. Optical memory

    DOEpatents

    Mao, Samuel S; Zhang, Yanfeng

    2013-07-02

    Optical memory comprising: a semiconductor wire, a first electrode, a second electrode, a light source, a means for producing a first voltage at the first electrode, a means for producing a second voltage at the second electrode, and a means for determining the presence of an electrical voltage across the first electrode and the second electrode exceeding a predefined voltage. The first voltage, preferably less than 0 volts, different from said second voltage. The semiconductor wire is optically transparent and has a bandgap less than the energy produced by the light source. The light source is optically connected to the semiconductor wire. The first electrode and the second electrode are electrically insulated from each other and said semiconductor wire.

  4. Memory Matters

    MedlinePlus

    ... blood vessel (which carries the blood) bursts. continue Brain Injuries Affect Memory At any age, an injury to ... with somebody's memory. Some people who recover from brain injuries need to learn old things all over again, ...

  5. Effect of ion implantation energy for the synthesis of Ge nanocrystals in SiN films with HfO2/SiO2 stack tunnel dielectrics for memory application

    PubMed Central

    2011-01-01

    Ge nanocrystals (Ge-NCs) embedded in SiN dielectrics with HfO2/SiO2 stack tunnel dielectrics were synthesized by utilizing low-energy (≤5 keV) ion implantation method followed by conventional thermal annealing at 800°C, the key variable being Ge+ ion implantation energy. Two different energies (3 and 5 keV) have been chosen for the evolution of Ge-NCs, which have been found to possess significant changes in structural and chemical properties of the Ge+-implanted dielectric films, and well reflected in the charge storage properties of the Al/SiN/Ge-NC + SiN/HfO2/SiO2/Si metal-insulator-semiconductor (MIS) memory structures. No Ge-NC was detected with a lower implantation energy of 3 keV at a dose of 1.5 × 1016 cm-2, whereas a well-defined 2D-array of nearly spherical and well-separated Ge-NCs within the SiN matrix was observed for the higher-energy-implanted (5 keV) sample for the same implanted dose. The MIS memory structures implanted with 5 keV exhibits better charge storage and retention characteristics compared to the low-energy-implanted sample, indicating that the charge storage is predominantly in Ge-NCs in the memory capacitor. A significant memory window of 3.95 V has been observed under the low operating voltage of ± 6 V with good retention properties, indicating the feasibility of these stack structures for low operating voltage, non-volatile memory devices. PMID:21711708

  6. Memory dynamics in attractor networks.

    PubMed

    Li, Guoqi; Ramanathan, Kiruthika; Ning, Ning; Shi, Luping; Wen, Changyun

    2015-01-01

    As can be represented by neurons and their synaptic connections, attractor networks are widely believed to underlie biological memory systems and have been used extensively in recent years to model the storage and retrieval process of memory. In this paper, we propose a new energy function, which is nonnegative and attains zero values only at the desired memory patterns. An attractor network is designed based on the proposed energy function. It is shown that the desired memory patterns are stored as the stable equilibrium points of the attractor network. To retrieve a memory pattern, an initial stimulus input is presented to the network, and its states converge to one of stable equilibrium points. Consequently, the existence of the spurious points, that is, local maxima, saddle points, or other local minima which are undesired memory patterns, can be avoided. The simulation results show the effectiveness of the proposed method.

  7. Memory Dysfunction

    PubMed Central

    Matthews, Brandy R.

    2015-01-01

    Purpose of Review: This article highlights the dissociable human memory systems of episodic, semantic, and procedural memory in the context of neurologic illnesses known to adversely affect specific neuroanatomic structures relevant to each memory system. Recent Findings: Advances in functional neuroimaging and refinement of neuropsychological and bedside assessment tools continue to support a model of multiple memory systems that are distinct yet complementary and to support the potential for one system to be engaged as a compensatory strategy when a counterpart system fails. Summary: Episodic memory, the ability to recall personal episodes, is the subtype of memory most often perceived as dysfunctional by patients and informants. Medial temporal lobe structures, especially the hippocampal formation and associated cortical and subcortical structures, are most often associated with episodic memory loss. Episodic memory dysfunction may present acutely, as in concussion; transiently, as in transient global amnesia (TGA); subacutely, as in thiamine deficiency; or chronically, as in Alzheimer disease. Semantic memory refers to acquired knowledge about the world. Anterior and inferior temporal lobe structures are most often associated with semantic memory loss. The semantic variant of primary progressive aphasia (svPPA) is the paradigmatic disorder resulting in predominant semantic memory dysfunction. Working memory, associated with frontal lobe function, is the active maintenance of information in the mind that can be potentially manipulated to complete goal-directed tasks. Procedural memory, the ability to learn skills that become automatic, involves the basal ganglia, cerebellum, and supplementary motor cortex. Parkinson disease and related disorders result in procedural memory deficits. Most memory concerns warrant bedside cognitive or neuropsychological evaluation and neuroimaging to assess for specific neuropathologies and guide treatment. PMID:26039844

  8. Emerging memories

    NASA Astrophysics Data System (ADS)

    Baldi, Livio; Bez, Roberto; Sandhu, Gurtej

    2014-12-01

    Memory is a key component of any data processing system. Following the classical Turing machine approach, memories hold both the data to be processed and the rules for processing them. In the history of microelectronics, the distinction has been rather between working memory, which is exemplified by DRAM, and storage memory, exemplified by NAND. These two types of memory devices now represent 90% of all memory market and 25% of the total semiconductor market, and have been the technology drivers in the last decades. Even if radically different in characteristics, they are however based on the same storage mechanism: charge storage, and this mechanism seems to be near to reaching its physical limits. The search for new alternative memory approaches, based on more scalable mechanisms, has therefore gained new momentum. The status of incumbent memory technologies and their scaling limitations will be discussed. Emerging memory technologies will be analyzed, starting from the ones that are already present for niche applications, and which are getting new attention, thanks to recent technology breakthroughs. Maturity level, physical limitations and potential for scaling will be compared to existing memories. At the end the possible future composition of memory systems will be discussed.

  9. Memory protection

    NASA Technical Reports Server (NTRS)

    Denning, Peter J.

    1988-01-01

    Accidental overwriting of files or of memory regions belonging to other programs, browsing of personal files by superusers, Trojan horses, and viruses are examples of breakdowns in workstations and personal computers that would be significantly reduced by memory protection. Memory protection is the capability of an operating system and supporting hardware to delimit segments of memory, to control whether segments can be read from or written into, and to confine accesses of a program to its segments alone. The absence of memory protection in many operating systems today is the result of a bias toward a narrow definition of performance as maximum instruction-execution rate. A broader definition, including the time to get the job done, makes clear that cost of recovery from memory interference errors reduces expected performance. The mechanisms of memory protection are well understood, powerful, efficient, and elegant. They add to performance in the broad sense without reducing instruction execution rate.

  10. Energy.

    ERIC Educational Resources Information Center

    Online-Offline, 1998

    1998-01-01

    This issue focuses on the theme of "Energy," and describes several educational resources (Web sites, CD-ROMs and software, videos, books, activities, and other resources). Sidebars offer features on alternative energy, animal energy, internal combustion engines, and energy from food. Subthemes include harnessing energy, human energy, and…

  11. Energy.

    ERIC Educational Resources Information Center

    Online-Offline, 1998

    1998-01-01

    This issue focuses on the theme of "Energy," and describes several educational resources (Web sites, CD-ROMs and software, videos, books, activities, and other resources). Sidebars offer features on alternative energy, animal energy, internal combustion engines, and energy from food. Subthemes include harnessing energy, human energy, and…

  12. Declarative memory.

    PubMed

    Riedel, Wim J; Blokland, Arjan

    2015-01-01

    Declarative Memory consists of memory for events (episodic memory) and facts (semantic memory). Methods to test declarative memory are key in investigating effects of potential cognition-enhancing substances--medicinal drugs or nutrients. A number of cognitive performance tests assessing declarative episodic memory tapping verbal learning, logical memory, pattern recognition memory, and paired associates learning are described. These tests have been used as outcome variables in 34 studies in humans that have been described in the literature in the past 10 years. Also, the use of episodic tests in animal research is discussed also in relation to the drug effects in these tasks. The results show that nutritional supplementation of polyunsaturated fatty acids has been investigated most abundantly and, in a number of cases, but not all, show indications of positive effects on declarative memory, more so in elderly than in young subjects. Studies investigating effects of registered anti-Alzheimer drugs, cholinesterase inhibitors in mild cognitive impairment, show positive and negative effects on declarative memory. Studies mainly carried out in healthy volunteers investigating the effects of acute dopamine stimulation indicate enhanced memory consolidation as manifested specifically by better delayed recall, especially at time points long after learning and more so when drug is administered after learning and if word lists are longer. The animal studies reveal a different picture with respect to the effects of different drugs on memory performance. This suggests that at least for episodic memory tasks, the translational value is rather poor. For the human studies, detailed parameters of the compositions of word lists for declarative memory tests are discussed and it is concluded that tailored adaptations of tests to fit the hypothesis under study, rather than "off-the-shelf" use of existing tests, are recommended.

  13. Harvesting Mechanical and Thermal Energy by Combining ZnO Nanowires and NiTi Shape Memory Alloy

    DOE PAGES

    Radousky, Harry; Qian, Fang; An, Yonghao; ...

    2017-02-19

    In the expanding world of small scale energy harvesting, the ability to combine thermal and mechanical harvesting is growing ever more important. Here, we demonstrate the feasibility of using ZnO nanowires to harvest both mechanical and low-quality thermal energy in simple, scalable devices. These devices were fabricated on kapton films and used ZnO nanowires with the same growth direction to assure alignment of the piezoelectric potentials of all of the wires. Mechanical harvesting from these devices was demonstrated using a periodic application of force, modeling the motion of the human body. Tapping the device from the top of the devicemore » with a wood stick, for example yielded an Open Circuit Voltage (OCV) of 0.2 - 4 V, which is in an ideal range for device applications. In order to demonstrate thermal harvesting from low quality heat sources, a commercially available Nitinol (Ni-Ti alloy) foil was attached to the nanowire piezoelectric device to create a compound thermoelectric. When bent at room temperature and then heated to 50°C, the Nitinol foil was restored to its original flat shape, which yielded an output voltage of nearly 1 V from the ZnO nanowire device.« less

  14. Flashbulb Memories

    PubMed Central

    Hirst, William; Phelps, Elizabeth A.

    2015-01-01

    We review and analyze the key theories, debates, findings, and omissions of the existing literature on flashbulb memories (FBMs), including what factors affect their formation, retention, and degree of confidence. We argue that FBMs do not require special memory mechanisms and are best characterized as involving both forgetting and mnemonic distortions, despite a high level of confidence. Factual memories for FBM-inducing events generally follow a similar pattern. Although no necessary and sufficient factors straightforwardly account for FBM retention, media attention particularly shapes memory for the events themselves. FBMs are best characterized in term of repetitions, even of mnemonic distortions, whereas event memories evidence corrections. The bearing of this literature on social identity and traumatic memories is also discussed. PMID:26997762

  15. Skilled Memory.

    DTIC Science & Technology

    1980-11-06

    Morse code (Bryan & Harter , 1899). In every case, memory performance of the expert seems to violate the established limits of short- term memory. How is...of immediate memory. Quarterly Journal of Experimental psychology, 1958, 10, 12-21. Bryan, W. L., & Harter N. psychological Review, 1899, 6, 345-375...16, 1980 Page 5 Civil Govt Non Govt Dr. Susan Chipman 1 Dr. John R. Anderson Learning and Development Department of Psychology National Institute of

  16. Virtual memory

    NASA Technical Reports Server (NTRS)

    Denning, P. J.

    1986-01-01

    Virtual memory was conceived as a way to automate overlaying of program segments. Modern computers have very large main memories, but need automatic solutions to the relocation and protection problems. Virtual memory serves this need as well and is thus useful in computers of all sizes. The history of the idea is traced, showing how it has become a widespread, little noticed feature of computers today.

  17. Technical Seminar "Shape Memory Alloys"

    NASA Image and Video Library

    Shape memory alloys are a unique group of materials that remember their original shape and return to that shape after being strained. How could the aerospace, automotive, and energy exploration ind...

  18. Shape Memory Alloy Actuator

    NASA Technical Reports Server (NTRS)

    Baumbick, Robert J. (Inventor)

    2000-01-01

    The present invention discloses and teaches a unique, remote optically controlled micro actuator particularly suitable for aerospace vehicle applications wherein hot gas, or in the alternative optical energy, is employed as the medium by which shape memory alloy elements are activated. In gas turbine powered aircraft the source of the hot gas may be the turbine engine compressor or turbine sections.

  19. Shape Memory Alloy Actuator

    NASA Technical Reports Server (NTRS)

    Baumbick, Robert J. (Inventor)

    2002-01-01

    The present invention discloses and teaches a unique, remote optically controlled micro actuator particularly suitable for aerospace vehicle applications wherein hot gas, or in the alternative optical energy, is employed as the medium by which shape memory alloy elements are activated. In gas turbine powered aircraft the source of the hot gas may be the turbine engine compressor or turbine sections.

  20. High-energy synchrotron X-ray diffraction measurements of simple bending of pseudoelastic NiTi shape memory alloy wires

    SciTech Connect

    Zhang, Baozhuo; Young, Marcus L.

    2016-05-23

    Many technological applications of austenitic shape memory alloys (SMAs) involve cyclical mechanical loading and unloading in order to take advantage of pseudoelasticity. In this paper, we investigated the effect of mechanical bending of pseudoelastic NiTi SMA wires using high-energy synchrotron radiation X-ray diffraction (SR-XRD). Differential scanning calorimetry was performed to identify the phase transformation temperatures. Scanning electron microscopy images show that micro-cracks in compressive regions of the wire propagate with increasing bend angle, while tensile regions tend not to exhibit crack propagation. SR-XRD patterns were analyzed to study the phase transformation and investigate micromechanical properties. By observing the various diffraction peaks such as the austenite (200) and the martensite (${\\bar 1}12$), (${\\bar 1}03$), (${\\bar 1}11$), and (101) planes, intensities and residual strain values exhibit strong anisotropy, depending upon whether the sample is in compression or tension during bending.

  1. Memory Metals

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Under contract to NASA during preparations for the space station, Memry Technologies Inc. investigated shape memory effect (SME). SME is a characteristic of certain metal alloys that can change shape in response to temperature variations. In the late 1980s and early 1990s, Memry used its NASA-acquired expertise to produce a line of home and industrial safety products, and refined the technology in the mid-1990s. Among the new products they developed are three MemrySafe units which prevent scalding from faucets. Each system contains a small valve that reacts to temperature, not pressure. When the water reaches dangerous temperatures, the unit reduces the flow to a trickle; when the scalding temperature subsides, the unit restores normal flow. Other products are the FIRECHEK 2 and 4, heat-activated shutoff valves for industrial process lines, which sense excessive heat and cut off pneumatic pressure. The newest of these products is Memry's Demand Management Water Heater which shifts the electricity requirement from peak to off-peak demands, conserving energy and money.

  2. Episodic Memories

    ERIC Educational Resources Information Center

    Conway, Martin A.

    2009-01-01

    An account of episodic memories is developed that focuses on the types of knowledge they represent, their properties, and the functions they might serve. It is proposed that episodic memories consist of "episodic elements," summary records of experience often in the form of visual images, associated to a "conceptual frame" that provides a…

  3. Collaging Memories

    ERIC Educational Resources Information Center

    Wallach, Michele

    2011-01-01

    Even middle school students can have memories of their childhoods, of an earlier time. The art of Romare Bearden and the writings of Paul Auster can be used to introduce ideas about time and memory to students and inspire works of their own. Bearden is an exceptional role model for young artists, not only because of his astounding art, but also…

  4. Memory Magic.

    ERIC Educational Resources Information Center

    Hartman, Thomas G.; Nowak, Norman

    This paper outlines several "tricks" that aid students in improving their memories. The distinctions between operational and figural thought processes are noted. Operational memory is described as something that allows adults to make generalizations about numbers and the rules by which they may be combined, thus leading to easier memorization.…

  5. Collaging Memories

    ERIC Educational Resources Information Center

    Wallach, Michele

    2011-01-01

    Even middle school students can have memories of their childhoods, of an earlier time. The art of Romare Bearden and the writings of Paul Auster can be used to introduce ideas about time and memory to students and inspire works of their own. Bearden is an exceptional role model for young artists, not only because of his astounding art, but also…

  6. Episodic Memories

    ERIC Educational Resources Information Center

    Conway, Martin A.

    2009-01-01

    An account of episodic memories is developed that focuses on the types of knowledge they represent, their properties, and the functions they might serve. It is proposed that episodic memories consist of "episodic elements," summary records of experience often in the form of visual images, associated to a "conceptual frame" that provides a…

  7. Memory conformity affects inaccurate memories more than accurate memories.

    PubMed

    Wright, Daniel B; Villalba, Daniella K

    2012-01-01

    After controlling for initial confidence, inaccurate memories were shown to be more easily distorted than accurate memories. In two experiments groups of participants viewed 50 stimuli and were then presented with these stimuli plus 50 fillers. During this test phase participants reported their confidence that each stimulus was originally shown. This was followed by computer-generated responses from a bogus participant. After being exposed to this response participants again rated the confidence of their memory. The computer-generated responses systematically distorted participants' responses. Memory distortion depended on initial memory confidence, with uncertain memories being more malleable than confident memories. This effect was moderated by whether the participant's memory was initially accurate or inaccurate. Inaccurate memories were more malleable than accurate memories. The data were consistent with a model describing two types of memory (i.e., recollective and non-recollective memories), which differ in how susceptible these memories are to memory distortion.

  8. Energy

    ERIC Educational Resources Information Center

    Boyer, Ernest L.

    1977-01-01

    Schools must teach pupils about the wide nature of our energy dilemma and prepare them for a future in which not only will conservation of energy be essential, but also the conservation and preservation of our total natural resources. (JD)

  9. Memory loss

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003257.htm Memory loss To use the sharing features on this ... Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health Page last updated: ...

  10. Energy

    DTIC Science & Technology

    2003-01-01

    Canada, Britain, and Spain. We found that the energy industry is not in crisis ; however, U.S. government policies, laws, dollars, and even public...CEIMAT (Centro de Investagaciones Energeticas , Medioambeintales y Tecnologicas) Research and development Page 3 of 28ENERGY 8/10/04http://www.ndu.edu...procurement or storage of standard, common use fuels. NATURAL GAS Natural gas, abundant globally and domestically, offers energy versatility among

  11. Memory consolidation.

    PubMed

    Squire, Larry R; Genzel, Lisa; Wixted, John T; Morris, Richard G

    2015-08-03

    Conscious memory for a new experience is initially dependent on information stored in both the hippocampus and neocortex. Systems consolidation is the process by which the hippocampus guides the reorganization of the information stored in the neocortex such that it eventually becomes independent of the hippocampus. Early evidence for systems consolidation was provided by studies of retrograde amnesia, which found that damage to the hippocampus-impaired memories formed in the recent past, but typically spared memories formed in the more remote past. Systems consolidation has been found to occur for both episodic and semantic memories and for both spatial and nonspatial memories, although empirical inconsistencies and theoretical disagreements remain about these issues. Recent work has begun to characterize the neural mechanisms that underlie the dialogue between the hippocampus and neocortex (e.g., "neural replay," which occurs during sharp wave ripple activity). New work has also identified variables, such as the amount of preexisting knowledge, that affect the rate of consolidation. The increasing use of molecular genetic tools (e.g., optogenetics) can be expected to further improve understanding of the neural mechanisms underlying consolidation. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

  12. Memory Consolidation

    PubMed Central

    Squire, Larry R.; Genzel, Lisa; Wixted, John T.; Morris, Richard G.

    2015-01-01

    Conscious memory for a new experience is initially dependent on information stored in both the hippocampus and neocortex. Systems consolidation is the process by which the hippocampus guides the reorganization of the information stored in the neocortex such that it eventually becomes independent of the hippocampus. Early evidence for systems consolidation was provided by studies of retrograde amnesia, which found that damage to the hippocampus-impaired memories formed in the recent past, but typically spared memories formed in the more remote past. Systems consolidation has been found to occur for both episodic and semantic memories and for both spatial and nonspatial memories, although empirical inconsistencies and theoretical disagreements remain about these issues. Recent work has begun to characterize the neural mechanisms that underlie the dialogue between the hippocampus and neocortex (e.g., “neural replay,” which occurs during sharp wave ripple activity). New work has also identified variables, such as the amount of preexisting knowledge, that affect the rate of consolidation. The increasing use of molecular genetic tools (e.g., optogenetics) can be expected to further improve understanding of the neural mechanisms underlying consolidation. PMID:26238360

  13. Fear Memory.

    PubMed

    Izquierdo, Ivan; Furini, Cristiane R G; Myskiw, Jociane C

    2016-04-01

    Fear memory is the best-studied form of memory. It was thoroughly investigated in the past 60 years mostly using two classical conditioning procedures (contextual fear conditioning and fear conditioning to a tone) and one instrumental procedure (one-trial inhibitory avoidance). Fear memory is formed in the hippocampus (contextual conditioning and inhibitory avoidance), in the basolateral amygdala (inhibitory avoidance), and in the lateral amygdala (conditioning to a tone). The circuitry involves, in addition, the pre- and infralimbic ventromedial prefrontal cortex, the central amygdala subnuclei, and the dentate gyrus. Fear learning models, notably inhibitory avoidance, have also been very useful for the analysis of the biochemical mechanisms of memory consolidation as a whole. These studies have capitalized on in vitro observations on long-term potentiation and other kinds of plasticity. The effect of a very large number of drugs on fear learning has been intensively studied, often as a prelude to the investigation of effects on anxiety. The extinction of fear learning involves to an extent a reversal of the flow of information in the mentioned structures and is used in the therapy of posttraumatic stress disorder and fear memories in general.

  14. Is external memory memory? Biological memory and extended mind.

    PubMed

    Michaelian, Kourken

    2012-09-01

    Clark and Chalmers (1998) claim that an external resource satisfying the following criteria counts as a memory: (1) the agent has constant access to the resource; (2) the information in the resource is directly available; (3) retrieved information is automatically endorsed; (4) information is stored as a consequence of past endorsement. Research on forgetting and metamemory shows that most of these criteria are not satisfied by biological memory, so they are inadequate. More psychologically realistic criteria generate a similar classification of standard putative external memories, but the criteria still do not capture the function of memory. An adequate account of memory function, compatible with its evolution and its roles in prospection and imagination, suggests that external memory performs a function not performed by biological memory systems. External memory is thus not memory. This has implications for: extended mind theorizing, ecological validity of memory research, the causal theory of memory. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. Working memory.

    PubMed

    Baddeley, A

    1992-01-31

    The term working memory refers to a brain system that provides temporary storage and manipulation of the information necessary for such complex cognitive tasks as language comprehension, learning, and reasoning. This definition has evolved from the concept of a unitary short-term memory system. Working memory has been found to require the simultaneous storage and processing of information. It can be divided into the following three subcomponents: (i) the central executive, which is assumed to be an attentional-controlling system, is important in skills such as chess playing and is particularly susceptible to the effects of Alzheimer's disease; and two slave systems, namely (ii) the visuospatial sketch pad, which manipulates visual images and (iii) the phonological loop, which stores and rehearses speech-based information and is necessary for the acquisition of both native and second-language vocabulary.

  16. Retracing Memories

    ERIC Educational Resources Information Center

    Harrison, David L.

    2005-01-01

    There are plenty of paths to poetry but few are as accessible as retracing ones own memories. When students are asked to write about something they remember, they are given them the gift of choosing from events that are important enough to recall. They remember because what happened was funny or scary or embarrassing or heartbreaking or silly.…

  17. Fueling Memories

    PubMed Central

    Powell, Jonathan D.; Pollizzi, Kristen

    2012-01-01

    A hallmark of the adaptive immune response is rapid and robust activation upon rechallenge. In the current issue of Immunity van der Windt et al. (2012) provide an important link between mitochondrial respiratory capacity and the development of CD8+ T cell memory. PMID:22284413

  18. Childhood Memories.

    ERIC Educational Resources Information Center

    Soto, Lourdes Diaz

    2001-01-01

    Describes how artwork can be a valuable catalyst for discussions in preservice education classes, allowing students to explore how their work as educators relates to their childhood memories and can be shaped by childhood experiences. Examines an art exhibition in which diverse artists depicted autobiographical text in their paintings. Discusses…

  19. Childhood Memories.

    ERIC Educational Resources Information Center

    Soto, Lourdes Diaz

    2001-01-01

    Describes how artwork can be a valuable catalyst for discussions in preservice education classes, allowing students to explore how their work as educators relates to their childhood memories and can be shaped by childhood experiences. Examines an art exhibition in which diverse artists depicted autobiographical text in their paintings. Discusses…

  20. Hollow memories

    NASA Astrophysics Data System (ADS)

    2014-04-01

    A hollow-core optical fibre filled with warm caesium atoms can temporarily store the properties of photons. Michael Sprague from the University of Oxford, UK, explains to Nature Photonics how this optical memory could be a useful building block for fibre-based quantum optics.

  1. Energy.

    ERIC Educational Resources Information Center

    Shanebrook, J. Richard

    This document describes a course designed to acquaint students with the many societal and technological problems facing the United States and the world due to the increasing demand for energy. The course begins with a writing assignment that involves readings on the environmental philosophy of Native Americans and the Chernobyl catastrophe.…

  2. [Neural correlates of memory].

    PubMed

    Fujii, Toshikatsu

    2013-01-01

    Memory can be divided into several types, although all of them involve three successive processes: encoding, storage, and retrieval. In terms of the duration of retention, neurologists classify memory into immediate, recent, and remote memories, whereas psychologists classify memory into short-term and long-term memories. In terms of the content, episodic, semantic, and procedural memories are considered to be different types of memory. Furthermore, researchers on memory have proposed relatively new concepts of memory, i.e., working memory and prospective memory. This article first provides explanations for these several types of memory. Next, neuropsychological characteristics of amnesic syndrome are briefly outlined. Finally, how several different types of memory are affected (or preserved) in patients with amnesic syndrome is described.

  3. Mechanisms of Memory.

    ERIC Educational Resources Information Center

    Squire, Larry R.

    1986-01-01

    Focuses on the brain processes and brain systems involved in learning and memory from a neuropsychological perspective of analysis. Reports findings related to the locus of memory storage, types of memory and knowledge, and memory consolidation. Models of animal memory are also examined. An extensive reference list is included. (ML)

  4. Electronic implementation of associative memory based on neural network models

    NASA Technical Reports Server (NTRS)

    Moopenn, A.; Lambe, John; Thakoor, A. P.

    1987-01-01

    An electronic embodiment of a neural network based associative memory in the form of a binary connection matrix is described. The nature of false memory errors, their effect on the information storage capacity of binary connection matrix memories, and a novel technique to eliminate such errors with the help of asymmetrical extra connections are discussed. The stability of the matrix memory system incorporating a unique local inhibition scheme is analyzed in terms of local minimization of an energy function. The memory's stability, dynamic behavior, and recall capability are investigated using a 32-'neuron' electronic neural network memory with a 1024-programmable binary connection matrix.

  5. Electronic implementation of associative memory based on neural network models

    NASA Technical Reports Server (NTRS)

    Moopenn, A.; Lambe, John; Thakoor, A. P.

    1987-01-01

    An electronic embodiment of a neural network based associative memory in the form of a binary connection matrix is described. The nature of false memory errors, their effect on the information storage capacity of binary connection matrix memories, and a novel technique to eliminate such errors with the help of asymmetrical extra connections are discussed. The stability of the matrix memory system incorporating a unique local inhibition scheme is analyzed in terms of local minimization of an energy function. The memory's stability, dynamic behavior, and recall capability are investigated using a 32-'neuron' electronic neural network memory with a 1024-programmable binary connection matrix.

  6. Shape Memory Alloy Rock Splitters (SMARS)

    NASA Technical Reports Server (NTRS)

    Benafan, Othmane (Inventor); Noebe, Ronald D. (Inventor)

    2017-01-01

    Shape memory alloys (SMAs) may be used for static rock splitting. The SMAs may be used as high-energy multifunctional materials, which have a unique ability to recover large deformations and generate high stresses in response to thermal loads.

  7. Method and apparatus for managing access to a memory

    DOEpatents

    DeBenedictis, Erik

    2017-08-01

    A method and apparatus for managing access to a memory of a computing system. A controller transforms a plurality of operations that represent a computing job into an operational memory layout that reduces a size of a selected portion of the memory that needs to be accessed to perform the computing job. The controller stores the operational memory layout in a plurality of memory cells within the selected portion of the memory. The controller controls a sequence by which a processor in the computing system accesses the memory to perform the computing job using the operational memory layout. The operational memory layout reduces an amount of energy consumed by the processor to perform the computing job.

  8. Memory effects in turbulence

    NASA Technical Reports Server (NTRS)

    Hinze, J. O.

    1979-01-01

    Experimental investigations of the wake flow of a hemisphere and cylinder show that such memory effects can be substantial and have a significant influence on momentum transport. Memory effects are described in terms of suitable memory functions.

  9. Adiabatic Quantum Optimization for Associative Memory Recall

    NASA Astrophysics Data System (ADS)

    Seddiqi, Hadayat; Humble, Travis

    2014-12-01

    Hopfield networks are a variant of associative memory that recall patterns stored in the couplings of an Ising model. Stored memories are conventionally accessed as fixed points in the network dynamics that correspond to energetic minima of the spin state. We show that memories stored in a Hopfield network may also be recalled by energy minimization using adiabatic quantum optimization (AQO). Numerical simulations of the underlying quantum dynamics allow us to quantify AQO recall accuracy with respect to the number of stored memories and noise in the input key. We investigate AQO performance with respect to how memories are stored in the Ising model according to different learning rules. Our results demonstrate that AQO recall accuracy varies strongly with learning rule, a behavior that is attributed to differences in energy landscapes. Consequently, learning rules offer a family of methods for programming adiabatic quantum optimization that we expect to be useful for characterizing AQO performance.

  10. Adiabatic quantum optimization for associative memory recall

    DOE PAGES

    Seddiqi, Hadayat; Humble, Travis S.

    2014-12-22

    Hopfield networks are a variant of associative memory that recall patterns stored in the couplings of an Ising model. Stored memories are conventionally accessed as fixed points in the network dynamics that correspond to energetic minima of the spin state. We show that memories stored in a Hopfield network may also be recalled by energy minimization using adiabatic quantum optimization (AQO). Numerical simulations of the underlying quantum dynamics allow us to quantify AQO recall accuracy with respect to the number of stored memories and noise in the input key. We investigate AQO performance with respect to how memories are storedmore » in the Ising model according to different learning rules. Our results demonstrate that AQO recall accuracy varies strongly with learning rule, a behavior that is attributed to differences in energy landscapes. Consequently, learning rules offer a family of methods for programming adiabatic quantum optimization that we expect to be useful for characterizing AQO performance.« less

  11. Adiabatic quantum optimization for associative memory recall

    SciTech Connect

    Seddiqi, Hadayat; Humble, Travis S.

    2014-12-22

    Hopfield networks are a variant of associative memory that recall patterns stored in the couplings of an Ising model. Stored memories are conventionally accessed as fixed points in the network dynamics that correspond to energetic minima of the spin state. We show that memories stored in a Hopfield network may also be recalled by energy minimization using adiabatic quantum optimization (AQO). Numerical simulations of the underlying quantum dynamics allow us to quantify AQO recall accuracy with respect to the number of stored memories and noise in the input key. We investigate AQO performance with respect to how memories are stored in the Ising model according to different learning rules. Our results demonstrate that AQO recall accuracy varies strongly with learning rule, a behavior that is attributed to differences in energy landscapes. Consequently, learning rules offer a family of methods for programming adiabatic quantum optimization that we expect to be useful for characterizing AQO performance.

  12. Computer memory power control for the Galileo spacecraft

    NASA Technical Reports Server (NTRS)

    Detwiler, R. C.

    1983-01-01

    The developmental history, major design drives, and final topology of the computer memory power system on the Galileo spacecraft are described. A unique method of generating memory backup power directly from the fault current drawn during a spacecraft power overload or fault condition allows this system to provide continuous memory power. This concept provides a unique solution to the problem of volatile memory loss without the use of a battery of other large energy storage elements usually associated with uninterrupted power supply designs.

  13. Computer memory power control for the Galileo spacecraft

    NASA Technical Reports Server (NTRS)

    Detwiler, R. C.

    1983-01-01

    The developmental history, major design drives, and final topology of the computer memory power system on the Galileo spacecraft are described. A unique method of generating memory backup power directly from the fault current drawn during a spacecraft power overload or fault condition allows this system to provide continuous memory power. This concept provides a unique solution to the problem of volatile memory loss without the use of a battery of other large energy storage elements usually associated with uninterrupted power supply designs.

  14. Towards Terabit Memories

    NASA Astrophysics Data System (ADS)

    Hoefflinger, Bernd

    Memories have been the major yardstick for the continuing validity of Moore's law. In single-transistor-per-Bit dynamic random-access memories (DRAM), the number of bits per chip pretty much gives us the number of transistors. For decades, DRAM's have offered the largest storage capacity per chip. However, DRAM does not scale any longer, both in density and voltage, severely limiting its power efficiency to 10 fJ/b. A differential DRAM would gain four-times in density and eight-times in energy. Static CMOS RAM (SRAM) with its six transistors/cell is gaining in reputation because it scales well in cell size and operating voltage so that its fundamental advantage of speed, non-destructive read-out and low-power standby could lead to just 2.5 electrons/bit in standby and to a dynamic power efficiency of 2aJ/b. With a projected 2020 density of 16 Gb/cm², the SRAM would be as dense as normal DRAM and vastly better in power efficiency, which would mean a major change in the architecture and market scenario for DRAM versus SRAM. Non-volatile Flash memory have seen two quantum jumps in density well beyond the roadmap: Multi-Bit storage per transistor and high-density TSV (through-silicon via) technology. The number of electrons required per Bit on the storage gate has been reduced since their first realization in 1996 by more than an order of magnitude to 400 electrons/Bit in 2010 for a complexity of 32Gbit per chip at the 32 nm node. Chip stacking of eight chips with TSV has produced a 32GByte solid-state drive (SSD). A stack of 32 chips with 2 b/cell at the 16 nm node will reach a density of 2.5 Terabit/cm². Non-volatile memory with a density of 10 × 10 nm²/Bit is the target for widespread development. Phase-change memory (PCM) and resistive memory (RRAM) lead in cell density, and they will reach 20 Gb/cm² in 2D and higher with 3D chip stacking. This is still almost an order-of-magnitude less than Flash. However, their read-out speed is ~10-times faster, with as yet

  15. A Beginner's Guide to Memory.

    ERIC Educational Resources Information Center

    Hughes, Elizabeth M.

    1981-01-01

    This article is designed to equip the reader with the information needed to deal with questions of computer memory. Discussed are core memory; semiconductor memory; size of memory; expanding memory; charge-coupled device memories; magnetic bubble memory; and read-only and read-mostly memories. (KC)

  16. Memory Retrieval and Interference: Working Memory Issues

    ERIC Educational Resources Information Center

    Radvansky, Gabriel A.; Copeland, David E.

    2006-01-01

    Working memory capacity has been suggested as a factor that is involved in long-term memory retrieval, particularly when that retrieval involves a need to overcome some sort of interference (Bunting, Conway, & Heitz, 2004; Cantor & Engle, 1993). Previous work has suggested that working memory is related to the acquisition of information during…

  17. Single-step formation of ZnO/ZnWO(x) bilayer structure via interfacial engineering for high performance and low energy consumption resistive memory with controllable high resistance states.

    PubMed

    Lin, Shih-Ming; Huang, Jian-Shiou; Chang, Wen-Chih; Hou, Te-Chien; Huang, Hsin-Wei; Huang, Chi-Hsin; Lin, Su-Jien; Chueh, Yu-Lun

    2013-08-28

    A spontaneously formed ZnO/ZnWOx bilayer resistive memory via an interfacial engineering by one-step sputtering process with controllable high resistance states was demonstrated. The detailed formation mechanism and microstructure of the ZnWOx layer was explored by X-ray photoemission spectroscopy (XPS) and transmission electron microscope in detail. The reduced trapping depths from 0.46 to 0.29 eV were found after formation of ZnWOx layer, resulting in an asymmetric I-V behavior. In particular, the reduction of compliance current significantly reduces the switching current to reach the stable operation of device, enabling less energy consumption. Furthermore, we demonstrated an excellent performance of the complementary resistive switching (CRS) based on the ZnO/ZnWOx bilayer structure with DC endurance >200 cycles for a possible application in three-dimensional multilayer stacking.

  18. 39% access time improvement, 11% energy reduction, 32 kbit 1-read/1-write 2-port static random-access memory using two-stage read boost and write-boost after read sensing scheme

    NASA Astrophysics Data System (ADS)

    Yamamoto, Yasue; Moriwaki, Shinichi; Kawasumi, Atsushi; Miyano, Shinji; Shinohara, Hirofumi

    2016-04-01

    We propose novel circuit techniques for 1 clock (1CLK) 1 read/1 write (1R/1W) 2-port static random-access memories (SRAMs) to improve read access time (tAC) and write margins at low voltages. Two-stage read boost (TSR-BST) and write word line boost (WWL-BST) after the read sensing schemes have been proposed. TSR-BST reduces the worst read bit line (RBL) delay by 61% and RBL amplitude by 10% at V DD = 0.5 V, which improves tAC by 39% and reduces energy dissipation by 11% at V DD = 0.55 V. WWL-BST after read sensing scheme improves minimum operating voltage (V min) by 140 mV. A 32 kbit 1CLK 1R/1W 2-port SRAM with TSR-BST and WWL-BST has been developed using a 40 nm CMOS.

  19. Atomic memory

    NASA Astrophysics Data System (ADS)

    Brewer, R. G.; Hahn, E. L.

    1984-12-01

    The fundamental principles of atomic-memory effects related to the Loschmidt paradox in the second law of thermodynamics are introduced and illustrated with simple analogies, photographs, and diagrams; and the results of RF and laser experiments are summarized. Nuclear-spin echoes in response to RF pulses and the NMR free-induction decay phenomenon are described, and the extension of these concepts to the visible spectrum in laser-frequency-switching and multipulsed-laser experiments is examined with an emphasis on studies of free-induction decay in LaF3 crystals containing Pr impurities (DeVoe and Brewster). The laser-induced phenomena can be applied to studies of intramolecular and intermolecular interactions, and an improved understanding of the RF effects is needed to enhance the performance of medical NMR imaging systems.

  20. Order-memory and association-memory.

    PubMed

    Caplan, Jeremy B

    2015-09-01

    Two highly studied memory functions are memory for associations (items presented in pairs, such as SALT-PEPPER) and memory for order (a list of items whose order matters, such as a telephone number). Order- and association-memory are at the root of many forms of behaviour, from wayfinding, to language, to remembering people's names. Most researchers have investigated memory for order separately from memory for associations. Exceptions to this, associative-chaining models build an ordered list from associations between pairs of items, quite literally understanding association- and order-memory together. Alternatively, positional-coding models have been used to explain order-memory as a completely distinct function from association-memory. Both classes of model have found empirical support and both have faced serious challenges. I argue that models that combine both associative chaining and positional coding are needed. One such hybrid model, which relies on brain-activity rhythms, is promising, but remains to be tested rigourously. I consider two relatively understudied memory behaviours that demand a combination of order- and association-information: memory for the order of items within associations (is it William James or James William?) and judgments of relative order (who left the party earlier, Hermann or William?). Findings from these underexplored procedures are already difficult to reconcile with existing association-memory and order-memory models. Further work with such intermediate experimental paradigms has the potential to provide powerful findings to constrain and guide models into the future, with the aim of explaining a large range of memory functions, encompassing both association- and order-memory. (c) 2015 APA, all rights reserved).

  1. Emotional memory persists longer than event memory.

    PubMed

    Kuriyama, Kenichi; Soshi, Takahiro; Fujii, Takeshi; Kim, Yoshiharu

    2010-03-01

    The interaction between amygdala-driven and hippocampus-driven activities is expected to explain why emotion enhances episodic memory recognition. However, overwhelming behavioral evidence regarding the emotion-induced enhancement of immediate and delayed episodic memory recognition has not been obtained in humans. We found that the recognition performance for event memory differs from that for emotional memory. Although event recognition deteriorated equally for episodes that were or were not emotionally salient, emotional recognition remained high for only stimuli related to emotional episodes. Recognition performance pertaining to delayed emotional memory is an accurate predictor of the context of past episodes.

  2. Memory and Aging

    MedlinePlus

    ... meet your neighbor for coffee? Episodic memory, which captures the “what,” “where,” and “when” of our daily ... This type of memory also includes vocabulary and knowledge of language. In addition, procedural memory, your memory ...

  3. Exponential lifetime improvement in topological quantum memories

    NASA Astrophysics Data System (ADS)

    Bardyn, Charles-Edouard; Karzig, Torsten

    2016-09-01

    We propose a simple yet efficient mechanism for passive error correction in topological quantum memories. Our scheme relies on driven-dissipative ancilla systems which couple to local excitations (anyons) and make them "sink" in energy, with no required interaction among ancillae or anyons. Through this process, anyons created by some thermal environment end up trapped in potential "trenches" that they themselves generate, which can be interpreted as a "memory foam" for anyons. This self-trapping mechanism provides an energy barrier for anyon propagation and removes entropy from the memory by favoring anyon recombination over anyon separation (responsible for memory errors). We demonstrate that our scheme leads to an exponential increase of the memory-coherence time with system size L , up to an upper bound Lmax, which can increase exponentially with Δ /T , where T is the temperature and Δ is some energy scale defined by potential trenches. This results in a double exponential increase of the memory time with Δ /T , which greatly improves over the Arrhenius (single-exponential) scaling found in typical quantum memories.

  4. Maintaining memories by reactivation.

    PubMed

    Rasch, Björn; Born, Jan

    2007-12-01

    According to a widely held concept, the formation of long-term memories relies on a reactivation and redistribution of newly acquired memory representations from temporary storage to neuronal networks supporting long-term storage. Here, we review evidence showing that this process of system consolidation takes place preferentially during sleep as an 'off-line' period during which memories are spontaneously reactivated and redistributed in the absence of interfering external inputs. Moreover, postlearning sleep leads to a reorganization of neuronal representations and qualitative changes of memory content. We propose that memory reactivations during sleep are accompanied by a transient destabilization of memory traces. Unlike wake reactivations that form part of an updating of memories with respect to current perceptual input, reactivations during sleep allow for gradually adapting newly acquired memories to pre-existing long-term memories whereby invariants and certain other features of these memories become extracted.

  5. The molecular basis of memory.

    PubMed

    Marx, Gerard; Gilon, Chaim

    2012-08-15

    We propose a tripartite biochemical mechanism for memory. Three physiologic components are involved, namely, the neuron (individual and circuit), the surrounding neural extracellular matrix, and the various trace metals distributed within the matrix. The binding of a metal cation affects a corresponding nanostructure (shrinking, twisting, expansion) and dielectric sensibility of the chelating node (address) within the matrix lattice, sensed by the neuron. The neural extracellular matrix serves as an electro-elastic lattice, wherein neurons manipulate multiple trace metals (n > 10) to encode, store, and decode coginive information. The proposed mechanism explains brains low energy requirements and high rates of storage capacity described in multiples of Avogadro number (N(A) = 6 × 10(23)). Supportive evidence correlates memory loss to trace metal toxicity or deficiency, or breakdown in the delivery/transport of metals to the matrix, or its degradation. Inherited diseases revolving around dysfunctional trace metal metabolism and memory dysfunction, include Alzheimer's disease (Al, Zn, Fe), Wilson's disease (Cu), thalassemia (Fe), and autism (metallothionein). The tripartite mechanism points to the electro-elastic interactions of neurons with trace metals distributed within the neural extracellular matrix, as the molecular underpinning of "synaptic plasticity" affecting short-term memory, long-term memory, and forgetting.

  6. The Molecular Basis of Memory

    PubMed Central

    2012-01-01

    We propose a tripartite biochemical mechanism for memory. Three physiologic components are involved, namely, the neuron (individual and circuit), the surrounding neural extracellular matrix, and the various trace metals distributed within the matrix. The binding of a metal cation affects a corresponding nanostructure (shrinking, twisting, expansion) and dielectric sensibility of the chelating node (address) within the matrix lattice, sensed by the neuron. The neural extracellular matrix serves as an electro-elastic lattice, wherein neurons manipulate multiple trace metals (n > 10) to encode, store, and decode coginive information. The proposed mechanism explains brains low energy requirements and high rates of storage capacity described in multiples of Avogadro number (NA = 6 × 1023). Supportive evidence correlates memory loss to trace metal toxicity or deficiency, or breakdown in the delivery/transport of metals to the matrix, or its degradation. Inherited diseases revolving around dysfunctional trace metal metabolism and memory dysfunction, include Alzheimer's disease (Al, Zn, Fe), Wilson’s disease (Cu), thalassemia (Fe), and autism (metallothionein). The tripartite mechanism points to the electro-elastic interactions of neurons with trace metals distributed within the neural extracellular matrix, as the molecular underpinning of “synaptic plasticity” affecting short-term memory, long-term memory, and forgetting. PMID:23050060

  7. Improved read disturb and write error rates in voltage-control spintronics memory (VoCSM) by controlling energy barrier height

    NASA Astrophysics Data System (ADS)

    Inokuchi, T.; Yoda, H.; Kato, Y.; Shimizu, M.; Shirotori, S.; Shimomura, N.; Koi, K.; Kamiguchi, Y.; Sugiyama, H.; Oikawa, S.; Ikegami, K.; Ishikawa, M.; Altansargai, B.; Tiwari, A.; Ohsawa, Y.; Saito, Y.; Kurobe, A.

    2017-06-01

    A hybrid writing scheme that combines the spin Hall effect and voltage-controlled magnetic-anisotropy effect is investigated in Ta/CoFeB/MgO/CoFeB/Ru/CoFe/IrMn junctions. The write current and control voltage are applied to Ta and CoFeB/MgO/CoFeB junctions, respectively. The critical current density required for switching the magnetization in CoFeB was modulated 3.6-fold by changing the control voltage from -1.0 V to +1.0 V. This modulation of the write current density is explained by the change in the surface anisotropy of the free layer from 1.7 mJ/m2 to 1.6 mJ/m2, which is caused by the electric field applied to the junction. The read disturb rate and write error rate, which are important performance parameters for memory applications, are drastically improved, and no error was detected in 5 × 108 cycles by controlling read and write sequences.

  8. Automatic memory management policies for low power, memory limited, and delay intolerant devices

    NASA Astrophysics Data System (ADS)

    Jahid, Md. Abu

    Mobile devices such as smartphones and tablets are energy and memory limited, and implement graphical user interfaces that are intolerant of computational delays. Mobile device platforms supporting apps implemented in languages that require automatic memory management, such as the Dalvik (Java) virtual machine within Google's Android, have become dominant. It is essential that automatic memory management avoid causing unacceptable interface delays while responsibly managing energy and memory resource usage. Dalvik's automatic memory management policies for heap growth and garbage collection scheduling utilize heuristics tuned to minimize memory footprint. These policies result in only marginally acceptable response times and garbage collection signicantly contributes to apps' CPU time and therefore energy consumption. The primary contributions of this research include a characterization of Dalvik's "baseline" automatic memory management policy, the development of a new "adaptive" policy, and an investigation of the performance of this policy. The investigation indicates that this adaptive policy consumes less CPU time and improves interactive performance at the cost of increasing memory footprint size by an acceptable amount.

  9. Formation of microcraters and hierarchically-organized surface structures in TiNi shape memory alloy irradiated with a low-energy, high-current electron beam

    SciTech Connect

    Meisner, L. L. Meisner, S. N.; Markov, A. B. Ozur, G. E. Yakovlev, E. V.; Rotshtein, V. P.; Gudimova, E. Yu.

    2015-10-27

    The regularities of surface cratering in TiNi alloy irradiated with a low-energy, high-current electron beam (LEHCEB) in dependence on energy density and number of pulses are studied. LEHCEB processing of TiNi samples was carried out using RITM-SP facility. Energy density E{sub s} was varied from 1 to 5 J/cm{sup 2}, pulse duration was 2.5–3.0 μs, the number of pulses n = 1–128. The dominant role of non-metallic inclusions [mainly, TiC(O)] in the nucleation of microcraters was found. It was revealed that at small number of pulses (n = 2), an increase in energy density leads both to increasing average diameter and density of microcraters. An increase in the number of pulses leads to a monotonic decrease in density of microcraters, and, therefore, that of the proportion of the area occupied by microcraters, as well as a decrease in the surface roughness. The multiple LEHCEB melting of TiNi alloy in crater-free modes enables to form quasi-periodical, hierarchically-organized microsized surface structures.

  10. 1'-Acetoxychavicol acetate ameliorates age-related spatial memory deterioration by increasing serum ketone body production as a complementary energy source for neuronal cells.

    PubMed

    Kojima-Yuasa, Akiko; Yamamoto, Tomiya; Yaku, Keisuke; Hirota, Shiori; Takenaka, Shigeo; Kawabe, Kouichi; Matsui-Yuasa, Isao

    2016-09-25

    1'-Acetoxychavicol acetate (ACA) is naturally obtained from the rhizomes and seeds of Alpinia galangal. Here, we examined the effect of ACA on learning and memory in senescence-accelerated mice prone 8 (SAMP8). In mice that were fed a control diet containing 0.02% ACA for 25 weeks, the learning ability in the Morris water maze test was significantly enhanced in comparison with mice that were fed the control diet alone. In the Y-maze test, SAMP8 mice showed decreased spontaneous alterations in comparison with senescence-accelerated resistant/1 (SAMR1) mice, a homologous control, which was improved by ACA pretreatment. Serum metabolite profiles were obtained by GC-MS analysis, and each metabolic profile was plotted on a 3D score plot. Based upon the diagram, it can be seen that the distribution areas for the three groups were completely separate. Furthermore, the contents of β-hydroxybutyric acid and palmitic acid in the serum of SAMP8-ACA mice were higher than those of SAMP8-control mice and SAMR1-control mice. We also found that SAMR1 mice did not show histological abnormalities, whereas histological damage in the CA1 region of the hippocampus in SAMP8-control mice was observed. However, SAMP8-ACA mice were observed in a similar manner as SAMR1 mice. These findings confirm that ACA increases the serum concentrations of β-hydroxybutyric acid and palmitic acid levels and thus these fuels might contribute to the maintenance of the cognitive performance of SAMP8 mice.

  11. Memory distortion and false memory creation.

    PubMed

    Loftus, E F

    1996-01-01

    The 1990s have brought to public attention thousands of cases that began when a grown-up daughter or son walked into a therapist's office seeking help for depression, low self-esteem, or any of a number of life's problems. Many of these cases grew to involve memories of childhood sexual abuse recovered while in therapy--memories that did not exist, or at least were not remembered, before therapy began. Many of these cases also involved families torn violently apart. What should we make of these new-found memories? Are they true memories that were successfully revived in therapy? Are they false memories that were unwittingly planted? Are they symbolic expressions--historically false but representing some deep underlying truth? Insights from cognitive psychology may shed some light. Much of the litigation that has resulted from the emergence of "repressed memories" has been hazardous to the patients, and their families, as well as to the therapists who treat them.

  12. Memory beyond expression.

    PubMed

    Delorenzi, A; Maza, F J; Suárez, L D; Barreiro, K; Molina, V A; Stehberg, J

    2014-01-01

    The idea that memories are not invariable after the consolidation process has led to new perspectives about several mnemonic processes. In this framework, we review our studies on the modulation of memory expression during reconsolidation. We propose that during both memory consolidation and reconsolidation, neuromodulators can determine the probability of the memory trace to guide behavior, i.e. they can either increase or decrease its behavioral expressibility without affecting the potential of persistent memories to be activated and become labile. Our hypothesis is based on the findings that positive modulation of memory expression during reconsolidation occurs even if memories are behaviorally unexpressed. This review discusses the original approach taken in the studies of the crab Neohelice (Chasmagnathus) granulata, which was then successfully applied to test the hypothesis in rodent fear memory. Data presented offers a new way of thinking about both weak trainings and experimental amnesia: memory retrieval can be dissociated from memory expression. Furthermore, the strategy presented here allowed us to show in human declarative memory that the periods in which long-term memory can be activated and become labile during reconsolidation exceeds the periods in which that memory is expressed, providing direct evidence that conscious access to memory is not needed for reconsolidation. Specific controls based on the constraints of reminders to trigger reconsolidation allow us to distinguish between obliterated and unexpressed but activated long-term memories after amnesic treatments, weak trainings and forgetting. In the hypothesis discussed, memory expressibility--the outcome of experience-dependent changes in the potential to behave--is considered as a flexible and modulable attribute of long-term memories. Expression seems to be just one of the possible fates of re-activated memories.

  13. Problems of neural memory

    NASA Astrophysics Data System (ADS)

    Mikaelian, Andrei L.

    2005-01-01

    The paper considers the neural memory of the human brain from the viewpoint of visual information processing. A model that explains the principle of data recording and storing, memory relaxation, associative remembering and other memory functions is offered. The model of associative memory is based on the methods of holography, "wave biochemistry" and autowaves. Brief consideration is given to the associative properties of holographic neural structures and the memory architecture using running chemical reactions. The paper also outlines the problem of developing artificial memory elements for restoring the brain functions and possible interface devices for coupling neurons to electronic systems.

  14. Benzodiazepines and memory

    PubMed Central

    Roth, T.; Roehrs, T.; Wittig, R.; Zorick, F.

    1984-01-01

    1 Benzodiazepines possess anterograde amnesic properties, disrupting both short-term and long-term memory function. 2 The amount of amnesia is systematically related to dose effects and half-life differences among the benzodiazepines. 3 Memory deficits are found for episodic, semantic, and iconic memory function. 4 The deficits in long-term memory are probably the result of a disruption of consolidation of information in memory and not retrieval from memory. The disruption is produced by rapid sleep onset. 5 Thus the long-term amnesia is really a retrograde effect of sleep and not the anterograde effect of the drug. PMID:6151849

  15. Interfacial phase-change memory.

    PubMed

    Simpson, R E; Fons, P; Kolobov, A V; Fukaya, T; Krbal, M; Yagi, T; Tominaga, J

    2011-07-03

    Phase-change memory technology relies on the electrical and optical properties of certain materials changing substantially when the atomic structure of the material is altered by heating or some other excitation process. For example, switching the composite Ge(2)Sb(2)Te(5) (GST) alloy from its covalently bonded amorphous phase to its resonantly bonded metastable cubic crystalline phase decreases the resistivity by three orders of magnitude, and also increases reflectivity across the visible spectrum. Moreover, phase-change memory based on GST is scalable, and is therefore a candidate to replace Flash memory for non-volatile data storage applications. The energy needed to switch between the two phases depends on the intrinsic properties of the phase-change material and the device architecture; this energy is usually supplied by laser or electrical pulses. The switching energy for GST can be reduced by limiting the movement of the atoms to a single dimension, thus substantially reducing the entropic losses associated with the phase-change process. In particular, aligning the c-axis of a hexagonal Sb(2)Te(3) layer and the 〈111〉 direction of a cubic GeTe layer in a superlattice structure creates a material in which Ge atoms can switch between octahedral sites and lower-coordination sites at the interface of the superlattice layers. Here we demonstrate GeTe/Sb(2)Te(3) interfacial phase-change memory (IPCM) data storage devices with reduced switching energies, improved write-erase cycle lifetimes and faster switching speeds.

  16. Martensitic transformation of Ni2FeGa ferromagnetic shape-memory alloy studied via transmission electron microscopy and electron energy-loss spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, H. R.; Ma, C.; Tian, H. F.; Wu, G. H.; Li, J. Q.

    2008-06-01

    The structural properties of Ni2FeGa Heusler alloy synthesized by melt-spinning technique have been systematically studied by means of in situ heating and cooling transmission electron microscopy. It was found that the Ni2FeGa alloy was annealed into a well-defined L21 structure at around 980 K, and complex microstructural domains appeared along with lowering temperature. At room temperature (293 K), a rich variety of micromodulated domains were observed. The domain structures were aligned along the ⟨110⟩ or ⟨100⟩ directions resulting to complex tweed structures. Below martensitic transformation (MT) temperature (Ms,˜142K) , the cubic parent phase transformed into unmodulated martensitic variants and modulated martensitic variants. The variants were alternated along the ⟨100⟩ direction with various arrangements and steplike incommensurate boundaries. The modulated martensitic variants were composed of lamellar structures that have predominately a 5M modulation structure along the ⟨110⟩ directions. The electron energy-loss spectroscopy analysis of the low-loss region and the electron energy-loss near-edge fine structure revealed a visible change of the electronic structure along with MT, which can be well interpreted by means of intra-atomic or intraband charge redistribution due to spd orbital hybridization among the Ni-Fe-Ga atoms.

  17. Gravitational wave memory: A new approach to study modified gravity

    NASA Astrophysics Data System (ADS)

    Du, Song Ming; Nishizawa, Atsushi

    2016-11-01

    It is well known that two types of gravitational wave memory exist in general relativity (GR): the linear memory and the nonlinear, or Christodoulou, memory. These effects, especially the latter, depend on the specific form of the Einstein equation. It can then be speculated that, in modified theories of gravity, the memory can differ from the GR prediction and provides novel phenomena to study these theories. We support this speculation by considering scalar-tensor theories, for which we find two new types of memory: the T memory and the S memory, which contribute to the tensor and scalar components of a gravitational wave, respectively. Specifically, the former is caused by the burst of energy carried away by scalar radiation, while the latter is intimately related to the no scalar hair property of black holes in scalar-tensor gravity. We estimate the size of these two types of memory in gravitational collapses and formulate a detection strategy for the S memory, which can be singled out from tensor gravitational waves. We show that (i) the S memory exists even in spherical symmetry and is observable under current model constraints, and (ii) while the T memory is usually much weaker than the S memory, it can become comparable in the case of spontaneous scalarization.

  18. Searching for repressed memory.

    PubMed

    McNally, Richard J

    2012-01-01

    This chapter summarizes the work of my research group on adults who report either repressed, recovered, or continuous memories of childhood sexual abuse (CSA) or who report no history of CSA. Adapting paradigms from cognitive psychology, we tested hypotheses inspired by both the "repressed memory" and "false memory" perspectives on recovered memories of CSA. We found some evidence for the false memory perspective, but no evidence for the repressed memory perspective. However, our work also suggests a third perspective on recovered memories that does not require the concept of repression. Some children do not understand their CSA when it occurs, and do not experience terror. Years later, they recall the experience, and understanding it as abuse, suffer intense distress. The memory failed to come to mind for years, partly because the child did not encode it as terrifying (i.e., traumatic), not because the person was unable to recall it.

  19. Emotional Memory Persists Longer than Event Memory

    ERIC Educational Resources Information Center

    Kuriyama, Kenichi; Soshi, Takahiro; Fujii, Takeshi; Kim, Yoshiharu

    2010-01-01

    The interaction between amygdala-driven and hippocampus-driven activities is expected to explain why emotion enhances episodic memory recognition. However, overwhelming behavioral evidence regarding the emotion-induced enhancement of immediate and delayed episodic memory recognition has not been obtained in humans. We found that the recognition…

  20. Emotional Memory Persists Longer than Event Memory

    ERIC Educational Resources Information Center

    Kuriyama, Kenichi; Soshi, Takahiro; Fujii, Takeshi; Kim, Yoshiharu

    2010-01-01

    The interaction between amygdala-driven and hippocampus-driven activities is expected to explain why emotion enhances episodic memory recognition. However, overwhelming behavioral evidence regarding the emotion-induced enhancement of immediate and delayed episodic memory recognition has not been obtained in humans. We found that the recognition…

  1. Defect formation energy and magnetic structure of shape memory alloys Ni-X-Ga (X=Mn, Fe, Co) by first principle calculation

    NASA Astrophysics Data System (ADS)

    Bai, J.; Raulot, J. M.; Zhang, Y. D.; Esling, C.; Zhao, X.; Zuo, L.

    2010-09-01

    The crystallographic and magnetic structures of the Ni2XGa (X=Mn, Fe, Co), are systematically investigated by means of the first-principles calculations within the framework of density functional theory using the VIENNA AB INITIO SOFTWARE PACKAGE. The formation energies of several kinds of defects (atomic exchange, antisite, vacancy) are estimated. The Ga atoms stabilize the cubic structure, and the effect of X atoms on the structural stability is opposite. For most cases of the site occupation, the excess atoms of the rich component directly occupy the site(s) of the deficient one(s), except for Ga-rich Ni-deficient type. The magnitude of the variation in Ni moments is much larger than that of Mn in defective Ni2XGa. The value of Ni magnetic moment sensitively depends on the distance between Ni and X. Excess Mn could be ferromagnetic or antiferromagnetic, depending on the distance between the neighboring Mn atoms.

  2. Music, memory and emotion.

    PubMed

    Jäncke, Lutz

    2008-08-08

    Because emotions enhance memory processes and music evokes strong emotions, music could be involved in forming memories, either about pieces of music or about episodes and information associated with particular music. A recent study in BMC Neuroscience has given new insights into the role of emotion in musical memory.

  3. Origins of Autobiographical Memory.

    ERIC Educational Resources Information Center

    Harley, Keryn; Reese, Elaine

    1999-01-01

    Tested predictions of infantile amnesia theory compared with social-interactionist account of autobiographical memory. Found maternal reminiscing style and self-recognition when child was 19 months old uniquely predicted children's shared memory reports across time, even with children's initial language and nonverbal memory factored out.…

  4. Music, memory and emotion

    PubMed Central

    Jäncke, Lutz

    2008-01-01

    Because emotions enhance memory processes and music evokes strong emotions, music could be involved in forming memories, either about pieces of music or about episodes and information associated with particular music. A recent study in BMC Neuroscience has given new insights into the role of emotion in musical memory. PMID:18710596

  5. Memory and the Self

    ERIC Educational Resources Information Center

    Conway, Martin A.

    2005-01-01

    The Self-Memory System (SMS) is a conceptual framework that emphasizes the interconnectedness of self and memory. Within this framework memory is viewed as the data base of the self. The self is conceived as a complex set of active goals and associated self-images, collectively referred to as the "working self." The relationship between the…

  6. Memory and the Self

    ERIC Educational Resources Information Center

    Conway, Martin A.

    2005-01-01

    The Self-Memory System (SMS) is a conceptual framework that emphasizes the interconnectedness of self and memory. Within this framework memory is viewed as the data base of the self. The self is conceived as a complex set of active goals and associated self-images, collectively referred to as the "working self." The relationship between the…

  7. Make-Believe Memories

    ERIC Educational Resources Information Center

    Loftus, Elizabeth F.

    2003-01-01

    Research on memory distortion has shown that postevent suggestion can contaminate what a person remembers. Moreover, suggestion can lead to false memories being injected outright into the minds of people. These findings have implications for police investigation, clinical practice, and other settings in which memory reports are solicited.

  8. Nickel porphyrins for memory optical applications

    DOEpatents

    Shelnutt, John A.; Jia, Songling; Medforth, Craig; Holten, Dewey; Nelson, Nora Y.; Smith, Kevin M.

    2000-01-01

    The present invention relates to a nickel-porphyrin derivative in a matrix, the nickel-porphyrin derivative comprising at least two conformational isomers, a lower-energy-state conformer and a higher-energy-state conformer, such that when the higher-energy-state conformer is generated from the lower-energy-state conformer following absorption of a photon of suitable energy, the time to return to the lower-energy-state conformer is greater than 40 nanoseconds at approximately room temperature. The nickel-porphyrin derivative is useful in optical memory applications.

  9. Magnetic anisotropy energy of ferromagnetic shape memory alloys Ni2X(X=Fe, Co)Ga by first-principles calculations

    NASA Astrophysics Data System (ADS)

    He, Wangqiang; Ma, Xingqiao; Liu, Zhuhong; Wang, Yi; Chen, Long-Qing

    2017-07-01

    First-principles calculations were employed to explore magnetocrystalline anisotropy energy (MAE) of Ni2X(X=Fe, Co)Ga alloys. The MAE of Ni2FeGa is found to show a concave behavior as a function of tetragonal distortion and easy-axis of magnetization in martensitic phase is along long axis, which have been interpreted by the shift of Fe dxy+dyz peak in minority spin channel near Fermi level. The substitution of Ni by Co in Ni2FeGa alloys rotates magnetic easy axis from long axis to short axis in non-modulated phase while substitution of Fe by Co did not, which is in agreement with experiment. Magnetic anisotropy constant and magnetic stress have been estimated with calculated MAE of martensite phases. By comparing first-principles estimated values of magnetic and twinning stresses, we confirmed the condition, whether large magnetic field-induced strains in FSMAs could be obtained or not. This information can provide theoretical guidance in searching new types of FSMAs with large magnetic field induced strain.

  10. Memory: Organization and Control

    PubMed Central

    Eichenbaum, Howard

    2017-01-01

    A major goal of memory research is to understand how cognitive processes in memory are supported at the level of brain systems and network representations. Especially promising in this direction are new findings in humans and animals that converge in indicating a key role for the hippocampus in the systematic organization of memories. New findings also indicate that the prefrontal cortex may play an equally important role in the active control of memory organization during both encoding and retrieval. Observations about the dialog between the hippocampus and prefrontal cortex provide new insights into the operation of the larger brain system that serves memory. PMID:27687117

  11. Shape-Memory-Alloy Actuator For Flight Controls

    NASA Technical Reports Server (NTRS)

    Barret, Chris

    1995-01-01

    Report proposes use of shape-memory-alloy actuators, instead of hydraulic actuators, for aerodynamic flight-control surfaces. Actuator made of shape-memory alloy converts thermal energy into mechanical work by changing shape as it makes transitions between martensitic and austenitic crystalline phase states of alloy. Because both hot exhaust gases and cryogenic propellant liquids available aboard launch rockets, shape-memory-alloy actuators exceptionally suited for use aboard such rockets.

  12. Shape-Memory-Alloy Actuator For Flight Controls

    NASA Technical Reports Server (NTRS)

    Barret, Chris

    1995-01-01

    Report proposes use of shape-memory-alloy actuators, instead of hydraulic actuators, for aerodynamic flight-control surfaces. Actuator made of shape-memory alloy converts thermal energy into mechanical work by changing shape as it makes transitions between martensitic and austenitic crystalline phase states of alloy. Because both hot exhaust gases and cryogenic propellant liquids available aboard launch rockets, shape-memory-alloy actuators exceptionally suited for use aboard such rockets.

  13. Memory operation mechanism of fullerene-containing polymer memory

    SciTech Connect

    Nakajima, Anri Fujii, Daiki

    2015-03-09

    The memory operation mechanism in fullerene-containing nanocomposite gate insulators was investigated while varying the kind of fullerene in a polymer gate insulator. It was cleared what kind of traps and which positions in the nanocomposite the injected electrons or holes are stored in. The reason for the difference in the easiness of programming was clarified taking the role of the charging energy of an injected electron into account. The dependence of the carrier dynamics on the kind of fullerene molecule was investigated. A nonuniform distribution of injected carriers occurred after application of a large magnitude programming voltage due to the width distribution of the polystyrene barrier between adjacent fullerene molecules. Through the investigations, we demonstrated a nanocomposite gate with fullerene molecules having excellent retention characteristics and a programming capability. This will lead to the realization of practical organic memories with fullerene-containing polymer nanocomposites.

  14. Memory dynamics under stress.

    PubMed

    Quaedflieg, Conny W E M; Schwabe, Lars

    2017-06-19

    Stressful events have a major impact on memory. They modulate memory formation in a time-dependent manner, closely linked to the temporal profile of action of major stress mediators, in particular catecholamines and glucocorticoids. Shortly after stressor onset, rapidly acting catecholamines and fast, non-genomic glucocorticoid actions direct cognitive resources to the processing and consolidation of the ongoing threat. In parallel, control of memory is biased towards rather rigid systems, promoting habitual forms of memory allowing efficient processing under stress, at the expense of "cognitive" systems supporting memory flexibility and specificity. In this review, we discuss the implications of this shift in the balance of multiple memory systems for the dynamics of the memory trace. Specifically, stress appears to hinder the incorporation of contextual details into the memory trace, to impede the integration of new information into existing knowledge structures, to impair the flexible generalisation across past experiences, and to hamper the modification of memories in light of new information. Delayed, genomic glucocorticoid actions might reverse the control of memory, thus restoring homeostasis and "cognitive" control of memory again.

  15. Immunological memory is associative

    SciTech Connect

    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 associative recall in the immune response can be both beneficial and detrimental to the fitness of an individual.

  16. Origins of autobiographical memory.

    PubMed

    Harley, K; Reese, E

    1999-09-01

    This study tested the predictions of M. L. Howe and M. L. Courage's (1993, 1997) theory of infantile amnesia compared with a social-interactionist account of autobiographical memory development (R. Fivush & E. Reese, 1992; K. Nelson, 1993b). Fifty-eight mother-child dyads were assessed for maternal styles of talking about the past and for children's self-recognition, language production, and nonverbal memory when the children were 19 months old. Children's shared and independent memory reports were then assessed from 19 to 32 months. Maternal reminiscing style and self-recognition uniquely predicted children's shared memory reports across time, even with children's initial language and nonverbal memory factored out. Self-recognition skills also predicted children's later independent memory. These results support a pluralistic account of the origins of autobiographical memory.

  17. 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

  18. Memory access in shared virtual memory

    SciTech Connect

    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.

  19. Memory access in shared virtual memory

    SciTech Connect

    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.

  20. Stochastic memory: memory enhancement due to noise.

    PubMed

    Stotland, Alexander; Di Ventra, Massimiliano

    2012-01-01

    There are certain classes of resistors, capacitors, and inductors that, when subject to a periodic input of appropriate frequency, develop hysteresis loops in their characteristic response. Here we show that the hysteresis of such memory elements can also be induced by white noise of appropriate intensity even at very low frequencies of the external driving field. We illustrate this phenomenon using a physical model of memory resistor realized by TiO(2) thin films sandwiched between metallic electrodes and discuss under which conditions this effect can be observed experimentally. We also discuss its implications on existing memory systems described in the literature and the role of colored noise.

  1. Stochastic memory: Memory enhancement due to noise

    NASA Astrophysics Data System (ADS)

    Stotland, Alexander; di Ventra, Massimiliano

    2012-01-01

    There are certain classes of resistors, capacitors, and inductors that, when subject to a periodic input of appropriate frequency, develop hysteresis loops in their characteristic response. Here we show that the hysteresis of such memory elements can also be induced by white noise of appropriate intensity even at very low frequencies of the external driving field. We illustrate this phenomenon using a physical model of memory resistor realized by TiO2 thin films sandwiched between metallic electrodes and discuss under which conditions this effect can be observed experimentally. We also discuss its implications on existing memory systems described in the literature and the role of colored noise.

  2. Optical Bidirectional Associative Memories

    NASA Astrophysics Data System (ADS)

    Kosko, Bart; Guest, Clark

    1987-06-01

    Four optical implementations of bidirectional associative memories (BAMs) are presented. BAMs are heteroassociative content addressable memories (CAMs). A BAM stores the m binary associations (A1, B1), ..., (Am, Bm) , where A is a point in the Boolean n-cube and B is a point in the Boolean p-cube. A is a neural network of n bivalent or continuous neurons ai; B is a network of p bivalent or continuous neurons bi. The fixed synaptic connections between the A and B networks are represented by some n-by-p real matrix M. Bidirectionality, forward and backward information flow, in neural nets produces two-way associative search for the nearest stored pair (Ai, Bi) to an input key. Every matrix is a bidirectionally stable hetero-associative CAM for boh bivalent and continuous networks. This generalizes the well-known unidirectional stability for autoassociative networks with square symmetric M. When the BAM neurons are activated, the network quickly evolves to a stable state of two-pattern reverberation, or pseudo-adaptive resonance. The stable reverberation corresponds to a system energy local minimum. Heteroassociative pairs (Ai, Bi) are encoded in a BAM M by summing bipolar correlation matrices, M = X1T Y1 + ... + XmT Ym , where Xi (Yi) is the bipolar version of Ai (Bi), with -1s replacing Os. the BAM storage capacity for reliable recall is roughly m < min(n, p)--pattern number is bounded by pattern dimensionality. BAM optical implementations are divided into two approaches: matrix vector multipliers and holographic correlators. The four optical BAMs described respectively emphasize a spatial light modulator, laser diodes and high-speed detectors, a reflection hologram, and a transmission hologram.

  3. Memory functions of magnetic skyrmions

    NASA Astrophysics Data System (ADS)

    Koshibae, Wataru; Kaneko, Yoshio; Iwasaki, Junichi; Kawasaki, Masashi; Tokura, Yoshinori; Nagaosa, Naoto

    2015-05-01

    We study, by microsimulation on the chiral magnets, the elementary functions of magnetic skyrmions and the design principles of skyrmionic memory devices. The external stimuli, such as local heating, magnetic field, electric field and electric current, trigger the creation and annihilation of the skyrmion. These procedures, corresponding to the writing and erasing operations, are achieved typically within of the order of nano or pico seconds. We also examine the current driven motion of the skyrmions and find that the gyro-dynamics, which is induced by the topological nature of the skyrmion, leads to the variety of useful functions including the remarkable enhancement of the spin-transfer-torque effect. These features are shown to be advantageous for (a) high-density data-storage, (b) nonvolatile memory, and (c) ultra-low current and energy cost manipulation.

  4. Reconsolidation of drug memories

    PubMed Central

    Sorg, Barbara A.

    2012-01-01

    Persistent, unwanted memories are believed to be key contributors to drug addiction and the chronic relapse problem over the lifetime of the addict. Contrary to the long-held idea that memories are static and fixed, new studies in the last decade have shown that memories are dynamic and changeable. However, they are changeable only under specific conditions. When a memory is retrieved (reactivated), it becomes labile for a period of minutes to hours and then is reconsolidated to maintain long-term memory. Recent findings indicate that even well-established long-term memories may be susceptible to disruption by interfering with reconsolidation through delivery of certain amnestic agents during memory retrieval. Here I review the growing literature on memory reconsolidation in animal models of addiction, including sensitization, conditioned place preference and self-administration. I also discuss (a) several issues that need to be considered in interpreting the findings from reconsolidation studies and (b) future challenges and directions for memory reconsolidation studies in the field of addiction. The findings indicate promise for using this approach as a therapy for disrupting the long-lasting memories that can trigger relapse. PMID:22342780

  5. Overdistribution in source memory.

    PubMed

    Brainerd, C J; Reyna, V F; Holliday, R E; Nakamura, K

    2012-03-01

    Semantic false memories are confounded with a second type of error, overdistribution, in which items are attributed to contradictory episodic states. Overdistribution errors have proved to be more common than false memories when the 2 are disentangled. We investigated whether overdistribution is prevalent in another classic false memory paradigm: source monitoring. It is. Conventional false memory responses (source misattributions) were predominantly overdistribution errors, but unlike semantic false memory, overdistribution also accounted for more than half of true memory responses (correct source attributions). Experimental control of overdistribution was achieved via a series of manipulations that affected either recollection of contextual details or item memory (concreteness, frequency, list order, number of presentation contexts, and individual differences in verbatim memory). A theoretical model was used to analyze the data (conjoint process dissociation) that predicts that (a) overdistribution is directly proportional to item memory but inversely proportional to recollection and (b) item memory is not a necessary precondition for recollection of contextual details. The results were consistent with both predictions. 2012 APA, all rights reserved

  6. Psychophysiology of prospective memory.

    PubMed

    Rothen, Nicolas; Meier, Beat

    2014-01-01

    Prospective memory involves the self-initiated retrieval of an intention upon an appropriate retrieval cue. Cue identification can be considered as an orienting reaction and may thus trigger a psychophysiological response. Here we present two experiments in which skin conductance responses (SCRs) elicited by prospective memory cues were compared to SCRs elicited by aversive stimuli to test whether a single prospective memory cue triggers a similar SCR as an aversive stimulus. In Experiment 2 we also assessed whether cue specificity had a differential influence on prospective memory performance and on SCRs. We found that detecting a single prospective memory cue is as likely to elicit a SCR as an aversive stimulus. Missed prospective memory cues also elicited SCRs. On a behavioural level, specific intentions led to better prospective memory performance. However, on a psychophysiological level specificity had no influence. More generally, the results indicate reliable SCRs for prospective memory cues and point to psychophysiological measures as valuable approach, which offers a new way to study one-off prospective memory tasks. Moreover, the findings are consistent with a theory that posits multiple prospective memory retrieval stages.

  7. Human memory B cells.

    PubMed

    Seifert, M; Küppers, R

    2016-12-01

    A key feature of the adaptive immune system is the generation of memory B and T cells and long-lived plasma cells, providing protective immunity against recurring infectious agents. Memory B cells are generated in germinal center (GC) reactions in the course of T cell-dependent immune responses and are distinguished from naive B cells by an increased lifespan, faster and stronger response to stimulation and expression of somatically mutated and affinity matured immunoglobulin (Ig) genes. Approximately 40% of human B cells in adults are memory B cells, and several subsets were identified. Besides IgG(+) and IgA(+) memory B cells, ∼50% of peripheral blood memory B cells express IgM with or without IgD. Further smaller subpopulations have additionally been described. These various subsets share typical memory B cell features, but likely also fulfill distinct functions. IgM memory B cells appear to have the propensity for refined adaptation upon restimulation in additional GC reactions, whereas reactivated IgG B cells rather differentiate directly into plasma cells. The human memory B-cell pool is characterized by (sometimes amazingly large) clonal expansions, often showing extensive intraclonal IgV gene diversity. Moreover, memory B-cell clones are frequently composed of members of various subsets, showing that from a single GC B-cell clone a variety of memory B cells with distinct functions is generated. Thus, the human memory B-cell compartment is highly diverse and flexible. Several B-cell malignancies display features suggesting a derivation from memory B cells. This includes a subset of chronic lymphocytic leukemia, hairy cell leukemia and marginal zone lymphomas. The exposure of memory B cells to oncogenic events during their generation in the GC, the longevity of these B cells and the ease to activate them may be key determinants for their malignant transformation.

  8. "Brain-specific" nutrients: a memory cure?

    PubMed

    McDaniel, Mark A; Maier, Steven F; Einstein, Gilles O

    2003-01-01

    benefit of piracetam. Vinpocetine increases blood circulation and metabolism in the brain. Animal studies have shown that vinpocetine can reduce the loss of neurons due to decreased blood flow. In three studies of older adults with memory problems associated with poor brain circulation or dementia-related disease, vinpocetine produced significantly more improvement than a placebo in performance on global cognitive tests reflecting attention, concentration, and memory. Effects on episodic memory per se have been tested minimally, if at all. ALC participates in cellular energy production, a process especially important in neurons, and in removal of toxic accumulation of fatty acids. Animal studies show that ALC reverses the age-related decline in the number of neuron membrane receptors. Studies of patients with probable Alzheimer's disease have reported nominal advantages over a range of memory tests for ALC-treated patients relative to placebo groups. Significant differences have been reported rarely, however. Whether ALC would have mnemonic benefits for aging adults without brain disease is untested as far as we know. Antioxidants help neutralize tissue-damaging free radicals, which become more prevalent as organisms age. It is hypothesized that increasing antioxidant levels in the organism might retard or reverse the damaging effects of free radicals on neurons. Thus far, however, studies have found that vitamin E does not significantly slow down memory decline for Alzheimer's patients and does not produce significant memory benefits among early Parkinson's patients. Neither did a combination of vitamins E and C significantly improve college students' performance on several cognitive tasks. In sum, for most of the "brain-specific" nutrients we review, some mildly suggestive effects have been found in preliminary controlled studies using standard psychometric memory assessments or more general tests designed to reveal cognitive impairment. We suggest that future

  9. Human learning and memory.

    PubMed

    Johnson, M K; Hasher, L

    1987-01-01

    There have been several notable recent trends in the area of learning and memory. Problems with the episodic/semantic distinction have become more apparent, and new efforts have been made (exemplar models, distributed-memory models) to represent general knowledge without assuming a separate semantic system. Less emphasis is being placed on stable, prestored prototypes and more emphasis on a flexible memory system that provides the basis for a multitude of categories or frames of reference, derived on the spot as tasks demand. There is increasing acceptance of the idea that mental models are constructed and stored in memory in addition to, rather than instead of, memorial representations that are more closely tied to perceptions. This gives rise to questions concerning the conditions that permit inferences to be drawn and mental models to be constructed, and to questions concerning the similarities and differences in the nature of the representations in memory of perceived and generated information and in their functions. There has also been a swing from interest in deliberate strategies to interest in automatic, unconscious (even mechanistic!) processes, reflecting an appreciation that certain situations (e.g. recognition, frequency judgements, savings in indirect tasks, aspects of skill acquisition, etc) seem not to depend much on the products of strategic, effortful or reflective processes. There is a lively interest in relations among memory measures and attempts to characterize memory representations and/or processes that could give rise to dissociations among measures. Whether the pattern of results reflects the operation of functional subsystems of memory and, if so, what the "modules" are is far from clear. This issue has been fueled by work with amnesics and has contributed to a revival of interaction between researchers studying learning and memory in humans and those studying learning and memory in animals. Thus, neuroscience rivals computer science as a

  10. Conscious and unconscious memory systems.

    PubMed

    Squire, Larry R; Dede, Adam J O

    2015-03-02

    The idea that memory is not a single mental faculty has a long and interesting history but became a topic of experimental and biologic inquiry only in the mid-20th century. It is now clear that there are different kinds of memory, which are supported by different brain systems. One major distinction can be drawn between working memory and long-term memory. Long-term memory can be separated into declarative (explicit) memory and a collection of nondeclarative (implicit) forms of memory that include habits, skills, priming, and simple forms of conditioning. These memory systems depend variously on the hippocampus and related structures in the parahippocampal gyrus, as well as on the amygdala, the striatum, cerebellum, and the neocortex. This work recounts the discovery of declarative and nondeclarative memory and then describes the nature of declarative memory, working memory, nondeclarative memory, and the relationship between memory systems. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

  11. Conscious and Unconscious Memory Systems

    PubMed Central

    Squire, Larry R.; Dede, Adam J.O.

    2015-01-01

    The idea that memory is not a single mental faculty has a long and interesting history but became a topic of experimental and biologic inquiry only in the mid-20th century. It is now clear that there are different kinds of memory, which are supported by different brain systems. One major distinction can be drawn between working memory and long-term memory. Long-term memory can be separated into declarative (explicit) memory and a collection of nondeclarative (implicit) forms of memory that include habits, skills, priming, and simple forms of conditioning. These memory systems depend variously on the hippocampus and related structures in the parahippocampal gyrus, as well as on the amygdala, the striatum, cerebellum, and the neocortex. This work recounts the discovery of declarative and nondeclarative memory and then describes the nature of declarative memory, working memory, nondeclarative memory, and the relationship between memory systems. PMID:25731765

  12. A generalized memory test algorithm

    NASA Technical Reports Server (NTRS)

    Milner, E. J.

    1982-01-01

    A general algorithm for testing digital computer memory is presented. The test checks that (1) every bit can be cleared and set in each memory work, and (2) bits are not erroneously cleared and/or set elsewhere in memory at the same time. The algorithm can be applied to any size memory block and any size memory word. It is concise and efficient, requiring the very few cycles through memory. For example, a test of 16-bit-word-size memory requries only 384 cycles through memory. Approximately 15 seconds were required to test a 32K block of such memory, using a microcomputer having a cycle time of 133 nanoseconds.

  13. Memory-controlled diffusion

    NASA Astrophysics Data System (ADS)

    Trimper, Steffen; Zabrocki, Knud; Schulz, Michael

    2004-11-01

    Memory effects require for their incorporation into random-walk models an extension of the conventional equations. The linear Fokker-Planck equation for the probability density p(r⃗,t) is generalized by including nonlinear and nonlocal spatial-temporal memory effects. The realization of the memory kernel is restricted due the conservation of the basic quantity p . A general criteria is given for the existence of stationary solutions. In case the memory kernel depends on p polynomially, transport may be prevented. Owing to the delay effects a finite amount of particles remains localized and the further transport is terminated. For diffusion with nonlinear memory effects we find an exact solution in the long-time limit. Although the mean square displacement exhibits diffusive behavior, higher order cumulants offer differences to diffusion and they depend on the memory strength.

  14. Shape memory polymers

    DOEpatents

    Wilson, Thomas S.; Bearinger, Jane P.

    2017-08-29

    New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

  15. Shape memory polymers

    DOEpatents

    Wilson, Thomas S.; Bearinger, Jane P.

    2015-06-09

    New shape memory polymer compositions, methods for synthesizing new shape memory polymers, and apparatus comprising an actuator and a shape memory polymer wherein the shape memory polymer comprises at least a portion of the actuator. A shape memory polymer comprising a polymer composition which physically forms a network structure wherein the polymer composition has shape-memory behavior and can be formed into a permanent primary shape, re-formed into a stable secondary shape, and controllably actuated to recover the permanent primary shape. Polymers have optimal aliphatic network structures due to minimization of dangling chains by using monomers that are symmetrical and that have matching amine and hydroxyl groups providing polymers and polymer foams with clarity, tight (narrow temperature range) single transitions, and high shape recovery and recovery force that are especially useful for implanting in the human body.

  16. Does fascia hold memories?

    PubMed

    Tozzi, Paolo

    2014-04-01

    The idea that tissues may possess some sort of memory is a controversial topic in manual medicine, calling for research and clinical exploration. Many bodyworkers, at some point in their practice, have experienced phenomena that may be interpreted as representing a release of memory traces when working on dysfunctional tissues. This feeling may have been accompanied by some type of sensory experience, for the therapist and/or the patient. In some cases, early traumatic experiences may be recalled. When this happens, the potency of the memory may be erased or eased, along with restoration of tissue function. Hence the questions: can memories be held in the fascia? And: are these memories accessible during manual fascial work? Modern research has proposed a variety of different interpretations as to how memory might be stored in soft tissues, possibly involving other forms of information storage not exclusively processed neurologically (Box 1). Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Regulatory T cell memory

    PubMed Central

    Rosenblum, Michael D.; Way, Sing Sing; Abbas, Abul K.

    2016-01-01

    Memory for antigen is a defining feature of adaptive immunity. Antigen-specific lymphocyte populations show an increase in number and function after antigen encounter and more rapidly re-expand upon subsequent antigen exposure. Studies of immune memory have primarily focused on effector B cells and T cells with microbial specificity, using prime challenge models of infection. However, recent work has also identified persistently expanded populations of antigen-specific regulatory T cells that protect against aberrant immune responses. In this Review, we consider the parallels between memory effector T cells and memory regulatory T cells, along with the functional implications of regulatory memory in autoimmunity, antimicrobial host defence and maternal fetal tolerance. In addition, we discuss emerging evidence for regulatory T cell memory in humans and key unanswered questions in this rapidly evolving field. PMID:26688349

  18. Psychopharmacology and memory

    PubMed Central

    Glannon, W

    2006-01-01

    Psychotropic and other drugs can alter brain mechanisms regulating the formation, storage, and retrieval of different types of memory. These include “off label” uses of existing drugs and new drugs designed specifically to target the neural bases of memory. This paper discusses the use of beta‐adrenergic antagonists to prevent or erase non‐conscious pathological emotional memories in the amygdala. It also discusses the use of novel psychopharmacological agents to enhance long term semantic and short term working memory by altering storage and retrieval mechanisms in the hippocampus and prefrontal cortex. Although intervention in the brain to alter memory as therapy or enhancement holds considerable promise, the long term effects of experimental drugs on the brain and memory are not known. More studies are needed to adequately assess the potential benefits and risks of these interventions. PMID:16446410

  19. Myrmics Memory Allocator

    SciTech Connect

    Lymperis, S.

    2011-09-23

    MMA is a stand-alone memory management system for MPI clusters. It implements a shared Partitioned Global Address Space, where multiple MPI processes request objects from the allocator and the latter provides them with system-wide unique memory addresses for each object. It provides applications with an intuitive way of managing the memory system in a unified way, thus enabling easier writing of irregular application code.

  20. Content Addressable Memory Project

    DTIC Science & Technology

    1990-11-01

    The Content Addressable M1-emory Project consists of the development of several experimental software systems on an AMT Distributed Array Processor...searching (database) compiler algorithms memory management other systems software) Linear C is an unlovely hybrid language which imports the CAM...memory from AMT’s operating system for the DAP; how- ever, other than this limitation, the memory management routines work exactly as their C counterparts

  1. Sparse distributed memory

    NASA Technical Reports Server (NTRS)

    Kanerva, Pentti

    1988-01-01

    Theoretical models of the human brain and proposed neural-network computers are developed analytically. Chapters are devoted to the mathematical foundations, background material from computer science, the theory of idealized neurons, neurons as address decoders, and the search of memory for the best match. Consideration is given to sparse memory, distributed storage, the storage and retrieval of sequences, the construction of distributed memory, and the organization of an autonomous learning system.

  2. Magnetic bubble domain memories

    NASA Technical Reports Server (NTRS)

    Ypma, J. E.

    1974-01-01

    Some attractive features of Bubble Domain Memory and its relation to existing technologies are discussed. Two promising applications are block access mass memory and tape recorder replacement. The required chip capabilities for these uses are listed, and the specifications for a block access mass memory designed to fit between core and HPT disk are presented. A feasibility model for a tape recorder replacement is introduced.

  3. Random Access Memory Technologies.

    DTIC Science & Technology

    1985-02-01

    extreme temperatures. True nonvolatility is offered by the NVRAM or shadow RAM. In the NVRAM , a volatile NMOS static RAM memory cell is merged with the...or reapplied, and no longer require special power sources. The size of the nine-device memory cell required for the NVRAM has limited its capacity to...4K. While 8K NVRAMs are expected in 1985, the 30 . . .’o .-. . high cost of these devices will hamper further development for larger capacity memories

  4. Sparse distributed memory

    SciTech Connect

    Kanerva, P.

    1988-01-01

    Theoretical models of the human brain and proposed neural-network computers are developed analytically. Chapters are devoted to the mathematical foundations, background material from computer science, the theory of idealized neurons, neurons as address decoders, and the search of memory for the best match. Consideration is given to sparse memory, distributed storage, the storage and retrieval of sequences, the construction of distributed memory, and the organization of an autonomous learning system. 63 refs.

  5. Memory Load and Dump

    NASA Astrophysics Data System (ADS)

    Welty, Alan

    2009-07-01

    This proposal is a test and verification of the STIS dump of memory capability.Areas of Control Section {CS} to dump include: EDAC RAM, EEPROM, and CS PROM {with the CS in Operate}. Areas of MIE memory to dump include: MIE RAM and MIE PROM {with the MIE in Operate}. Note that the MIE memory must first be copied to CS buffer RAM as images, which are then dumped.Supports Activity STIS-02

  6. Memory Golf Clubs

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Memory Corporation's investigation of shape memory effect, stemming from Marshall Space Flight Center contracts to study materials for the space station, has aided in the development of Zeemet, a proprietary, high-damping shape memory alloy for the golf industry. The Nicklaus Golf Company has created a new line of golf clubs using Zeemet inserts. Its superelastic and high damping attributes translate into more spin on the ball, greater control, and a solid feel.

  7. Sparse distributed memory

    NASA Technical Reports Server (NTRS)

    Kanerva, Pentti

    1988-01-01

    Theoretical models of the human brain and proposed neural-network computers are developed analytically. Chapters are devoted to the mathematical foundations, background material from computer science, the theory of idealized neurons, neurons as address decoders, and the search of memory for the best match. Consideration is given to sparse memory, distributed storage, the storage and retrieval of sequences, the construction of distributed memory, and the organization of an autonomous learning system.

  8. Myrmics Memory Allocator

    SciTech Connect

    Lymperis, S.

    2011-09-23

    MMA is a stand-alone memory management system for MPI clusters. It implements a shared Partitioned Global Address Space, where multiple MPI processes request objects from the allocator and the latter provides them with system-wide unique memory addresses for each object. It provides applications with an intuitive way of managing the memory system in a unified way, thus enabling easier writing of irregular application code.

  9. Networks of Memories

    DTIC Science & Technology

    2013-03-01

    2000). The construction of  autobiographical   memories in the self­memory system. Psychological Review, 107(2), 261­288. Dennis, S., & Chapman, A. (2010...AFRL-OSR-VA-TR-2013-0131 Networks of Memories Simon Dennis, Mikhail Belkin Ohio State University March 2013 Final...Back (Rev. 8/98) 1 Networks of  Memories FA9550­09­1­0614 Professor Jay Myung PI: Simon Dennis Ohio State University February 15, 2013 2 Introduction

  10. Hypnosis, memory and amnesia.

    PubMed Central

    Kihlstrom, J F

    1997-01-01

    Hypnotized subjects respond to suggestions from the hypnotist for imaginative experiences involving alterations in perception and memory. Individual differences in hypnotizability are only weakly related to other forms of suggestibility. Neuropsychological speculations about hypnosis focus on the right hemisphere and/or the frontal lobes. Posthypnotic amnesia refers to subjects' difficulty in remembering, after hypnosis, the events and experiences that transpired while they were hypnotized. Posthypnotic amnesia is not an instance of state-dependent memory, but it does seem to involve a disruption of retrieval processes similar to the functional amnesias observed in clinical dissociative disorders. Implicit memory, however, is largely spared, and may underlie subjects' ability to recognize events that they cannot recall. Hypnotic hypermnesia refers to improved memory for past events. However, such improvements are illusory: hypermnesia suggestions increase false recollection, as well as subjects' confidence in both true and false memories. Hypnotic age regression can be subjectively compelling, but does not involve the ablation of adult memory, or the reinstatement of childlike modes of mental functioning, or the revivification of memory. The clinical and forensic use of hypermnesia and age regression to enhance memory in patients, victims and witnesses (e.g. recovered memory therapy for child sexual abuse) should be discouraged. PMID:9415925

  11. Retrieval of Emotional Memories

    PubMed Central

    Buchanan, Tony W.

    2008-01-01

    Long-term memories are influenced by the emotion experienced during learning as well as by the emotion experienced during memory retrieval. The present article reviews the literature addressing the effects of emotion on retrieval, focusing on the cognitive and neurological mechanisms that have been revealed. The reviewed research suggests that the amygdala, in combination with the hippocampus and prefrontal cortex, plays an important role in the retrieval of memories for emotional events. The neural regions necessary for online emotional processing also influence emotional memory retrieval, perhaps through the reexperience of emotion during the retrieval process. PMID:17723029

  12. Hypnosis, memory and amnesia.

    PubMed

    Kihlstrom, J F

    1997-11-29

    Hypnotized subjects respond to suggestions from the hypnotist for imaginative experiences involving alterations in perception and memory. Individual differences in hypnotizability are only weakly related to other forms of suggestibility. Neuropsychological speculations about hypnosis focus on the right hemisphere and/or the frontal lobes. Posthypnotic amnesia refers to subjects' difficulty in remembering, after hypnosis, the events and experiences that transpired while they were hypnotized. Posthypnotic amnesia is not an instance of state-dependent memory, but it does seem to involve a disruption of retrieval processes similar to the functional amnesias observed in clinical dissociative disorders. Implicit memory, however, is largely spared, and may underlie subjects' ability to recognize events that they cannot recall. Hypnotic hypermnesia refers to improved memory for past events. However, such improvements are illusory: hypermnesia suggestions increase false recollection, as well as subjects' confidence in both true and false memories. Hypnotic age regression can be subjectively compelling, but does not involve the ablation of adult memory, or the reinstatement of childlike modes of mental functioning, or the revivification of memory. The clinical and forensic use of hypermnesia and age regression to enhance memory in patients, victims and witnesses (e.g. recovered memory therapy for child sexual abuse) should be discouraged.

  13. Sparse distributed memory overview

    NASA Technical Reports Server (NTRS)

    Raugh, Mike

    1990-01-01

    The Sparse Distributed Memory (SDM) project is investigating the theory and applications of massively parallel computing architecture, called sparse distributed memory, that will support the storage and retrieval of sensory and motor patterns characteristic of autonomous systems. The immediate objectives of the project are centered in studies of the memory itself and in the use of the memory to solve problems in speech, vision, and robotics. Investigation of methods for encoding sensory data is an important part of the research. Examples of NASA missions that may benefit from this work are Space Station, planetary rovers, and solar exploration. Sparse distributed memory offers promising technology for systems that must learn through experience and be capable of adapting to new circumstances, and for operating any large complex system requiring automatic monitoring and control. Sparse distributed memory is a massively parallel architecture motivated by efforts to understand how the human brain works. Sparse distributed memory is an associative memory, able to retrieve information from cues that only partially match patterns stored in the memory. It is able to store long temporal sequences derived from the behavior of a complex system, such as progressive records of the system's sensory data and correlated records of the system's motor controls.

  14. Neural network based feed-forward high density associative memory

    NASA Technical Reports Server (NTRS)

    Daud, T.; Moopenn, A.; Lamb, J. L.; Ramesham, R.; Thakoor, A. P.

    1987-01-01

    A novel thin film approach to neural-network-based high-density associative memory is described. The information is stored locally in a memory matrix of passive, nonvolatile, binary connection elements with a potential to achieve a storage density of 10 to the 9th bits/sq cm. Microswitches based on memory switching in thin film hydrogenated amorphous silicon, and alternatively in manganese oxide, have been used as programmable read-only memory elements. Low-energy switching has been ascertained in both these materials. Fabrication and testing of memory matrix is described. High-speed associative recall approaching 10 to the 7th bits/sec and high storage capacity in such a connection matrix memory system is also described.

  15. Near-field NanoThermoMechanical memory

    SciTech Connect

    Elzouka, Mahmoud; Ndao, Sidy

    2014-12-15

    In this letter, we introduce the concept of NanoThermoMechanical Memory. Unlike electronic memory, a NanoThermoMechanical memory device uses heat instead of electricity to record, store, and recover data. Memory function is achieved through the coupling of near-field thermal radiation and thermal expansion resulting in negative differential thermal resistance and thermal latching. Here, we demonstrate theoretically via numerical modeling the concept of near-field thermal radiation enabled negative differential thermal resistance that achieves bistable states. Design and implementation of a practical silicon based NanoThermoMechanical memory device are proposed along with a study of its dynamic response under write/read cycles. With more than 50% of the world's energy losses being in the form of heat along with the ever increasing need to develop computer technologies which can operate in harsh environments (e.g., very high temperatures), NanoThermoMechanical memory and logic devices may hold the answer.

  16. Near-field NanoThermoMechanical memory

    NASA Astrophysics Data System (ADS)

    Elzouka, Mahmoud; Ndao, Sidy

    2014-12-01

    In this letter, we introduce the concept of NanoThermoMechanical Memory. Unlike electronic memory, a NanoThermoMechanical memory device uses heat instead of electricity to record, store, and recover data. Memory function is achieved through the coupling of near-field thermal radiation and thermal expansion resulting in negative differential thermal resistance and thermal latching. Here, we demonstrate theoretically via numerical modeling the concept of near-field thermal radiation enabled negative differential thermal resistance that achieves bistable states. Design and implementation of a practical silicon based NanoThermoMechanical memory device are proposed along with a study of its dynamic response under write/read cycles. With more than 50% of the world's energy losses being in the form of heat along with the ever increasing need to develop computer technologies which can operate in harsh environments (e.g., very high temperatures), NanoThermoMechanical memory and logic devices may hold the answer.

  17. [Memory disorders in schizophrenia].

    PubMed

    Danion, J M; Peretti, S; Gras-Vincendon, A; Singer, L

    1992-01-01

    The current interest in memory disorders in schizophrenia results from the way perceptions of schizophrenia--whose organic origin is becoming increasingly evident--and memory--according to which there exist not one, but several memories--have developed. Memory disorders in the schizophrenic cannot be considered in isolation from knowledge accumulated in other areas of the cognitive and neuro-sciences; a more detailed understanding of these disorders requires a comparison of the different cognitive approaches, both with each other and with the neurobiological and clinical approaches, so that they can be integrated. Despite numerous methodological and conceptual difficulties, it now appears to have been established that the schizophrenic's memory deficit should be seen in the context of a wider cognitive deficit, that the memory tasks are not all disturbed and that the memory deficit cannot be identified with one specific form of memory. Thus, iconic formation, short-term memory in the traditionally accepted sense and implicit memory are hardly, if at all, affected; in contrast, the early processing of information, working memory and explicit memory are disturbed, probably to the extent that they require the implementation of strategies to organise the information to be memorized. Finally, in certain tasks, such as those evaluating latent inhibition or negative priming, schizophrenics perform better than normal subjects, suggesting that schizophrenics' cognitive deficit is localised. This profile of memory disorders is compatible with a dysfunction predominating in the frontal and temporo-hippocampal regions. Neuroleptics and anticholinergics have opposite effects on cognitive and mnesic performance, which is improved by the former and aggravated by the latter. The influence of clinical symptoms, positive or negative, institutionalisation of patients and chronic tardive dyskinesia is unclear. Among the theoretical proposals put forward to account for the observed

  18. [Repeated measurement of memory with valenced test items: verbal memory, working memory and autobiographic memory].

    PubMed

    Kuffel, A; Terfehr, K; Uhlmann, C; Schreiner, J; Löwe, B; Spitzer, C; Wingenfeld, K

    2013-07-01

    A large number of questions in clinical and/or experimental neuropsychology require the multiple repetition of memory tests at relatively short intervals. Studies on the impact of the associated exercise and interference effects on the validity of the test results are rare. Moreover, hardly any neuropsychological instruments exist to date to record the memory performance with several parallel versions in which the emotional valence of the test material is also taken into consideration. The aim of the present study was to test whether a working memory test (WST, a digit-span task with neutral or negative distraction stimuli) devised by our workgroup can be used with repeated measurements. This question was also examined in parallel versions of a wordlist learning paradigm and an autobiographical memory test (AMT). Both tests contained stimuli with neutral, positive and negative valence. Twenty-four participants completed the memory testing including the working memory test and three versions of a wordlist and the AMT at intervals of a week apiece (measuring points 1. - 3.). The results reveal consistent performances across the three measuring points in the working and autobiographical memory test. The valence of the stimulus material did not influence the memory performance. In the delayed recall of the wordlist an improvement in memory performance over time was seen. The tests on working memory presented and the parallel versions for the declarative and autobiographical memory constitute informal economic instruments within the scope of the measurement repeatability designs. While the WST and AMT are appropriate for study designs with repeated measurements at relatively short intervals, longer intervals might seem more favourable for the use of wordlist learning paradigms. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Memory cell operation based on small Josephson junctions arrays

    NASA Astrophysics Data System (ADS)

    Braiman, Y.; Nair, N.; Rezac, J.; Imam, N.

    2016-12-01

    In this paper we analyze a cryogenic memory cell circuit based on a small coupled array of Josephson junctions. All the basic memory operations (e.g., write, read, and reset) are implemented on the same circuit and different junctions in the array can in principle be utilized for these operations. The presented memory operation paradigm is fundamentally different from conventional single quantum flux operation logics (SFQ). As an example, we demonstrate memory operation driven by a SFQ pulse employing an inductively coupled array of three Josephson junctions. We have chosen realistic Josephson junction parameters based on state-of-the-art fabrication capabilities and have calculated access times and access energies for basic memory cell operations. We also implemented an optimization procedure based on the simulated annealing algorithm to calculate the optimized and typical values of access times and access energies.

  20. Cavity-Enhanced Room-Temperature Broadband Raman Memory

    NASA Astrophysics Data System (ADS)

    Saunders, D. J.; Munns, J. H. D.; Champion, T. F. M.; Qiu, C.; Kaczmarek, K. T.; Poem, E.; Ledingham, P. M.; Walmsley, I. A.; Nunn, J.

    2016-03-01

    Broadband quantum memories hold great promise as multiplexing elements in future photonic quantum information protocols. Alkali-vapor Raman memories combine high-bandwidth storage, on-demand readout, and operation at room temperature without collisional fluorescence noise. However, previous implementations have required large control pulse energies and have suffered from four-wave-mixing noise. Here, we present a Raman memory where the storage interaction is enhanced by a low-finesse birefringent cavity tuned into simultaneous resonance with the signal and control fields, dramatically reducing the energy required to drive the memory. By engineering antiresonance for the anti-Stokes field, we also suppress the four-wave-mixing noise and report the lowest unconditional noise floor yet achieved in a Raman-type warm vapor memory, (15 ±2 )×10-3 photons per pulse, with a total efficiency of (9.5 ±0.5 )%.

  1. A cannabinoid link between mitochondria and memory.

    PubMed

    Hebert-Chatelain, Etienne; Desprez, Tifany; Serrat, Román; Bellocchio, Luigi; Soria-Gomez, Edgar; Busquets-Garcia, Arnau; Pagano Zottola, Antonio Christian; Delamarre, Anna; Cannich, Astrid; Vincent, Peggy; Varilh, Marjorie; Robin, Laurie M; Terral, Geoffrey; García-Fernández, M Dolores; Colavita, Michelangelo; Mazier, Wilfrid; Drago, Filippo; Puente, Nagore; Reguero, Leire; Elezgarai, Izaskun; Dupuy, Jean-William; Cota, Daniela; Lopez-Rodriguez, Maria-Luz; Barreda-Gómez, Gabriel; Massa, Federico; Grandes, Pedro; Bénard, Giovanni; Marsicano, Giovanni

    2016-11-24

    Cellular activity in the brain depends on the high energetic support provided by mitochondria, the cell organelles which use energy sources to generate ATP. Acute cannabinoid intoxication induces amnesia in humans and animals, and the activation of type-1 cannabinoid receptors present at brain mitochondria membranes (mtCB1) can directly alter mitochondrial energetic activity. Although the pathological impact of chronic mitochondrial dysfunctions in the brain is well established, the involvement of acute modulation of mitochondrial activity in high brain functions, including learning and memory, is unknown. Here, we show that acute cannabinoid-induced memory impairment in mice requires activation of hippocampal mtCB1 receptors. Genetic exclusion of CB1 receptors from hippocampal mitochondria prevents cannabinoid-induced reduction of mitochondrial mobility, synaptic transmission and memory formation. mtCB1 receptors signal through intra-mitochondrial Gαi protein activation and consequent inhibition of soluble-adenylyl cyclase (sAC). The resulting inhibition of protein kinase A (PKA)-dependent phosphorylation of specific subunits of the mitochondrial electron transport system eventually leads to decreased cellular respiration. Hippocampal inhibition of sAC activity or manipulation of intra-mitochondrial PKA signalling or phosphorylation of the Complex I subunit NDUFS2 inhibit bioenergetic and amnesic effects of cannabinoids. Thus, the G protein-coupled mtCB1 receptors regulate memory processes via modulation of mitochondrial energy metabolism. By directly linking mitochondrial activity to memory formation, these data reveal that bioenergetic processes are primary acute regulators of cognitive functions.

  2. Regret as Autobiographical Memory

    ERIC Educational Resources Information Center

    Davison, Ian M.; Feeney, Aidan

    2008-01-01

    We apply an autobiographical memory framework to the study of regret. Focusing on the distinction between regrets for specific and general events we argue that the temporal profile of regret, usually explained in terms of the action-inaction distinction, is predicted by models of autobiographical memory. In two studies involving participants in…

  3. Memory Efficient Ranking.

    ERIC Educational Resources Information Center

    Moffat, Alistair; And Others

    1994-01-01

    Describes an approximate document ranking process that uses a compact array of in-memory, low-precision approximations for document length. Combined with another rule for reducing the memory required by partial similarity accumulators, the approximation heuristic allows the ranking of large document collections using less than one byte of memory…

  4. Memory technology survey

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The current status of semiconductor, magnetic, and optical memory technologies is described. Projections based on these research activities planned for the shot term are presented. Conceptual designs of specific memory buffer pplications employing bipola, CMOS, GaAs, and Magnetic Bubble devices are discussed.

  5. An Exceptional Memory

    ERIC Educational Resources Information Center

    Hunter, Ian M. L.

    1977-01-01

    An account is given of the exceptional memory of the late Professor A. C. Aitken who was also a distinguished mathematician and mental calculator. Compared with Shereshevskii, another man with exceptional memory, he shows the scholar's reliance on conceptual mapping rather than the mnemonist's reliance on perceptual chaining. (Editor)

  6. Eavesdropping without quantum memory

    SciTech Connect

    Bechmann-Pasquinucci, H.

    2006-04-15

    In quantum cryptography the optimal eavesdropping strategy requires that the eavesdropper uses ancillas and quantum memories in order to optimize her information. What happens if the eavesdropper has no quantum memory? It is shown that in this case the eavesdropper obtains a better information/disturbance trade-off by adopting the simple intercept/resend strategy.

  7. Working Memory and Attitudes

    ERIC Educational Resources Information Center

    Jung, Eun Sook; Reid, Norman

    2009-01-01

    Working memory capacity has been shown to be an important factor in controlling understanding in the sciences. Attitudes related to studies in the sciences are also known to be important in relation to success in learning. It might be argued that if working memory capacity is a rate controlling feature of learning and success in understanding…

  8. Human Learning and Memory

    ERIC Educational Resources Information Center

    Lieberman, David A.

    2012-01-01

    This innovative textbook is the first to integrate learning and memory, behaviour, and cognition. It focuses on fascinating human research in both memory and learning (while also bringing in important animal studies) and brings the reader up to date with the latest developments in the subject. Students are encouraged to think critically: key…

  9. Human Memory: The Basics

    ERIC Educational Resources Information Center

    Martinez, Michael E.

    2010-01-01

    The human mind has two types of memory: short-term and long-term. In all types of learning, it is best to use that structure rather than to fight against it. One way to do that is to ensure that learners can fit new information into patterns that can be stored in and more easily retrieved from long-term memory.

  10. Memory Metals (Marchon Eyewear)

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Another commercial application of memory metal technology is found in a "smart" eyeglass frame that remembers its shape and its wearer's fit. A patented "memory encoding process" makes this possible. Heat is not required to return the glasses to shape. A large commercial market is anticipated.

  11. Visual Memory at Birth.

    ERIC Educational Resources Information Center

    Slater, Alan; And Others

    1982-01-01

    Explored new-born babys' capacity for forming visual memories. Used an habituation procedure that accommodated individual differences by allowing each infant to control the time course of habituation trials. Found significant novelty preference, providing strong evidence that recognition memory can be reliably demonstrated from birth. (Author/JAC)

  12. Human Memory: The Basics

    ERIC Educational Resources Information Center

    Martinez, Michael E.

    2010-01-01

    The human mind has two types of memory: short-term and long-term. In all types of learning, it is best to use that structure rather than to fight against it. One way to do that is to ensure that learners can fit new information into patterns that can be stored in and more easily retrieved from long-term memory.

  13. Human Learning and Memory

    ERIC Educational Resources Information Center

    Lieberman, David A.

    2012-01-01

    This innovative textbook is the first to integrate learning and memory, behaviour, and cognition. It focuses on fascinating human research in both memory and learning (while also bringing in important animal studies) and brings the reader up to date with the latest developments in the subject. Students are encouraged to think critically: key…

  14. Reading, Memory, and Metacognition.

    ERIC Educational Resources Information Center

    Byrd, Diana M.; Gholson, Barry

    1985-01-01

    This study was designed to explore relations among reading skills, metareading, memory, and metamemory. Interactions among these skills were investigated as related to reading ability, operativity, and grade level. The effects of experience, operativity, and metacognition on reading and memory skills were discussed. (Author/DWH)

  15. [Learning and memory].

    PubMed

    Lombroso, Paul

    2004-09-01

    Memory is broadly divided into declarative and nondeclarative forms of memory. The hippocampus is required for the formation of declarative memories, while a number of other brain regions including the striatum, amygdala and nucleus accumbens are involved in the formation of nondeclarative memories. The formation of all memories require morphological changes of synapses: new ones must be formed or old ones strengthened. These changes are thought to reflect the underlying cellular basis for persistent memories. Considerable advances have occurred over the last decade in our understanding of the molecular bases of how these memories are formed. A key regulator of synaptic plasticity is a signaling pathway that includes the mitogen activated protein (MAP) kinase. As this pathway is required for normal memory and learning, it is not surprising that mutations in members of this pathway lead to disruptions in learning. Neurofibromatosis, Coffin-Lowry syndrome and Rubinstein-Taybi syndrome are three examples of developmental disorders that have mutations in key components of the MAP kinase signaling pathway.

  16. Predicting Reasoning from Memory

    ERIC Educational Resources Information Center

    Heit, Evan; Hayes, Brett K.

    2011-01-01

    In an effort to assess the relations between reasoning and memory, in 8 experiments, the authors examined how well responses on an inductive reasoning task are predicted from responses on a recognition memory task for the same picture stimuli. Across several experimental manipulations, such as varying study time, presentation frequency, and the…

  17. Memorial symptom assessment scale.

    PubMed

    Chang, Victor T; Hwang, Shirley S; Thaler, Howard T; Kasimis, Basil S; Portenoy, Russell K

    2004-04-01

    Patients with advanced illnesses often have multiple symptoms. As interest in palliative care and interventions for symptom control increase, the ability to assess multiple symptoms has become more important. A number of instruments have been developed to meet this need in cancer patients. This article reviews the development and applications of a multidimensional instrument, the Memorial Symptom Assessment Scale. The Memorial Symptom Assessment Scale has 32 symptoms and three dimensions of frequency, severity, and distress. Shorter versions - The Memorial Symptom Assessment Scale Short Form (32 symptoms with one dimension) and the Condensed Memorial Symptom Assessment Scale (14 symptoms with one dimension), and a version for children aged 7-12 years, have also been developed. A distinctive feature is the summary subscales for physical distress, psychological distress, and The Global Distress Index. The Memorial Symptom Assessment Scale has proven useful in description of symptom epidemiology, the role of symptoms in pain, fatigue, and spirituality; as a predictor of survival, and in proxy assessments of pain. The Memorial Symptom Assessment Scale has been used in studies of cancer and AIDS patients, and patients with advanced medical illnesses. Possible future roles of instruments such as the Memorial Symptom Assessment Scale include use in clinical trials, for pharmacoeconomic analyses, definition of symptom clusters and symptom burden, the development of symptom outcome measures, symptom monitoring, and improving care for patients. Continued research is needed for the versions of the Memorial Symptom Assessment Scale and other symptom instruments in different populations and applications.

  18. Experimental Optoelectronic Associative Memory

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin

    1992-01-01

    Optoelectronic associative memory responds to input image by displaying one of M remembered images. Which image to display determined by optoelectronic analog computation of resemblance between input image and each remembered image. Does not rely on precomputation and storage of outer-product synapse matrix. Size of memory needed to store and process images reduced.

  19. Memories of Physical Education

    ERIC Educational Resources Information Center

    Sidwell, Amy M.; Walls, Richard T.

    2014-01-01

    The purpose of this investigation was to explore college students' autobiographical memories of physical education (PE). Questionnaires were distributed to students enrolled in undergraduate Introduction to PE and Introduction to Communications courses. The 261 participants wrote about memories of PE. These students recalled events from Grades…

  20. Regret as Autobiographical Memory

    ERIC Educational Resources Information Center

    Davison, Ian M.; Feeney, Aidan

    2008-01-01

    We apply an autobiographical memory framework to the study of regret. Focusing on the distinction between regrets for specific and general events we argue that the temporal profile of regret, usually explained in terms of the action-inaction distinction, is predicted by models of autobiographical memory. In two studies involving participants in…

  1. Experimental Optoelectronic Associative Memory

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin

    1992-01-01

    Optoelectronic associative memory responds to input image by displaying one of M remembered images. Which image to display determined by optoelectronic analog computation of resemblance between input image and each remembered image. Does not rely on precomputation and storage of outer-product synapse matrix. Size of memory needed to store and process images reduced.

  2. Memory's Role in Catechesis.

    ERIC Educational Resources Information Center

    Williams, Robert Bryan

    The aim of this dissertation is to explicate memory's role in catechesis. Catechesis is a term that early Christians chose to describe their "...work of teaching the gospel and...to mean 'instruction given by word of mouth.'" A brief historical overview confirms the continuity between catechesis and memory from apostolic to present…

  3. Memories of Physical Education

    ERIC Educational Resources Information Center

    Sidwell, Amy M.; Walls, Richard T.

    2014-01-01

    The purpose of this investigation was to explore college students' autobiographical memories of physical education (PE). Questionnaires were distributed to students enrolled in undergraduate Introduction to PE and Introduction to Communications courses. The 261 participants wrote about memories of PE. These students recalled events from Grades…

  4. A Space for Memory

    ERIC Educational Resources Information Center

    Charman, Karen

    2015-01-01

    In this article I examine the possibilities of reparation in an era of privatisation and de-industrialisation. I examine the effect of a recent project Sunshine Memory Space, a space, designed to evoke memories of a de-industrialised urban Melbourne suburb Sunshine. This project offered the opportunity for the effects of industrial change to be…

  5. Distributed multiport memory architecture

    NASA Technical Reports Server (NTRS)

    Kohl, W. H. (Inventor)

    1983-01-01

    A multiport memory architecture is diclosed for each of a plurality of task centers connected to a command and data bus. Each task center, includes a memory and a plurality of devices which request direct memory access as needed. The memory includes an internal data bus and an internal address bus to which the devices are connected, and direct timing and control logic comprised of a 10-state ring counter for allocating memory devices by enabling AND gates connected to the request signal lines of the devices. The outputs of AND gates connected to the same device are combined by OR gates to form an acknowledgement signal that enables the devices to address the memory during the next clock period. The length of the ring counter may be effectively lengthened to any multiple of ten to allow for more direct memory access intervals in one repetitive sequence. One device is a network bus adapter which serially shifts onto the command and data bus, a data word (8 bits plus control and parity bits) during the next ten direct memory access intervals after it has been granted access. The NBA is therefore allocated only one access in every ten intervals, which is a predetermined interval for all centers. The ring counters of all centers are periodically synchronized by DMA SYNC signal to assure that all NBAs be able to function in synchronism for data transfer from one center to another.

  6. Towards self-correcting quantum memories

    NASA Astrophysics Data System (ADS)

    Michnicki, Kamil

    This thesis presents a model of self-correcting quantum memories where quantum states are encoded using topological stabilizer codes and error correction is done using local measurements and local dynamics. Quantum noise poses a practical barrier to developing quantum memories. This thesis explores two types of models for suppressing noise. One model suppresses thermalizing noise energetically by engineering a Hamiltonian with a high energy barrier between code states. Thermalizing dynamics are modeled phenomenologically as a Markovian quantum master equation with only local generators. The second model suppresses stochastic noise with a cellular automaton that performs error correction using syndrome measurements and a local update rule. Several ways of visualizing and thinking about stabilizer codes are presented in order to design ones that have a high energy barrier: the non-local Ising model, the quasi-particle graph and the theory of welded stabilizer codes. I develop the theory of welded stabilizer codes and use it to construct a code with the highest known energy barrier in 3-d for spin Hamiltonians: the welded solid code. Although the welded solid code is not fully self correcting, it has some self correcting properties. It has an increased memory lifetime for an increased system size up to a temperature dependent maximum. One strategy for increasing the energy barrier is by mediating an interaction with an external system. I prove a no-go theorem for a class of Hamiltonians where the interaction terms are local, of bounded strength and commute with the stabilizer group. Under these conditions the energy barrier can only be increased by a multiplicative constant. I develop cellular automaton to do error correction on a state encoded using the toric code. The numerical evidence indicates that while there is no threshold, the model can extend the memory lifetime significantly. While of less theoretical importance, this could be practical for real

  7. Animal models of source memory.

    PubMed

    Crystal, Jonathon D

    2016-01-01

    Source memory is the aspect of episodic memory that encodes the origin (i.e., source) of information acquired in the past. Episodic memory (i.e., our memories for unique personal past events) typically involves source memory because those memories focus on the origin of previous events. Source memory is at work when, for example, someone tells a favorite joke to a person while avoiding retelling the joke to the friend who originally shared the joke. Importantly, source memory permits differentiation of one episodic memory from another because source memory includes features that were present when the different memories were formed. This article reviews recent efforts to develop an animal model of source memory using rats. Experiments are reviewed which suggest that source memory is dissociated from other forms of memory. The review highlights strengths and weaknesses of a number of animal models of episodic memory. Animal models of source memory may be used to probe the biological bases of memory. Moreover, these models can be combined with genetic models of Alzheimer's disease to evaluate pharmacotherapies that ultimately have the potential to improve memory.

  8. Is random access memory random?

    NASA Technical Reports Server (NTRS)

    Denning, P. J.

    1986-01-01

    Most software is contructed on the assumption that the programs and data are stored in random access memory (RAM). Physical limitations on the relative speeds of processor and memory elements lead to a variety of memory organizations that match processor addressing rate with memory service rate. These include interleaved and cached memory. A very high fraction of a processor's address requests can be satified from the cache without reference to the main memory. The cache requests information from main memory in blocks that can be transferred at the full memory speed. Programmers who organize algorithms for locality can realize the highest performance from these computers.

  9. Imaging autobiographical memory.

    PubMed

    Fossati, Philippe

    2013-12-01

    Autobiographical memory (AM) defines the memory systems that encode, consolidate, and retrieve personal events and facts, AM is strongly related to self-perception and self representation. We review here the neural correlates of AM retrieval. AM retrieval encompasses a large neural network including the prefrontal, temporal, and parietal cortex, and limbic structures. All these regions subserve the cognitive processes (episodic remembering, cognitive control, self-processing, and scene construction) at play during memory retrieval. We emphasize the specific role of medial prefrontal cortex and precuneus in self-processing during autobiographical memory retrieval. Overall, these data call for further studies in psychiatric patients, to investigate the neural underpinnings of autobiographical memory and self-representation in mental disorders.

  10. Serotonin transporter and memory.

    PubMed

    Meneses, Alfredo; Perez-Garcia, Georgina; Ponce-Lopez, Teresa; Tellez, Ruth; Castillo, Carlos

    2011-09-01

    The serotonin transporter (SERT) has been associated to diverse functions and diseases, though seldom to memory. Therefore, we made an attempt to summarize and discuss the available publications implicating the involvement of the SERT in memory, amnesia and anti-amnesic effects. Evidence indicates that Alzheimer's disease and drugs of abuse like d-methamphetamine (METH) and (+/-)3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") have been associated to decrements in the SERT expression and memory deficits. Several reports have indicated that memory formation and amnesia affected the SERT expression. The SERT expression seems to be a reliable neural marker related to memory mechanisms, its alterations and potential treatment. The pharmacological, neural and molecular mechanisms associated to these changes are of great importance for investigation.

  11. Computer memory management system

    DOEpatents

    Kirk, III, Whitson John

    2002-01-01

    A computer memory management system utilizing a memory structure system of "intelligent" pointers in which information related to the use status of the memory structure is designed into the pointer. Through this pointer system, The present invention provides essentially automatic memory management (often referred to as garbage collection) by allowing relationships between objects to have definite memory management behavior by use of coding protocol which describes when relationships should be maintained and when the relationships should be broken. In one aspect, the present invention system allows automatic breaking of strong links to facilitate object garbage collection, coupled with relationship adjectives which define deletion of associated objects. In another aspect, The present invention includes simple-to-use infinite undo/redo functionality in that it has the capability, through a simple function call, to undo all of the changes made to a data model since the previous `valid state` was noted.

  12. Predicting reasoning from memory.

    PubMed

    Heit, Evan; Hayes, Brett K

    2011-02-01

    In an effort to assess the relations between reasoning and memory, in 8 experiments, the authors examined how well responses on an inductive reasoning task are predicted from responses on a recognition memory task for the same picture stimuli. Across several experimental manipulations, such as varying study time, presentation frequency, and the presence of stimuli from other categories, there was a high correlation between reasoning and memory responses (average r = .87), and these manipulations showed similar effects on the 2 tasks. The results point to common mechanisms underlying inductive reasoning and recognition memory abilities. A mathematical model, GEN-EX (generalization from examples), derived from exemplar models of categorization, is presented, which predicts both reasoning and memory responses from pairwise similarities among the stimuli, allowing for additional influences of subtyping and deterministic responding.

  13. Cosmological memory effect

    NASA Astrophysics Data System (ADS)

    Tolish, Alexander; Wald, Robert M.

    2016-08-01

    The "memory effect" is the permanent change in the relative separation of test particles resulting from the passage of gravitational radiation. We investigate the memory effect for a general, spatially flat Friedmann-Lemaître-Robertson-Walker (FLRW) cosmology by considering the radiation associated with emission events involving particle-like sources. We find that if the resulting perturbation is decomposed into scalar, vector, and tensor parts, only the tensor part contributes to memory. Furthermore, the tensor contribution to memory depends only on the cosmological scale factor at the source and observation events, not on the detailed expansion history of the universe. In particular, for sources at the same luminosity distance, the memory effect in a spatially flat FLRW spacetime is enhanced over the Minkowski case by a factor of (1 +z ).

  14. Memory B cells.

    PubMed

    Kurosaki, Tomohiro; Kometani, Kohei; Ise, Wataru

    2015-03-01

    The immune system can remember a previously experienced pathogen and can evoke an enhanced response to reinfection that depends on memory lymphocyte populations. Recent advances in tracking antigen-experienced memory B cells have revealed the existence of distinct classes of cells that have considerable functional differences. Some of these differences seem to be determined by the stimulation history during memory cell formation. To induce rapid recall antibody responses, the contributions of other types of cells, such as memory T follicular helper cells, have also now begun to be appreciated. In this Review, we discuss these and other recent advances in our understanding of memory B cells, focusing on the underlying mechanisms that are required for rapid and effective recall antibody responses.

  15. Memory: Pandora's hippocampus?

    PubMed

    Gabrieli, John D E

    2004-01-01

    Greater knowledge of the human brain has enabled us to begin devising therapies to rescue or modify memory for the afflicted, such as Alzheimer's patients or post-traumatic stress disorder victims. This same knowledge could also allow us to alter how normal, healthy memory operates; we may become able to enhance memory and learning through biological intervention. But the brain consists of complex, interactive networks, and unintended consequences could easily occur. Moreover, memory is woven into our individuality. Altering our memory processes therefore risks altering us fundamentally. We may not be able to resist opening this neuroscientific Pandora's Box, John Gabrieli writes, but we must proceed with all the wisdom we can muster.

  16. Neuromodulation for restoring memory.

    PubMed

    Bick, Sarah K B; Eskandar, Emad N

    2016-05-01

    Disorders of learning and memory have a large social and economic impact in today's society. Unfortunately, existing medical treatments have shown limited clinical efficacy or potential for modification of the disease course. Deep brain stimulation is a successful treatment for movement disorders and has shown promise in a variety of other diseases including psychiatric disorders. The authors review the potential of neuromodulation for the treatment of disorders of learning and memory. They briefly discuss learning circuitry and its involvement in Alzheimer disease and traumatic brain injury. They then review the literature supporting various targets for neuromodulation to improve memory in animals and humans. Multiple targets including entorhinal cortex, fornix, nucleus basalis of Meynert, basal ganglia, and pedunculopontine nucleus have shown a promising potential for improving dysfunctional memory by mechanisms such as altering firing patterns in neuronal networks underlying memory and increasing synaptic plasticity and neurogenesis. Significant work remains to be done to translate these findings into durable clinical therapies.

  17. Innate Memory T cells

    PubMed Central

    Jameson, Stephen C.; Lee, You Jeong; Hogquist, Kristin A.

    2015-01-01

    Memory T cells are usually considered to be a feature of a successful immune response against a foreign antigen, and such cells can mediate potent immunity. However, in mice, alternative pathways have been described, through which naïve T cells can acquire the characteristics and functions of memory T cells without encountering specific foreign antigen or the typical signals required for conventional T cell differentiation. Such cells reflect a response to the internal rather the external environment, and hence such cells are called innate memory T cells. In this review, we describe how innate memory subsets were identified, the signals that induce their generation and their functional properties and potential role in the normal immune response. The existence of innate memory T cells in mice raises questions about whether parallel populations exist in humans, and we discuss the evidence for such populations during human T cell development and differentiation. PMID:25727290

  18. Gravitational memory, BMS supertranslations and soft theorems

    NASA Astrophysics Data System (ADS)

    Strominger, Andrew; Zhiboedov, Alexander

    2016-01-01

    The transit of a gravitating radiation pulse past arrays of detectors stationed near future null infinity in the vacuum is considered. It is shown that the relative positions and clock times of the detectors before and after the radiation transit differ by a BMS supertranslation. An explicit expression for the supertranslation in terms of moments of the radiation energy flux is given. The relative spatial displacement found for a pair of nearby detectors reproduces the well-known and potentially measurable gravitational memory effect. The displacement memory formula is shown to be equivalent to Weinberg's formula for soft graviton production.

  19. Molecular implementation of molecular shift register memories

    NASA Technical Reports Server (NTRS)

    Beratan, David N. (Inventor); Onuchic, Jose N. (Inventor)

    1991-01-01

    An electronic shift register memory (20) at the molecular level is described. The memory elements are based on a chain of electron transfer molecules (22) and the information is shifted by photoinduced (26) electron transfer reactions. Thus, multi-step sequences of charge transfer reactions are used to move charge with high efficiency down a molecular chain. The device integrates compositions of the invention onto a VLSI substrate (36), providing an example of a molecular electronic device which may be fabricated. Three energy level schemes, molecular implementation of these schemes, optical excitation strategies, charge amplification strategies, and error correction strategies are described.

  20. Aging Memories: Differential Decay of Episodic Memory Components

    ERIC Educational Resources Information Center

    Talamini, Lucia M.; Gorree, Eva

    2012-01-01

    Some memories about events can persist for decades, even a lifetime. However, recent memories incorporate rich sensory information, including knowledge on the spatial and temporal ordering of event features, while old memories typically lack this "filmic" quality. We suggest that this apparent change in the nature of memories may reflect a…

  1. Single-Item Memory, Associative Memory, and the Human Hippocampus

    ERIC Educational Resources Information Center

    Squire, Larry R.; Gold, Jeffrey J.; Hopkins, Ramona O.

    2006-01-01

    We tested recognition memory for items and associations in memory-impaired patients with bilateral lesions thought to be limited to the hippocampal region. In Experiment 1 (Combined memory test), participants studied words and then took a memory test in which studied words, new words, studied word pairs, and recombined word pairs were presented in…

  2. Aging Memories: Differential Decay of Episodic Memory Components

    ERIC Educational Resources Information Center

    Talamini, Lucia M.; Gorree, Eva

    2012-01-01

    Some memories about events can persist for decades, even a lifetime. However, recent memories incorporate rich sensory information, including knowledge on the spatial and temporal ordering of event features, while old memories typically lack this "filmic" quality. We suggest that this apparent change in the nature of memories may reflect a…

  3. Single-Item Memory, Associative Memory, and the Human Hippocampus

    ERIC Educational Resources Information Center

    Squire, Larry R.; Gold, Jeffrey J.; Hopkins, Ramona O.

    2006-01-01

    We tested recognition memory for items and associations in memory-impaired patients with bilateral lesions thought to be limited to the hippocampal region. In Experiment 1 (Combined memory test), participants studied words and then took a memory test in which studied words, new words, studied word pairs, and recombined word pairs were presented in…

  4. Memory, language, and ageing.

    PubMed Central

    Burke, D M; Mackay, D G

    1997-01-01

    This overview provides both theoretical and empirical reasons for emphasizing practice and familiar skills as a practical strategy for enhancing cognitive functioning in old age. Our review of empirical research on age-related changes in memory and language reveals a consistent pattern of spared and impaired abilities in normal old age. Relatively preserved in old age is memory performance involving highly practised skills and familiar information, including factual, semantic and autobiographical information. Relatively impaired in old age is memory performance that requires the formation of new connections, for example, recall of recent autobiographical experiences, new facts or the source of newly acquired facts. This pattern of impaired new learning versus preserved old learning cuts across distinctions between semantic memory, episodic memory, explicit memory and perhaps also implicit memory. However, familiar verbal information is not completely preserved when accessed on the output side rather than the input side: aspects of language production, namely word finding and spelling, exhibit significant age-related declines. This emerging pattern of preserved and impaired abilities presents a fundamental challenge for theories of cognitive ageing, which must explain why some aspects of language and memory are more vulnerable to the effects of ageing than others. Information-universal theories, involving mechanisms such as general slowing that are independent of the type or structure of the information being processed, require additional mechanisms to account for this pattern of cognitive aging. Information-specific theories, where the type or structure of the postulated memory units can influence the effects of cognitive ageing, are able to account for this emerging pattern, but in some cases require further development to account for comprehensive cognitive changes such as general slowing. PMID:9460069

  5. Sleep and memory.

    PubMed

    Roth, T; Roehrs, T; Zwyghuizen-Doorenbos, A; Stepanski, E; Wittig, R

    1988-01-01

    Generally sleep is considered a time of amnesia. It is not uncommon for an individual to experience 8 h of sleep and have no memory for events during that time. Similarly, a substantial proportion of the population has no memory for dreams that occurred during the night, despite the fact that the literature on awakening during rapid eye movement (REM) sleep clearly shows that individuals normally have four to six "dream experiences" a night. Research on this issue seems to indicate that the lack of memory cannot be explained by the organisms' inability to perceive stimuli. The data indicate that although perceptual thresholds are elevated, organisms can clearly perceive stimuli, and, in fact, can discriminate between them during sleep. The amnesia also cannot be explained by a defect in long-term memory, as studies have indicated that stimuli put into the memory during wakefulness are more efficiently retrieved after a sleep period than after a comparable period of wakefulness. The most likely explanation for the amnestic property of sleep seems to be the inability of organisms to transfer information from short-term memory to long-term memory during sleep. There are several sources of evidence to support this hypothesis. First, the probability of remembering a stimulus given during wakefulness is related to the proximity of sleep onset to the stimulus. Generally, information put into the system within 5 min of sleep onset is lost from memory. Secondly, disorders of excessive daytime somnolence which cause individuals to have frequent microsleeps are often associated with complains of memory problems.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Purely antiferromagnetic magnetoelectric random access memory.

    PubMed

    Kosub, Tobias; Kopte, Martin; Hühne, Ruben; Appel, Patrick; Shields, Brendan; Maletinsky, Patrick; Hübner, René; Liedke, Maciej Oskar; Fassbender, Jürgen; Schmidt, Oliver G; Makarov, Denys

    2017-01-03

    Magnetic random access memory schemes employing magnetoelectric coupling to write binary information promise outstanding energy efficiency. We propose and demonstrate a purely antiferromagnetic magnetoelectric random access memory (AF-MERAM) that offers a remarkable 50-fold reduction of the writing threshold compared with ferromagnet-based counterparts, is robust against magnetic disturbances and exhibits no ferromagnetic hysteresis losses. Using the magnetoelectric antiferromagnet Cr2O3, we demonstrate reliable isothermal switching via gate voltage pulses and all-electric readout at room temperature. As no ferromagnetic component is present in the system, the writing magnetic field does not need to be pulsed for readout, allowing permanent magnets to be used. Based on our prototypes, we construct a comprehensive model of the magnetoelectric selection mechanisms in thin films of magnetoelectric antiferromagnets, revealing misfit induced ferrimagnetism as an important factor. Beyond memory applications, the AF-MERAM concept introduces a general all-electric interface for antiferromagnets and should find wide applicability in antiferromagnetic spintronics.

  7. Purely antiferromagnetic magnetoelectric random access memory

    NASA Astrophysics Data System (ADS)

    Kosub, Tobias; Kopte, Martin; Hühne, Ruben; Appel, Patrick; Shields, Brendan; Maletinsky, Patrick; Hübner, René; Liedke, Maciej Oskar; Fassbender, Jürgen; Schmidt, Oliver G.; Makarov, Denys

    2017-01-01

    Magnetic random access memory schemes employing magnetoelectric coupling to write binary information promise outstanding energy efficiency. We propose and demonstrate a purely antiferromagnetic magnetoelectric random access memory (AF-MERAM) that offers a remarkable 50-fold reduction of the writing threshold compared with ferromagnet-based counterparts, is robust against magnetic disturbances and exhibits no ferromagnetic hysteresis losses. Using the magnetoelectric antiferromagnet Cr2O3, we demonstrate reliable isothermal switching via gate voltage pulses and all-electric readout at room temperature. As no ferromagnetic component is present in the system, the writing magnetic field does not need to be pulsed for readout, allowing permanent magnets to be used. Based on our prototypes, we construct a comprehensive model of the magnetoelectric selection mechanisms in thin films of magnetoelectric antiferromagnets, revealing misfit induced ferrimagnetism as an important factor. Beyond memory applications, the AF-MERAM concept introduces a general all-electric interface for antiferromagnets and should find wide applicability in antiferromagnetic spintronics.

  8. Tunable and Memory Metamaterials

    DTIC Science & Technology

    2015-12-02

    AFRL-AFOSR-VA-TR-2015-0402 TUNABLE AND MEMORY METAMATERIALS Dimitri Basov UNIVERSITY OF CALIFORNIA SAN DIEGO Final Report 12/02/2015 DISTRIBUTION A...DATES COVERED (From - To) 15-08-2010 to 14-08-2015 4. TITLE AND SUBTITLE TUNABLE AND MEMORY METAMATERIALS 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550...the area of the metamaterial. 15. SUBJECT TERMS MEMORY , MATAMATERIALS 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES

  9. Plated wire memory subsystem

    NASA Technical Reports Server (NTRS)

    Carpenter, K. H.

    1974-01-01

    The design, construction, and test history of a 4096 word by 18 bit random access NDRO Plated Wire Memory for use in conjunction with a spacecraft input/output and central processing unit is reported. A technical and functional description is given along with diagrams illustrating layout and systems operation. Test data is shown on the procedures and results of system level and memory stack testing, and hybrid circuit screening. A comparison of the most significant physical and performance characteristics of the memory unit versus the specified requirements is also included.

  10. Eliciting Sound Memories.

    PubMed

    Harris, Anna

    2015-11-01

    Sensory experiences are often considered triggers of memory, most famously a little French cake dipped in lime blossom tea. Sense memory can also be evoked in public history research through techniques of elicitation. In this article I reflect on different social science methods for eliciting sound memories such as the use of sonic prompts, emplaced interviewing, and sound walks. I include examples from my research on medical listening. The article considers the relevance of this work for the conduct of oral histories, arguing that such methods "break the frame," allowing room for collaborative research connections and insights into the otherwise unarticulatable.

  11. 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.

  12. Memory on the beach: an Australian memory (and hypnosis) laboratory.

    PubMed

    Barnier, Amanda J; Bryant, Richard A; Campbell, Leah; Cox, Rochelle; Harris, Celia; Hung, Lynette; Maccallum, Fiona; Sharman, Stefanie J

    2005-12-01

    The memory (and hypnosis) lab at the University of New South Wales investigates a broad range of memory topics. We try to find innovative methods from cognitive and clinical psychology to address theoretical and empirical questions about memory. We aso use hypnosis as one major methodological tool in our investigations of memory (as well as other cognitive processes). In this paper, we review the projects currently underway in our memory (and hypnosis) lab.

  13. Topological order and memory time in marginally-self-correcting quantum memory

    NASA Astrophysics Data System (ADS)

    Siva, Karthik; Yoshida, Beni

    2017-03-01

    We examine two proposals for marginally-self-correcting quantum memory: the cubic code by Haah and the welded code by Michnicki. In particular, we prove explicitly that they are absent of topological order above zero temperature, as their Gibbs ensembles can be prepared via a short-depth quantum circuit from classical ensembles. Our proof technique naturally gives rise to the notion of free energy associated with excitations. Further, we develop a framework for an ergodic decomposition of Davies generators in CSS codes which enables formal reduction to simpler classical memory problems. We then show that memory time in the welded code is doubly exponential in inverse temperature via the Peierls argument. These results introduce further connections between thermal topological order and self-correction from the viewpoint of free energy and quantum circuit depth.

  14. Memory Retrieval as Temporal Discrimination

    ERIC Educational Resources Information Center

    Brown, Gordon D. A.; Vousden, Janet I.; McCormack, Teresa

    2009-01-01

    Temporal distinctiveness models of memory retrieval claim that memories are organised partly in terms of their positions along a temporal dimension, and suggest that memory retrieval involves temporal discrimination. According to such models the retrievability of memories should be related to the discriminability of their temporal distances at the…

  15. Reduced False Memory after Sleep

    ERIC Educational Resources Information Center

    Fenn, Kimberly M.; Gallo, David A.; Margoliash, Daniel; Roediger, Henry L., III; Nusbaum, Howard C.

    2009-01-01

    Several studies have shown that sleep contributes to the successful maintenance of previously encoded information. This research has focused exclusively on memory for studied events, as opposed to false memories. Here we report three experiments showing that sleep reduces false memories in the Deese-Roediger-McDermott (DRM) memory illusion. False…

  16. Reduced False Memory after Sleep

    ERIC Educational Resources Information Center

    Fenn, Kimberly M.; Gallo, David A.; Margoliash, Daniel; Roediger, Henry L., III; Nusbaum, Howard C.

    2009-01-01

    Several studies have shown that sleep contributes to the successful maintenance of previously encoded information. This research has focused exclusively on memory for studied events, as opposed to false memories. Here we report three experiments showing that sleep reduces false memories in the Deese-Roediger-McDermott (DRM) memory illusion. False…

  17. Integrated photonics with programmable non-volatile memory

    NASA Astrophysics Data System (ADS)

    Song, Jun-Feng; Luo, Xian-Shu; Lim, Andy Eu-Jin; Li, Chao; Fang, Qing; Liow, Tsung-Yang; Jia, Lian-Xi; Tu, Xiao-Guang; Huang, Ying; Zhou, Hai-Feng; Lo, Guo-Qiang

    2016-03-01

    Silicon photonics integrated circuits (Si-PIC) with well-established active and passive building elements are progressing towards large-scale commercialization in optical communications and high speed optical interconnects applications. However, current Si-PICs do not have memory capabilities, in particular, the non-volatile memory functionality for energy efficient data storage. Here, we propose an electrically programmable, multi-level non-volatile photonics memory cell (PMC) fabricated by standard complementary-metal-oxide-semiconductor (CMOS) compatible processes. A micro-ring resonator (MRR) was built using the PMC to optically read the memory states. Switching energy smaller than 20 pJ was achieved. Additionally, a MRR memory array was employed to demonstrate a four-bit memory read capacity. Theoretically, this can be increased up to ~400 times using a 100 nm free spectral range broadband light source. The fundamental concept of this design provides a route to eliminate the von Neumann bottleneck. The energy-efficient optical storage can complement on-chip optical interconnects for neutral networking, memory input/output interfaces and other computational intensive applications.

  18. Integrated photonics with programmable non-volatile memory.

    PubMed

    Song, Jun-Feng; Luo, Xian-Shu; Lim, Andy Eu-Jin; Li, Chao; Fang, Qing; Liow, Tsung-Yang; Jia, Lian-Xi; Tu, Xiao-Guang; Huang, Ying; Zhou, Hai-Feng; Lo, Guo-Qiang

    2016-03-04

    Silicon photonics integrated circuits (Si-PIC) with well-established active and passive building elements are progressing towards large-scale commercialization in optical communications and high speed optical interconnects applications. However, current Si-PICs do not have memory capabilities, in particular, the non-volatile memory functionality for energy efficient data storage. Here, we propose an electrically programmable, multi-level non-volatile photonics memory cell (PMC) fabricated by standard complementary-metal-oxide-semiconductor (CMOS) compatible processes. A micro-ring resonator (MRR) was built using the PMC to optically read the memory states. Switching energy smaller than 20 pJ was achieved. Additionally, a MRR memory array was employed to demonstrate a four-bit memory read capacity. Theoretically, this can be increased up to ~400 times using a 100 nm free spectral range broadband light source. The fundamental concept of this design provides a route to eliminate the von Neumann bottleneck. The energy-efficient optical storage can complement on-chip optical interconnects for neutral networking, memory input/output interfaces and other computational intensive applications.

  19. Integrated photonics with programmable non-volatile memory

    PubMed Central

    Song, Jun-Feng; Luo, Xian-Shu; Lim, Andy Eu-Jin; Li, Chao; Fang, Qing; Liow, Tsung-Yang; Jia, Lian-Xi; Tu, Xiao-Guang; Huang, Ying; Zhou, Hai-Feng; Lo, Guo-Qiang

    2016-01-01

    Silicon photonics integrated circuits (Si-PIC) with well-established active and passive building elements are progressing towards large-scale commercialization in optical communications and high speed optical interconnects applications. However, current Si-PICs do not have memory capabilities, in particular, the non-volatile memory functionality for energy efficient data storage. Here, we propose an electrically programmable, multi-level non-volatile photonics memory cell (PMC) fabricated by standard complementary-metal-oxide-semiconductor (CMOS) compatible processes. A micro-ring resonator (MRR) was built using the PMC to optically read the memory states. Switching energy smaller than 20 pJ was achieved. Additionally, a MRR memory array was employed to demonstrate a four-bit memory read capacity. Theoretically, this can be increased up to ~400 times using a 100 nm free spectral range broadband light source. The fundamental concept of this design provides a route to eliminate the von Neumann bottleneck. The energy-efficient optical storage can complement on-chip optical interconnects for neutral networking, memory input/output interfaces and other computational intensive applications. PMID:26941113

  20. TOPICAL REVIEW Nanoscale memory devices

    NASA Astrophysics Data System (ADS)

    Chung, Andy; Deen, Jamal; Lee, Jeong-Soo; Meyyappan, M.

    2010-10-01

    This article reviews the current status and future prospects for the use of nanomaterials and devices in memory technology. First, the status and continuing scaling trends of the flash memory are discussed. Then, a detailed discussion on technologies trying to replace flash in the near-term is provided. This includes phase change random access memory, Fe random access memory and magnetic random access memory. The long-term nanotechnology prospects for memory devices include carbon-nanotube-based memory, molecular electronics and memristors based on resistive materials such as TiO2.

  1. Prospective memory: A comparative perspective

    PubMed Central

    Crystal, Jonathon D.; Wilson, A. George

    2014-01-01

    Prospective memory consists of forming a representation of a future action, temporarily storing that representation in memory, and retrieving it at a future time point. Here we review the recent development of animal models of prospective memory. We review experiments using rats that focus on the development of time-based and event-based prospective memory. Next, we review a number of prospective-memory approaches that have been used with a variety of non-human primates. Finally, we review selected approaches from the human literature on prospective memory to identify targets for development of animal models of prospective memory. PMID:25101562

  2. Positive consequences of false memories.

    PubMed

    Howe, Mark L; Garner, Sarah R; Patel, Megan

    2013-01-01

    Previous research is replete with examples of the negative consequences of false memories. In the current research, we provide a different perspective on false memories and their development and demonstrate that false memories can have positive consequences. Specifically, we examined the role false memories play in subsequent problem-solving tasks. Children and adults studied and recalled neutral or survival-relevant lists of associated words. They then solved age-normed compound remote associates, some of whose solutions had been primed by false memories created when studying the previous lists. The results showed that regardless of age: (a) survival-related words were not only better recollected but were also more susceptible than neutral words to false memory illusions; and (b) survival-related false memories were better than neutral false memories as primes for problem-solving. These findings are discussed in the context of recent speculation concerning the positive consequences of false memories, and the adaptive nature of reconstructive memory.

  3. Memory Circuit Fault Simulator

    NASA Technical Reports Server (NTRS)

    Sheldon, Douglas J.; McClure, Tucker

    2013-01-01

    Spacecraft are known to experience significant memory part-related failures and problems, both pre- and postlaunch. These memory parts include both static and dynamic memories (SRAM and DRAM). These failures manifest themselves in a variety of ways, such as pattern-sensitive failures, timingsensitive failures, etc. Because of the mission critical nature memory devices play in spacecraft architecture and operation, understanding their failure modes is vital to successful mission operation. To support this need, a generic simulation tool that can model different data patterns in conjunction with variable write and read conditions was developed. This tool is a mathematical and graphical way to embed pattern, electrical, and physical information to perform what-if analysis as part of a root cause failure analysis effort.

  4. Medications for Memory Loss

    MedlinePlus

    ... memory loss, confusion, and problems with thinking and reasoning) of Alzheimer's disease. There is also a medication ... the latest Alzheimer's medications available today, and the clinical trials that may bring us closer to new ...

  5. Coping with Memory Loss

    MedlinePlus

    ... either using computerized axial tomography (CAT) scans or magnetic resonance imaging (MRI) – can help to identify strokes and tumors, which can sometimes cause memory loss. “The goal is to rule out factors ...

  6. Memory on time

    PubMed Central

    Eichenbaum, Howard

    2013-01-01

    Considerable recent work has shown that the hippocampus is critical for remembering the order of events in distinct experiences, a defining feature of episodic memory. Correspondingly, hippocampal neuronal activity can ‘replay’ sequential events in memories and hippocampal neuronal ensembles represent a gradually changing temporal context signal. Most strikingly, single hippocampal neurons – called time cells – encode moments in temporally structured experiences much as the well-known place cells encode locations in spatially structured experiences. These observations bridge largely disconnected literatures on the role of the hippocampus in episodic memory and spatial mapping, and suggest that the fundamental function of the hippocampus is to establish spatio-temporal frameworks for organizing memories. PMID:23318095

  7. Memory, Memoir, Story.

    ERIC Educational Resources Information Center

    Johnson, Nancy J.; Giorgis, Cyndi

    2000-01-01

    Offers brief descriptions of 41 good books for children offering a treasury of memory, memoir, and stories. Presents books in the following categories: storytellers, folktales, voices, family, artifacts, and preservation. (SR)

  8. Serriform Strip Crosstie Memory.

    DTIC Science & Technology

    edge effect of the margin serrations upon magnetization, a form of shape anisotropy, inherently defines memory cell boundaries in the domain walls, thereby giving the crossties and Bloch lines preferred locations and allowing the use of a simplified propagation

  9. Magnetic vortex racetrack memory

    NASA Astrophysics Data System (ADS)

    Geng, Liwei D.; Jin, Yongmei M.

    2017-02-01

    We report a new type of racetrack memory based on current-controlled movement of magnetic vortices in magnetic nanowires with rectangular cross-section and weak perpendicular anisotropy. Data are stored through the core polarity of vortices and each vortex carries a data bit. Besides high density, non-volatility, fast data access, and low power as offered by domain wall racetrack memory, magnetic vortex racetrack memory has additional advantages of no need for constrictions to define data bits, changeable information density, adjustable current magnitude for data propagation, and versatile means of ultrafast vortex core switching. By using micromagnetic simulations, current-controlled motion of magnetic vortices in cobalt nanowire is demonstrated for racetrack memory applications.

  10. Multiresonator quantum memory

    NASA Astrophysics Data System (ADS)

    Moiseev, S. A.; Gubaidullin, F. F.; Kirillov, R. S.; Latypov, R. R.; Perminov, N. S.; Petrovnin, K. V.; Sherstyukov, O. N.

    2017-01-01

    In this paper we present universal broadband multiresonator quantum memory based on the spatial-frequency combs of the microresonators coupled with a common waveguide. We find a Bragg-type impedance matching condition for the coupling of the microresonators with a waveguide field that provides an efficient broadband quantum storage. The analytical solution obtained for the microresonator fields enables sustainable parametric control of all the memory characteristics. We also construct an experimental prototype of the studied quantum memory in the microwave spectral range that demonstrates basic properties of the microwave microresonators, their coupling with a common waveguide, and independent control of the microresonator frequencies. Experimentally observed narrow lines of the microresonators confirm the possibility of multiresonator quantum memory implementation.

  11. Ontogeny of Memory

    ERIC Educational Resources Information Center

    Campbell, Byron; Spear, Norman E.

    1972-01-01

    Authors call for renewed research into phenomenon of infantile amnesia"--the inability of human beings to retain memories from infancy. Included are summaries of neurological, psychological and physiological studies and theories to date. (PD)

  12. Working Memory and Neurofeedback.

    PubMed

    YuLeung To, Eric; Abbott, Kathy; Foster, Dale S; Helmer, D'Arcy

    2016-01-01

    Impairments in working memory are typically associated with impairments in other cognitive faculties such as attentional processes and short-term memory. This paper briefly introduces neurofeedback as a treatment modality in general, and, more specifically, we review several of the current modalities successfully used in neurofeedback (NF) for the treatment of working memory deficits. Two case studies are presented to illustrate how neurofeedback is applied in treatment. The development of Low Resolution Electromagnetic Tomography (LORETA) and its application in neurofeedback now makes it possible to specifically target deep cortical/subcortical brain structures. Developments in neuroscience concerning neural networks, combined with highly specific yet practical NF technologies, makes neurofeedback of particular interest to neuropsychological practice, including the emergence of specific methodologies for treating very difficult working memory (WM) problems.

  13. 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.

  14. Perception and Memory of Pictures

    DTIC Science & Technology

    1991-08-20

    altogether. His explanation for the efftct is similar to that proposed by Raijmakers and Shiffrin (1981) in the SAM model of memory : Items from...implicit memory , explicit memory , recognition memory , perce ’ptual fluency, priming, RSVP, fragmented pictures, connectionist models , PDP models 19...of implicit and explicit memory . A connectionist model of picture recognition which was developed and tested in collaboration with Elliot Hirshman

  15. Epigenetic memory in plants.

    PubMed

    Iwasaki, Mayumi; Paszkowski, Jerzy

    2014-09-17

    Epigenetics refers to heritable changes in patterns of gene expression that occur without alterations in DNA sequence. The epigenetic mechanisms involve covalent modifications of DNA and histones, which affect transcriptional activity of chromatin. Since chromatin states can be propagated through mitotic and meiotic divisions, epigenetic mechanisms are thought to provide heritable 'cellular memory'. Here, we review selected examples of epigenetic memory in plants and briefly discuss underlying mechanisms.

  16. Plated wire memory subsystem

    NASA Technical Reports Server (NTRS)

    Reynolds, L.; Tweed, H.

    1972-01-01

    The work performed entailed the design, development, construction and testing of a 4000 word by 18 bit random access, NDRO plated wire memory for use in conjunction with a spacecraft imput/output unit and central processing unit. The primary design parameters, in order of importance, were high reliability, low power, volume and weight. A single memory unit, referred to as a qualification model, was delivered.

  17. Effects of daytime food intake on memory consolidation during sleep or sleep deprivation.

    PubMed

    Herzog, Nina; Friedrich, Alexia; Fujita, Naoko; Gais, Steffen; Jauch-Chara, Kamila; Oltmanns, Kerstin M; Benedict, Christian

    2012-01-01

    Sleep enhances memory consolidation. Bearing in mind that food intake produces many metabolic signals that can influence memory processing in humans (e.g., insulin), the present study addressed the question as to whether the enhancing effect of sleep on memory consolidation is affected by the amount of energy consumed during the preceding daytime. Compared to sleep, nocturnal wakefulness has been shown to impair memory consolidation in humans. Thus, a second question was to examine whether the impaired memory consolidation associated with sleep deprivation (SD) could be compensated by increased daytime energy consumption. To these aims, 14 healthy normal-weight men learned a finger tapping sequence (procedural memory) and a list of semantically associated word pairs (declarative memory). After the learning period, standardized meals were administered, equaling either ∼50% or ∼150% of the estimated daily energy expenditure. In the morning, after sleep or wakefulness, memory consolidation was tested. Plasma glucose was measured both before learning and retrieval. Polysomnographic sleep recordings were performed by electroencephalography (EEG). Independent of energy intake, subjects recalled significantly more word pairs after sleep than they did after SD. When subjects stayed awake and received an energy oversupply, the number of correctly recalled finger sequences was equal to those seen after sleep. Plasma glucose did not differ among conditions, and sleep time in the sleep conditions was not influenced by the energy intake interventions. These data indicate that the daytime energy intake level affects neither sleep's capacity to boost the consolidation of declarative and procedural memories, nor sleep's quality. However, high energy intake was followed by an improved procedural but not declarative memory consolidation under conditions of SD. This suggests that the formation of procedural memory is not only triggered by sleep but is also sensitive to the

  18. Effects of Daytime Food Intake on Memory Consolidation during Sleep or Sleep Deprivation

    PubMed Central

    Herzog, Nina; Friedrich, Alexia; Fujita, Naoko; Gais, Steffen; Jauch-Chara, Kamila; Oltmanns, Kerstin M.; Benedict, Christian

    2012-01-01

    Sleep enhances memory consolidation. Bearing in mind that food intake produces many metabolic signals that can influence memory processing in humans (e.g., insulin), the present study addressed the question as to whether the enhancing effect of sleep on memory consolidation is affected by the amount of energy consumed during the preceding daytime. Compared to sleep, nocturnal wakefulness has been shown to impair memory consolidation in humans. Thus, a second question was to examine whether the impaired memory consolidation associated with sleep deprivation (SD) could be compensated by increased daytime energy consumption. To these aims, 14 healthy normal-weight men learned a finger tapping sequence (procedural memory) and a list of semantically associated word pairs (declarative memory). After the learning period, standardized meals were administered, equaling either ∼50% or ∼150% of the estimated daily energy expenditure. In the morning, after sleep or wakefulness, memory consolidation was tested. Plasma glucose was measured both before learning and retrieval. Polysomnographic sleep recordings were performed by electroencephalography (EEG). Independent of energy intake, subjects recalled significantly more word pairs after sleep than they did after SD. When subjects stayed awake and received an energy oversupply, the number of correctly recalled finger sequences was equal to those seen after sleep. Plasma glucose did not differ among conditions, and sleep time in the sleep conditions was not influenced by the energy intake interventions. These data indicate that the daytime energy intake level affects neither sleep’s capacity to boost the consolidation of declarative and procedural memories, nor sleep’s quality. However, high energy intake was followed by an improved procedural but not declarative memory consolidation under conditions of SD. This suggests that the formation of procedural memory is not only triggered by sleep but is also sensitive to the

  19. Mechanisms of Memory Enhancement

    PubMed Central

    Stern, Sarah A.

    2012-01-01

    The ongoing quest for memory enhancement is one that grows necessary as the global population increasingly ages. The extraordinary progress that has been made in the past few decades elucidating the underlying mechanisms of how long-term memories are formed has provided insight into how memories might also be enhanced. Capitalizing on this knowledge, it has been postulated that targeting many of the same mechanisms, including CREB activation, AMPA/NMDA receptor trafficking, neuromodulation (e.g. via dopamine, adrenaline, cortisol or acetylcholine) and metabolic processes (e.g. via glucose and insulin) may all lead to the enhancement of memory. These and other mechanisms and/or approaches have been tested via genetic or pharmacological methods in animal models, and several have been investigated in humans as well. In addition, a number of behavioral methods, including exercise and reconsolidation, may also serve to strengthen and enhance memories. By capitalizing on this knowledge and continuing to investigate these promising avenues, memory enhancement may indeed be achieved in the future. PMID:23151999

  20. Immune memory in invertebrates.

    PubMed

    Milutinović, Barbara; Kurtz, Joachim

    2016-08-01

    Evidence for innate immune memory (or 'priming') in invertebrates has been accumulating over the last years. We here provide an in-depth review of the current state of evidence for immune memory in invertebrates, and in particular take a phylogenetic viewpoint. Invertebrates are a very heterogeneous group of animals and accordingly, evidence for the phenomenon of immune memory as well as the hypothesized molecular underpinnings differ largely for the diverse invertebrate taxa. The majority of research currently focuses on Arthropods, while evidence from many other groups of invertebrates is fragmentary or even lacking. We here concentrate on immune memory that is induced by pathogenic challenges, but also extent our view to a non-pathogenic context, i.e. allograft rejection, which can also show forms of memory and can inform us about general principles of specific self-nonself recognition. We discuss definitions of immune memory and a number of relevant aspects such as the type of antigens used, the route of exposure, and the kinetics of reactions following priming. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Emergence of Collective Memories

    PubMed Central

    Lee, Sungmin; Ramenzoni, Verónica C.; Holme, Petter

    2010-01-01

    Background We understand the dynamics of the world around us as by associating pairs of events, where one event has some influence on the other. These pairs of events can be aggregated into a web of memories representing our understanding of an episode of history. The events and the associations between them need not be directly experienced—they can also be acquired by communication. In this paper we take a network approach to study the dynamics of memories of history. Methodology/Principal Findings First we investigate the network structure of a data set consisting of reported events by several individuals and how associations connect them. We focus our measurement on degree distributions, degree correlations, cycles (which represent inconsistencies as they would break the time ordering) and community structure. We proceed to model effects of communication using an agent-based model. We investigate the conditions for the memory webs of different individuals to converge to collective memories, how groups where the individuals have similar memories (but different from other groups) can form. Conclusions/Significance Our work outlines how the cognitive representation of memories and social structure can co-evolve as a contagious process. We generate some testable hypotheses including that the number of groups is limited as a function of the total population size. PMID:20824141

  2. False memories and confabulation.

    PubMed

    Johnson, M K; Raye, C L

    1998-04-01

    Memory distortions range from the benign (thinking you mailed a check that you only thought about mailing), to the serious (confusing what you heard after a crime with what you actually saw), to the fantastic (claiming you piloted a spaceship). We review theoretical ideas and empirical evidence about the source monitoring processes underlying both true and false memories. Neuropsychological studies show that certain forms of brain damage (such as combined frontal and medial-temporal lesions) might result in profound source confusions, called confabulations. Neuroimaging techniques provide new evidence regarding more specific links between underlying brain mechanisms and the normal cognitive processes involved in evaluating memories. One hypothesis is that the right prefrontal cortex (PFC) subserves heuristic judgments based on easily assessed qualities (such as familiarity or perceptual detail) and the left PFC (or the right and left PFC together) subserves more systematic judgments requiring more careful analysis of memorial qualities or retrieval and evaluation of additional supporting or disconfirming information. Such heuristic and systematic processes can be disrupted not only by brain damage but also, for example, by hypnosis, social demands and motivational factors, suggesting caution in the methods used by `memory exploring' professions (therapists, police officers, lawyers, etc.) in order to avoid inducing false memories.

  3. [Memory and epilepsy].

    PubMed

    Dupont, Sophie

    2010-01-01

    Medial temporal lobe epilepsy is a chronic neurological disease that begins in the early age and that is associated with frequent and disturbing memory deficits. Repeated seizures will lead to the formation of an epileptogenic network that may interfere with physiological neuronal networks and thus with normal brain function: by direct activation or indirectly by deactivation during a seizure, see for example the dreamy state or the ''déja vécu'' phenomenon during temporal seizures; by ictal or post-ictal inhibition, see for example ictal or post-ictal amnesia; by a repetitive and chronic modulation leading to a reorganization of the physiological neuronal networks. The study of these interactions between epileptic and physiological neural networks must lead to better explore the patient's memory and predict memory worsening before temporal lobe surgery and to better understand the reorganization of memory networks in chronic epilepsy. The goal is double: (1) improve the prediction of post-operative memory worsening and guide rehabilitation in epileptic clinical practice; (2) improve the pathophysiological knowledge about memory processes. © Société de Biologie, 2010.

  4. Music evokes vivid autobiographical memories.

    PubMed

    Belfi, Amy M; Karlan, Brett; Tranel, Daniel

    2016-08-01

    Music is strongly intertwined with memories-for example, hearing a song from the past can transport you back in time, triggering the sights, sounds, and feelings of a specific event. This association between music and vivid autobiographical memory is intuitively apparent, but the idea that music is intimately tied with memories, seemingly more so than other potent memory cues (e.g., familiar faces), has not been empirically tested. Here, we compared memories evoked by music to those evoked by famous faces, predicting that music-evoked autobiographical memories (MEAMs) would be more vivid. Participants listened to 30 songs, viewed 30 faces, and reported on memories that were evoked. Memories were transcribed and coded for vividness as in Levine, B., Svoboda, E., Hay, J. F., Winocur, G., & Moscovitch, M. [2002. Aging and autobiographical memory: Dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677-689]. In support of our hypothesis, MEAMs were more vivid than autobiographical memories evoked by faces. MEAMs contained a greater proportion of internal details and a greater number of perceptual details, while face-evoked memories contained a greater number of external details. Additionally, we identified sex differences in memory vividness: for both stimulus categories, women retrieved more vivid memories than men. The results show that music not only effectively evokes autobiographical memories, but that these memories are more vivid than those evoked by famous faces.

  5. Effects of aging and working memory demands on prospective memory.

    PubMed

    West, Robert; Bowry, Ritvij

    2005-11-01

    The current study used event-related brain potentials (ERPs) to examine the effects of aging, increasing the working memory demands of the ongoing activity, and a prospective memory load on the neural correlates of prospective remembering and target recognition. The behavioral data revealed that the success of prospective memory was sensitive to working memory load in younger, but not older, adults and that a prospective memory load had a greater effect on the performance of older adults than that of younger adults. The ERP data revealed age-related differences in the neural correlates of the detection of prospective cues, post-retrieval processes that support prospective memory, and target recognition. Our results support the hypothesis that there are age-related differences in the ability to recruit preparatory attentional processes that underlie prospective memory, and demonstrate that younger and older adults may recruit somewhat different neural generators to support prospective memory and working memory.

  6. Essays in petroleum futures market, convenience yield, and long memory

    NASA Astrophysics Data System (ADS)

    Mazaheri, Ataollah

    This thesis is a collection of three essays which address some empirical applications of long memory processes with specific interest in financial economics of energy futures market. The first essay 'Evidence of Long Memory in the Petroleum Market' studies evidence of long memory in the energy market using daily and weekly futures data. This essay concentrates on the question of interdependence between crude oil futures and the corresponding products. The empirical results provide strong support for long memory in the energy futures market. The cointegrating relations between crude oil and heating oil futures as well as crude oil and unleaded gasoline futures exhibit long memory, whereas the individual series are unit-root. The second essay 'Convenience Yield, Mean Reversion and Long Memory in the Petroleum Market' analyzes convenience yields in the petroleum market. The focus of this essay is the behavior of the spot and futures prices over the long run. The implied convenience yield for petroleum and petroleum products is found to be driven by a nonstationary and mean reverting long memory process. The theoretical implication of this finding is established. It is discussed that this might be attributed to the fact that the market is expecting mean reversion in the spot prices. Furthermore, the volatility process and its relation with the mean process and the corresponding direction of causality have been studied in detail. The third essay 'Long Memory and Conditional Heteroskedasticity, A Monte Carlo Investigation', unlike the first two, looks at the econometrics of the estimators of the long memory process. It evaluates performance of three methods of estimating the parameter of fractionally integrated noise: the exact maximum likelihood estimator (MLE), the quasi maximum likelihood estimator (QMLE), and the GPH under different realizations for variance.

  7. Working memory and attentional bias on reinforcing efficacy of food.

    PubMed

    Carr, Katelyn A; Epstein, Leonard H

    2017-09-01

    Reinforcing efficacy of food, or the relationship between food prices and purchasing, is related to obesity status and energy intake in adults. Determining how to allocate resources for food is a decision making process influenced by executive functions. Attention to appetitive cues, as well as working memory capacity, or the ability to flexibly control attention while mentally retaining information, may be important executive functions involved in food purchasing decisions. In two studies, we examined how attention bias to food and working memory capacity are related to reinforcing efficacy of both high energy-dense and low energy-dense foods. The first study examined 48 women of varying body mass index (BMI) and found that the relationship between attentional processes and reinforcing efficacy was moderated by working memory capacity. Those who avoid food cues and had high working memory capacity had the lowest reinforcing efficacy, as compared to those with low working memory capacity. Study 2 systematically replicated the methods of study 1 with assessment of maintained attention in a sample of 48 overweight/obese adults. Results showed the relationship between maintained attention to food cues and reinforcing efficacy was moderated by working memory capacity. Those with a maintained attention to food and high working memory capacity had higher reinforcing efficacy than low working memory capacity individuals. These studies suggest working memory capacity moderated the relationship between different aspects of attention and food reinforcement. Understanding how decision making process are involved in reinforcing efficacy may help to identify future intervention targets. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. What people believe about memory.

    PubMed

    Magnussen, Svein; Andersson, Jan; Cornoldi, Cesare; De Beni, Rossana; Endestad, Tor; Goodman, Gail S; Helstrup, Tore; Koriat, Asher; Larsson, Maria; Melinder, Annika; Nilsson, Lars-Göran; Rönnberg, Jerker; Zimmer, Hubert

    2006-07-01

    Two representative samples of adult Norwegians (n=2000) were asked a set of general and specific questions regarding their beliefs and opinions about human memory. The results indicate that on many questions, such as time of the earliest memories, inhibiting effects of collaboration, and memory for dramatic versus ordinary events, the views of the general public concurred with current research findings, and people in general had realistic views about their own memory performance. On other questions, such as the reliability of olfactory as compared with visual and auditory memory, the memory of small children in comparison with that of adults, the likelihood of repression of adult traumatic memories, and on more general questions such as the possibility of training memory and the capacity limitations of long-term memory, a large proportion of the participants expressed views that are less supported by scientific evidence. Implications of these findings are briefly discussed.

  9. False memories for aggressive acts.

    PubMed

    Laney, Cara; Takarangi, Melanie K T

    2013-06-01

    Can people develop false memories for committing aggressive acts? How does this process compare to developing false memories for victimhood? In the current research we used a simple false feedback procedure to implant false memories for committing aggressive acts (causing a black eye or spreading malicious gossip) or for victimhood (receiving a black eye). We then compared these false memories to other subjects' true memories for equivalent events. False aggressive memories were all too easy to implant, particularly in the minds of individuals with a proclivity towards aggression. Once implanted, the false memories were indistinguishable from true memories for the same events, on several dimensions, including emotional content. Implications for aggression-related memory more generally as well as false confessions are discussed.

  10. Embodied memory: unconscious smiling modulates emotional evaluation of episodic memories

    PubMed Central

    Arminjon, Mathieu; Preissmann, Delphine; Chmetz, Florian; Duraku, Andrea; Ansermet, François; Magistretti, Pierre J.

    2015-01-01

    Since Damasio introduced the somatic markers hypothesis in Damasio (1994), it has spread through the psychological community, where it is now commonly acknowledged that somatic states are a factor in producing the qualitative dimension of our experiences. Present actions are emotionally guided by those somatic states that were previously activated in similar experiences. In this model, somatic markers serve as a kind of embodied memory. Here, we test whether the manipulation of somatic markers can modulate the emotional evaluation of negative memories. Because facial feedback has been shown to be a powerful means of modifying emotional judgements, we used it to manipulate somatic markers. Participants first read a sad story in order to induce a negative emotional memory and then were asked to rate their emotions and memory about the text. Twenty-four hours later, the same participants were asked to assume a predetermined facial feedback (smiling) while reactivating their memory of the sad story. The participants were once again asked to fill in emotional and memory questionnaires about the text. Our results showed that participants who had smiled during memory reactivation later rated the text less negatively than control participants. However, the contraction of the zygomaticus muscles during memory reactivation did not have any impact on episodic memory scores. This suggests that manipulating somatic states modified emotional memory without affecting episodic memory. Thus, modulating memories through bodily states might pave the way to studying memory as an embodied function and help shape new kinds of psychotherapeutic interventions. PMID:26074833

  11. A Hierarchical Statistic Methodology for Advanced Memory System Evaluation

    SciTech Connect

    Sun, X.-J.; He, D.; Cameron, K.W.; Luo, Y.

    1999-04-12

    Advances in technology have resulted in a widening of the gap between computing speed and memory access time. Data access time has become increasingly important for computer system design. Various hierarchical memory architectures have been developed. The performance of these advanced memory systems, however, varies with applications and problem sizes. How to reach an optimal cost/performance design eludes researchers still. In this study, the authors introduce an evaluation methodology for advanced memory systems. This methodology is based on statistical factorial analysis and performance scalability analysis. It is two fold: it first determines the impact of memory systems and application programs toward overall performance; it also identifies the bottleneck in a memory hierarchy and provides cost/performance comparisons via scalability analysis. Different memory systems can be compared in terms of mean performance or scalability over a range of codes and problem sizes. Experimental testing has been performed extensively on the Department of Energy's Accelerated Strategic Computing Initiative (ASCI) machines and benchmarks available at the Los Alamos National Laboratory to validate this newly proposed methodology. Experimental and analytical results show this methodology is simple and effective. It is a practical tool for memory system evaluation and design. Its extension to general architectural evaluation and parallel computer systems are possible and should be further explored.

  12. Static Memory Deduplication for Performance Optimization in Cloud Computing.

    PubMed

    Jia, Gangyong; Han, Guangjie; Wang, Hao; Yang, Xuan

    2017-04-27

    In a cloud computing environment, the number of virtual machines (VMs) on a single physical server and the number of applications running on each VM are continuously growing. This has led to an enormous increase in the demand of memory capacity and subsequent increase in the energy consumption in the cloud. Lack of enough memory has become a major bottleneck for scalability and performance of virtualization interfaces in cloud computing. To address this problem, memory deduplication techniques which reduce memory demand through page sharing are being adopted. However, such techniques suffer from overheads in terms of number of online comparisons required for the memory deduplication. In this paper, we propose a static memory deduplication (SMD) technique which can reduce memory capacity requirement and provide performance optimization in cloud computing. The main innovation of SMD is that the process of page detection is performed offline, thus potentially reducing the performance cost, especially in terms of response time. In SMD, page comparisons are restricted to the code segment, which has the highest shared content. Our experimental results show that SMD efficiently reduces memory capacity requirement and improves performance. We demonstrate that, compared to other approaches, the cost in terms of the response time is negligible.

  13. Memory function and supportive technology

    PubMed Central

    Charness, Neil; Best, Ryan; Souders, Dustin

    2013-01-01

    Episodic and working memory processes show pronounced age-related decline, with other memory processes such as semantic, procedural, and metamemory less affected. Older adults tend to complain the most about prospective and retrospective memory failures. We introduce a framework for deciding how to mitigate memory decline using augmentation and substitution and discuss techniques that change the user, through mnemonics training, and change the tool or environment, by providing environmental support. We provide examples of low-tech and high-tech memory supports and discuss constraints on the utility of high-tech systems including effectiveness of devices, attitudes toward memory aids, and reliability of systems. PMID:24379752

  14. Neurocognitive architecture of working memory

    PubMed Central

    Eriksson, Johan; Vogel, Edward K.; Lansner, Anders; Bergström, Fredrik; Nyberg, Lars

    2015-01-01

    The crucial role of working memory for temporary information processing and guidance of complex behavior has been recognized for many decades. There is emerging consensus that working memory maintenance results from the interactions among long-term memory representations and basic processes, including attention, that are instantiated as reentrant loops between frontal and posterior cortical areas, as well as subcortical structures. The nature of such interactions can account for capacity limitations, lifespan changes, and restricted transfer after working-memory training. Recent data and models indicate that working memory may also be based on synaptic plasticity, and that working memory can operate on non-consciously perceived information. PMID:26447571

  15. Perturbative and gauge invariant treatment of gravitational wave memory

    NASA Astrophysics Data System (ADS)

    Bieri, Lydia; Garfinkle, David

    2014-04-01

    We present a perturbative treatment of gravitational wave memory. The coordinate invariance of Einstein's equations leads to a type of gauge invariance in perturbation theory. As with any gauge invariant theory, results are more clear when expressed in terms of manifestly gauge invariant quantities. Therefore we derive all our results from the perturbed Weyl tensor rather than the perturbed metric. We derive gravitational wave memory for the Einstein equations coupled to a general energy-momentum tensor that reaches null infinity.

  16. Nanoporous silicon oxide memory.

    PubMed

    Wang, Gunuk; Yang, Yang; Lee, Jae-Hwang; Abramova, Vera; Fei, Huilong; Ruan, Gedeng; Thomas, Edwin L; Tour, James M

    2014-08-13

    Oxide-based two-terminal resistive random access memory (RRAM) is considered one of the most promising candidates for next-generation nonvolatile memory. We introduce here a new RRAM memory structure employing a nanoporous (NP) silicon oxide (SiOx) material which enables unipolar switching through its internal vertical nanogap. Through the control of the stochastic filament formation at low voltage, the NP SiOx memory exhibited an extremely low electroforming voltage (∼ 1.6 V) and outstanding performance metrics. These include multibit storage ability (up to 9-bits), a high ON-OFF ratio (up to 10(7) A), a long high-temperature lifetime (≥ 10(4) s at 100 °C), excellent cycling endurance (≥ 10(5)), sub-50 ns switching speeds, and low power consumption (∼ 6 × 10(-5) W/bit). Also provided is the room temperature processability for versatile fabrication without any compliance current being needed during electroforming or switching operations. Taken together, these metrics in NP SiOx RRAM provide a route toward easily accessed nonvolatile memory applications.

  17. Vertical bloch line memory

    NASA Technical Reports Server (NTRS)

    Katti, Romney R. (Inventor); Stadler, Henry L. (Inventor); Wu, Jiin-chuan (Inventor)

    1995-01-01

    A new read gate design for the vertical Bloch line (VBL) memory is disclosed which offers larger operating margin than the existing read gate designs. In the existing read gate designs, a current is applied to all the stripes. The stripes that contain a VBL pair are chopped, while the stripes that do not contain a VBL pair are not chopped. The information is then detected by inspecting the presence or absence of the bubble. The margin of the chopping current amplitude is very small, and sometimes non-existent. A new method of reading Vertical Bloch Line memory is also disclosed. Instead of using the wall chirality to separate the two binary states, the spatial deflection of the stripe head is used. Also disclosed herein is a compact memory which uses vertical Bloch line (VBL) memory technology for providing data storage. A three-dimensional arrangement in the form of stacks of VBL memory layers is used to achieve high volumetric storage density. High data transfer rate is achieved by operating all the layers in parallel. Using Hall effect sensing, and optical sensing via the Faraday effect to access the data from within the three-dimensional packages, an even higher data transfer rate can be achieved due to parallel operation within each layer.

  18. A balanced memory network.

    PubMed

    Roudi, Yasser; Latham, Peter E

    2007-09-01

    A fundamental problem in neuroscience is understanding how working memory--the ability to store information at intermediate timescales, like tens of seconds--is implemented in realistic neuronal networks. The most likely candidate mechanism is the attractor network, and a great deal of effort has gone toward investigating it theoretically. Yet, despite almost a quarter century of intense work, attractor networks are not fully understood. In particular, there are still two unanswered questions. First, how is it that attractor networks exhibit irregular firing, as is observed experimentally during working memory tasks? And second, how many memories can be stored under biologically realistic conditions? Here we answer both questions by studying an attractor neural network in which inhibition and excitation balance each other. Using mean-field analysis, we derive a three-variable description of attractor networks. From this description it follows that irregular firing can exist only if the number of neurons involved in a memory is large. The same mean-field analysis also shows that the number of memories that can be stored in a network scales with the number of excitatory connections, a result that has been suggested for simple models but never shown for realistic ones. Both of these predictions are verified using simulations with large networks of spiking neurons.

  19. MEMORIAL WALK WITH MEMORIALS, TOWARD ENTRANCE GATE. VIEW TO WEST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    MEMORIAL WALK WITH MEMORIALS, TOWARD ENTRANCE GATE. VIEW TO WEST. - Rock Island National Cemetery, Rock Island Arsenal, 0.25 mile north of southern tip of Rock Island, Rock Island, Rock Island County, IL

  20. Memory Loss: 7 Tips to Improve Your Memory

    MedlinePlus

    ... re not alone. Everyone forgets things occasionally. Still, memory loss is nothing to take lightly. Although there are no guarantees when it comes to preventing memory loss or dementia, certain activities might help. Consider ...

  1. Bergson's "Matter and Memory" and modern selectionist theories of memory.

    PubMed

    McNamara, P

    1996-03-01

    Bergson's reflections (in Matter and Memory, 1896) on memory anticipated development of modern selectionist theories of memory. Selectionist models offer new and potentially useful approaches to a theory of remembering. On the model of natural selection, these selectionist theories require at least two processing components: a device which generates a range of memory representations and a selection process which preserves a subset of those representations. Bergson shows how the subjective experience of remembering might be understood within a selectionist framework.

  2. Complementary resistive switches for passive nanocrossbar memories.

    PubMed

    Linn, Eike; Rosezin, Roland; Kügeler, Carsten; Waser, Rainer

    2010-05-01

    On the road towards higher memory density and computer performance, a significant improvement in energy efficiency constitutes the dominant goal in future information technology. Passive crossbar arrays of memristive elements were suggested a decade ago as non-volatile random access memories (RAM) and can also be used for reconfigurable logic circuits. As such they represent an interesting alternative to the conventional von Neumann based computer chip architectures. Crossbar architectures hold the promise of a significant reduction in energy consumption because of their ultimate scaling potential and because they allow for a local fusion of logic and memory, thus avoiding energy consumption by data transfer on the chip. However, the expected paradigm change has not yet taken place because the general problem of selecting a designated cell within a passive crossbar array without interference from sneak-path currents through neighbouring cells has not yet been solved satisfactorily. Here we introduce a complementary resistive switch. It consists of two antiserial memristive elements and allows for the construction of large passive crossbar arrays by solving the sneak path problem in combination with a drastic reduction of the power consumption.

  3. Emotion and Autobiographical Memory

    PubMed Central

    Holland, Alisha C.; Kensinger, Elizabeth A.

    2010-01-01

    Autobiographical memory encompasses our recollections of specific, personal events. In this article, we review the interactions between emotion and autobiographical memory, focusing on two broad ways in which these interactions occur. First, the emotional content of an experience can influence the way in which the event is remembered. Second, emotions and emotional goals experienced at the time of autobiographical retrieval can influence the information recalled. We discuss the behavioral manifestations of each of these types of interactions and describe the neural mechanisms that may support those interactions. We discuss how findings from the clinical literature (e.g., regarding depression) and the social psychology literature (e.g., on emotion regulation) might inform future investigations of the interplay between the emotions experienced at the time of retrieval and the memories recalled, and we present ideas for future research in this domain. PMID:20374933

  4. Echoic memory in pigeons.

    PubMed

    Kretzschmar, Christina; Kalenscher, Tobias; Güntürkün, Onur; Kaernbach, Christian

    2008-10-01

    It is unknown whether birds are able to retain the memory of purely sensory auditory information such as white noise over an extended period of time. In a Pavlovian heart rate conditioning paradigm, four pigeons were trained to associate a mild electric shock with periodic random waveforms, and no shock with aperiodic noise. Periodic waveform detection requires echoic memory, i.e., the online retention of a waveform pattern over a limited time. Starting with 40ms, the waveform period was increased after successful learning until no significant stimulus discrimination could be found. Significant discrimination was achieved at periods of up to 2560ms. This is the first demonstration that echoic memory performance in birds is clearly superior to cats and gerbils, and comparable to naive human performance.

  5. 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.

  6. Emotion and autobiographical memory

    NASA Astrophysics Data System (ADS)

    Holland, Alisha C.; Kensinger, Elizabeth A.

    2010-03-01

    Autobiographical memory encompasses our recollections of specific, personal events. In this article, we review the interactions between emotion and autobiographical memory, focusing on two broad ways in which these interactions occur. First, the emotional content of an experience can influence the way in which the event is remembered. Second, emotions and emotional goals experienced at the time of autobiographical retrieval can influence the information recalled. We discuss the behavioral manifestations of each of these types of interactions and describe the neural mechanisms that may support those interactions. We discuss how findings from the clinical literature (e.g., regarding depression) and the social psychology literature (e.g., on emotion regulation) might inform future investigations of the interplay between the emotions experienced at the time of retrieval and the memories recalled, and we present ideas for future research in this domain.

  7. An overview of advanced nonvolatile memory technologies

    SciTech Connect

    Dressendorfer, P.V.

    1991-01-01

    This report is an overview of advanced nonvolatile memory technologies. The memory technologies discussed are: floating gate nonvolatile memory technologies; SNOS nonvolatile technology; ferroelectric technology; and thin film magnetic memories.

  8. Psychobiology of Active and Inactive Memory.

    ERIC Educational Resources Information Center

    Lewis, Donald J.

    1979-01-01

    Argues that the distinction between short-term memory and long-term memory is no longer adequate for either human or animal memory data. Recommends additional research on the physiological brain processes underlying memory interference and retrieval. (MP)

  9. Mere Memory Testing Creates False Memories in Children.

    ERIC Educational Resources Information Center

    Brainerd, C. J.; Reyna, V. F.

    1996-01-01

    Two studies with 80 5- and 8-year olds found that initial recognition tests elevated children's false-memory responses on delayed tests, and that false-memory creation exceeded true-memory inoculation in 5- and 8-year olds, producing net loss of accuracy over time. (MDM)

  10. Occupational Memory Practice and Memory Beliefs with Age

    ERIC Educational Resources Information Center

    Huet, Nathalie; Marquie, Jean-Claude; Bacon, Elisabeth

    2010-01-01

    This study examined effects of intensive memory use during one's profession on metamemory beliefs. Fifty-one actors and 60 controls aged from 20 to 73 years were compared with the Metamemory Inventory in Adulthood. Both intensive job-related memory practice and younger age were associated with stronger memory self-efficacy beliefs. Irrespective of…

  11. Negative Affect Impairs Associative Memory but Not Item Memory

    ERIC Educational Resources Information Center

    Bisby, James A.; Burgess, Neil

    2014-01-01

    The formation of associations between items and their context has been proposed to rely on mechanisms distinct from those supporting memory for a single item. Although emotional experiences can profoundly affect memory, our understanding of how it interacts with different aspects of memory remains unclear. We performed three experiments to examine…

  12. Negative Affect Impairs Associative Memory but Not Item Memory

    ERIC Educational Resources Information Center

    Bisby, James A.; Burgess, Neil

    2014-01-01

    The formation of associations between items and their context has been proposed to rely on mechanisms distinct from those supporting memory for a single item. Although emotional experiences can profoundly affect memory, our understanding of how it interacts with different aspects of memory remains unclear. We performed three experiments to examine…

  13. Occupational Memory Practice and Memory Beliefs with Age

    ERIC Educational Resources Information Center

    Huet, Nathalie; Marquie, Jean-Claude; Bacon, Elisabeth

    2010-01-01

    This study examined effects of intensive memory use during one's profession on metamemory beliefs. Fifty-one actors and 60 controls aged from 20 to 73 years were compared with the Metamemory Inventory in Adulthood. Both intensive job-related memory practice and younger age were associated with stronger memory self-efficacy beliefs. Irrespective of…

  14. Making sense of memory.

    PubMed

    Bernstein, Daniel M

    2005-09-01

    The current work explores how people make recognition and belief judgments in the presence of obvious repetition primes. In two experiments, subjects received a 200-ms prime ("cheetah"), either before or after reading a trivia question ("What is the fastest animal?") but always before being presented with the target answer ("cheetah"). Results showed that repetition priming decreased "old" claims (Recognition--Experiment 1), while it increased truth claims (Belief--Experiment 2). Furthermore, repetition prime placement affected recognition but not belief. Combined, these results suggest that dissociations in memory performance are a natural outcome of task and processing demands and reflect the dynamic, flexible nature of memory.

  15. Natural Killer Cell Memory

    PubMed Central

    O’Sullivan, Timothy E.; Sun, Joseph C.; Lanier, Lewis L.

    2015-01-01

    Natural killer (NK) cells have historically been considered short-lived cytolytic cells that can rapidly respond against pathogens and tumors in an antigen-independent manner, and then undergo cell death. Recently, however, NK cells have been shown to possess traits of adaptive immunity, and can acquire immunological memory in a similar manner to T and B cells. In this review, we discuss evidence for NK cell memory and the mechanisms involved in the generation and survival of these innate lymphocytes. PMID:26488815

  16. Dreams, conscience, and memory.

    PubMed

    Stein, M H

    1991-04-01

    The interpretation of certain dreams, as opposed to the direct examination of behavior, makes it possible to explore the conscience of the dreamer, detect hidden sources of guilt, and interpret them with less likelihood of arousing intractable resistance. Through the recovery of memories and the establishment of an intimate familiarity with one's personal history, it becomes possible to resolve problems of "neurotic" guilt, based ultimately on distortions of repressed childhood memories. The resolution of these conflicts allows a greater role for the operation of "appropriate" guilt, based on genuine transgressions, and the establishment of a more mature ethical structure.

  17. Natural Killer Cell Memory.

    PubMed

    O'Sullivan, Timothy E; Sun, Joseph C; Lanier, Lewis L

    2015-10-20

    Natural killer (NK) cells have historically been considered short-lived cytolytic cells that can rapidly respond against pathogens and tumors in an antigen-independent manner and then undergo cell death. Recently, however, NK cells have been shown to possess traits of adaptive immunity and can acquire immunological memory in a manner similar to that of T and B cells. In this review, we discuss evidence of NK cell memory and the mechanisms involved in the generation and survival of these innate lymphocytes.

  18. Multiple memory stores and operant conditioning: a rationale for memory's complexity.

    PubMed

    Meeter, Martijn; Veldkamp, Rob; Jin, Yaochu

    2009-02-01

    Why does the brain contain more than one memory system? Genetic algorithms can play a role in elucidating this question. Here, model animals were constructed containing a dorsal striatal layer that controlled actions, and a ventral striatal layer that controlled a dopaminergic learning signal. Both layers could gain access to three modeled memory stores, but such access was penalized as energy expenditure. Model animals were then selected on their fitness in simulated operant conditioning tasks. Results suggest that having access to multiple memory stores and their representations is important in learning to regulate dopamine release, as well as in contextual discrimination. For simple operant conditioning, as well as stimulus discrimination, hippocampal compound representations turned out to suffice, a counterintuitive result given findings that hippocampal lesions tend not to affect performance in such tasks. We argue that there is in fact evidence to support a role for compound representations and the hippocampus in even the simplest conditioning tasks.

  19. Emotional organization of autobiographical memory.

    PubMed

    Schulkind, Matthew D; Woldorf, Gillian M

    2005-09-01

    The emotional organization of autobiographical memory was examined by determining whether emotional cues would influence autobiographical retrieval in younger and older adults. Unfamiliar musical cues that represented orthogonal combinations of positive and negative valence and high and low arousal were used. Whereas cue valence influenced the valence of the retrieved memories, cue arousal did not affect arousal ratings. However, high-arousal cues were associated with reduced response latencies. A significant bias to report positive memories was observed, especially for the older adults, but neither the distribution of memories across the life span nor response latencies varied across memories differing in valence or arousal. These data indicate that emotional information can serve as effective cues for autobiographical memories and that autobiographical memories are organized in terms of emotional valence but not emotional arousal. Thus, current theories of autobiographical memory must be expanded to include emotional valence as a primary dimension of organization.

  20. Memory for syntax despite amnesia

    PubMed Central

    Ferreira, Victor S.; Bock, Kathryn; Wilson, Michael P.; Cohen, Neal J.

    2009-01-01

    Syntactic persistence is a tendency for speakers to reproduce sentence structures independently of accompanying meanings, words, or sounds. The memory mechanisms behind syntactic persistence are not fully understood. Though some properties of syntactic persistence suggest a role for procedural memory, current evidence suggests that procedural memory (unlike declarative memory) does not maintain the abstract, relational features that are inherent to syntactic structures. To evaluate the contribution of procedural memory to syntactic persistence, patients with anterograde amnesia and matched control speakers (a) reproduced prime sentences with different syntactic structures; (b) reproduced 0, 1, 6, or 10 neutral sentences; (c) described pictures that elicited the primed structures spontaneously; and (d) made recognition judgments for the prime sentences. Amnesic and control speakers showed significant and equivalent syntactic persistence, despite the amnesic speakers’ profoundly impaired recognition memory for primes. Syntax is thus maintained by procedural memory mechanisms, revealing that procedural memory is capable of supporting abstract, relational knowledge. PMID:18947361

  1. Memory and Forgetfulness: NIH Research

    MedlinePlus

    ... of this page please turn Javascript on. Feature: Memory & Forgetfulness NIH Research Past Issues / Summer 2013 Table ... agency for research on Alzheimer's disease and related memory research. An analysis funded by the NIA finds ...

  2. [Memory lapses and memory: relationship between objective and subjective memory in old age].

    PubMed

    Calero-García, M Dolores; Navarro-González, Elena; Gómez-Ceballos, Laura; López Pérez-Díaz, Angel; Torres-Carbonell, Isabel; Calero-García, M José

    2008-01-01

    research into memory in geriatrics and gerontology has become increasingly important in recent years. However, various studies have shown that not all aspects or types of memory are affected in the same way or with the same severity by old age. the present study aimed to establish differential profiles in objective and subjective memory associated with old age with a view to establishing criteria that could be used to distinguish between age-associated memory loss and pathological memory loss, thus aiding diagnosis of cognitive impairment. a total of 143 participants between 60 and 98 years of age were evaluated using a battery of tests comprising the validated Spanish version of the Mini-Mental State Examination [Lobo's Mini-Examen Cognoscitivo (MEC)], diverse tests for objective memory [the auditory verbal learning test of learning potential (AVLT-LP) and a working memory test], and the subjective memory questionnaire. significant differences were found between distinct age groups in different measures of subjective and objective memory. In general terms, persons who complained most about memory problems were not those with poorer performance on objective memory tests. The results show that measures of subjective and objective memory assess different aspects of memory.

  3. About sleep's role in memory.

    PubMed

    Rasch, Björn; Born, Jan

    2013-04-01

    Over more than a century of research has established the fact that sleep benefits the retention of memory. In this review we aim to comprehensively cover the field of "sleep and memory" research by providing a historical perspective on concepts and a discussion of more recent key findings. Whereas initial theories posed a passive role for sleep enhancing memories by protecting them from interfering stimuli, current theories highlight an active role for sleep in which memories undergo a process of system consolidation during sleep. Whereas older research concentrated on the role of rapid-eye-movement (REM) sleep, recent work has revealed the importance of slow-wave sleep (SWS) for memory consolidation and also enlightened some of the underlying electrophysiological, neurochemical, and genetic mechanisms, as well as developmental aspects in these processes. Specifically, newer findings characterize sleep as a brain state optimizing memory consolidation, in opposition to the waking brain being optimized for encoding of memories. Consolidation originates from reactivation of recently encoded neuronal memory representations, which occur during SWS and transform respective representations for integration into long-term memory. Ensuing REM sleep may stabilize transformed memories. While elaborated with respect to hippocampus-dependent memories, the concept of an active redistribution of memory representations from networks serving as temporary store into long-term stores might hold also for non-hippocampus-dependent memory, and even for nonneuronal, i.e., immunological memories, giving rise to the idea that the offline consolidation of memory during sleep represents a principle of long-term memory formation established in quite different physiological systems.

  4. A hybrid ferroelectric-flash memory cells

    NASA Astrophysics Data System (ADS)

    Park, Jae Hyo; Byun, Chang Woo; Seok, Ki Hwan; Kim, Hyung Yoon; Chae, Hee Jae; Lee, Sol Kyu; Son, Se Wan; Ahn, Donghwan; Joo, Seung Ki

    2014-09-01

    A ferroelectric-flash (F-flash) memory cells having a metal-ferroelectric-nitride-oxynitride-silicon structure are demonstrated, and the ferroelectric materials were perovskite-dominated Pb(Zr,Ti)O3 (PZT) crystallized by Pt gate electrode. The PZT thin-film as a blocking layer improves electrical and memorial performance where programming and erasing mechanism are different from the metal-ferroelectric-insulator-semiconductor device or the conventional silicon-oxide-nitride-oxide-silicon device. F-flash cells exhibit not only the excellent electrical transistor performance, having 442.7 cm2 V-1 s-1 of field-effect mobility, 190 mV dec-1 of substhreshold slope, and 8 × 105 on/off drain current ratio, but also a high reliable memory characteristics, having a large memory window (6.5 V), low-operating voltage (0 to -5 V), faster P/E switching speed (50/500 μs), long retention time (>10 years), and excellent fatigue P/E cycle (>105) due to the boosting effect, amplification effect, and energy band distortion of nitride from the large polarization. All these characteristics correspond to the best performances among conventional flash cells reported so far.

  5. Dual redundant core memory systems

    NASA Technical Reports Server (NTRS)

    Hull, F. E.

    1972-01-01

    Electronic memory system consisting of series redundant drive switch circuits, triple redundant majority voted memory timing functions, and two data registers to provide functional dual redundancy is described. Signal flow through the circuits is illustrated and equence of events which occur within the memory system is explained.

  6. Memory Storage and Neural Systems.

    ERIC Educational Resources Information Center

    Alkon, Daniel L.

    1989-01-01

    Investigates memory storage and molecular nature of associative-memory formation by analyzing Pavlovian conditioning in marine snails and rabbits. Presented is the design of a computer-based memory system (neural networks) using the rules acquired in the investigation. Reports that the artificial network recognized patterns well. (YP)

  7. Origins of Adolescents' Autobiographical Memories

    ERIC Educational Resources Information Center

    Reese, Elaine; Jack, Fiona; White, Naomi

    2010-01-01

    Adolescents (N = 46; M = 12.46 years) who had previously participated in a longitudinal study of autobiographical memory development narrated their early childhood memories, interpreted life events, and completed a family history questionnaire and language assessment. Three distinct components of adolescent memory emerged: (1) age of earliest…

  8. Play Memories and Place Identity.

    ERIC Educational Resources Information Center

    Sandberg, Anette

    2003-01-01

    This retrospective study examined play memories from childhood to adulthood of 478 university students between ages 20 and 62 as exhibited in drawings of play memories and questionnaire responses. The study focused on the role of the physical environment and place identity in play memories and individual identity development. Findings showed that…

  9. Motor Action and Emotional Memory

    ERIC Educational Resources Information Center

    Casasanto, Daniel; Dijkstra, Katinka

    2010-01-01

    Can simple motor actions affect how efficiently people retrieve emotional memories, and influence what they choose to remember? In Experiment 1, participants were prompted to retell autobiographical memories with either positive or negative valence, while moving marbles either upward or downward. They retrieved memories faster when the direction…

  10. First Words and First Memories

    ERIC Educational Resources Information Center

    Morrison, Catriona M.; Conway, Martin A.

    2010-01-01

    In two experiments autobiographical memories from childhood were recalled to cue words naming common objects, locations, activities and emotions. Participants recalled their earliest specific memory associated with each word and dated their age at the time of the remembered event. A striking and specific finding emerged: age of earliest memory was…

  11. Origins of Adolescents' Autobiographical Memories

    ERIC Educational Resources Information Center

    Reese, Elaine; Jack, Fiona; White, Naomi

    2010-01-01

    Adolescents (N = 46; M = 12.46 years) who had previously participated in a longitudinal study of autobiographical memory development narrated their early childhood memories, interpreted life events, and completed a family history questionnaire and language assessment. Three distinct components of adolescent memory emerged: (1) age of earliest…

  12. Stroke and Episodic Memory Disorders

    ERIC Educational Resources Information Center

    Lim, Chun; Alexander, Michael P.

    2009-01-01

    Memory impairments are common after stroke, and the anatomical basis for impairments may be quite variable. To determine the range of stroke-related memory impairment, we identified all case reports and group studies through the Medline database and the Science Citation Index. There is no hypothesis about memory that is unique to stroke, but there…

  13. Play Memories and Place Identity.

    ERIC Educational Resources Information Center

    Sandberg, Anette

    2003-01-01

    This retrospective study examined play memories from childhood to adulthood of 478 university students between ages 20 and 62 as exhibited in drawings of play memories and questionnaire responses. The study focused on the role of the physical environment and place identity in play memories and individual identity development. Findings showed that…

  14. Memory Storage and Neural Systems.

    ERIC Educational Resources Information Center

    Alkon, Daniel L.

    1989-01-01

    Investigates memory storage and molecular nature of associative-memory formation by analyzing Pavlovian conditioning in marine snails and rabbits. Presented is the design of a computer-based memory system (neural networks) using the rules acquired in the investigation. Reports that the artificial network recognized patterns well. (YP)

  15. First Words and First Memories

    ERIC Educational Resources Information Center

    Morrison, Catriona M.; Conway, Martin A.

    2010-01-01

    In two experiments autobiographical memories from childhood were recalled to cue words naming common objects, locations, activities and emotions. Participants recalled their earliest specific memory associated with each word and dated their age at the time of the remembered event. A striking and specific finding emerged: age of earliest memory was…

  16. Memory Processes in Media Effects.

    ERIC Educational Resources Information Center

    Kellermann, Kathy

    1985-01-01

    Explores the role of memory in mediating mass communication effects. Examines (1) the nature of memory, (2) issues in retention and recall of media messages, (3) methods of promoting retention and recall of media messages, and (4) implications of memory processes for mass media effects. (PD)

  17. Stress disrupts response memory retrieval.

    PubMed

    Guenzel, Friederike M; Wolf, Oliver T; Schwabe, Lars

    2013-08-01

    Stress effects on memory are well-known. Most studies, however, focused on the impact of stress on hippocampus-dependent 'declarative' memory processes. Less is known about whether stress influences also striatum-based memory processes, such as stimulus-response (S-R) memory. First evidence from rodent experiments shows that glucocorticoid stress hormones may enhance the consolidation of S-R memories. Whether stress affects also S-R memory retrieval remains largely elusive. Therefore, we tested in the present experiment in humans the effect of stress on the retrieval of S-R memories. Healthy men and women were trained to locate three objects in an S-R version of a virtual eight-arm radial maze. One week later, participants underwent a stressor or a control condition before their memory of the S-R task was tested. Our results showed that participants (n=43) who were exposed to the stressor before retention testing made significantly more errors in this test trial, suggesting that stress impaired S-R memory retrieval. Moreover, high cortisol concentrations were associated with reduced S-R memory. These findings indicate that stress may affect memory retrieval processes in humans beyond hippocampal 'declarative' memory.

  18. Motor Action and Emotional Memory

    ERIC Educational Resources Information Center

    Casasanto, Daniel; Dijkstra, Katinka

    2010-01-01

    Can simple motor actions affect how efficiently people retrieve emotional memories, and influence what they choose to remember? In Experiment 1, participants were prompted to retell autobiographical memories with either positive or negative valence, while moving marbles either upward or downward. They retrieved memories faster when the direction…

  19. Stroke and Episodic Memory Disorders

    ERIC Educational Resources Information Center

    Lim, Chun; Alexander, Michael P.

    2009-01-01

    Memory impairments are common after stroke, and the anatomical basis for impairments may be quite variable. To determine the range of stroke-related memory impairment, we identified all case reports and group studies through the Medline database and the Science Citation Index. There is no hypothesis about memory that is unique to stroke, but there…

  20. When Autobiographical Memory Begins

    ERIC Educational Resources Information Center

    Howe, Mark L.; Courage, Mary L.; Edison, Shannon C.

    2003-01-01

    The authors review competing theories concerning the emergence and early development of autobiographical memory. It is argued that the differences between these accounts, although important, may be more apparent than real. The crux of these disagreements lies not in "what" processes are important, but rather, the role these different processes…

  1. Dreams Memories & Photography

    ERIC Educational Resources Information Center

    Young, Bernard

    2012-01-01

    Photography students spend a considerable amount of time working on technical issues in shooting, composing, editing, and processing prints. Another aspect of their learning should include the conception and communication of their ideas. A student's memories and dreams can serve as motivation to create images in visual art. Some artists claim that…

  2. Memory Mechanisms in Grasping

    ERIC Educational Resources Information Center

    Hesse, Constanze; Franz, Volker H.

    2009-01-01

    The availability of visual information influences the execution of goal-directed movements. This is very prominent in memory conditions, where a delay is introduced between stimulus presentation and execution of the movement. The corresponding effects could be due to a decay of the visual information or to different processing mechanisms used for…

  3. High density associative memory

    NASA Technical Reports Server (NTRS)

    Moopenn, Alexander W. (Inventor); Thakoor, Anilkumar P. (Inventor); Daud, Taher (Inventor); Lambe, John J. (Inventor)

    1989-01-01

    A multi-layered, thin-film, digital memory having associative recall. There is a first memory matrix and a second memory matrix. Each memory matrix comprises, a first layer comprising a plurality of electrically separated row conductors; a second layer comprising a plurality of electrically separated column conductors intersecting but electrically separated from the row conductors; and, a plurality of resistance elements electrically connected between the row condutors and the column conductors at respective intersections of the row conductors and the column conductors, each resistance element comprising, in series, a first resistor of sufficiently high ohmage to conduct a sensible element current therethrough with virtually no heat-generating power consumption when a low voltage as employed in thin-film applications is applied thereacross and a second resistor of sufficiently high ohmage to conduct no sensible current therethrough when a low voltage as employed in thin-film applications is applied thereacross, the second resistor having the quality of breaking down to create a short therethrough upon the application of a breakdown level voltage across the first and second resistors.

  4. Memorials: Art for Remembering.

    ERIC Educational Resources Information Center

    Art to Zoo: Teaching With the Power of Objects, 1995

    1995-01-01

    Throughout history, in all parts of the world, people have struggled with the problem of loss. Moving words have been written and beautiful objects created to preserve the memory of people and their achievements. This theme issue explores the different ways that people have been praised and remembered in works of art. An introduction suggests a…

  5. Working Memory and Reactivity

    ERIC Educational Resources Information Center

    Goo, Jaemyung

    2010-01-01

    The present study explores the relationship between working memory capacity (WMC) and think-alouds, focusing on the issue of reactivity. Two WM span tasks (listening span and operation span) were administered to 42 English-speaking learners of Spanish. Learner performance on reading comprehension and written production was measured under two…

  6. Memory Loss and Retrieval

    ERIC Educational Resources Information Center

    Reid, Ian

    2016-01-01

    Underlying the generally oblivious attitude of teachers and learners towards the past is insufficient respect for the role of memory in giving meaning to experience and access to knowledge. We shape our identity by making sense of our past and its relationship to present and future selves, a process that should be intensively cultivated when we…

  7. Dreams Memories & Photography

    ERIC Educational Resources Information Center

    Young, Bernard

    2012-01-01

    Photography students spend a considerable amount of time working on technical issues in shooting, composing, editing, and processing prints. Another aspect of their learning should include the conception and communication of their ideas. A student's memories and dreams can serve as motivation to create images in visual art. Some artists claim that…

  8. Radiation Tolerant Embedded Memory

    DTIC Science & Technology

    2007-11-02

    REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 ...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1 . REPORT DATE (DD-MM-YYYY) 27-06-2003 2. REPORT TYPE SBIR...Tolerant Embedded Memory 1 Table of Contents: Table of Contents

  9. A Balanced Memory Network

    PubMed Central

    Roudi, Yasser; Latham, Peter E

    2007-01-01

    A fundamental problem in neuroscience is understanding how working memory—the ability to store information at intermediate timescales, like tens of seconds—is implemented in realistic neuronal networks. The most likely candidate mechanism is the attractor network, and a great deal of effort has gone toward investigating it theoretically. Yet, despite almost a quarter century of intense work, attractor networks are not fully understood. In particular, there are still two unanswered questions. First, how is it that attractor networks exhibit irregular firing, as is observed experimentally during working memory tasks? And second, how many memories can be stored under biologically realistic conditions? Here we answer both questions by studying an attractor neural network in which inhibition and excitation balance each other. Using mean-field analysis, we derive a three-variable description of attractor networks. From this description it follows that irregular firing can exist only if the number of neurons involved in a memory is large. The same mean-field analysis also shows that the number of memories that can be stored in a network scales with the number of excitatory connections, a result that has been suggested for simple models but never shown for realistic ones. Both of these predictions are verified using simulations with large networks of spiking neurons. PMID:17845070

  10. Judgments of Associative Memory

    ERIC Educational Resources Information Center

    Maki, William S.

    2007-01-01

    Judgments of associative memory (JAM) were indexed by ratings given to pairs of cue and response words. The normed probabilities, p(response|cue), were obtained from free association norms. The ratings were linearly related to the probabilities. The JAM functions were characterized by high intercepts (approximately 50 on a 100 point scale) and…

  11. The Grammar of Memory

    ERIC Educational Resources Information Center

    Sawyer, Wayne

    2016-01-01

    This essay focuses on two sites of memory in my professional life. One is from my very early years of teaching, the second from about 10 years later. Each is centred on a moment of controversy in English curriculum in New South Wales, Australia, and each is to do with the teaching of writing and the supposed neglect of language study, including…

  12. Judgments of Associative Memory

    ERIC Educational Resources Information Center

    Maki, William S.

    2007-01-01

    Judgments of associative memory (JAM) were indexed by ratings given to pairs of cue and response words. The normed probabilities, p(response|cue), were obtained from free association norms. The ratings were linearly related to the probabilities. The JAM functions were characterized by high intercepts (approximately 50 on a 100 point scale) and…

  13. Advanced image memory architecture

    NASA Astrophysics Data System (ADS)

    Vercillo, Richard; McNeill, Kevin M.

    1994-05-01

    A workstation for radiographic images, known as the Arizona Viewing Console (AVC), was developed at the University of Arizona Health Sciences Center in the Department of Radiology. This workstation has been in use as a research tool to aid us in investigating how a radiologist interacts with a workstation, to determine which image processing features are required to aid the radiologist, to develop user interfaces and to support psychophysical and clinical studies. Results from these studies have show a need to increase the current image memory's available storage in order to accommodate high resolution images. The current triple-ported image memory can be allocated to store any number of images up to a combined total of 4 million pixels. Over the past couple of years, higher resolution images have become easier to generate with the advent of laser digitizers and computed radiology systems. As part of our research, a larger 32 million pixel image memory for AVC has been designed to replace the existing image memory.

  14. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    Former Secretary of the Treasury John Snow speaks during a memorial service celebrating the life of Neil Armstrong at the Washington National Cathedral, Thursday, Sept. 13, 2012. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Bill Ingalls)

  15. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    The Right Rev. Mariann Edgar Budde, bishop of Washington, delivers the Homily during a memorial service celebrating the life of Neil Armstrong at the Washington National Cathedral, Thursday, Sept. 13, 2012. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit:(NASA/Paul E. Alers)

  16. Person Memory and Judgment.

    ERIC Educational Resources Information Center

    Srull, Thomas K.; Wyer, Robert S., Jr.

    1989-01-01

    A theoretical model of person memory and judgment--the processes underlying the formation of person impressions--is presented. It incorporates both specific behaviors and abstract personality dispositions or behavioral tendencies. The model accounts for factors affecting recall of social information and interpersonal judgments and is applicable to…

  17. When Autobiographical Memory Begins

    ERIC Educational Resources Information Center

    Howe, Mark L.; Courage, Mary L.; Edison, Shannon C.

    2003-01-01

    The authors review competing theories concerning the emergence and early development of autobiographical memory. It is argued that the differences between these accounts, although important, may be more apparent than real. The crux of these disagreements lies not in "what" processes are important, but rather, the role these different processes…

  18. Memory Loss and Retrieval

    ERIC Educational Resources Information Center

    Reid, Ian

    2016-01-01

    Underlying the generally oblivious attitude of teachers and learners towards the past is insufficient respect for the role of memory in giving meaning to experience and access to knowledge. We shape our identity by making sense of our past and its relationship to present and future selves, a process that should be intensively cultivated when we…

  19. Antenatal memories and psychopathology

    PubMed Central

    Neighbour, Roger

    1981-01-01

    A case is described of suicidal impulses apparently stemming from the patient's experience before and during his birth. By using a technique of `rebirthing', antenatal memories were relived and their traumatic effects resolved. Theoretical and practical accounts of rebirthing are given, and its significance for general practitioners is discussed. PMID:7338871

  20. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    Acolytes lead the recessional through the Nave at the conclusion of a memorial service celebrating the life of Neil Armstrong at the Washington National Cathedral, Thursday, Sept. 13, 2012. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit:(NASA/Paul E. Alers)

  1. Quantum Memory in Solids

    NASA Astrophysics Data System (ADS)

    Sellars, Matthew

    2008-05-01

    Quantum memories are likely to be critical components in any future long range quantum communication network. A method is described for storing light that operates by controlling the local group velocity of light in a crystal, using an applied electric field gradient to Stark shift an optical transition. Unlike other proposals for quantum memories no optical control pulses are required greatly simplifying the operation of the memory and improving its signal to noise. It is shown that the technique has the potential to operate with near 100% efficiency with little excess noise, making it suitable as a quantum memory. Preliminary experimental results will be presented demonstrating efficiencies up to 45%. These experiments utilized the ^3H4<->^1D2 optical transition (605.7 nm) in a 4 mm long crystal of Pr^3+:Y2SiO5 cooled to liquid helium temperatures. The experiments are well described by Maxwell-Bloch simulations and such simulations suggest efficiencies much closer to unity should be possible with only modest improvements to the experiment. This work was carried out in collaboration with G. Hetet, J. J. Longdell, A. L. Alexander, P. K. Lam and M. P. Hedges.

  2. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    An image of Neil Armstrong is projected on a television screen as attendees sit in the Nave during a memorial service celebrating the life of Neil Armstrong at the Washington National Cathedral, Thursday, Sept. 13, 2012. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Bill Ingalls)

  3. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    Attendees to the memorial service for Neil Armstrong sing a hymnal, Thursday, Sept. 13, 2012, at the Washington National Cathedral. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Bill Ingalls)

  4. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    Apollo 17 mission commander Gene Cernan, the last man to walk on the moon, speaks during a memorial service celebrating the life of Neil Armstrong at the Washington National Cathedral, Thursday, Sept. 13, 2012. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Bill Ingalls)

  5. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    John H. Dalton, former United States Secretary of the Navy, delivers the Reading during a memorial service celebrating the life of Neil Armstrong at the Washington National Cathedral, Thursday, Sept. 13, 2012. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Bill Ingalls)

  6. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    Musician Diana Krall sings ""Fly Me to the Moon" during a memorial service celebrating the life of Neil Armstrong at the Washington National Cathedral, Thursday, Sept. 13, 2012. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Paul E. Alers)

  7. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    Former U.S. Sen. John Glenn, left, and Buzz Aldrin shake hands prior to a memorial service celebrating the life of Neil Armstrong, Thursday, Sept. 13, 2012, at the Washington National Cathedral. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Bill Ingalls)

  8. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    Members of the Cathedral Choirsters sing "For the Beauty of the Earth" during a memorial service celebrating the life of Neil Armstrong at the Washington National Cathedral, Thursday, Sept. 13, 2012. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit:(NASA/Paul E. Alers)

  9. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    Apollo 17 astronaut Gene Cernan, the last man to walk on the moon, speaks during a memorial service celebrating the life of Neil Armstrong at the Washington National Cathedral, Thursday, Sept. 13, 2012. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Paul E. Alers)

  10. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    Former U.S. Sen. John Glenn, left, and musician Diana Krall bow there heads in prayer during a memorial service celebrating the life of Neil Armstrong, Thursday, Sept. 13, 2012, at the Washington National Cathedral. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Bill Ingalls)

  11. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    Apollo 17 mission commander Gene Cernan, the last man to walk on the moon, looks skyward during a memorial service celebrating the life of Neil Armstrong at the Washington National Cathedral, Thursday, Sept. 13, 2012. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Bill Ingalls)

  12. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    The Rev. Gina Gilland Campbell, acting director of worship, Washington National Cathedral, reads the Gospel during a memorial service celebrating the life of Neil Armstrong at the Washington National Cathedral, Thursday, Sept. 13, 2012. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Paul E. Alers)

  13. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    NASA Administrator Charles Bolden delivers a tribute during a memorial service celebrating the life of Neil Armstrong, Thursday, Sept. 13, 2012, at the Washington National Cathedral. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Bill Ingalls)

  14. Representation in Memory.

    DTIC Science & Technology

    1983-06-07

    appear to contain visual, auditory, kinesthetic , and emotive components, in addition to the more abstract com- ponents necessary for the kinds of causal...it gets interpreted. . . . . . . . . o,. Rumelhart and Norman Representation in Memory June 7, 1983 81 being learned. The learner is expected to

  15. Bubble Memory Module.

    DTIC Science & Technology

    1980-12-01

    104 7-13 Four switch drive hybrid ........................................................................ 104 7-14...operation. Address Ready. - This signal is an output signal to the user which acknowledges that the module is busy. Input address is latched in the...expandable in 6.55 M bit increments. Detector noise is minimized by locating sense circuits, cell select switches , and memory cells on the same board

  16. Metal oxide-resistive memory using graphene-edge electrodes

    PubMed Central

    Lee, Seunghyun; Sohn, Joon; Jiang, Zizhen; Chen, Hong-Yu; Philip Wong, H.-S.

    2015-01-01

    The emerging paradigm of ‘abundant-data' computing requires real-time analytics on enormous quantities of data collected by a mushrooming network of sensors. Todays computing technology, however, cannot scale to satisfy such big data applications with the required throughput and energy efficiency. The next technology frontier will be monolithically integrated chips with three-dimensionally interleaved memory and logic for unprecedented data bandwidth with reduced energy consumption. In this work, we exploit the atomically thin nature of the graphene edge to assemble a resistive memory (∼3 Å thick) stacked in a vertical three-dimensional structure. We report some of the lowest power and energy consumption among the emerging non-volatile memories due to an extremely thin electrode with unique properties, low programming voltages, and low current. Circuit analysis of the three-dimensional architecture using experimentally measured device properties show higher storage potential for graphene devices compared that of metal based devices. PMID:26406356

  17. Metal oxide-resistive memory using graphene-edge electrodes

    NASA Astrophysics Data System (ADS)

    Lee, Seunghyun; Sohn, Joon; Jiang, Zizhen; Chen, Hong-Yu; Philip Wong, H.-S.

    2015-09-01

    The emerging paradigm of `abundant-data' computing requires real-time analytics on enormous quantities of data collected by a mushrooming network of sensors. Todays computing technology, however, cannot scale to satisfy such big data applications with the required throughput and energy efficiency. The next technology frontier will be monolithically integrated chips with three-dimensionally interleaved memory and logic for unprecedented data bandwidth with reduced energy consumption. In this work, we exploit the atomically thin nature of the graphene edge to assemble a resistive memory (~3 Å thick) stacked in a vertical three-dimensional structure. We report some of the lowest power and energy consumption among the emerging non-volatile memories due to an extremely thin electrode with unique properties, low programming voltages, and low current. Circuit analysis of the three-dimensional architecture using experimentally measured device properties show higher storage potential for graphene devices compared that of metal based devices.

  18. The role of stress during memory reactivation on intrusive memories.

    PubMed

    Cheung, Jessica; Garber, Benjamin; Bryant, Richard A

    2015-09-01

    Intrusive memories are unwanted recollections that maintain distress in psychological disorders. Increasing evidence suggests that memories that are reactivated through retrieval become temporarily vulnerable to environmental or pharmacological manipulation, including changes in levels of circulating stress hormones. This study investigated the influence of stress during memory reactivation of an emotionally arousing trauma film on subsequent intrusive memories. Three groups of participants (N=63) viewed a trauma film depicting a serious car accident at baseline. Two days later (Time 2), one group received a reactivation induction following a socially evaluated cold pressor test (SECPT; Stress/Reactivation condition), whilst the second group reactivated the memory after a control procedure (Reactivation condition). A third group underwent the SECPT but was not asked to reactivate memory of the trauma film (Stress condition). Two days later (Time 3), all participants received a surprise cued memory recall test and intrusions questionnaire which they completed online. Results showed that those in the Stress/Reactivation group had higher intrusions scores than the other two groups, suggesting that acute stress promotes intrusive memories only when the memory trace is reactivated shortly afterwards. Increased cortisol predicted enhanced intrusive experiences in the Stress/Reactivation condition but not in the other conditions. This pattern of results suggests that acute stress during the reactivation of emotional material impacts on involuntary emotional memories. These findings suggest a possible explanation for the mechanism underlying the maintenance of intrusive memories in clinical disorders.

  19. False memories in highly superior autobiographical memory individuals

    PubMed Central

    Patihis, Lawrence; Frenda, Steven J.; LePort, Aurora K. R.; Petersen, Nicole; Nichols, Rebecca M.; Stark, Craig E. L.; McGaugh, James L.; Loftus, Elizabeth F.

    2013-01-01

    The recent identification of highly superior autobiographical memory (HSAM) raised the possibility that there may be individuals who are immune to memory distortions. We measured HSAM participants’ and age- and sex-matched controls’ susceptibility to false memories using several research paradigms. HSAM participants and controls were both susceptible to false recognition of nonpresented critical lure words in an associative word-list task. In a misinformation task, HSAM participants showed higher overall false memory compared with that of controls for details in a photographic slideshow. HSAM participants were equally as likely as controls to mistakenly report they had seen nonexistent footage of a plane crash. Finding false memories in a superior-memory group suggests that malleable reconstructive mechanisms may be fundamental to episodic remembering. Paradoxically, HSAM individuals may retrieve abundant and accurate autobiographical memories using fallible reconstructive processes. PMID:24248358

  20. False memories in highly superior autobiographical memory individuals.

    PubMed

    Patihis, Lawrence; Frenda, Steven J; LePort, Aurora K R; Petersen, Nicole; Nichols, Rebecca M; Stark, Craig E L; McGaugh, James L; Loftus, Elizabeth F

    2013-12-24

    The recent identification of highly superior autobiographical memory (HSAM) raised the possibility that there may be individuals who are immune to memory distortions. We measured HSAM participants' and age- and sex-matched controls' susceptibility to false memories using several research paradigms. HSAM participants and controls were both susceptible to false recognition of nonpresented critical lure words in an associative word-list task. In a misinformation task, HSAM participants showed higher overall false memory compared with that of controls for details in a photographic slideshow. HSAM participants were equally as likely as controls to mistakenly report they had seen nonexistent footage of a plane crash. Finding false memories in a superior-memory group suggests that malleable reconstructive mechanisms may be fundamental to episodic remembering. Paradoxically, HSAM individuals may retrieve abundant and accurate autobiographical memories using fallible reconstructive processes.

  1. False memories and memory confidence in borderline patients.

    PubMed

    Schilling, Lisa; Wingenfeld, Katja; Spitzer, Carsten; Nagel, Matthias; Moritz, Steffen

    2013-12-01

    Mixed results have been obtained regarding memory in patients with borderline personality disorder (BPD). Prior reports and anecdotal evidence suggests that patients with BPD are prone to false memories but this assumption has to been put to firm empirical test, yet. Memory accuracy and confidence was assessed in 20 BPD patients and 22 healthy controls using a visual variant of the false memory (Deese-Roediger-McDermott) paradigm which involved a negative and a positive-valenced picture. Groups did not differ regarding veridical item recognition. Importantly, patients did not display more false memories than controls. At trend level, borderline patients rated more items as new with high confidence compared to healthy controls. The results tentatively suggest that borderline patients show uncompromised visual memory functions and display no increased susceptibility for distorted memories. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. About Sleep's Role in Memory

    PubMed Central

    2013-01-01

    Over more than a century of research has established the fact that sleep benefits the retention of memory. In this review we aim to comprehensively cover the field of “sleep and memory” research by providing a historical perspective on concepts and a discussion of more recent key findings. Whereas initial theories posed a passive role for sleep enhancing memories by protecting them from interfering stimuli, current theories highlight an active role for sleep in which memories undergo a process of system consolidation during sleep. Whereas older research concentrated on the role of rapid-eye-movement (REM) sleep, recent work has revealed the importance of slow-wave sleep (SWS) for memory consolidation and also enlightened some of the underlying electrophysiological, neurochemical, and genetic mechanisms, as well as developmental aspects in these processes. Specifically, newer findings characterize sleep as a brain state optimizing memory consolidation, in opposition to the waking brain being optimized for encoding of memories. Consolidation originates from reactivation of recently encoded neuronal memory representations, which occur during SWS and transform respective representations for integration into long-term memory. Ensuing REM sleep may stabilize transformed memories. While elaborated with respect to hippocampus-dependent memories, the concept of an active redistribution of memory representations from networks serving as temporary store into long-term stores might hold also for non-hippocampus-dependent memory, and even for nonneuronal, i.e., immunological memories, giving rise to the idea that the offline consolidation of memory during sleep represents a principle of long-term memory formation established in quite different physiological systems. PMID:23589831

  3. Milestoning with transition memory

    NASA Astrophysics Data System (ADS)

    Hawk, Alexander T.; Makarov, Dmitrii E.

    2011-12-01

    Milestoning is a method used to calculate the kinetics and thermodynamics of molecular processes occurring on time scales that are not accessible to brute force molecular dynamics (MD). In milestoning, the conformation space of the system is sectioned by hypersurfaces (milestones), an ensemble of trajectories is initialized on each milestone, and MD simulations are performed to calculate transitions between milestones. The transition probabilities and transition time distributions are then used to model the dynamics of the system with a Markov renewal process, wherein a long trajectory of the system is approximated as a succession of independent transitions between milestones. This approximation is justified if the transition probabilities and transition times are statistically independent. In practice, this amounts to a requirement that milestones are spaced such that trajectories lose position and velocity memory between subsequent transitions. Unfortunately, limiting the number of milestones limits both the resolution at which a system's properties can be analyzed, and the computational speedup achieved by the method. We propose a generalized milestoning procedure, milestoning with transition memory (MTM), which accounts for memory of previous transitions made by the system. When a reaction coordinate is used to define the milestones, the MTM procedure can be carried out at no significant additional expense as compared to conventional milestoning. To test MTM, we have applied its version that allows for the memory of the previous step to the toy model of a polymer chain undergoing Langevin dynamics in solution. We have computed the mean first passage time for the chain to attain a cyclic conformation and found that the number of milestones that can be used, without incurring significant errors in the first passage time is at least 8 times that permitted by conventional milestoning. We further demonstrate that, unlike conventional milestoning, MTM permits

  4. The Relationships of Working Memory, Secondary Memory, and General Fluid Intelligence: Working Memory Is Special

    ERIC Educational Resources Information Center

    Shelton, Jill Talley; Elliott, Emily M.; Matthews, Russell A.; Hill, B. D.; Gouvier, Wm. Drew

    2010-01-01

    Recent efforts have been made to elucidate the commonly observed link between working memory and reasoning ability. The results have been inconsistent, with some work suggesting that the emphasis placed on retrieval from secondary memory by working memory tests is the driving force behind this association (Mogle, Lovett, Stawski, & Sliwinski,…

  5. Episodic memory in nonhuman animals

    PubMed Central

    Templer, Victoria L.

    2013-01-01

    Summary Episodic memories differ from other types of memory because they represent aspects of the past not present in other memories, such as the time, place, or social context in which the memories were formed. Focus on phenomenal experience in human memory, such as the sense of “having been there” has resulted in conceptualizations of episodic memory that are difficult or impossible to apply to nonhumans. It is therefore a significant challenge for investigators to agree on objective behavioral criteria that can be applied in nonhumans and still capture features of memory thought to be critical in humans. Some investigators have attempted to use neurobiological parallels to bridge this gap. However, defining memory types on the basis of the brain structures involved rather than on identified cognitive mechanisms risks missing the most crucial functional aspects of episodic memory, which are ultimately behavioral. The most productive way forward is likely a combination of neurobiology and sophisticated cognitive testing that identifies the mental representations present in episodic memory. Investigators that have refined their approach from asking the naïve question “do nonhuman animals have episodic memory” to instead asking “what aspects of episodic memory are shared by humans and nonhumans” are making progress. PMID:24028963

  6. Atomic memory access hardware implementations

    DOEpatents

    Ahn, Jung Ho; Erez, Mattan; Dally, William J

    2015-02-17

    Atomic memory access requests are handled using a variety of systems and methods. According to one example method, a data-processing circuit having an address-request generator that issues requests to a common memory implements a method of processing the requests using a memory-access intervention circuit coupled between the generator and the common memory. The method identifies a current atomic-memory access request from a plurality of memory access requests. A data set is stored that corresponds to the current atomic-memory access request in a data storage circuit within the intervention circuit. It is determined whether the current atomic-memory access request corresponds to at least one previously-stored atomic-memory access request. In response to determining correspondence, the current request is implemented by retrieving data from the common memory. The data is modified in response to the current request and at least one other access request in the memory-access intervention circuit.

  7. Intracranial recordings and human memory.

    PubMed

    Johnson, Elizabeth L; Knight, Robert T

    2015-04-01

    Recent work involving intracranial recording during human memory performance provides superb spatiotemporal resolution on mnemonic processes. These data demonstrate that the cortical regions identified in neuroimaging studies of memory fall into temporally distinct networks and the hippocampal theta activity reported in animal memory literature also plays a central role in human memory. Memory is linked to activity at multiple interacting frequencies, ranging from 1 to 500Hz. High-frequency responses and coupling between different frequencies suggest that frontal cortex activity is critical to human memory processes, as well as a potential key role for the thalamus in neocortical oscillations. Future research will inform unresolved questions in the neuroscience of human memory and guide creation of stimulation protocols to facilitate function in the damaged brain. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Vector computer memory bank contention

    NASA Technical Reports Server (NTRS)

    Bailey, D. H.

    1985-01-01

    A number of vector supercomputers feature very large memories. Unfortunately the large capacity memory chips that are used in these computers are much slower than the fast central processing unit (CPU) circuitry. As a result, memory bank reservation times (in CPU ticks) are much longer than on previous generations of computers. A consequence of these long reservation times is that memory bank contention is sharply increased, resulting in significantly lowered performance rates. The phenomenon of memory bank contention in vector computers is analyzed using both a Markov chain model and a Monte Carlo simulation program. The results of this analysis indicate that future generations of supercomputers must either employ much faster memory chips or else feature very large numbers of independent memory banks.

  9. Vector computer memory bank contention

    NASA Technical Reports Server (NTRS)

    Bailey, David H.

    1987-01-01

    A number of vector supercomputers feature very large memories. Unfortunately the large capacity memory chips that are used in these computers are much slower than the fast central processing unit (CPU) circuitry. As a result, memory bank reservation times (in CPU ticks) are much longer than on previous generations of computers. A consequence of these long reservation times is that memory bank contention is sharply increased, resulting in significantly lowered performance rates. The phenomenon of memory bank contention in vector computers is analyzed using both a Markov chain model and a Monte Carlo simulation program. The results of this analysis indicate that future generations of supercomputers must either employ much faster memory chips or else feature very large numbers of independent memory banks.

  10. Memory loss in Alzheimer's disease.

    PubMed

    Jahn, Holger

    2013-12-01

    Loss of memory is among the first symptoms reported by patients suffering from Alzheimer's disease (AD) and by their caretakers. Working memory and long-term declarative memory are affected early during the course of the disease. The individual pattern of impaired memory functions correlates with parameters of structural or functional brain integrity. AD pathology interferes with the formation of memories from the molecular level to the framework of neural networks. The investigation of AD memory loss helps to identify the involved neural structures, such as the default mode network, the influence of epigenetic and genetic factors, such as ApoE4 status, and evolutionary aspects of human cognition. Clinically, the analysis of memory assists the definition of AD subtypes, disease grading, and prognostic predictions. Despite new AD criteria that allow the earlier diagnosis of the disease by inclusion of biomarkers derived from cerebrospinal fluid or hippocampal volume analysis, neuropsychological testing remains at the core of AD diagnosis.

  11. Sleep deprivation and false memories.

    PubMed

    Frenda, Steven J; Patihis, Lawrence; Loftus, Elizabeth F; Lewis, Holly C; Fenn, Kimberly M

    2014-09-01

    Many studies have investigated factors that affect susceptibility to false memories. However, few have investigated the role of sleep deprivation in the formation of false memories, despite overwhelming evidence that sleep deprivation impairs cognitive function. We examined the relationship between self-reported sleep duration and false memories and the effect of 24 hr of total sleep deprivation on susceptibility to false memories. We found that under certain conditions, sleep deprivation can increase the risk of developing false memories. Specifically, sleep deprivation increased false memories in a misinformation task when participants were sleep deprived during event encoding, but did not have a significant effect when the deprivation occurred after event encoding. These experiments are the first to investigate the effect of sleep deprivation on susceptibility to false memories, which can have dire consequences.

  12. Vector computer memory bank contention

    NASA Technical Reports Server (NTRS)

    Bailey, David H.

    1987-01-01

    A number of vector supercomputers feature very large memories. Unfortunately the large capacity memory chips that are used in these computers are much slower than the fast central processing unit (CPU) circuitry. As a result, memory bank reservation times (in CPU ticks) are much longer than on previous generations of computers. A consequence of these long reservation times is that memory bank contention is sharply increased, resulting in significantly lowered performance rates. The phenomenon of memory bank contention in vector computers is analyzed using both a Markov chain model and a Monte Carlo simulation program. The results of this analysis indicate that future generations of supercomputers must either employ much faster memory chips or else feature very large numbers of independent memory banks.

  13. Heat engine based on shape-memory alloys

    SciTech Connect

    Goldstein, D.

    1989-12-01

    This patent application discloses a tubular gear made of shape memory alloy in sheet form, having longitudinal corrugations and being floating supported for rotation about an axis fixedly spaced from the rotational axis of a roller gear in meshing engagement with the corrugations. The tubular gear is sequentially deformed by exposure to radiated heat causing the shape memory alloy to expand circumferentially and by said meshing engagement with roller gear. Such deformation of the tubular gear within differential temperature regions established by restricted exposure to the radiated heat, induces and sustains rotation of the tubular gear to convert the heat energy into mechanical energy.

  14. The relation between verbal and visuospatial memory and autobiographical memory.

    PubMed

    Janssen, Steve M J; Kristo, Gert; Rouw, Romke; Murre, Jaap M J

    2015-01-01

    The basic-systems approach (Rubin, 2005, 2006) states that autobiographical memory is supported by other cognitive systems and argues that autobiographical memories are constructed from interactions between cognitive systems, such as language, vision and emotion. Although deficiencies in one or more of the basic systems influence the properties of autobiographical memories, little is known about how these cognitive abilities and autobiographical memory are related. To assert whether participants with stronger cognitive abilities also perform better on autobiographical memory tests, participants who completed verbal and visuospatial memory tests also recorded one personal event, which they recalled after a certain interval. Participants who performed well on the verbal memory tests also had better retention for the personal event, providing support for the basic-systems approach to autobiographical memory and preliminary support for the view that people have more memories from adolescence and early adulthood because the memory system works optimally in these lifetime periods. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  15. Method and apparatus for faulty memory utilization

    DOEpatents

    Cher, Chen-Yong; Andrade Costa, Carlos H.; Park, Yoonho; Rosenburg, Bryan S.; Ryu, Kyung D.

    2016-04-19

    A method for faulty memory utilization in a memory system includes: obtaining information regarding memory health status of at least one memory page in the memory system; determining an error tolerance of the memory page when the information regarding memory health status indicates that a failure is predicted to occur in an area of the memory system affecting the memory page; initiating a migration of data stored in the memory page when it is determined that the data stored in the memory page is non-error-tolerant; notifying at least one application regarding a predicted operating system failure and/or a predicted application failure when it is determined that data stored in the memory page is non-error-tolerant and cannot be migrated; and notifying at least one application regarding the memory failure predicted to occur when it is determined that data stored in the memory page is error-tolerant.

  16. Plant-based torsional actuator with memory

    NASA Astrophysics Data System (ADS)

    Plaza, Nayomi; Zelinka, Samuel L.; Stone, Don S.; Jakes, Joseph E.

    2013-07-01

    A bundle of a few loblolly pine (Pinus taeda) cells are moisture-activated torsional actuators that twist multiple revolutions per cm length in direct proportion to moisture content. The bundles generate 10 N m kg-1 specific torque during both twisting and untwisting, which is higher than an electric motor. Additionally, the bundles exhibit a moisture-activated, shape memory twist effect. Over 70% of the twist in a wetted bundle can be locked-in by drying under constraint and then released by rewetting the bundle. Our results indicate that hemicelluloses dominate the shape fixity mechanism and lignin is primarily responsible for remembering the bundle’s original form. The bundles demonstrate proof of a high specific torque actuator with large angles of rotation and shape memory twist capabilities that can be used in microactuators, sensors, and energy harvesters.

  17. Content addressable memory project

    NASA Technical Reports Server (NTRS)

    Hall, Josh; Levy, Saul; Smith, D.; Wei, S.; Miyake, K.; Murdocca, M.

    1991-01-01

    The progress on the Rutgers CAM (Content Addressable Memory) Project is described. The overall design of the system is completed at the architectural level and described. The machine is composed of two kinds of cells: (1) the CAM cells which include both memory and processor, and support local processing within each cell; and (2) the tree cells, which have smaller instruction set, and provide global processing over the CAM cells. A parameterized design of the basic CAM cell is completed. Progress was made on the final specification of the CPS. The machine architecture was driven by the design of algorithms whose requirements are reflected in the resulted instruction set(s). A few of these algorithms are described.

  18. Basic memory module

    NASA Technical Reports Server (NTRS)

    Tietze, F. C.

    1974-01-01

    Construction and electrical characterization of the 4096 x 2-bit Basic Memory Module (BMM) are reported for the Space Ultrareliable Modular Computer (SUMC) program. The module uses four 2K x 1-bit N-channel FET, random access memory chips, called array chips, and two sense amplifier chips, mounted and interconnected on a ceramic substrate. Four 5% tolerance power supplies are required. At the Module, the address, chip select, and array select lines require a 0-8.5 V MOS signal level. The data output, read-strobe, and write-enable lines operate at TTl levels. Although the module is organized as 4096 x 2 bits, it can be used in a 8196 x 1-bit application with appropriate external connections. A 4096 x 1-bit organization can be obtained by depopulating chips.

  19. Optoelectronic associative memory

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin (Inventor)

    1993-01-01

    An associative optical memory including an input spatial light modulator (SLM) in the form of an edge enhanced liquid crystal light valve (LCLV) and a pair of memory SLM's in the form of liquid crystal televisions (LCTV's) forms a matrix array of an input image which is cross correlated with a matrix array of stored images. The correlation product is detected and nonlinearly amplified to illuminate a replica of the stored image array to select the stored image correlating with the input image. The LCLV is edge enhanced by reducing the bias frequency and voltage and rotating its orientation. The edge enhancement and nonlinearity of the photodetection improves the orthogonality of the stored image. The illumination of the replicate stored image provides a clean stored image, uncontaminated by the image comparison process.

  20. Learning, memory, and synesthesia.

    PubMed

    Witthoft, Nathan; Winawer, Jonathan

    2013-03-01

    People with color-grapheme synesthesia experience color when viewing written letters or numerals, usually with a particular color evoked by each grapheme. Here, we report on data from 11 color-grapheme synesthetes who had startlingly similar color-grapheme pairings traceable to childhood toys containing colored letters. These are the first and only data to show learned synesthesia of this kind in more than a single individual. Whereas some researchers have focused on genetic and perceptual aspects of synesthesia, our results indicate that a complete explanation of synesthesia must also incorporate a central role for learning and memory. We argue that these two positions can be reconciled by thinking of synesthesia as the automatic retrieval of highly specific mnemonic associations, in which perceptual contents are brought to mind in a manner akin to mental imagery or the perceptual-reinstatement effects found in memory studies.

  1. Learning, Memory, and Synesthesia

    PubMed Central

    Witthoft, Nathan; Winawer, Jonathan

    2013-01-01

    People with color-grapheme synesthesia experience color when viewing written letters or numerals, usually with a particular color evoked by each grapheme. Here we report on 11 color-grapheme synesthetes with startlingly similar color-grapheme pairings traceable to childhood toys containing colored letters. These data are the first and only to show learned synesthesia of this kind in a group larger than a single case. While some researchers have focused on genetic and perceptual aspects of synesthesia, these results indicate that a complete explanation of synesthesia must also incorporate a central role for learning and memory. We argue that these two positions can be reconciled by thinking of synesthesia as the automatic retrieval of highly specific mnemonic associations, where perceptual contents are brought to mind, akin to mental imagery or the perceptual reinstatement effects found in the memory literature. PMID:23307940

  2. Mechanisms of epigenetic memory

    PubMed Central

    D’Urso, Agustina; Brickner, Jason H.

    2014-01-01

    Although genetics play an essential role in defining an organism’s development, morphology and physiology, epigenetic mechanisms play an essential role in modulating these properties by regulating gene expression. During development, epigenetic mechanisms establish stable gene expression patterns to ensure proper differentiation. Epigenetic mechanisms also allow organisms to adapt to environmental changes and previous experiences can impact the future responsiveness of an organism to a stimulus over long time scales and even over generations. Here we discuss the concept of epigenetic memory, defined as the stable propagation of a change in gene expression or potentially induced by developmental or environmental stimuli. We highlight three distinct paradigms of epigenetic memory that operate on different time scales. PMID:24780085

  3. TED KYCIA MEMORIAL SYMPOSIUM.

    SciTech Connect

    LITTENBERG, L.; RUBINSTEIN, R.; SAMIOS, N.; LI, K.; GIACOMELLI, G.; MOCKETT, P.; CARROLL, A.; JOHNSON, R.; BRYMAN, D.; TIPPENS, B.

    2000-05-19

    On the afternoon of May 19 2000, a Memorial Seminar was held in the BNL physics Large Seminar Room to honor the memory of Ted Kyeia, a prominent particle physicist who had been a member of the BNL staff for 40 years. Although it was understandably a somewhat sad occasion because Ted was no longer with us, nevertheless there was much for his colleagues and friends to celebrate in recalling the outstanding contributions that he had made in those four decades. The Seminar speakers were all people who had worked with Ted during that period; each discussed one aspect of his career, but also included anecdotes and personal reminiscences. This booklet contains the Seminar program, listing the speakers, and also copies of transparencies of the talks (and one paper which was a later expansion of a talk); sadly, not all of the personal remarks appeared on the transparencies.

  4. Memory for humorous cartoons.

    PubMed

    Schmidt, S R; Williams, A R

    2001-03-01

    Incidental memory for three types of cartoons was compared: original cartoons, literal translations of the originals, and weird cartoons created by inserting incongruous material into the literal translations. In Experiment 1, the three types of cartoons were mixed together in lists. In Experiment 2, each list contained only two cartoon types. In both experiments, original cartoons were remembered better than the literal and the weird cartoons, whereas the literal and the weird cartoons were equally well remembered. The detection of incongruities, or attempts to resolve those incongruities, cannot adequately explain the observed humor effects. The results were also inconsistent with both rehearsal and distinctiveness interpretations. Rather, humor per se appears to support good memory performance. Perhaps participants elaborated or gave sustained attention to humorous material at the expense of less humorous material.

  5. The Memory Jog Service

    NASA Astrophysics Data System (ADS)

    Dimakis, Nikolaos; Soldatos, John; Polymenakos, Lazaros; Sturm, Janienke; Neumann, Joachim; Casas, Josep R.

    The CHIL Memory Jog service focuses on facilitating the collaboration of participants in meetings, lectures, presentations, and other human interactive events, occurring in indoor CHIL spaces. It exploits the whole set of the perceptual components that have been developed by the CHIL Consortium partners (e.g., person tracking, face identification, audio source localization, etc) along with a wide range of actuating devices such as projectors, displays, targeted audio devices, speakers, etc. The underlying set of perceptual components provides a constant flow of elementary contextual information, such as “person at location x0,y0”, “speech at location x0,y0”, information that alone is not of significant use. However, the CHIL Memory Jog service is accompanied by powerful situation identification techniques that fuse all the incoming information and creates complex states that drive the actuating logic.

  6. Plant electrical memory.

    PubMed

    Volkov, Alexander G; Carrell, Holly; Adesina, Tejumade; Markin, Vladislav S; Jovanov, Emil

    2008-07-01

    Electrical signaling, short-term memory and rapid closure of the carnivorous plant Dionaea muscipula Ellis (Venus flytrap) have been attracting the attention of researchers since the XIX century. We found that the electrical stimulus between a midrib and a lobe closes the Venus flytrap upper leaf without mechanical stimulation of trigger hairs. The closing time of Venus flytrap by electrical stimulation is the same as mechanically induced closing. Transmission of a single electrical charge between a lobe and the midrib causes closure of the trap and induces an electrical signal propagating between both lobes and midrib. The Venus flytrap can accumulate small subthreshold charges, and when the threshold value is reached, the trap closes. Repeated application of smaller charges demonstrates the summation of stimuli. The cumulative character of electrical stimuli points to the existence of short-term electrical memory in the Venus flytrap.

  7. Place memory in crickets

    PubMed Central

    Wessnitzer, Jan; Mangan, Michael; Webb, Barbara

    2008-01-01

    Certain insect species are known to relocate nest or food sites using landmarks, but the generality of this capability among insects, and whether insect place memory can be used in novel task settings, is not known. We tested the ability of crickets to use surrounding visual cues to relocate an invisible target in an analogue of the Morris water maze, a standard paradigm for spatial memory tests on rodents. Adult female Gryllus bimaculatus were released into an arena with a floor heated to an aversive temperature, with one hidden cool spot. Over 10 trials, the time taken to find the cool spot decreased significantly. The best performance was obtained when a natural scene was provided on the arena walls. Animals can relocate the position from novel starting points. When the scene is rotated, they preferentially approach the fictive target position corresponding to the rotation. We note that this navigational capability does not necessarily imply the animal has an internal spatial representation. PMID:18230590

  8. Misaligned feeding impairs memories

    PubMed Central

    Loh, Dawn H; Jami, Shekib A; Flores, Richard E; Truong, Danny; Ghiani, Cristina A; O’Dell, Thomas J; Colwell, Christopher S

    2015-01-01

    Robust sleep/wake rhythms are important for health and cognitive function. Unfortunately, many people are living in an environment where their circadian system is challenged by inappropriate meal- or work-times. Here we scheduled food access to the sleep time and examined the impact on learning and memory in mice. Under these conditions, we demonstrate that the molecular clock in the master pacemaker, the suprachiasmatic nucleus (SCN), is unaltered while the molecular clock in the hippocampus is synchronized by the timing of food availability. This chronic circadian misalignment causes reduced hippocampal long term potentiation and total CREB expression. Importantly this mis-timed feeding resulted in dramatic deficits in hippocampal-dependent learning and memory. Our findings suggest that the timing of meals have far-reaching effects on hippocampal physiology and learned behaviour. DOI: http://dx.doi.org/10.7554/eLife.09460.001 PMID:26652002

  9. Sparse distributed memory

    NASA Technical Reports Server (NTRS)

    Denning, Peter J.

    1989-01-01

    Sparse distributed memory was proposed be Pentti Kanerva as a realizable architecture that could store large patterns and retrieve them based on partial matches with patterns representing current sensory inputs. This memory exhibits behaviors, both in theory and in experiment, that resemble those previously unapproached by machines - e.g., rapid recognition of faces or odors, discovery of new connections between seemingly unrelated ideas, continuation of a sequence of events when given a cue from the middle, knowing that one doesn't know, or getting stuck with an answer on the tip of one's tongue. These behaviors are now within reach of machines that can be incorporated into the computing systems of robots capable of seeing, talking, and manipulating. Kanerva's theory is a break with the Western rationalistic tradition, allowing a new interpretation of learning and cognition that respects biology and the mysteries of individual human beings.

  10. Skill and Working Memory.

    DTIC Science & Technology

    1982-04-30

    finally we will discuss our latest work with a mental calculation expert, a waiter who memorizes food orders, and we will discuss extensions of our...associations vs short-term memory occupancy and rote repetition underlies the empirical distinction between elaborative and maintenance rehearsal ( Bjork , 1975...temperature (5 alternatives) with a starch (3 alternatives) and a choice of salad-dressing (5 alternatives) and during the first part of the experiment also a

  11. Memory metal actuator

    NASA Technical Reports Server (NTRS)

    Ruoff, C. F. (Inventor)

    1985-01-01

    A mechanical actuator can be constructed by employing a plurality of memory metal actuator elements in parallel to control the amount of actuating force. In order to facilitate direct control by digital control signals provided by a computer or the like, the actuating elements may vary in stiffness according to a binary relationship. The cooling or reset time of the actuator elements can be reduced by employing Peltier junction cooling assemblies in the actuator.

  12. Fuzzy associative memories

    NASA Technical Reports Server (NTRS)

    Kosko, Bart

    1991-01-01

    Mappings between fuzzy cubes are discussed. This level of abstraction provides a surprising and fruitful alternative to the propositional and predicate-calculas reasoning techniques used in expert systems. It allows one to reason with sets instead of propositions. Discussed here are fuzzy and neural function estimators, neural vs. fuzzy representation of structured knowledge, fuzzy vector-matrix multiplication, and fuzzy associative memory (FAM) system architecture.

  13. Reading: Interactions with Memory.

    DTIC Science & Technology

    1991-07-23

    cue, than all other discourse entities. Following current global memory models ( Gillund & Shiffrin , 1984; Hintzman, 1988; Murdock, 1982; Ratcliff, 1978...global parallel retrieval models (e.g., Gillund & Shiffrin , 194; Hintzman, 1988; Murdock, 1982; Ratcliff, 1978). McKoon Page 21 Hence, we replace the...described in section I ( Gillund & Shiffrin , 1984; Hintzman, 1988; Murdock, 1982; Ratcliff, 1978; see also Gernsbacher, 1989). In the proposed process, the

  14. Shape Memory Actuator System

    DTIC Science & Technology

    1998-07-31

    The advantage in utilizing 15 shape-memory cables made of Nitinol for size reduction of the remote control actuator system is 1 Fi well suited for...a submarine environment because of its non-magnetic and corrosion resistance 17 properties. Use of thermoelastic Nitinol introduces other...problems because of the cooling and 18 resetting properties of Nitinol cables. It is therefore an important object of the present invention 19 on to

  15. Carter Memorial Lecture 2003

    NASA Astrophysics Data System (ADS)

    Gledhill, Robin

    2003-09-01

    The 2003 Carter Memorial Lecture was given in May by Dr Ben R Oppenheimer, Kalbfleisch Research Fellow in the Department of Astrophysics at the American Museum of Natural History in New York. Public lectures entitled "Aliens: The Scientific Search for Life on Other Planets" were given in Nelson, Dunedin, Christchurch, Wellington, Wanganui, Napier, Hamilton and Auckland. University seminars entitled "The Lyot Project" were given in Christchurch, Wellington, Hamilton and Auckland.

  16. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    Apollo 11 command module pilot Michael Collins is framed by the upraised Bible held by the Rev. Gina Gilland Campbell during a memorial service celebrating the life of Neil Armstrong at the Washington National Cathedral, Thursday, Sept. 13, 2012. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Bill Ingalls)

  17. Armstrong Memorial Service

    NASA Image and Video Library

    2012-09-13

    Carol Armstrong, center, her son Eric, right, and daughter Molly Van Wagenen hold their hands to their hearts during a memorial service celebrating the life of Neil Armstrong at the Washington National Cathedral, Thursday, Sept. 13, 2012. Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, died Saturday, Aug. 25. He was 82. Photo Credit: (NASA/Bill Ingalls)

  18. Tracking memory's trace

    PubMed Central

    Horn, Gabriel; Nicol, Alister U.; Brown, Malcolm W.

    2001-01-01

    There is strong converging evidence that the intermediate and medial part of the hyperstriatum ventrale of the chick brain is a memory store for information acquired through the learning process of imprinting. Neurons in this memory system come, through imprinting, to respond selectively to the imprinting stimulus (IS) neurons and so possess the properties of a memory trace. Therefore, the responses of the intermediate and medial part of the hyperstriatum ventrale neurons to a visual imprinting stimulus were determined before, during, and after training. Of the total recorded population, the proportions of IS neurons shortly after each of two 1-h training sessions were significantly higher (approximately 2 times) than the pretraining proportion. However, ≈4.5 h later this proportion had fallen significantly and did not differ significantly from the pretraining proportion. Nevertheless, ≈21.5 h after the end of training, the proportion of IS neurons was at its highest (approximately 3 times the pretraining level). No significant fluctuations occurred in the proportions of neurons responding to the alternative stimulus. In addition, nonmonotonic changes were found commonly in the activity of 230 of the neurons tracked individually from before training to shortly after the end of training. Thus the pattern of change in responsiveness both at the population level and at the level of individual neurons was highly nonmonotonic. Such a pattern of change is not consistent with simple models of memory based on synaptic strengthening to asymptote. A model is proposed that accounts for the changes in the population responses to the imprinting stimulus in terms of changes in the responses of individual neurons. PMID:11296266

  19. Epigenetic memory in plants

    PubMed Central

    Iwasaki, Mayumi; Paszkowski, Jerzy

    2014-01-01

    Epigenetics refers to heritable changes in patterns of gene expression that occur without alterations in DNA sequence. The epigenetic mechanisms involve covalent modifications of DNA and histones, which affect transcriptional activity of chromatin. Since chromatin states can be propagated through mitotic and meiotic divisions, epigenetic mechanisms are thought to provide heritable ‘cellular memory’. Here, we review selected examples of epigenetic memory in plants and briefly discuss underlying mechanisms. PMID:25104823

  20. Shape memory alloy actuator

    DOEpatents

    Varma, Venugopal K.

    2001-01-01

    An actuator for cycling between first and second positions includes a first shaped memory alloy (SMA) leg, a second SMA leg. At least one heating/cooling device is thermally connected to at least one of the legs, each heating/cooling device capable of simultaneously heating one leg while cooling the other leg. The heating/cooling devices can include thermoelectric and/or thermoionic elements.

  1. [From memories about war].

    PubMed

    Spivak, B A

    2010-04-01

    The article presents publication of memories of a military physician Spivak B.A., finished the First Kiev medical institute in 1941. The author held rank: from August 1941--chief of sanitary service of a separated battalion, April 1942-June 1945--chief of operation-bandaging unit of 246 SMSB SD. After war served in military treatment institutes on ranks of surgical profile, finished the military service in the rank of chief of surgical unit of Kovel garrison hospital in 1964.

  2. Transistor and memory devices based on novel organic and biomaterials

    NASA Astrophysics Data System (ADS)

    Tseng, Jia-Hung

    Organic semiconductor devices have aroused considerable interest because of the enormous potential in many technological applications. Organic electroluminescent devices have been extensively applied in display technology. Rapid progress has also been made in transistor and memory devices. This thesis considers aspects of the transistor based on novel organic single crystals and memory devices using hybrid nanocomposites comprising polymeric/inorganic nanoparticles, and biomolecule/quantum dots. Organic single crystals represent highly ordered structures with much less imperfections compared to amorphous thin films for probing the intrinsic charge transport in transistor devices. We demonstrate that free-standing, thin organic single crystals with natural flexing ability can be fabricated as flexible transistors. We study the surface properties of the organic crystals to determine a nearly perfect surface leading to high performance transistors. The flexible transistors can maintain high performance under reversible bending conditions. Because of the high quality crystal technique, we further develop applications on organic complementary circuits and organic single crystal photovoltaics. In the second part, two aspects of memory devices are studied. We examine the charge transfer process between conjugated polymers and metal nanoparticles. This charge transfer process is essential for the conductance switching in nanoseconds to induce the memory effect. Under the reduction condition, the charge transfer process is eliminated as well as the memory effect, raising the importance of coupling between conjugated systems and nanoparticle accepters. The other aspect of memory devices focuses on the interaction of virus biomolecules with quantum dots or metal nanoparticles in the devices. We investigate the impact of memory function on the hybrid bio-inorganic system. We perform an experimental analysis of the charge storage activation energy in tobacco mosaic virus with

  3. Cache directory look-up re-use as conflict check mechanism for speculative memory requests

    DOEpatents

    Ohmacht, Martin

    2013-09-10

    In a cache memory, energy and other efficiencies can be realized by saving a result of a cache directory lookup for sequential accesses to a same memory address. Where the cache is a point of coherence for speculative execution in a multiprocessor system, with directory lookups serving as the point of conflict detection, such saving becomes particularly advantageous.

  4. Histamine regulates memory consolidation.

    PubMed

    Passani, Maria Beatrice; Benetti, Fernando; Blandina, Patrizio; Furini, Cristiane R G; de Carvalho Myskiw, Jociane; Izquierdo, Ivan

    2017-08-23

    Recent findings have reasserted the role of histamine in the regulation of memory consolidation first proposed in 1986 in an inhibitory avoidance task in rats. They indicate that histamine is indeed a major regulator of memory consolidation in various tasks, through H2 receptors in the dorsal hippocampus and through H3 receptors in the basolateral amygdala, depending on the task. In the object recognition task, the memory enhancing effect is mediated by the three receptors (H1, H2, H3) in the dorsal hippocampus. In social recognition, the consolidation effect is mediated by H2 receptors in both amygdala and dorsal hippocampus. Data have suggested, in addition, influences on retrieval; this has been best studied in the dorsal hippocampus in step-down inhibitory avoidance task. Depending on the recent history of the conditioned stimulus (i.e., whether it has been recently reinforced or not), histamine acts on hippocampal H1 receptors, facilitating retrieval, or on H2 receptors, inhibiting it. Copyright © 2017. Published by Elsevier Inc.

  5. Sleep, Memory & Brain Rhythms.

    PubMed

    Watson, Brendon O; Buzsáki, György

    2015-01-01

    Sleep occupies roughly one-third of our lives, yet the scientific community is still not entirely clear on its purpose or function. Existing data point most strongly to its role in memory and homeostasis: that sleep helps maintain basic brain functioning via a homeostatic mechanism that loosens connections between overworked synapses, and that sleep helps consolidate and re-form important memories. In this review, we will summarize these theories, but also focus on substantial new information regarding the relation of electrical brain rhythms to sleep. In particular, while REM sleep may contribute to the homeostatic weakening of overactive synapses, a prominent and transient oscillatory rhythm called "sharp-wave ripple" seems to allow for consolidation of behaviorally relevant memories across many structures of the brain. We propose that a theory of sleep involving the division of labor between two states of sleep-REM and non-REM, the latter of which has an abundance of ripple electrical activity-might allow for a fusion of the two main sleep theories. This theory then postulates that sleep performs a combination of consolidation and homeostasis that promotes optimal knowledge retention as well as optimal waking brain function.

  6. Unifying Memory and Database Transactions

    NASA Astrophysics Data System (ADS)

    Dias, Ricardo J.; Lourenço, João M.

    Software Transactional Memory is a concurrency control technique gaining increasing popularity, as it provides high-level concurrency control constructs and eases the development of highly multi-threaded applications. But this easiness comes at the expense of restricting the operations that can be executed within a memory transaction, and operations such as terminal and file I/O are either not allowed or incur in serious performance penalties. Database I/O is another example of operations that usually are not allowed within a memory transaction. This paper proposes to combine memory and database transactions in a single unified model, benefiting from the ACID properties of the database transactions and from the speed of main memory data processing. The new unified model covers, without differentiating, both memory and database operations. Thus, the users are allowed to freely intertwine memory and database accesses within the same transaction, knowing that the memory and database contents will always remain consistent and that the transaction will atomically abort or commit the operations in both memory and database. This approach allows to increase the granularity of the in-memory atomic actions and hence, simplifies the reasoning about them.

  7. Sleep Loss Produces False Memories

    PubMed Central

    Diekelmann, Susanne; Landolt, Hans-Peter; Lahl, Olaf; Born, Jan; Wagner, Ullrich

    2008-01-01

    People sometimes claim with high confidence to remember events that in fact never happened, typically due to strong semantic associations with actually encoded events. Sleep is known to provide optimal neurobiological conditions for consolidation of memories for long-term storage, whereas sleep deprivation acutely impairs retrieval of stored memories. Here, focusing on the role of sleep-related memory processes, we tested whether false memories can be created (a) as enduring memory representations due to a consolidation-associated reorganization of new memory representations during post-learning sleep and/or (b) as an acute retrieval-related phenomenon induced by sleep deprivation at memory testing. According to the Deese, Roediger, McDermott (DRM) false memory paradigm, subjects learned lists of semantically associated words (e.g., “night”, “dark”, “coal”,…), lacking the strongest common associate or theme word (here: “black”). Subjects either slept or stayed awake immediately after learning, and they were either sleep deprived or not at recognition testing 9, 33, or 44 hours after learning. Sleep deprivation at retrieval, but not sleep following learning, critically enhanced false memories of theme words. This effect was abolished by caffeine administration prior to retrieval, indicating that adenosinergic mechanisms can contribute to the generation of false memories associated with sleep loss. PMID:18946511

  8. The evolution of episodic memory

    PubMed Central

    Allen, Timothy A.; Fortin, Norbert J.

    2013-01-01

    One prominent view holds that episodic memory emerged recently in humans and lacks a “(neo)Darwinian evolution” [Tulving E (2002) Annu Rev Psychol 53:1–25]. Here, we review evidence supporting the alternative perspective that episodic memory has a long evolutionary history. We show that fundamental features of episodic memory capacity are present in mammals and birds and that the major brain regions responsible for episodic memory in humans have anatomical and functional homologs in other species. We propose that episodic memory capacity depends on a fundamental neural circuit that is similar across mammalian and avian species, suggesting that protoepisodic memory systems exist across amniotes and, possibly, all vertebrates. The implication is that episodic memory in diverse species may primarily be due to a shared underlying neural ancestry, rather than the result of evolutionary convergence. We also discuss potential advantages that episodic memory may offer, as well as species-specific divergences that have developed on top of the fundamental episodic memory architecture. We conclude by identifying possible time points for the emergence of episodic memory in evolution, to help guide further research in this area. PMID:23754432

  9. Sleep loss produces false memories.

    PubMed

    Diekelmann, Susanne; Landolt, Hans-Peter; Lahl, Olaf; Born, Jan; Wagner, Ullrich

    2008-01-01

    People sometimes claim with high confidence to remember events that in fact never happened, typically due to strong semantic associations with actually encoded events. Sleep is known to provide optimal neurobiological conditions for consolidation of memories for long-term storage, whereas sleep deprivation acutely impairs retrieval of stored memories. Here, focusing on the role of sleep-related memory processes, we tested whether false memories can be created (a) as enduring memory representations due to a consolidation-associated reorganization of new memory representations during post-learning sleep and/or (b) as an acute retrieval-related phenomenon induced by sleep deprivation at memory testing. According to the Deese, Roediger, McDermott (DRM) false memory paradigm, subjects learned lists of semantically associated words (e.g., "night", "dark", "coal",...), lacking the strongest common associate or theme word (here: "black"). Subjects either slept or stayed awake immediately after learning, and they were either sleep deprived or not at recognition testing 9, 33, or 44 hours after learning. Sleep deprivation at retrieval, but not sleep following learning, critically enhanced false memories of theme words. This effect was abolished by caffeine administration prior to retrieval, indicating that adenosinergic mechanisms can contribute to the generation of false memories associated with sleep loss.

  10. Predicting confidence in flashbulb memories.

    PubMed

    Day, Martin V; Ross, Michael

    2014-01-01

    Years after a shocking news event many people confidently report details of their flashbulb memories (e.g., what they were doing). People's confidence is a defining feature of their flashbulb memories, but it is not well understood. We tested a model that predicted confidence in flashbulb memories. In particular we examined whether people's social bond with the target of a news event predicts confidence. At a first session shortly after the death of Michael Jackson participants reported their sense of attachment to Michael Jackson, as well as their flashbulb memories and emotional and other reactions to Jackson's death. At a second session approximately 18 months later they reported their flashbulb memories and confidence in those memories. Results supported our proposed model. A stronger sense of attachment to Jackson was related to reports of more initial surprise, emotion, and rehearsal during the first session. Participants' bond with Michael Jackson predicted their confidence but not the consistency of their flashbulb memories 18 months later. We also examined whether participants' initial forecasts regarding the persistence of their flashbulb memories predicted the durability of their memories. Participants' initial forecasts were more strongly related to participants' subsequent confidence than to the actual consistency of their memories.

  11. Investigating Memory Development in Children and Infantile Amnesia in Adults

    ERIC Educational Resources Information Center

    Kazemi Tari, Somayeh

    2008-01-01

    Although many researchers have worked on memory development, still little is known about what develops in memory development. When one reviews the literature about memory, she encounters many types of memories such as short term vs. long term memory, working memory, explicit vs. implicit memory, trans-saccadic memory, autobiographical memory,…

  12. Dreams are made of memories, but maybe not for memory.

    PubMed

    Blagrove, Mark; Ruby, Perrine; Eichenlaub, Jean-Baptiste

    2013-12-01

    Llewellyn's claim that rapid eye movement (REM) dream imagery may be related to the processes involved in memory consolidation during sleep is plausible. However, whereas there is voluntary and deliberate intention behind the construction of images in the ancient art of memory (AAOM) method, there is a lack of intentionality in producing dream images. The memory for dreams is also fragile, and dependent on encoding once awake.

  13. The Nature of Individual Differences in Working Memory Capacity: Active Maintenance in Primary Memory and Controlled Search from Secondary Memory

    ERIC Educational Resources Information Center

    Unsworth, Nash; Engle, Randall W.

    2007-01-01

    Studies examining individual differences in working memory capacity have suggested that individuals with low working memory capacities demonstrate impaired performance on a variety of attention and memory tasks compared with individuals with high working memory capacities. This working memory limitation can be conceived of as arising from 2…

  14. Material Engineering for Phase Change Memory

    NASA Astrophysics Data System (ADS)

    Cabrera, David M.

    As semiconductor devices continue to scale downward, and portable consumer electronics become more prevalent there is a need to develop memory technology that will scale with devices and use less energy, while maintaining performance. One of the leading prototypical memories that is being investigated is phase change memory. Phase change memory (PCM) is a non-volatile memory composed of 1 transistor and 1 resistor. The resistive structure includes a memory material alloy which can change between amorphous and crystalline states repeatedly using current/voltage pulses of different lengths and magnitudes. The most widely studied PCM materials are chalcogenides - Germanium-Antimony-Tellerium (GST) with Ge2Sb2Te3 and Germanium-Tellerium (GeTe) being some of the most popular stochiometries. As these cells are scaled downward, the current/voltage needed to switch these materials becomes comparable to the voltage needed to sense the cell's state. The International Roadmap for Semiconductors aims to raise the threshold field of these devices from 66.6 V/mum to be at least 375 V/mum for the year 2024. These cells are also prone to resistance drift between states, leading to bit corruption and memory loss. Phase change material properties are known to influence PCM device performance such as crystallization temperature having an effect on data retention and litetime, while resistivity values in the amorphous and crystalline phases have an effect on the current/voltage needed to write/erase the cell. Addition of dopants is also known to modify the phase change material parameters. The materials G2S2T5, GeTe, with dopants - nitrogen, silicon, titanium, and aluminum oxide and undoped Gallium-Antimonide (GaSb) are studied for these desired characteristics. Thin films of these compositions are deposited via physical vapor deposition at IBM Watson Research Center. Crystallization temperatures are investigated using time resolved x-ray diffraction at Brookhaven National Laboratory

  15. Electrophysiological measures of episodic memory control and memory retrieval.

    PubMed

    Wilding, E L; Herron, J E

    2006-10-01

    Event-related potentials (ERPs) index processes that occur before, during and after retrieval of information from episodic memory. In this selective review we provide a loose theoretical framework within which retrieval processes operating at these different stages can be considered. We go on to describe how ERPs have been employed in order to index processes operating at each of these stages. These data have contributed to current understanding of the processes that are engaged around the time of episodic memory retrieval, and also illustrate the potential that ERPs have for understanding in detail how memory retrieval processes changes in populations with memory impairments.

  16. Immune memory, immune oblivion: a lesson from Funes the memorious.

    PubMed

    Neuman, Yair

    2007-01-01

    We commonly think of the immune system as having a memory. However, memory is always accompanied by a complementary process of oblivion. Is there immune oblivion? In this theoretical paper, I address this question and suggest that oblivion is an integral aspect of memorization. In this context, I suggest that immune memory is an orchestration of reversible and irreversible processes of biological computation through feedback loops. Drawing on the linguistic metaphor, I inquire into the implications of this idea for a better understanding of immune memory and immune deficiency among the elderly.

  17. Sleep enhances false memories depending on general memory performance.

    PubMed

    Diekelmann, Susanne; Born, Jan; Wagner, Ullrich

    2010-04-02

    Memory is subject to dynamic changes, sometimes giving rise to the formation of false memories due to biased processes of consolidation or retrieval. Sleep is known to benefit memory consolidation through an active reorganization of representations whereas acute sleep deprivation impairs retrieval functions. Here, we investigated whether sleep after learning and sleep deprivation at retrieval enhance the generation of false memories in a free recall test. According to the Deese, Roediger, McDermott (DRM) false memory paradigm, subjects learned lists of semantically associated words (e.g., "night", "dark", "coal", etc.), lacking the strongest common associate or theme word (here: "black"). Free recall was tested after 9h following a night of sleep, a night of wakefulness (sleep deprivation) or daytime wakefulness. Compared with memory performance after a retention period of daytime wakefulness, both post-learning nocturnal sleep as well as acute sleep deprivation at retrieval significantly enhanced false recall of theme words. However, these effects were only observed in subjects with low general memory performance. These data point to two different ways in which sleep affects false memory generation through semantic generalization: one acts during consolidation on the memory trace per se, presumably by active reorganization of the trace in the post-learning sleep period. The other is related to the recovery function of sleep and affects cognitive control processes of retrieval. Both effects are unmasked when the material is relatively weakly encoded.

  18. Memory effects on mechanically stimulated electric signal; diversification of stimuli impact on material memory and comments on the observed features

    NASA Astrophysics Data System (ADS)

    Kyriazis, Panagiotis; Stavrakas, Ilias; Anastasiadis, Cimon; Triantis, Dimos; Stonham, John

    2010-05-01

    severely. (c) The short memory has temporary influence on the PSC signal and the impacts on the signal are milder. The main properties of the PSC signal, which are affected by the existence of memory, converge to an inertial attitude of the material to the same stimuli and they are quite common with the properties of other fracture induced signals (i.e. AE). Namely, they are the following: (a) The PSC peak evolution over loading cycles is a changing signal property either in the case of permanent or of temporary memory, with respect to the time interval between events, especially in the latter case. (b) The decrease of the dissipated electric energy during cyclic loading tests. (c) The PSC slower relaxation in each loading, quantified by the relaxation process parameters evolution. (d) The PSC signal response delay in each loading cycle increase The existence of memory effects on the mechanically stimulated electric signal is an indication that information about the deformation history (paleostresses) of the material reside inside the material. Under certain conditions such information can be revealed by analysis of the PSC signal response to specific external mechanical triggering.

  19. Developmental Dissociation Between the Maturation of Procedural Memory and Declarative Memory

    PubMed Central

    Finn, Amy S.; Kalra, Priya B.; Goetz, Calvin; Leonard, Julia A.; Sheridan, Margaret A.; Gabrieli, John D. E.

    2015-01-01

    Declarative memory and procedural memory are known to be two fundamentally different kinds of memory that are dissociable in their psychological characteristics and measurement (explicit versus implicit) and in the neural systems that subserve each kind of memory. Declarative memory abilities are known to improve from childhood through young adulthood, but the developmental maturation of procedural memory is largely unknown. We compared 10-year-old children and young adults on measures of declarative memory, working memory capacity, and four measures of procedural memory that have been strongly dissociated from declarative memory (mirror tracing, rotary pursuit, probabilistic classification, and artificial grammar). Children had lesser declarative memory ability and lesser working memory capacity than the adults, but exhibited learning equivalent to adults on all four measures of procedural memory. Declarative and procedural memory are, therefore, developmentally dissociable, with procedural memory being adult-like by age 10 and declarative memory continuing to mature into young adulthood. PMID:26560675

  20. Manganese oxide microswitch for electronic memory based on neural networks

    NASA Technical Reports Server (NTRS)

    Ramesham, R.; Daud, T.; Moopenn, A.; Thakoor, A. P.; Khanna, S. K.

    1989-01-01

    A solid-state, resistance tailorable, programmable-once, binary, nonvolatile memory switch based on manganese oxide thin films is reported. MnO(x) exhibits irreversible memory switching from conducting (on) to insulating (off) state, with the off and on resistance ratio of greater than 10,000. The switching mechanism is current-triggered chemical transformation of a conductive MnO(2-Delta) to an insulating Mn2O3 state. The energy required for switching is of the order of 4-20 nJ/sq micron. The low switching energy, stability of the on and off states, and tailorability of the on state resistance make these microswitches well suited as programmable binary synapses in electronic associative memories based on neural network models.

  1. Shape memory and superelastic ceramics at small scales.

    PubMed

    Lai, Alan; Du, Zehui; Gan, Chee Lip; Schuh, Christopher A

    2013-09-27

    Shape memory materials are a class of smart materials able to convert heat into mechanical strain (or strain into heat) by virtue of a martensitic phase transformation. Some brittle materials such as intermetallics and ceramics exhibit a martensitic transformation but fail by cracking at low strains and after only a few applied strain cycles. Here we show that such failure can be suppressed in normally brittle martensitic ceramics by providing a fine-scale structure with few crystal grains. Such oligocrystalline structures reduce internal mismatch stresses during the martensitic transformation and lead to robust shape memory ceramics that are capable of many superelastic cycles up to large strains; here we describe samples cycled as many as 50 times and samples that can withstand strains over 7%. Shape memory ceramics with these properties represent a new class of actuators or smart materials with a set of properties that include high energy output, high energy damping, and high-temperature usage.

  2. Context Memory in Alzheimer's Disease

    PubMed Central

    El Haj, Mohamad; Kessels, Roy P.C.

    2013-01-01

    Background Alzheimer's disease (AD) is a neurodegenerative disease characterized by a gradual loss of memory. Specifically, context aspects of memory are impaired in AD. Our review sheds light on the neurocognitive mechanisms of this memory component that forms the core of episodic memory function. Summary Context recall, an element of episodic memory, refers to remembering the context in which an event has occurred, such as from whom or to whom information has been transmitted. Key Messages Our review raises crucial questions. For example, (1) which context element is more prone to being forgotten in the disease? (2) How do AD patients fail to bind context features together? (3) May distinctiveness heuristic or decisions based on metacognitive expectations improve context retrieval in these patients? (4) How does cueing at retrieval enhance reinstating of encoding context in AD? By addressing these questions, our work contributes to the understanding of the memory deficits in AD. PMID:24403906

  3. Memory distortion: an adaptive perspective

    PubMed Central

    Schacter, Daniel L.; Guerin, Scott A.; St. Jacques, Peggy L.

    2011-01-01

    Memory is prone to distortions that can have serious consequences in everyday life. Here we integrate emerging evidence that several types of memory distortions – imagination inflation, gist-based and associative memory errors, and post-event misinformation – reflect adaptive cognitive processes that contribute to the efficient functioning of memory, but produce distortions as a consequence of doing so. We consider recent cognitive and neuroimaging studies that link these distortions with adaptive processes, including simulation of future events, semantic and contextual encoding, creativity, and memory updating. We also discuss new evidence concerning factors that can influence the occurrence of memory distortions, such as sleep and retrieval conditions, as well as conceptual issues related to the development of an adaptive perspective. PMID:21908231

  4. Electrophysiological measures of familiarity memory.

    PubMed

    Mecklinger, Axel

    2006-10-01

    Event-related potentials are a valuable tool for the study of human memory function. This selective review provides a brief introduction in models of recognition memory and then describes how ERPs can be used to investigate familiarity memory, an acontextual form of remembering that can be distinguished from the recollection of detailed information of prior events. ERP studies on the mid-frontal old/new effect, the putative electrophysiological correlate of familiarity memory are reviewed. It will be illustrated how familiarity memory is reflected in this effect, how it can electrophysiologically be dissociated from other forms of memory and which brain systems mediate this form of remembering. Recent studies will be reviewed that illustrate that familiarity is not only restricted to single items but can also support the retrieval of associative information.

  5. Motivated recruitment of autobiographical memories.

    PubMed

    Sanitioso, R; Kunda, Z; Fong, G T

    1990-08-01

    We hypothesized that people motivated to believe that they possess a given trait search for autobiographical memories that reflect that trait, so as to justify their desired self-view. We led subjects to believe that either extraversion or introversion was desirable, and obtained convergent evidence from open-ended memory-listing tasks as well as from reaction-time tasks measuring the speed with which memories could be generated that this manipulation enhanced the accessibility of memories reflecting the desired trait. If people rely on their memories to construct desired self-concepts, motivated changes in self-concepts should be constrained by the content of available memories. Our final study demonstrates such constraints.

  6. Memory B cells: total recall.

    PubMed

    Phan, Tri Giang; Tangye, Stuart G

    2017-03-28

    Immunological memory is a cornerstone of adaptive immune responses in higher vertebrates. The remarkable ability to generate memory cells following Ag exposure, in the context of natural infection or immunization, provides long-lived protection against infectious diseases, often for the hosts' lifetime. Indeed, the generation of memory B cells and long-lived plasma cells underpins the success of most vaccines. The concept of immunological memory is not new-it was first proposed nearly 2500 years ago. While our understanding of the complexities of humoral and cell-mediated memory continues to evolve, important aspects of this process remain unresolved. Here, we will provide an overview of recent advances in B-cell memory in mice and humans, and in health and disease.

  7. Black phosphorus nonvolatile transistor memory

    NASA Astrophysics Data System (ADS)

    Lee, Dain; Choi, Yongsuk; Hwang, Euyheon; Kang, Moon Sung; Lee, Seungwoo; Cho, Jeong Ho

    2016-04-01

    We demonstrated nanofloating gate transistor memory devices (NFGTMs) using mechanically-exfoliated few-layered black phosphorus (BP) channels and gold nanoparticle (AuNPs) charge trapping layers. The resulting BP-NFGTMs exhibited excellent memory performances, including the five-level data storage, large memory window (58.2 V), stable retention (104 s), and cyclic endurance (1000 cycles).We demonstrated nanofloating gate transistor memory devices (NFGTMs) using mechanically-exfoliated few-layered black phosphorus (BP) channels and gold nanoparticle (AuNPs) charge trapping layers. The resulting BP-NFGTMs exhibited excellent memory performances, including the five-level data storage, large memory window (58.2 V), stable retention (104 s), and cyclic endurance (1000 cycles). Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr02078j

  8. Is memory for music special?

    PubMed

    Schulkind, Matthew D

    2009-07-01

    Although psychologists since Hermann Ebbinghaus have studied memory, research in this area has focused on visual and verbal stimuli with little attention paid to music. This bias is surprising because of the ubiquity of music in human cultures across history as well as current cultural beliefs that memory for music is "special." This paper examines the question of whether memory for music is special by addressing two related questions: First, do cultural beliefs about the mnemonic power of music stand up to empirical test? Second, can theories designed to explain memory for non-musical stimuli be applied to musical stimuli? A review of the literature suggests that music is special in some circumstances but not others and that some theories designed to explain cognitive processing of linguistic stimuli apply reasonably well to musical stimuli. Thus, although the question of whether memory for music is special remains open, the unique structure of musical stimuli strongly suggests that memory for music is indeed special.

  9. Computational Cognitive Neuroscience of Early Memory Development

    ERIC Educational Resources Information Center

    Munakata, Yuko

    2004-01-01

    Numerous brain areas work in concert to subserve memory, with distinct memory functions relying differentially on distinct brain areas. For example, semantic memory relies heavily on posterior cortical regions, episodic memory on hippocampal regions, and working memory on prefrontal cortical regions. This article reviews relevant findings from…

  10. The Source for Learning & Memory Strategies.

    ERIC Educational Resources Information Center

    Richards, Regina G.

    This book is a comprehensive guide to learning and memory strategies for all students and especially those with learning problems. Chapter 1, on memory and the brain, explains brain cells, the cortex, function of the cerebral lobes, and other brain structures. Chapter 2 examines the memory process and discusses sensory memory, short-term memory,…

  11. Memory Reconsolidation and Computational Learning

    DTIC Science & Technology

    2010-03-01

    Cooper and H.T. Siegelmann, "Memory Reconsolidation for Natural Language Processing," Cognitive Neurodynamics , 3, 2009: 365-372. M.M. Olsen, N...computerized memories and other state of the art cognitive architectures, our memory system has the ability to process on-line and in real-time as...on both continuous and binary inputs, unlike state of the art methods in case based reasoning and in cognitive architectures, which are bound to

  12. Load and dump onboard memory

    NASA Astrophysics Data System (ADS)

    Welty, Alan

    2009-07-01

    This proposal is a test and verification of the ACS dump of memory capability.Areas of Control Section {CS} to dump include: EDAC RAM, EEPROM, and CS PROM {with the CS in Operate}. Areas of MIE memory to dump include: MIE RAM and MIE PROM {with the MIE in Operate}. Note that the MIE memory must first be copied to CS buffer RAM as images, which are then dumped.Supports Activity ACS-01

  13. Memory performance of Prolog architectures

    SciTech Connect

    Tick, E.

    1988-01-01

    Memory Performance of Prolog Architectures addresses these problems and reports dynamic data and instruction referencing characteristics of both sequential and parallel prolog architectures and corresponding uni-processor and multi-processor memory-hierarchy performance tradeoffs. Computer designers and logic programmers will find this work to be a valuable reference with many practical applications. Memory Performance of Prolog Architectures will also serve as an important textbook for graduate level courses in computer architecture and/or performance analysis.

  14. Shape Memory Composite Hybrid Hinge

    NASA Technical Reports Server (NTRS)

    Fang, Houfei; Im, Eastwood; Lin, John; Scarborough, Stephen

    2012-01-01

    There are two conventional types of hinges for in-space deployment applications. The first type is mechanically deploying hinges. A typical mechanically deploying hinge is usually composed of several tens of components. It is complicated, heavy, and bulky. More components imply higher deployment failure probability. Due to the existence of relatively moving components among a mechanically deploying hinge, it unavoidably has microdynamic problems. The second type of conventional hinge relies on strain energy for deployment. A tape-spring hinge is a typical strain energy hinge. A fundamental problem of a strain energy hinge is that its deployment dynamic is uncontrollable. Usually, its deployment is associated with a large impact, which is unacceptable for many space applications. Some damping technologies have been experimented with to reduce the impact, but they increased the risks of an unsuccessful deployment. Coalescing strain energy components with shape memory composite (SMC) components to form a hybrid hinge is the solution. SMCs are well suited for deployable structures. A SMC is created from a high-performance fiber and a shape memory polymer resin. When the resin is heated to above its glass transition temperature, the composite becomes flexible and can be folded or packed. Once cooled to below the glass transition temperature, the composite remains in the packed state. When the structure is ready to be deployed, the SMC component is reheated to above the glass transition temperature, and it returns to its as-fabricated shape. A hybrid hinge is composed of two strain energy flanges (also called tape-springs) and one SMC tube. Two folding lines are placed on the SMC tube to avoid excessive strain on the SMC during folding. Two adapters are used to connect the hybrid hinge to its adjacent structural components. While the SMC tube is heated to above its glass transition temperature, a hybrid hinge can be folded and stays at folded status after the temperature

  15. Memory mechanisms supporting syntactic comprehension

    PubMed Central

    Waters, Gloria

    2013-01-01

    Efforts to characterize the memory system that supports sentence comprehension have historically drawn extensively on short-term memory as a source of mechanisms that might apply to sentences. The focus of these efforts has changed significantly in the past decade. As a result of changes in models of short-term working memory (ST-WM) and developments in models of sentence comprehension, the effort to relate entire components of an ST-WM system, such as those in the model developed by Baddeley (Nature Reviews Neuroscience 4: 829–839, 2003) to sentence comprehension has largely been replaced by an effort to relate more specific mechanisms found in modern models of ST-WM to memory processes that support one aspect of sentence comprehension—the assignment of syntactic structure (parsing) and its use in determining sentence meaning (interpretation) during sentence comprehension. In this article, we present the historical background to recent studies of the memory mechanisms that support parsing and interpretation and review recent research into this relation. We argue that the results of this research do not converge on a set of mechanisms derived from ST-WM that apply to parsing and interpretation. We argue that the memory mechanisms supporting parsing and interpretation have features that characterize another memory system that has been postulated to account for skilled performance—long-term working memory. We propose a model of the relation of different aspects of parsing and interpretation to ST-WM and long-term working memory. PMID:23319178

  16. Gender differences in episodic memory.

    PubMed

    Herlitz, A; Nilsson, L G; Bäckman, L

    1997-11-01

    The relationship between gender and memory has been largely neglected by research, despite occasional studies reporting gender differences in episodic memory performance. The present study examined potential gender differences in episodic memory, semantic memory, primary memory, and priming. Five hundred thirty women and 470 men, randomly sampled from the city of Umeå, Sweden, 35-80 years of age, participated in the study. There were no differences between men and women with regard to age or education, or on a measure of global intellectual functioning. As has been demonstrated previously, men out performed women on a visuospatial task and women outperformed men on tests of verbal fluency. In addition, the results demonstrated that women consistently performed at a higher level than did men on the episodic memory tasks, although there were no differences between men and women on the tasks assessing semantic memory, primary memory, or priming. The women's higher level of performance on the episodic memory tasks could not be fully explained by their higher verbal ability.

  17. Synaptic Tagging During Memory Allocation

    PubMed Central

    Rogerson, Thomas; Cai, Denise; Frank, Adam; Sano, Yoshitake; Shobe, Justin; Aranda, Manuel L.; Silva, Alcino J.

    2014-01-01

    There is now compelling evidence that the allocation of memory to specific neurons (neuronal allocation) and synapses (synaptic allocation) in a neurocircuit is not random and that instead specific mechanisms, such as increases in neuronal excitability and synaptic tagging and capture, determine the exact sites where memories are stored. We propose an integrated view of these processes, such that neuronal allocation, synaptic tagging and capture, spine clustering and metaplasticity reflect related aspects of memory allocation mechanisms. Importantly, the properties of these mechanisms suggest a set of rules that profoundly affect how memories are stored and recalled. PMID:24496410

  18. Dreaming and offline memory consolidation.

    PubMed

    Wamsley, Erin J

    2014-03-01

    Converging evidence suggests that dreaming is influenced by the consolidation of memory during sleep. Following encoding, recently formed memory traces are gradually stabilized and reorganized into a more permanent form of long-term storage. Sleep provides an optimal neurophysiological state to facilitate this process, allowing memory networks to be repeatedly reactivated in the absence of new sensory input. The process of memory reactivation and consolidation in the sleeping brain appears to influence conscious experience during sleep, contributing to dream content recalled on awakening. This article outlines several lines of evidence in support of this hypothesis, and responds to some common objections.

  19. Characterization of fear memory reconsolidation.

    PubMed

    Duvarci, Sevil; Nader, Karim

    2004-10-20

    Reactivation of consolidated memories returns them to a protein synthesis-dependent state. One interpretation of these findings is that the memory reconsolidates after use. Two alternative interpretations are that protein synthesis inhibition facilitates extinction and that postreactivation protein synthesis inhibition leads to an inability to retrieve the consolidated memory. First, using two different approaches, we report that reconsolidation cannot be reduced down to facilitated extinction. We show that the reconsolidation deficit does not show renewal after a contextual shift, whereas an extinguished auditory fear memory does under the same conditions and the deficit occurs regardless of whether the memory is reactivated with an extinction [conditioned stimulus (CS) alone] or a reinforced trial (CS-unconditioned stimulus). To address the issue of whether postreactivation anisomycin leads to an inability to retrieve the consolidated memory, we used two traditional assays for retrieval deficits. First, we demonstrate that the amnesia induced by blockade of reconsolidation does not show any spontaneous recovery. Second, we show that application of reminder shock does not result in the reinstatement of the memory. These findings support the idea that reactivation of consolidated memories initiates a second time-dependent memory formation process.

  20. Recognition memory, and head injury.

    PubMed

    Brooks, D N

    1974-07-01

    Severely head injured adults were tested on a recognition memory procedure involving the identification of eight recurring shapes among a series of 160. Compared with a control group, the tested patients showed many fewer correct responses. Their type of error was commonly a failure to recognize rather than a false recognition. The severity of the memory deficit was related to the length of post-traumatic amnesia (PTA), but to neither the presence of neurological signs at the time of memory testing, nor to the time after injury at which the patients were tested. The older patients showed a more significant relationship between PTA and memory score than the younger patients.