• 제목/요약/키워드: Memory management

검색결과 1,064건 처리시간 0.023초

Nootropic Potential of Murraya koenigii leaves in Rats

  • Vasudevan, Mani;Parle, Milind;Sengottuvelu, Singaravel;Shanmugapriya, Thulasimani
    • Advances in Traditional Medicine
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    • 제8권4호
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    • pp.365-373
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    • 2008
  • Murraya koenigii leaves commonly known as 'curry patta' are routinely added to Indian gravy and vegetarian dishes by south Indian as a favourate condiment. The present study was undertaken to investigate the effects of Murraya koenigii leaves (MKL) on memory in rats. Elevated plus-maze and Hebb-Williams maze served as the exteroceptive behavioral models for testing memory. Diazepam-, scopolamine- and ageing-induced amnesia served as the interoceptive behavioral models. MKL fed orally to various groups of young and aged rats with diet containing 2, 4 and 8% w/w of MKL for 30 days consecutively were investigated. The MKL diets produced a significant dose-dependent improvement in memory scores of young and aged rats and significantly reduced the amnesia induced by scopolamine (0.4 mg/kg, i.p.) and diazepam (1 mg/kg, i.p.). Therefore, it would be worthwhile to specifically investigate the therapeutic potential of MKL in the management of dementia patients.

유효 페이지 색인 테이블을 활용한 NAND Flash Translation Layer 설계 (Design of NAND Flash Translation Layer Based on Valid Page Lookup Table)

  • 신정환;이인환
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 컴퓨터소사이어티 추계학술대회논문집
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    • pp.15-18
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    • 2003
  • Flash memory becomes more important for its fast access speed, low-power, shock resistance and nonvolatile storage. But its native restrictions that have limited 1ifetime, inability of update in place, different size unit of read/write and erase operations need to managed by FTL(Flash Translation Layer). FTL has to control the wear-leveling, address mapping, bad block management of flash memory. In this paper, we focuses on the fast access to address mapping table and proposed the way of faster valid page search in the flash memory using the VPLT(Valid Page Lookup Table). This method is expected to decrease the frequency of access of flash memory that have an significant effect on performance of read and block-transfer operations. For the validations, we implemented the FTL based on Windows CE platform and obtained an improved result.

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F-Tree : 휴대용 정보기기를 위한 플래시 메모리 기반 색인 기법 (F-Tree : Flash Memory based Indexing Scheme for Portable Information Devices)

  • 변시우
    • Journal of Information Technology Applications and Management
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    • 제13권4호
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    • pp.257-271
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    • 2006
  • Recently, flash memories are one of best media to support portable computer's storages in mobile computing environment. The features of non-volatility, low power consumption, and fast access time for read operations are sufficient grounds to support flash memory as major database storage components of portable computers. However, we need to improve traditional Indexing scheme such as B-Tree due to the relatively slow characteristics of flash operation as compared to RAM memory. In order to achieve this goal, we devise a new indexing scheme called F-Tree. F-Tree improves tree operation performance by compressing pointers and keys in tree nodes and rewriting the nodes without a slow erase operation in node insert/delete processes. Based on the results of the performance evaluation, we conclude that F-Tree indexing scheme outperforms the traditional indexing scheme.

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

  • 박찬규;임성묵;김우제;박순달
    • 산업공학
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    • 제11권2호
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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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고속 임베디드 저장 시스템을 위한 복제전환 기법 (Mirror-Switching Scheme for High-Speed Embedded Storage Systems)

  • 변시우;장석우
    • 정보저장시스템학회논문집
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    • 제7권1호
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    • pp.7-12
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    • 2011
  • The flash memory has been remarked as the next generation media of portable and desktop computers' storage devices. Their features include non-volatility, low power consumption, and fast access time for read operations, which are sufficient to present flash memories as major data storage components for desktop and servers. The purpose of our study is to upgrade a traditional mirroring scheme based on SSD storages due to the relatively slow or freezing characteristics of write operations, as compared to fast read operations. For this work, we propose a new storage management scheme called Memory Mirror-Switching based on traditional mirroring scheme. Our Mirror-Switching scheme improves flash operation performance by switching write-workloads from flash memory to RAM and delaying write operations to avoid freezing. Our test results show that our scheme significantly reduces the write operation delay and storage freezing.

트랜잭티브 메모리 역량과 사회적 자본이 지식공유의도에 미치는 영향: 근속년수의 조절효과 (The Effect of Transactive Memory Capability and Social Capital on Knowledge Sharing Intention: Moderating Effect of Tenure)

  • 한수진
    • Journal of Information Technology Applications and Management
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    • 제29권4호
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    • pp.35-49
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    • 2022
  • Knowledge sharing occurs through voluntary interactions between human actors. In this paper, from the perspective of social interaction, the effect of transactive memory capability and social capital (bridging social capital and bonding social capital) on knowledge sharing intention was analyzed, and tenure was demonstrated as a moderating factor that can strengthen their relationship. Therefore, the results of this study are summarized as follows. First, it was verified that the transactive memory capability had a significant positive effect on the knowledge sharing intention. Second, it was found that the bridging social capital and bonding social capital held by individuals had a significant positive effect on knowledge sharing intention. Social capital is understood to form an individual's voluntary motivation for knowledge sharing. Third, it was verified that the moderating effect of tenure suggested in this study was not significant. Based on the results of this study, implications and future research directions were presented.

A New Flash-aware Buffering Scheme Supporting Virtual Page Flushing

  • Lim, Seong-Chae
    • International Journal of Internet, Broadcasting and Communication
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    • 제14권3호
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    • pp.161-170
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    • 2022
  • Recently, NAND-type flash memory has been regarded to be new promising storage media for large-scale database systems. For flash memory to be employed for that purpose, we need to reduce its expensive update cost caused by the inablity of in-place updates. To remedy such a drawback in flash memory, we propose a new flash-aware buffering scheme that enables virtual flushing of dirty pages. To this end, we slightly alter the tradional algorithms used for the logging scheme and buffer management scheme. By using the mechanism of virtual flushing, our proposed buffering scheme can efficiently prevent the frequenct occureces of page updates in flash storage. Besides the advantage of reduced page updates, the proposed viurtual flushing mechanism works favorably for shorneing a recocery time in the presense of failure. This is because it can reduce the time for redo actions during a recovry process. Owing to those two benefits, we can say that our scheme couble be very profitable when it is incorporated into cutting-edge flash-based database systems.

만성 정신분열병 환자들의 인지 기능과 정서 인식 능력의 관련성 (The Relationship between Neurocognitive Functioning and Emotional Recognition in Chronic Schizophrenic Patients)

  • 황혜리;황태연;이우경;한은선
    • 생물정신의학
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    • 제11권2호
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    • pp.155-164
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    • 2004
  • Objective:The present study examined the association between basic neurocognitive functions and emotional recognition in chronic schizophrenia. Furthermore, to Investigate cognitive variable related to emotion recognition in Schizophrenia. Methods:Forty eight patients from the Yongin Psychiatric Rehabilitation Center were evaluated for neurocognitive function, and Emotional Recognition Test which has four subscales finding emotional clue, discriminating emotions, understanding emotional context and emotional capacity. Measures of neurocognitive functioning were selected based on hypothesized relationships to perception of emotion. These measures included:1) Letter Number Sequencing Test, a measure of working memory;2) Word Fluency and Block Design, a measure of executive function;3) Hopkins Verbal Learning Test-Korean version, a measure of verbal memory;4) Digit Span, a measure of immediate memory;5) Span of Apprehension Task, a measure of early visual processing, visual scanning;6) Continuous Performance Test, a measure of sustained attention functioning. Correlation analyses between specific neurocognitive measures and emotional recognition test were made. To examine the degree to which neurocognitive performance predicting emotional recognition, hierarchical regression analyses were also made. Results:Working memory, and verbal memory were closely related with emotional discrimination. Working memory, Span of Apprehension and Digit Span were closely related with contextual recognition. Among cognitive measures, Span of Apprehension, Working memory, Digit Span were most important variables in predicting emotional capacity. Conclusion:These results are relevant considering that emotional information processing depends, in part, on the abilities to scan the context and to use immediate working memory. These results indicated that mul- tifaceted cognitive training program added with Emotional Recognition Task(Cognitive Behavioral Rehabilitation Therapy added with Emotional Management Program) are promising.

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일 광역시 당뇨병 환자의 주관적 기억력 장애 관련 요인 (Factors Associated with Subjective Memory Impairment in Patients with Diabetes Mellitus in a Metropolitan City)

  • 박모니카;류소연;최성우;박종
    • 농촌의학ㆍ지역보건
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    • 제48권1호
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    • pp.1-12
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    • 2023
  • Objective: The purpose of this study was to identify factors associated with subjective memory impairment in patients with diabetes mellitus in a metropolitan city. Methods: The subjects of this study were 351 patients with diabetes mellitus aged 50 and over from five districts of Gwangju who participated in the 2018 Community Health Survey. We analyzed general characteristics, health-related behaviors and health related conditions and subjective experience of memory impairment. To find factors associated with subjective memory impairment, the chi-square test and multiple logistic regression analysis were used. Results: Of all subjects, 31.3% was reported subjective experience of memory impairment. The odds ratios (ORs; 95% confidence interval (CI)) for subjective memory impairment according to age were statistically significant at 1.9 (0.9-4.3) in patients in 60s and 2.2 (1.1-4.7) in patients in beyond 70s compared to those in 50s. The OR (95% CI) of ex-smoker compared to the non-smoker was 0.3 (0.8-0.9). The OR (95% CI) of depressive symptom compared to no depressive symptoms was 4.9 (95% CI: 1.8-13.7). Conclusion: In this study, subjective memory impairment in patients with diabets mellitus was associated with age, smoking, and depressive symptoms. Based on the results of this study, subjective memory impairment should be detected early through periodic cognitive function evaluation for elderly patients with diabetes mellitus, and a program for healthy cognitive function should be included in diabetes management program.

스토리지 쓰기량과 페이지 폴트를 줄이는 메모리 부하 적응형 페이지 교체 정책 (Page Replacement Policy for Memory Load Adaption to Reduce Storage Writes and Page Faults)

  • 반효경;박윤주
    • 한국인터넷방송통신학회논문지
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    • 제22권6호
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    • pp.57-62
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    • 2022
  • 최근 상변화메모리와 같은 고속 스토리지 매체의 출현으로 느린 디스크 스토리지에 적합하게 설계된 메모리 관리 기법에 대한 재고가 필요한 시점에 이르렀다. 본 논문에서는 상변화메모리를 가상메모리의 스왑장치로 이용하는 시스템을 위한 새로운 페이지 교체 정책을 제안한다. 제안하는 방식은 페이지 교체 정책이 전통적으로 추구하던 페이지 폴트 횟수 절감뿐 아니라 스왑 장치에 발생하는 쓰기량 절감을 동시에 추구한다. 이는 상변화메모리의 쓰기 연산이 느리고 쓰기 횟수에 제한이 있다는 점에 착안한 것이다. 구체적으로 살펴보면 메모리 부하가 높은 경우 페이지 폴트를 줄이는 데에 초점을 맞추고 메모리 공간에 여유가 있을 경우 스토리지 쓰기량을 줄이는 적응적인 방식을 채택한다. 이를 통해 제안하는 정책이 메모리 시스템의 성능을 저하시키지 않으면서 스토리지 쓰기량을 크게 절감함을 다양한 워크로드의 메모리 참조 트레이스를 재현하는 시뮬레이션 실험을 통해 보인다.