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Scaling out NUMA-Aware Applications with RDMA-Based Distributed Shared Memory
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作者 Yang Hong Yang Zheng +3 位作者 Fan Yang Bin-Yu Zang Hai-Bing Guan Hai-Bo Chen 《计算机科学技术学报:英文版》 SCIE EI CSCD 2019年第1期94-112,共19页
The multicore evolution has stimulated renewed interests in scaling up applications on shared-memory multiprocessors,significantly improving the scalability of many applications.But the scalability is limited within a... The multicore evolution has stimulated renewed interests in scaling up applications on shared-memory multiprocessors,significantly improving the scalability of many applications.But the scalability is limited within a single node;therefore programmers still have to redesign applications to scale out over multiple nodes.This paper revisits the design and implementation of distributed shared memory (DSM)as a way to scale out applications optimized for non-uniform memory access (NUMA)architecture over a well-connected cluster.This paper presents MAGI,an efficient DSM system that provides a transparent shared address space with scalable performance on a cluster with fast network interfaces.MAGI is unique in that it presents a NUMA abstraction to fully harness the multicore resources in each node through hierarchical synchronization and memory management.MAGI also exploits the memory access patterns of big-data applications and leverages a set of optimizations for remote direct memory access (RDMA)to reduce the number of page faults and the cost of the coherence protocol.MAGI has been implemented as a user-space library with pthread-compatible interfaces and can run existing multithreaded applications with minimized modifications.We deployed MAGI over an 8-node RDMA-enabled cluster.Experimental evaluation shows that MAGI achieves up to 9.25:4 speedup compared with an unoptimized implementation,leading to a sealable performance for large-scale data-intensive applications. 展开更多
关键词 distributed shared MEMORY (DSM) SCALABILITY multieore evolution NON-UNIFORM MEMORY ACCESS (NUMA) remote direct MEMORY ACCESS (RDMA)
Extending SSD Lifespan with Comprehensive Non-Volatile Memory-Based Write Buffers
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作者 Ziqi Fan Dongchul Park 《计算机科学技术学报:英文版》 SCIE EI CSCD 2019年第1期113-132,共20页
New non-volatile memory (NVM)technologies are expected to replace main memory DRAM (dynamic random access memory)in the near future.NAND flash technological breakthroughs have enabled wide adoption of solid state driv... New non-volatile memory (NVM)technologies are expected to replace main memory DRAM (dynamic random access memory)in the near future.NAND flash technological breakthroughs have enabled wide adoption of solid state drives (SSDs)in storage systems.However,flash-based SSDs,by nature,cannot avoid low endurance problems because each cell only allows a limited number of erasures.This can give rise to critical SSD reliability issues.Since many SSD write operations eventually cause many SSD erase operations,reducing SSD write traffic plays a crucial role in SSD reliability. This paper proposes two NVM-based buffer cache policies which can work together in different layers to maximally reduce SSD write traffic:a main memory buffer cache design named Hierarchical Adaptive Replacement Cache (H-ARC)and an internal SSD write buffer design named Write Traffic Reduction Buffer (WRB).H-ARC considers four factors (dirty,clean, recency,and frequency)to reduce write traffic and improve cache hit ratios in the host.WRB reduces block erasures and write traffic further inside an SSD by effectively exploiting temporal and spatial localities.These two comprehensive schemes significantly reduce total SSD write traffic at each different layer (i.e.,host and SSD)by up to 3x.Consequently,they help extend SSD lifespan without system performance degradation. 展开更多
关键词 BUFFER cache policy WRITE BUFFER non-volatile MEMORY solid state drive flash MEMORY
Modeling of program Vth distribution for 3-D TLC NAND flash memory
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作者 Kunliang WANG Gang DU +2 位作者 Zhiyuan LUN Wangyong CHEN Xiaoyan LIU 《中国科学:信息科学(英文版)》 SCIE EI CSCD 2019年第4期183-192,共10页
This paper proposes a simulation method to model the program Vth distribution of 3-D vertical channel TLC/QLC charge-trapping NAND flash memory. The program Vth distribution can be calculated by considering ISPP noise... This paper proposes a simulation method to model the program Vth distribution of 3-D vertical channel TLC/QLC charge-trapping NAND flash memory. The program Vth distribution can be calculated by considering ISPP noise, WL-WL interference, and the RTN effect of tunneling oxide and poly Si, which are the major physical factors affecting the width of program Vth distribution. Then, the program Vth distribution shapes with different ISPP incremental voltage steps are compared, and the results are found to be consistent with the experimental results. Code and layer-dependent coupling coefficients of WL-WL interference in 3-D vertical channel NAND flash memory are considered. The effect of RTN on the program Vth distribution is comprehensively studied. The program Vth distribution of a WL is calibrated with the measurement, and a good agreement is obtained, validating the array program Vth distribution simulation method. The simulation method can help in improving the reliability of 3-D TLC NAND flash memory and provides guidance for the design and optimization of 3-D QLC NAND flash memory technology. 展开更多
关键词 modeling and simulation measurement reliability PROGRAM Vth DISTRIBUTION charge-trapping MEMORY 3-D vertical channel TLC/QLC NAND flash MEMORY
寻常型银屑病患者的情绪记忆改变 预览
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作者 于浈 王红梅 《中国疗养医学》 2019年第2期116-118,共3页
目的通过情绪记忆测试对寻常型银屑病患者的情绪记忆功能进行评估,以探讨其情绪记忆的特征。方法使用不同效价的情绪图片学习-再认任务分别对33名寻常型银屑病患者及33名对照进行情绪记忆测试。结果学习阶段,三种情绪图片评分成绩,银屑... 目的通过情绪记忆测试对寻常型银屑病患者的情绪记忆功能进行评估,以探讨其情绪记忆的特征。方法使用不同效价的情绪图片学习-再认任务分别对33名寻常型银屑病患者及33名对照进行情绪记忆测试。结果学习阶段,三种情绪图片评分成绩,银屑病组与对照组比较,差异无统计学意义(均P>0.05)。再认阶段,总情绪图片再认正确得分,银屑病组(39.09±4.48)分与对照组(42.00±3.54)分比较,差异有统计学意义(P<0.05)。进一步分析显示,银屑病组对不同效价情绪图片再认存在分离现象:正性情绪图片再认正确得分,银屑病组(12.33±2.27)分较对照组(13.52±2.06)分明显下降,差异有统计学意义(P<0.05);中性情绪图片再认正确得分,银屑病组(12.82±2.30)分较对照组(13.97±2.13)分明显下降,差异有统计学意义(P<0.05);而在负性情绪图片再认正确得分,银屑病组(13.94±1.80)分与对照组(14.52±1.56)分比较,差异无统计学意义(P>0.05)。结论寻常型银屑病存在情绪记忆的受损,表现为正性、中性情绪记忆损害,而负性情绪记忆相对完整。 展开更多
关键词 寻常型银屑病 情绪 记忆
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火麻仁提取液对D-GAL致衰老大鼠认知功能的影响 预览
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作者 唐岚莹 彭均华 《大众科技》 2019年第4期65-67,共3页
目的:探究火麻提取物(EFC)对D-半乳糖(D-gal)诱导的衰老大鼠认知的影响。方法:随机选取3月龄的雄性大鼠48只,分为6组,每组8只:正常对照组(control)、D-gal模型组、EFC(200mg/kg)预防组、EFC(400mg/kg)预防组、D-gal+EFC(200mg/kg)组、D-... 目的:探究火麻提取物(EFC)对D-半乳糖(D-gal)诱导的衰老大鼠认知的影响。方法:随机选取3月龄的雄性大鼠48只,分为6组,每组8只:正常对照组(control)、D-gal模型组、EFC(200mg/kg)预防组、EFC(400mg/kg)预防组、D-gal+EFC(200mg/kg)组、D-gal+EFC(400mg/kg)组,对各组大鼠进行Morris水迷宫的测试。结果:D-gal模型组大鼠搜索平台潜伏期增加,寻找隐藏平台的路径更曲折。而EFC(400mg/kg)预防组和治疗组大鼠潜伏期明显缩短,寻找平台的路径则比较简单。这些结果表明,EFC可以有效地预防由D-gal引起的大鼠空间记忆障碍。结论:火麻仁提取液在一定程度上可以改善D-gal致衰老大鼠的认知功能。 展开更多
关键词 火麻仁提取液 认知 记忆
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Spy Films and Intellectual Alienation 预览
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作者 Reidar Due 《文化与宗教研究:英文版》 2019年第7期333-347,共15页
The article analyzes spy films as examples of alienation within modern office life. It shows how intellectual socialization within this type of life can lead to a corruption of a person’s moral capabilities. The arti... The article analyzes spy films as examples of alienation within modern office life. It shows how intellectual socialization within this type of life can lead to a corruption of a person’s moral capabilities. The article studies this corruption process with a focus on how the moral person, in this case the fictional spy character, uses her intellect in relation to other mental faculties and in relation to the person’s own biographical experience of time. With reference to Plato and Hannah Arendt, the article shows that the professional use of intellect has an active and a passive quality. It is passive in so far as the person acquires it gradually, through training. It is active on the other hand, since the person willingly submits to this training. The moral stakes of these spy narratives thus concerns the choice to become a certain kind of person by subjecting oneself to a certain type of intellectual training. Memory forms an entry into this question of choice in all the examined films, hence memory is also at the centre of my analysis. This psychological mode of interpretation is inspired by Paul Ricoeur’s philosophy of narrative. 展开更多
关键词 Memory INTELLECT Intelligence Motivation PLATO HERMENEUTICS Riceour ARENDT
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A Novel RRAM Based PUF for Anti-Machine Learning Attack and High Reliability
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作者 戴澜 闫强强 +2 位作者 易盛禹 刘文楷 钱鹤 《上海交通大学学报:英文版》 EI 2019年第1期101-106,共6页
Due to the unique response mechanism, physical unclonable function(PUF) has been extensively studied as a hardware security primitive. And compared to other PUFs, the resistive random access memory(RRAM)based PUF has ... Due to the unique response mechanism, physical unclonable function(PUF) has been extensively studied as a hardware security primitive. And compared to other PUFs, the resistive random access memory(RRAM)based PUF has more flexibility with the change of conductive filaments. In this work, we propose an exclusive or(XOR) strong PUF based on the 1 Kbit 1-transistor-1-resistor(1 T1 R) arrays, and unlike the traditional RRAM based strong PUF, the XOR PUF has a stronger anti-machine learning attack ability in our experiments. The reliability of XOR RRAM PUF is determined by the read instability, thermal dependence of RRAM resistance,and aging. We used a split current distribution scheme to make the reliability of XOR PUF significantly improved.After baking for 50 h at a high temperature of 150?C, the intra-chip Hamming distance(Intra-HD) only increased from 0 to 4.5%. The inter-chip Hamming distance(Inter-HD) and uniformity are close to 50%(ideally). And it is proven through the NIST test that XOR PUF has a high uniqueness. 展开更多
关键词 physical unclonable functions resistive random access memory MACHINE LEARNING ATTACK anti-machine LEARNING ATTACK XOR RRAM PUF
电针联合丰富环境对糖尿病大鼠空间学习记忆能力的影响 预览
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作者 唐明薇 梅希 王风波 《东南国防医药》 2019年第1期17-20,共4页
目的观察电针联合丰富环境对糖尿病大鼠空间学习记忆能力改善的影响作用。方法40只成年Wistar大鼠按随机数字表法分为空白组(n=8)、非干预组(n=8)、电针组(n=8)、丰富环境组(n=8)和电针联合丰富环境组(n=8),除空白组外其他4组大鼠采用... 目的观察电针联合丰富环境对糖尿病大鼠空间学习记忆能力改善的影响作用。方法40只成年Wistar大鼠按随机数字表法分为空白组(n=8)、非干预组(n=8)、电针组(n=8)、丰富环境组(n=8)和电针联合丰富环境组(n=8),除空白组外其他4组大鼠采用链脲佐菌素腹腔注射法制备糖尿病大鼠模型,并于模型制备成功次日开始电针干预及给予多感官刺激的丰富环境,所有大鼠于干预第4周进行Morris水迷宫空间学习记忆能力测验。结果与非干预组[(51.74±0.59)s]比较,电针组、丰富环境组、电针联合丰富环境组逃避潜伏期均显著缩短[(16.26±0.48)s、(15.41±0.87)s、(12.75±0.49)s,P<0.01];电针联合丰富环境组逃避潜伏期较电针组、丰富环境组大鼠缩短更明显(P<0.05)。与非干预组[(2.83±0.27)次]比较,电针组、丰富环境组、电针联合丰富环境组平台穿越次数均明显增加[(5.75±0.66)次、(6.35±0.44)次、(8.73±0.68)次,P<0.01];电针联合丰富环境组穿越次数多于电针组及丰富环境组(P<0.05)。结论电针联合丰富环境能显著改善糖尿病大鼠空间学习记忆能力,且优于单纯电针或丰富环境,提示电针联合丰富环境刺激更有利于糖尿病患者早期认知功能障碍的康复治疗。 展开更多
关键词 电针 丰富环境 糖尿病 学习 记忆
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情境体验式的乡村景观特征研究 预览
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作者 顾燕燕 郑军德 孙攀 《绿色科技》 2019年第7期191-193,共3页
指出了乡村景观作为乡村建设的重要组成部分,在取得重要成果的同时也存在一些问题。随着人的生活方式及需求转型升级,人们对乡村景观已不仅仅满足于功能及视觉上的需求,更偏向于精神体验和情感回归的情境景观空间。从情境体验角度出发,... 指出了乡村景观作为乡村建设的重要组成部分,在取得重要成果的同时也存在一些问题。随着人的生活方式及需求转型升级,人们对乡村景观已不仅仅满足于功能及视觉上的需求,更偏向于精神体验和情感回归的情境景观空间。从情境体验角度出发,深刻剖析了基于情境体验式景观的作用原理及三重情境体验分析。在此基础上,提出了情境体验式乡村景观主题设定分类及特征表现,以供参考。 展开更多
关键词 情境体验 乡村景观 特征 记忆
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Postnatal calpeptin treatment causes hippocampal neurodevelopmental defects in neonatal rats 预览
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作者 Zhu-Jin Song San-Juan Yang +2 位作者 Lan Han Bin Wang Guoqi Zhu 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第5期834-840,共7页
Our previous studies showed that the early use of calpain inhibitors reduces calpain activity in multiple brain regions,and that postnatal treatment with calpeptin may lead to cerebellar motor dysfunction.However,it r... Our previous studies showed that the early use of calpain inhibitors reduces calpain activity in multiple brain regions,and that postnatal treatment with calpeptin may lead to cerebellar motor dysfunction.However,it remains unclear whether postnatal calpeptin application affects hippocampus-related behaviors.In this study,Sprague-Dawley rats were purchased from the Animal Center of Anhui Medical University of China.For the experiments in the adult stage,rats were intraperitoneally injected with calpeptin,2 mg/kg,once a day,on postnatal days 7–14.Then on postnatal day 60,the Morris water maze test was used to evaluate spatial learning and memory abilities.The open field test was carried out to assess anxiety-like activities.Phalloidin staining was performed to observe synaptic morphology in the hippocampus.Immunohistochemistry was used to count the number of NeuN-positive cells in the hippocampal CA1 region.DiI was applied to label dendritic spines.Calpeptin administration impaired spatial memory,caused anxiety-like behavior in adulthood,reduced the number and area of apical dendritic spines,and decreased actin polymerization in the hippocampus,but did not affect the number of NeuN-positive cells in the hippocampal CA1 region.For the neonatal experiments,neonatal rats were intraperitoneally injected with calpeptin,2 mg/kg,on postnatal days 7 and 8.Western blot assay was performed to analyze the protein levels of Akt,Erk,p-Akt,p-Erk1/2,Erk1/2,SCOP,PTEN,mTOR,p-mTOR,CREB and p-CREB in the hippocampus.SCOP expression was increased,and the phosphorylation levels of Akt,mTOR and CREB were reduced in the hippocampus.These findings show that calpeptin administration after birth affects synaptic development in neonatal rats by inhibiting the Akt/mTOR signaling pathway,thereby perturbing hippocampal function.Therefore,calpeptin administration after birth is a risk factor for neurodevelopmental defects. 展开更多
关键词 nerve REGENERATION POSTNATAL calpeptin learning and memory HIPPOCAMPUS SPINE development SCOP AKT mTOR neural REGENERATION
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CZ-7, a new derivative of Claulansine F, ameliorates 2V0-induced vascular dementia in rats through a Nrf2-mediated antioxidant responses
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作者 Dan-dan Liu Xia Yuan +14 位作者 Shi-feng Chu Chen Chen Qian Ren Piao Luo Mei-yu Lin Sha-sha Wang Tian-bi Zhu Qi-di Ai Ying-da Zang Dong-ming Zhang Xin He Zhi-hua Huang Hong-shuo Sun Zhong-ping Feng Nai-hong Chen 《中国药理学报:英文版》 SCIE CAS CSCD 2019年第4期425-440,共16页
Vascular dementia (VD) results from accumulated damage in the vascular system, which is characterized by progressive impairments in memory and cognition and is second only to Alzheimer’s disease (AD) in prevalence am... Vascular dementia (VD) results from accumulated damage in the vascular system, which is characterized by progressive impairments in memory and cognition and is second only to Alzheimer’s disease (AD) in prevalence among all types of dementia. In contrast to AD, there is no FDA-approved treatment for VD owing to its multiple etiologies. In this study, we investigated whether CZ-7, a new derivative of Claulansine F (Clau F) with verified neuroprotective activity in vitro, could ameliorate the cognitive impairment of rats with permanent occlusion of bilateral common carotid arteries (2VO) and its potential mechanisms of action. The 2VO rats were orally administered CZ-7 (10, 20, 40?mg/kg) from day 27 to day 53 post-surgery. Morris water maze tests conducted at day 48–51 revealed that CZ-7 administration significantly reduced the escape latency in 2VO rats. After the rats were sacrificed on day 53, morphological studies using Nissl and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining showed that administration of CZ-7 markedly attenuated the pathological changes in CA1–CA3 area of the hippocampus, including neuronal cell loss, nuclear shrinkage, and dark staining of neurons, and significantly decreased the chronic cerebral hypoperfusion-induced cell loss. Klüver–Barrera staining study revealed that CZ-7 administration significantly improved the white matter lesions. 8-OHdG and reactive oxygen species (ROS) immunofluorescent analyses showed that CZ-7 administration significantly decreased oxidative stress in CA1–CA3 area of the hippocampus. Finally, we found that the CZ-7-improved oxidative stress might be mediated via the Nrf2 pathway, evidenced by the double immunofluorescent staining of Nrf2 and the elevation of expression levels of oxidative stress proteins HO-1 and NQO1. In conclusion, CZ-7 has therapeutic potential for VD by alleviating oxidative stress injury through Nrf2-mediated antioxidant responses. 展开更多
关键词 claulansine F CZ-7 vascular DEMENTIA 2VO RATS chronic cerebral HYPOPERFUSION spatial memory oxidative stress Nrf2 HO-1 NQO1
Effect of moxibustion on long-term memory in vascular dementia model rats
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作者 李悦 杨骏 +1 位作者 桂利 樊吟秋 《世界针灸杂志:英文版》 CSCD 2019年第1期63-68,共6页
Objective:To observe the effects on spatial long-term memory in the rats with vascular dementia(VD)treated with moxibustion for resolving stasis and promoting meridian circulation.Methods:The modified 2-vascular occlu... Objective:To observe the effects on spatial long-term memory in the rats with vascular dementia(VD)treated with moxibustion for resolving stasis and promoting meridian circulation.Methods:The modified 2-vascular occlusion(2-VO)method was used to prepare VD animal model.The rats were randomized into a sham-operation group,a model group,a moxibustion group and a western medication group,15 rats in each one.In the moxibustion group,mild warm moxibustion was applied to"BBihui(百会GV 20)""DazhuT(大椎GV 14)"and"Shentfng(神庭GV 24)",20 min at each point,once a day,for 3 weeks consecutively.In the western medicaion group,mouse nerve growth factor(NGF)was injected intraperitoneally,0.18 mL/kg,once a day,for 3 weeks consecutively.Morris water maze test was used,the time of the first passing platform,the frequency of passing-platform and swimming speed in 120s were determined of the rats in each group.Western blot were used to test the protein expressions of hippocampal Nestin and DCX.Results:At the end of three courses of treatment,compared with sham-operation group,the difference was not significant statistically in swimming speed in the model group,the moxibustion group and the western medication group separately(all P>0.05).Three days after modeling,the mean of escape latency was prolonged obviously in the modeled rats compared with the rats in the shamoperation group(88.84±19.94 vs 18.15±9.41,P<0.01).At the end of three courses of treatment,compared with the sham-operation,group(22.01±10.07),the mean of escape latency was different statistically in the model group(89.18±19.70),the moxibustion group(37.21±13.31)and the western medication group separately(51.50±16.15),all P<0.01.Compared with the model group,the mean of escape latency was shortened in the moxibustion group and western medication group respectively(37.21±13.31 vs 89.18±19.70,51.50±16.15 vs 89.18±19.70,both P<0.01).Compared with the western medication group,there was no statistical significant difference in the mean of escape latency in the 展开更多
关键词 VASCULAR DEMENTIA Water MAZE test MOXIBUSTION LONG TERM memory
Mesenchymal stem cell-derived exosomes promote neurogenesis and cognitive function recovery in a mouse model of Alzheimer’s disease 预览
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作者 Edwin E. Reza-Zaldivar Mercedes A. Hernández-Sapiéns +6 位作者 Yanet K. Gutiérrez-Mercado Sergio Sandoval-ávila Ulises Gomez-Pinedo Ana L. Márquez-Aguirre Estefanía Vázquez-Méndez Eduardo Padilla-Camberos Alejandro A. Canales-Aguirre 《中国神经再生研究:英文版》 SCIE CAS CSCD 2019年第9期1626-1634,共9页
Studies have shown that mesenchymal stem cell-derived exosomes can enhance neural plasticity and improve cognitive impairment.The purpose of this study was to investigate the effects of mesenchymal stem cell-derived e... Studies have shown that mesenchymal stem cell-derived exosomes can enhance neural plasticity and improve cognitive impairment.The purpose of this study was to investigate the effects of mesenchymal stem cell-derived exosomes on neurogenesis and cognitive capacity in a mouse model of Alzheimer’s disease.Alzheimer’s disease mouse models were established by injection of beta amyloid 1?42 aggregates into dentate gyrus bilaterally.Morris water maze and novel object recognition tests were performed to evaluate mouse cognitive deficits at 14 and 28 days after administration.Afterwards,neurogenesis in the subventricular zone was determined by immunofluorescence using doublecortin and PSA-NCAM antibodies.Results showed that mesenchymal stem cells-derived exosomes stimulated neurogenesis in the subventricular zone and alleviated beta amyloid 1?42-induced cognitive impairment,and these effects are similar to those shown in the mesenchymal stem cells.These findings provide evidence to validate the possibility of developing cell-free therapeutic strategies for Alzheimer’s disease.All procedures and experiments were approved by Institutional Animal Care and Use Committee(CICUAL)(approval No.CICUAL 2016-011)on April 25,2016. 展开更多
关键词 Alzheimer’s DISEASE neurodegenerative DISEASE COGNITIVE impairment memory Alzheimer’s DISEASE MOUSE model mesenchymal stem cell EXOSOMES NEUROGENESIS COGNITIVE improvement cell-free therapy neural regeneration
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High-Throughput Automatic Training System for Spatial Working Memory in Free-Moving Mice
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作者 Shimin Zou Chengyu Tony Li 《神经科学通报:英文版》 SCIE CAS CSCD 2019年第3期389-400,共12页
Effcient behavioral assays are crucial for understanding the neural mechanisms of cognitive functions.Here, we designed a high-throughput automatic training system for spatial cognition(HASS) for free-moving mice.Mice... Effcient behavioral assays are crucial for understanding the neural mechanisms of cognitive functions.Here, we designed a high-throughput automatic training system for spatial cognition(HASS) for free-moving mice.Mice were trained to return to the home arm and remain there during a delay period. Software was designed to enable automatic training in all its phases, including habituation, shaping, and learning. Using this system, we trained mice to successfully perform a spatially delayed nonmatch to sample task, which tested spatial cognition,working memory, and decision making. Performance depended on the delay duration, which is a hallmark of working memory tasks. The HASS enabled a human operator to train more than six mice simultaneously with minimal intervention, therefore greatly enhancing experimental efficiency and minimizing stress to the mice.Combined with the optogenetic method and neurophysiological techniques, the HASS will be useful in deciphering the neural circuitry underlying spatial cognition. 展开更多
关键词 COGNITIVE functions AUTOMATIC training Free-moving MICE Working memory Spatial COGNITION
Memway: In-Memory Waylaying Acceleration for Practical Rowhammer Attacks Against Binaries
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作者 Lai Xu Rongwei Yu +1 位作者 Lina Wang Weijie Liu 《清华大学学报自然科学版(英文版)》 EI CAS CSCD 2019年第5期535-545,共11页
The Rowhammer bug is a novel micro-architectural security threat, enabling powerful privilege-escalation attacks on various mainstream platforms. It works by actively flipping bits in Dynamic Random Access Memory(DRAM... The Rowhammer bug is a novel micro-architectural security threat, enabling powerful privilege-escalation attacks on various mainstream platforms. It works by actively flipping bits in Dynamic Random Access Memory(DRAM) cells with unprivileged instructions. In order to set up Rowhammer against binaries in the Linux page cache, the Waylaying algorithm has previously been proposed. The Waylaying method stealthily relocates binaries onto exploitable physical addresses without exhausting system memory. However, the proof-of-concept Waylaying algorithm can be easily detected during page cache eviction because of its high disk I/O overhead and long running time. This paper proposes the more advanced Memway algorithm, which improves on Waylaying in terms of both I/O overhead and speed. Running time and disk I/O overhead are reduced by 90% by utilizing Linux tmpfs and inmemory swapping to manage eviction files. Furthermore, by combining Memway with the unprivileged posix fadvise API, the binary relocation step is made 100 times faster. Equipped with our Memway+fadvise relocation scheme,we demonstrate practical Rowhammer attacks that take only 15–200 minutes to covertly relocate a victim binary,and less than 3 seconds to flip the target instruction bit. 展开更多
关键词 Rowhammer bug Waylaying algorithm in-memory SWAPPING page cache eviction
A Deep Learning Method for Chinese Singer Identification
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作者 Zebang Shen Binbin Yong +2 位作者 Gaofeng Zhang Rui Zhou Qingguo Zhou 《清华大学学报自然科学版(英文版)》 EI CAS CSCD 2019年第4期371-378,共8页
As a subfield of Multimedia Information Retrieval(MIR), Singer IDentification(SID) is still in the research phase. On one hand, SID cannot easily achieve high accuracy because the singing voice is difficult to model a... As a subfield of Multimedia Information Retrieval(MIR), Singer IDentification(SID) is still in the research phase. On one hand, SID cannot easily achieve high accuracy because the singing voice is difficult to model and always disturbed by the background instrumental music. On the other hand, the performance of conventional machine learning methods is limited by the scale of the training dataset. This study proposes a new deep learning approach based on Long Short-Term Memory(LSTM) and Mel-Frequency Cepstral Coefficient(MFCC) features to identify the singer of a song in large datasets. The results of this study indicate that LSTM can be used to build a representation of the relationships between different MFCC frames. The experimental results show that the proposed method achieves better accuracy for Chinese SID in the MIR-1 K dataset than the traditional approaches. 展开更多
关键词 SINGER IDENTIFICATION TIMBRE modeling DEEP learning LONG SHORT-TERM memory
Leakage Is Prohibited: Memory Protection Extensions Protected Address Space Randomization
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作者 Fei Yan Kai Wang 《清华大学学报自然科学版(英文版)》 EI CAS CSCD 2019年第5期546-556,共11页
Code reuse attacks pose a severe threat to modern applications. These attacks reuse existing code segments of vulnerable applications as attack payloads and hijack the control flow of a victim application. With high c... Code reuse attacks pose a severe threat to modern applications. These attacks reuse existing code segments of vulnerable applications as attack payloads and hijack the control flow of a victim application. With high code entropy and a relatively low performance overhead, Address Space Layout Randomization(ASLR) has become the most widely explored defense against code reuse attacks. However, a single memory disclosure vulnerability is able to compromise this defense. In this paper, we present Memory Protection Extensions(MPX)-assisted Address Space Layout Randomization(M-ASLR), a novel code-space randomization scheme. M-ASLR uses several characteristics of Intel MPX to restrict code pointers in memory. We have developed a fully functioning prototype of M-ALSR, and our evaluation results show that M-ASLR:(1) offers no interference with normal operation;(2) protects against buffer overflow attacks, code reuse attacks, and other sophisticated modern attacks;and(3) adds a very low performance overhead(3.3%) to C/C++ applications. 展开更多
关键词 ADDRESS SPACE Layout RANDOMIZATION (ASLR) Intel Memory Protection EXTENSIONS (MPX) code REUSE attack
Biomimetic Janus Paper with Controllable Swelling for Shape Memory and Energy Conversion
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作者 Pan Tian Zhiguang Guo 《仿生工程学报:英文版》 SCIE EI CSCD 2019年第1期1-12,共12页
Being inspired by the "seismonastic reaction"of Mimosa pudica,an asymmetric swelling system was constructed to induce the controllable directional deformation of filter paper.In this work,multifunctional bio... Being inspired by the "seismonastic reaction"of Mimosa pudica,an asymmetric swelling system was constructed to induce the controllable directional deformation of filter paper.In this work,multifunctional biomimetic Janus paper was facilely fabricated via depositing poly(vinylidene fluoride)(PVDF)on one side of Qualitative Filter Paper (QFP),the permeation of polymer solutions within filter paper was well controlled during fabrication.The wetting and swelling behavior of the prepared Janus paper were detected.The Janus paper showed controllable swelling-induced deformations in water.Both the degree and orientation of the deformation were fully investigated.On the one hand,the degree of deformation depends on the gradient wettability and hygroscopicity of the Janus paper,on the other hand,the orientation of deformation is related to the storage and release of stress.Additionally,the steady deformation during swelling endows the Janus paper with novel shape memory property both under idling and loading conditions.The Janus paper was also applied to achieve reversible energy conversion from the swelling potential energy to mechanical potential energy. 展开更多
关键词 JANUS PAPER SWELLING shape MEMORY energy CONVERSION
Neuroprotective effect of Sanqi Tongshuan Tablets on sequelae post-stroke in rats
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作者 Wei-ting Wang Chun-hua Hao +6 位作者 Shao-xiang Zhang Xiang-hua Zhang Feng Guo Shuang-yong Sun Rui Zhang Zhuan-you Zhao Li-da Tang 《中草药:英文版》 CAS 2019年第1期45-51,共7页
Objective: To identify the therapeutic effect and possible mechanisms of Chinese medicine Sanqi Tongshuan Tablets(SQTS) on sequelae post-stroke in rats.Methods: The rat cerebral ischemia sequelae post-stroke models we... Objective: To identify the therapeutic effect and possible mechanisms of Chinese medicine Sanqi Tongshuan Tablets(SQTS) on sequelae post-stroke in rats.Methods: The rat cerebral ischemia sequelae post-stroke models were successfully induced by blocking the middle cerebral artery with electric coagulator after the seventh week and balance beam test ≤ 4. The rats were then received with SQTS(0.5, 1, and 2 g/kg) and Naodesheng(NDS, 1.24 g/kg), Vinpocetine(VP,1.55 mg/kg) for 30 d. The beam-walking test and shuttle test were performed before and after 10, 20, and 30 d of administration. In addition, histopathology changes and GAP-43, GFAP were measured by H&E staining and immunohistochemisty.Results: The model displayed signs of brain damage on motor function, learning and memory function and histopathology. After 30 d of treatment, SQTS at different doses(0.5, 1.0, and 2.0 g/kg) restored the beam-walking scores by 21.7%(P > 0.05), 30.4%(P > 0.05), and 39.1%(P < 0.05);Decreased electric shock by 35.0%(P > 0.05), 50.0%(P > 0.05), and 75.0%(P < 0.05), respectively. On the other hand, the histological changes were less severe and the GAP-43 expression increased in hippocampal CA1 and cortical region.Conclusion: SQTS showed therapeutic benefits on sequelae post-stroke in rats, which might be through the pathway of regeneration or neuroplasticity. 展开更多
关键词 learning and MEMORY MOTOR function RATS Sanqi Tongshuan TABLETS SEQUELAE post-strokes
慢性失眠患者睡眠结构与注意力、记忆的相关性
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作者 宋立敏 鲁珊珊 +3 位作者 王大伟 吕鑫 高原 唐吉友 《山东大学学报:医学版》 CAS 北大核心 2019年第4期52-58,共7页
目的探讨慢性失眠患者的睡眠结构与注意力、记忆功能之间的关系。方法所有受试者均接受匹茨堡睡眠质量表(PSQI)、艾普沃斯量表(ESS)、失眠严重指数量表(ISI)的测评以及客观多导睡眠图(PSG)的监测,评估其睡眠质量及结构,据此分为慢性失眠... 目的探讨慢性失眠患者的睡眠结构与注意力、记忆功能之间的关系。方法所有受试者均接受匹茨堡睡眠质量表(PSQI)、艾普沃斯量表(ESS)、失眠严重指数量表(ISI)的测评以及客观多导睡眠图(PSG)的监测,评估其睡眠质量及结构,据此分为慢性失眠组(n=31)和正常睡眠组(n=26);注意力功能的评估采用韦氏记忆量表中心智、视觉记忆广度和数字广度测试,记忆功能的评估采用韦氏记忆量表中长时记忆(经历、定向)和短时记忆(联想学习、逻辑记忆)等分项测验。结果与正常睡眠组相比,慢性失眠组PSQI、ESS和ISI评分增高,入睡潜伏期、非快速眼动睡眠所占比例(NREM1%)、非快速眼动睡眠2期所占比例(NREM2%)、入睡后觉醒时间及觉醒次数增多,而非快速眠动睡眠3期所占比例(NREM3%)减少,差异有统计学意义(P<0.05);慢性失眠组注意力功能降低主要表现在心智和视觉记忆广度测试,短时记忆减退表现在联想学习和逻辑记忆;通过多因素Logistic回归分析,显示PSQI与心智、视觉记忆有关(P<0.05),NREM1%与联想记忆和逻辑记忆有关(P<0.05),NREM3%与逻辑记忆有关(P<0.01)。结论慢性失眠患者睡眠结构紊乱,注意力与短时记忆的损害主要与PSQI得分、NREM1%的增加以及NREM3%的减少相关。 展开更多
关键词 慢性失眠 认知功能 注意力 记忆 多导睡眠图
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