This thesis explores memory performance for smartphone workloads. We design a Video Conference Workload (VCW) to model typical smartphone usage. We describe a trace-based methodology which uses a software implementation to mimic the behaviour of specialised hardware accelerators. Our methodology stores dataflow information from the original application to maintain the relationships between requests. We first study seven address mapping schemes with our VCW, using a first-ready, first-come-first-served (FR-FCFS) memory scheduler. Our results show the best performing scheme is up to 82% faster than the worst. The VCW is memory intensive, with up to 86.8% bandwidth utilisation using the best performing scheme. We also test a Web Browsing and a set of computer vision workloads. Most are not memory intensive, with utilisation under 15%. Finally, we compare four schedulers and find that the FR-FCFS scheduler using the Write Drain mode [8] performed the best, outperforming the worst scheduler by 6.3%.

Background This thesis investigated the efficacy and safety of Bacopa monnieri in improving memory in healthy Australians over the age of 55-years. A review of the literature showed that memory impairment and dementia are increasingly prevalent in the current demographic climate of an ageing population. As well as the pathological cognitive loss of neurodegenerative disease, many older persons are experiencing memory loss as part of the physiological process of ageing. Bacopa monnieri is a herbal medicine used since antiquity in the traditional Ayurvedic medical system of India for its cognitive enhancing effects. A number of pre-clinical and clinical studies support this traditional usage. Laboratory studies have demonstrated antioxidant and cholinergic actions in the brain as well as improved memory and cognitive performance in animal models. Human trials of Bacopa have also demonstrated improved memory performance. Some of these trials are limited by methodological flaws such as lack of blinding, small sample sizes, or use of outcome measurements which are not well validated. However, a small number of well designed human trials provide evidence for efficacy in cognitive and memory performance improvement. The current study was employed to extend on previous findings by assessing the efficacy and safety of Bacopa in the aged population specifically, as it is in this population that memory impairment becomes apparent. Aims 1. To assess the efficacy of Bacopa monnieri in improving memory in healthy Australians over the age of 55-years. 2. To assess whether the use of Bacopa is associated with side-effects Design A 12-week, randomised, double-blind, placebo-controlled, parallel group clinical trial. Participants Participants were self selected from the general population. They were aged 55-years or over at the commencement of the trial. Participants were without dementia, depression or other serious health conditions and did not use psychotropic medications. Intervention Participants were randomised to one of two treatment conditions, either a tableted extract of Bacopa monnieri called Bacomind™ (300mg/day, standardised to contain at least 40% bacosides), or an identical placebo. Participants attended three clinical evaluations: the first an initial screening session, the second a baseline evaluation of neuropsychological function and subjective memory performance at the commencement of the trial and the third, an end-of-trial outcome evaluation at 12-weeks, during which neuropsychological function and subjective memory performance were again assessed along with side-effects and study compliance. Primary Outcome Measures Rey Auditory Verbal Learning Test (AVLT), Rey-Osterrieth Complex Figure Test (CFT), Memory Complaint Questionnaire (MAC-Q), and Trail Making Test (TMT) Results From 136 people who elected to participate, 103 people met study entry criteria and 98 of these commenced the trial. Of these, 81 participants completed the trial and provided evaluable data for the end point analysis. Bacopa monnieri versus placebo significantly improved verbal learning as well as delayed recall as measured by the AVLT (p<.05). Though improvements were noted in the CFT, MAC-Q and TMT, there were no significant differences between placebo and active groups found for these tests. The Bacopa group reported a higher incidence of gastro-intestinal (GIT) side-effects than the placebo group, these predominantly being increased stool frequency, abdominal cramps and nausea. No other significant adverse effects were found. Conclusions A clinical trial was carried out to assess the effects of 12-weeks administration of Bacopa monnieri (300mg/day) on memory performance in people over the age of 55-years. Primary outcome measures were well validated neuropsychological tests that objectively measured verbal and visual memory and a memory complaint questionnaire that measured subjective memory complaints. The results demonstrated that Bacopa significantly improved memory acquisition and retention in older Australians. This concurs with findings from previous human and animal studies, as well as supports traditional Ayurvedic claims and uses. The beneficial effects on memory observed may be due to previously demonstrated antioxidant and cholinergic effects of the herb on the central nervous system. The use of Bacopa was associated with GIT side-effects, particularly increased bowel movements, nausea and abdominal cramping, findings infrequently reported previously. Possible explanations for these side-effects include GIT irritation by the saponin constituents of the herb, or cholinergic stimulation of autonomic and motor responses in the GIT, or a combination of both of these factors. The side-effects observed in the current study provide supportive evidence that Bacopa may increase cholinergic activity in humans. A worthwhile future extension of the current study would be to assess whether the finding of Bacopa’s efficacy for improving memory performance is replicable in populations with either mild cognitive impairment or early dementia.

Background This thesis investigated the efficacy and safety of Bacopa monnieri in improving memory in healthy Australians over the age of 55-years. A review of the literature showed that memory impairment and dementia are increasingly prevalent in the current demographic climate of an ageing population. As well as the pathological cognitive loss of neurodegenerative disease, many older persons are experiencing memory loss as part of the physiological process of ageing. Bacopa monnieri is a herbal medicine used since antiquity in the traditional Ayurvedic medical system of India for its cognitive enhancing effects. A number of pre-clinical and clinical studies support this traditional usage. Laboratory studies have demonstrated antioxidant and cholinergic actions in the brain as well as improved memory and cognitive performance in animal models. Human trials of Bacopa have also demonstrated improved memory performance. Some of these trials are limited by methodological flaws such as lack of blinding, small sample sizes, or use of outcome measurements which are not well validated. However, a small number of well designed human trials provide evidence for efficacy in cognitive and memory performance improvement. The current study was employed to extend on previous findings by assessing the efficacy and safety of Bacopa in the aged population specifically, as it is in this population that memory impairment becomes apparent. Aims 1. To assess the efficacy of Bacopa monnieri in improving memory in healthy Australians over the age of 55-years. 2. To assess whether the use of Bacopa is associated with side-effects Design A 12-week, randomised, double-blind, placebo-controlled, parallel group clinical trial. Participants Participants were self selected from the general population. They were aged 55-years or over at the commencement of the trial. Participants were without dementia, depression or other serious health conditions and did not use psychotropic medications. Intervention Participants were randomised to one of two treatment conditions, either a tableted extract of Bacopa monnieri called Bacomind™ (300mg/day, standardised to contain at least 40% bacosides), or an identical placebo. Participants attended three clinical evaluations: the first an initial screening session, the second a baseline evaluation of neuropsychological function and subjective memory performance at the commencement of the trial and the third, an end-of-trial outcome evaluation at 12-weeks, during which neuropsychological function and subjective memory performance were again assessed along with side-effects and study compliance. Primary Outcome Measures Rey Auditory Verbal Learning Test (AVLT), Rey-Osterrieth Complex Figure Test (CFT), Memory Complaint Questionnaire (MAC-Q), and Trail Making Test (TMT) Results From 136 people who elected to participate, 103 people met study entry criteria and 98 of these commenced the trial. Of these, 81 participants completed the trial and provided evaluable data for the end point analysis. Bacopa monnieri versus placebo significantly improved verbal learning as well as delayed recall as measured by the AVLT (p<.05). Though improvements were noted in the CFT, MAC-Q and TMT, there were no significant differences between placebo and active groups found for these tests. The Bacopa group reported a higher incidence of gastro-intestinal (GIT) side-effects than the placebo group, these predominantly being increased stool frequency, abdominal cramps and nausea. No other significant adverse effects were found. Conclusions A clinical trial was carried out to assess the effects of 12-weeks administration of Bacopa monnieri (300mg/day) on memory performance in people over the age of 55-years. Primary outcome measures were well validated neuropsychological tests that objectively measured verbal and visual memory and a memory complaint questionnaire that measured subjective memory complaints. The results demonstrated that Bacopa significantly improved memory acquisition and retention in older Australians. This concurs with findings from previous human and animal studies, as well as supports traditional Ayurvedic claims and uses. The beneficial effects on memory observed may be due to previously demonstrated antioxidant and cholinergic effects of the herb on the central nervous system. The use of Bacopa was associated with GIT side-effects, particularly increased bowel movements, nausea and abdominal cramping, findings infrequently reported previously. Possible explanations for these side-effects include GIT irritation by the saponin constituents of the herb, or cholinergic stimulation of autonomic and motor responses in the GIT, or a combination of both of these factors. The side-effects observed in the current study provide supportive evidence that Bacopa may increase cholinergic activity in humans. A worthwhile future extension of the current study would be to assess whether the finding of Bacopa’s efficacy for improving memory performance is replicable in populations with either mild cognitive impairment or early dementia.

No description available.

Aim: The purpose of this study was to investigate acute effects of physical exercise of different intensities on working memory. Method: Twelve young adults, 20-40 years, 8 males and 4 females passed the screening and participated in a randomized experimental crossover within-subject design study with three experimental conditions. Working memory was measured with n-back consisting of three difficulty levels.  Results: No significant interaction effect within subjects between the three different exercise intensity conditions for accuracy or response time was found. A significant main effect of time was detected for n-back response time, F(1,11)=40.2, p=&lt;.001, reflecting an overall shorter response time after exercise compared to before, independent of exercise intensity condition. A two-way interaction effect on accuracy was found between n-back session 1 and 2 in the low fitness group.  Conclusions: The exercise intensity does not seem to matter for the improvement of working memory performance. However, participants response time was shown to be faster following any given exercise intensity.

Ungdomar tillhör idag det som kallas den digitala generationen och äruppvuxna i en verklighet där tekniska redskap är en självklarhet.Mobiltelefonanvändning under lektionstid innebär deladuppmärksamhet. Tidigare forskning visar att användning av tekniskaredskap vid inlärning påverkar studenters akademiska prestationnegativt. Gymnasieelever är en sällan undersökt målpopulation isamband med uppmärksamhet och inlärning. Syftet med denna studievar att undersöka om mobiltelefonanvändning vid inlärning påverkargymnasieelevers minnesprestation. Ett experiment bestående av ettfriåtergivningstest och ett läsförståelsetest genomfördes med 49deltagare. Deltagarna som använde delad uppmärksamhet mottog ochsvarade på ett meddelande i sin mobiltelefon under inkodning.Resultatet visade att mobiltelefonanvändning vid inlärning påverkargymnasieelevers minnesprestation negativt vid läsförståelse. Merspecifikt påverkades manliga gymnasieelever mer av deladuppmärksamhet vid läsförståelse. / Adolescents today are part of what is called the digital generation andare raised in a reality where technical instruments are part of everydaylife. Cell phone use in class results in divided attention. Previousresearch has shown that usage of technical instruments during learninghas a negative impact on students’ academic performance. Highschool students are seldom the target population in studies concerningattention and learning. The purpose of this study was to investigatewhether cell phone use during learning affects high school students’memory performance. An experiment including a test of free recalland a test of reading comprehension was conducted with 49participants. The participants in the divided attention conditionreceived and responded to a message in their cell phones at encoding.The results showed that cell phone use during learning had a negativeimpact on high school students’ reading comprehension. Specifically,male high school students’ reading comprehension was more affectedby divided attention.

Observed influences of system response delay in spoken human-machine dialogues are rather ambiguous and mainly focus on perceived system quality. Studies that systematically inspect effects on cognitive performance are still lacking, and effects of individual characteristics are also often neglected. Building on benefits of cognitive training for decelerating cognitive decline, this Wizard-of-Oz study addresses both issues by testing 62 elderly participants in a dialogue-based memory training with a virtual agent. Participants acquired the method of loci with fading instructional guidance and applied it afterward to memorizing and recalling lists of German nouns. System response delays were randomly assigned, and training performance was included as potential mediator. Participants’ age, gender, and subscales of affinity for technology (enthusiasm, competence, positive and negative perception of technology) were inspected as potential moderators. The results indicated positive effects on recall performance with higher training performance, female gender, and less negative perception of technology. Additionally, memory retention and facets of affinity for technology moderated increasing system response delays. Participants also provided higher ratings in perceived system quality with higher enthusiasm for technology but reported increasing frustration with a more positive perception of technology. Potential explanations and implications for the design of spoken dialogue systems are discussed.

No description available.

Ces dix dernières années, les technologies de stockage non-volatile Flash ont joué un rôle majeur dans le développement des appareils électroniques mobiles et multimedia (MP3, Smartphone, clés USB, ordinateurs ultraportables…). Afin d’améliorer davantage les performances, augmenter les capacités et diminuer les coûts de fabrication, de nouvelles solutions technologiques sont aujourd’hui étudiées pour pouvoir compléter ou remplacer la technologie Flash. Citées par l’ITRS, les mémoires résistives polymères présentent des caractéristiques très prometteuses : procédés de fabrication à faible coût et possibilité d’intégration haute densité au dessus des niveaux d’interconnexions CMOS ou sur substrat souple. Ce travail de thèse a été consacré au développement et à l'étude des mémoires résistifs organiques à base de polymère de poly-méthyl-méthacrylate (PMMA) et de molécules de fullerènes (C60). Trois axes de recherche ont été menés en parallèle: le développement et la caractérisation physico-chimique de matériaux composites, l’intégration du matériau organique dans des structures de test spécifiques et la caractérisation détaillée du fonctionnement électrique des dispositifs et des performances mémoires. / Over the past decade, non-volatile Flash storage technologies have played a major role in the development of mobile electronics and multimedia (MP3, Smartphone, USB, ultraportable computers ...). To further enhance performances, increase the capacity and reduce manufacturing costs, new technological solutions are now studied to provide complementary solutions or replace Flash technology. Cited by ITRS, the polymer resistive memories present very promising characteristics: low cost processing and ability for integration at high densities above CMOS interconnections or on flexible substrate. This PhD specifically focused on the development and study of composite material made of Poly-Methyl-Methacrylate (PMMA) polymer resist doped with C60 fullerene molecules. Studies were carried out on three different axes in parallel: Composite materials development & characterization, integration of the organic material in specific test structure and advanced devices and finally detailed electrical characterization of memory cells and performances analysis.