• Title/Summary/Keyword: memory mechanism

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Design of an Automated Testing Tool to Detect Dynamic Memory Access Errors in C Programs (C언어 기반 프로그램의 동적 메모리 접근 오류 테스트 자동화 도구 설계)

  • Cho, Dae-Wan;Oh, Seung-Uk;Kim, Hyeon-Soo
    • Journal of KIISE:Software and Applications
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    • v.34 no.8
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    • pp.708-720
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    • 2007
  • Memory access errors are frequently occurred in computer programs written in C programming language [1,2]. Accordingly, a number of research works have suggested a wide variety of methods to detect such errors automatically. However, they have one or more of the following problems: inability to detect all memory errors, changing the memory allocation mechanism, and excessive performance overhead. To cope with these problems, in this paper we suggest a new and automated tool to detect dynamic memory access errors in C programs.

Memory-improving effect of formulation-MSS by activation of hippocampal MAPK/ERK signaling pathway in rats

  • Kim, Sang-Won;Ha, Na-Young;Kim, Kyung-In;Park, Jin-Kyu;Lee, Yong-Heun
    • BMB Reports
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    • v.41 no.3
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    • pp.242-247
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    • 2008
  • MSS, a comprising mixture of maesil (Prunus mume Sieb. et Zucc) concentrate, disodium succinate and Span80 (3.6 : 4.6 : 1 ratio) showed a significant improvement of memory when daily administered (460 mg/kg day, p.o.) into the normal rats for 3 weeks. During the spatial learning of 4 days in Morris water maze test, both working memory and short-term working memory index were significantly increased when compared to untreated controls. We investigated a molecular signal transduction mechanism of MSS on the behaviors of spatial learning and memory. MSS treatment increased hippocampal mRNA levels of NR2B and TrkB without changes of NR1, NR2A, ERK1, ERK2 and CREB. However, the protein levels of pERK/ERK and pCREB/CREB were all significantly increased to $1.5{\pm}0.17$ times. These results suggest that the improving effect of spatial memory for MSS is linked to MAPK/ERK signaling pathway that ends up in the phosphorylation of CREB through TrkB and/or NR2B of NMDA receptor.

Protective Effect of Sesaminol Glucosides on Memory Impairment and ${\beta}$, ${\gamma}$-Secretase Activity In Vivo (Sesaminol Glucosides의 기억력 회복능 및 ${\beta}$, ${\gamma}$-Secretase)

  • Lee, Sun-Young;Son, Dong-Ju;Ha, Tae-Youl;Hong, Jin-Tae
    • YAKHAK HOEJI
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    • v.49 no.2
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    • pp.168-173
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    • 2005
  • Alzheimers disease (AD) is the most prevalent form of neurodegenerations associated with aging in the human population. This disease is characterized by the extracellular deposition of beta-amyloid (A ${\beta}$) peptide in cerebral plaques. The A ${\beta}$ peptide is derived from the ${\beta}$-amyloid precursor protein ( ${\beta}$APP). Photolytic processing of ${\beta}$APP by ${\beta}$-secretase(beta-site APP-cleaving enzyme, BASE) and ${\gamma}$-secretase generates the A ${\beta}$ peptide. Several lines of evidence support that A ${\beta}$-induced neuronal cell death is major mechanisms of development of AD. Accordingly, the ${\beta}$-and ${\gamma}$-secretase have been implicated to be excellent targets for the treatment of AD. We previously found that sesaminol glucosides have improving effect on memory functions through anti-oxidative mechanism. In this study, to elucidate possible other mechanism (inhibition of ${\beta}$-and ${\gamma}$-secretase) of sesaminol glucosides, we examined the improving effect of sesaminol glucosides in the scopolamine (1 mg/kg/mouse)-induced memory dysfunction using water maze test in the mice. Sesaminol glucosides (3.75, 7.5 mg/kg/6ml/day p.o., for 3 weeks) reversed the latency time, distance and velocity by scopolamine in dose dependent manner. Next, ${\beta}$-and ${\gamma}$-secretase activities were determined in different regions of brain. Sesaminol glucosides dose-dependently attenuated scopolamine-induced ${\beta}$-secretase activities in cortex and hippocampous and ${\gamma}$-secretase in cortex. This study therefore suggests that sesaminol glucosides may be a useful agent for prevention of the development or progression of AD, and its inhibitory effect on secretase may play a role in the improving action of sesaminol glucosides on memory function.

Analyzing the Overhead of the Memory Mapped File I/O for In-Memory File Systems (메모리 파일시스템에서 메모리 매핑을 이용한 파일 입출력의 오버헤드 분석)

  • Choi, Jungsik;Han, Hwansoo
    • KIISE Transactions on Computing Practices
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    • v.22 no.10
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    • pp.497-503
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    • 2016
  • Emerging next-generation storage technologies such as non-volatile memory will help eliminate almost all of the storage latency that has plagued previous storage devices. In conventional storage systems, the latency of slow storage devices dominates access latency; hence, software efficiency is not critical. With low-latency storage, software costs can quickly dominate memory latency. Hence, researchers have proposed the memory mapped file I/O to avoid the software overhead. Mapping a file into the user memory space enables users to access the file directly. Therefore, it is possible to avoid the complicated I/O stack. This minimizes the number of user/kernel mode switchings. In addition, there is no data copy between kernel and user areas. Despite of the benefits in the memory mapped file I/O, its overhead still needs to be addressed, as the existing mechanism for the memory mapped file I/O is designed for slow block devices. In this paper, we identify the overheads of the memory mapped file I/O via experiments.

Historical Reality and Cultural Memory: The Image of Peter I in Russian Literature and Folklore (역사적 현실과 문화적 기억 : 기록 문학과 구술 문학에 나타난 표트르 대제의 형상)

  • Seo, Seon Jeong
    • Cross-Cultural Studies
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    • v.29
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    • pp.201-232
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    • 2012
  • In the world history in the rein of totalitarianism cultural project of government had been activated, and consequently of it official culture had been organized. But at the same time on the other side of it people('narod'), who didn't have cultural means for active expression of own opinion on the reality, had expressed world-view and judgement informally in everyday language. In the literature of autocracy, subjected to censorship, had been expressed and fixed mythically idealized image of sovereign and his works. But in the folklore the image of ruler had been created by liberal fantasy of people. This article examined russian literature and folklore texts of 18 century, when russian people suffered from rapid and dramatic changes, caused by Peter I. Although russian literature of 18 century had gone over to the new literary regime, it still accepted political mechanism as dominant of age, and consequently in the literary texts of this century Peter I was represented as ideal person and great monarch. But various images in folklore texts show that people's opinion on ruler and his activities couldn't be controlled. In other worlds, diverse images of Peter I in folklore texts reflect clear and plain historical consciousness of people. This analysis reveals not only difference between mechanism of idealization of government and historical consciousness of people, but also meaning of cultural memory as indicator of historical reality.

Electric Properties of YBCO Superconductor for Neutron Irradiation (중성자 조사를 위한 초전도 선재의 특성)

  • Lee, Sang-Heon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.182-183
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    • 2006
  • An electromagnetic memory effect observed in superconducting YBCO system was studied. From the measurement of differential conductance, it was cleared that the mechanism of electromagnetic memory can not be explained by using conventional flux flow model. By changing the density of external magnetic flux, changes m inductance of a coil in which a superconducting bar is inserted were also measured. It was concluded that the electromagnetic memory effect aries from the interaction between the trapped magnetic flux and the weak link of the filament formed in the superconducting bar.

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Implementation of Maim Memory DBMS for Efficient Transactions based on Embedded System (임베디드 시스템 상에서의 고속 트랜잭션을 위한 메인메모리 기반 데이터베이스 시스템 구현)

  • Kim, Young-Hwan;Son, Jae-Gi;Park, Chang-Won
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.769-770
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    • 2008
  • Mani Memory DataBase(MMDB) system store their data in main physical memory and provide very high-speed access. Conventional database system are optimized for the particular characteristics of disk storage mechanism. Memory resident systems, on the other hand, use different optimizations to structure and organize data, as well as to make it reliable. This paper provides a brief overview on MMDBs and the results after evaluating the performance of our simple MMDB based on Embedded system.

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Synthesis of high functional Superconducting Precursor using Organic metal salts method for Electric power transmission (유기금속염을 이용한 전력 전송용 초전도체 합성)

  • Lee, Sang-Heon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.11a
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    • pp.348-349
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    • 2005
  • An electromagnetic memory effect observed in superconducting YBCO system was studied. From the measurement of differential conductance, it was cleared that the mechanism of electromagnetic memory can not be explained by using conventional flux flow model. By changing the density of external magnetic flux, changes in inductance of a coil in which a superconducting bar is inserted were also measured. It was concluded that the electromagnetic memory effect aries from the interaction between the trapped magnetic flux and the weak link of the filament formed in the superconducting bar.

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Experimental Comparisons of Simplex Method Program's Speed with Various Memory Referencing Techniques and Data Structures (여러 가지 컴퓨터 메모리 참조 방법과 자료구조에 대한 단체법 프로그램 수행 속도의 비교)

  • Park, Chan-Kyoo;Lim, Sung-Mook;Kim, Woo-Jae;Park, Soon-Dal
    • IE interfaces
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    • v.11 no.2
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    • pp.149-157
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    • 1998
  • In this paper, various techniques considering the characteristics of computer memory management are suggested, which can be used in the implementation of simplex method. First, reduction technique of indirect addressing, redundant references of memory, and scatter/gather technique are implemented, and the effectiveness of the techniques is shown. Loop-unrolling technique, which exploits the arithmetic operation mechanism of computer, is also implemented. Second, a subroutine frequently called is written in low-level language, and the effectiveness is proved by experimental results. Third, row-column linked list and Gustavson's data structure are compared as the data structure for the large sparse matrix in LU form. Last, buffering technique and memory-mapped file which can be used in reading large data file are implemented and the effectiveness is shown.

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