• 한국융합학회논문지
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• 제11권6호
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• pp.203-208
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• 2020

이 연구는 첫째, 경도인지장애(MCI)가 언어 기억 및 시공간 기억 등 특정 기억의 저하와 관련이 있는지를 파악하고, 둘째, 정상 노인으로부터 MCI를 감별하는 데 예측력이 우수한 지표를 탐색하였다. 표준화 된 기억검사를 수행한 189명(정상 노인 103 명, MCI 86 명)을 분석하였다. 언어 기억은 Seoul Verbal Learning Test를 이용하였고. 시공간 기억은 Rey Complex Figure Test를 이용해서 측정하였다. 다항 로지스틱 회귀모형을 이용하여 기억 검사의 예측력을 분석한 결과, 언어 기억과 시공간 기억은 정상 노인으로부터 MCI를 감별하는 데 예측 성능이 유의미하였다. 반면, 각 기억 검사의 수행결과를 포함하여 모든 혼란변수를 보정했을 때, 언어 기억의 즉시 회상만 정상 노인으로부터 MCI를 감별하는 데 예측력이 유의미하였으며, 시공간 기억의 즉시 회상은 예측력이 유의미하지 않았다. 이 결과는 MCI를 선별할 때 언어 기억과 시공간 기억의 지연 회상, 언어 기억의 즉시 회상이 MCI의 기억능력을 감별할 수 있는 최상의 조합임을 시사한다.

• 한국정보과학회논문지:시스템및이론
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• 제34권9호
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• pp.445-458
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• 2007

본 논문에서는 대용량 메모리 데이타 처리를 위한 범용 하드웨어 기반의 원격 메모리 시스템을 제안한다. 느린 디스크와 상대적으로 대단히 빠른 접근 속도를 보장하는 메모리 사이에 존재하게 되는 새로운 메모리 계층을 구현하기 위해, 본 논문에서는 다수의 일반적인 범용 데스크탑 PC들과 원격 직접메모리 접근 (이하 RDMA) 기능이 가능한 고속 네트워크를 최대한 활용하였다. 제안된 새로운 계층의 메모리는 합리적인 응답시간과 용량을 제공함으로서 비교적 적은 양의 성능 부담으로서 대용량의 메모리 상주 데이타베이스를 구동할 수 있게 되었다. 제안된 원격 메모리 시스템은 원격 메모리 페이지들을 관리하게 되는 원격 메모리 시스템과, 원격 메모리 페이지의 교체를 관리하게 되는 원격 메모리 페이저로 구성되어 있다. 범용으로 쓰이는 MySQL과 같은 데이타베이스를 이용한 TPC-C 실험 결과로 볼 때 제안된 원격 메모리 시스템은 일반적인 대용량 메모리 데이타 처리 시스템에서 요구하는 다양한 요구조건을 만족시킬 수 있을 것이라 생각된다.

• 한국산학기술학회논문지
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• 제15권8호
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• pp.5213-5218
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• 2014

유기메모리 제작을 위해 플라즈마 중합법에 의해 절연박막, 터널링 박막을 제작하였고, Au 메모리박막을 이용하여 플로팅게이트형 유기메모리를 제작하였다. 플로팅 게이트형 유기메모리의 메모리층의 전하충전 및 방전에 따른 유기메모리 동작특성을 생각해 보았고, 이를 증명하고자 게이트전압에 따른 히스테리전압 및 메모리전압을 측정하였다. 그 결과 게이트 전압의 인가에 따른 메모리층의 동작 이론을 증명하고자 게이트전압이 증가함에 따른 소스-드레인 전류의 히스테리시스 현상이 심해지는 것을 확인하였고, -60~60[V]전압 인가시 26[V]의 큰 히스테리시스 전압값을 보였다. 또한 게이트 전극에 쓰기전압인가에 따른 현상을 본 결과, 60[V]의 쓰기 전압을 인가하였을 시 13[V]의 memory 전압을 나타내었고, 80[V]의 쓰기전압을 인가하였을 시 18[V]로 memory 전압이 약 40[%] 향상된 수치를 보였다. 이로부터 메모리층의 전하 충전 및 방전에 따른 메모리 동작특성 이론을 실험적으로 검증하였다.

• ETRI Journal
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• 제35권5호
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• pp.808-818
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• 2013

Programmable memory built-in self-test (PMBIST) is an attractive approach for testing embedded memory. However, the main difficulties of the previous works are the large area overhead and low flexibility. To overcome these problems, a new flexible PMBIST (FPMBIST) architecture that can test both single-port memory and dual-port memory using various test algorithms is proposed. In the FPMBIST, a new instruction set is developed to minimize the FPMBIST area overhead and to maximize the flexibility. In addition, FPMBIST includes a diagnostic scheme that can improve the yield by supporting three types of diagnostic methods for repair and diagnosis. The experiment results show that the proposed FPMBIST has small area overhead despite the fact that it supports various test algorithms, thus having high flexibility.

• 대한임베디드공학회논문지
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• 제2권3호
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• pp.184-193
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• 2007

Flash memory adoption in the mobile devices is increasing or vanous multimedia services such as audio, videos, and games. Although the traditional research issues such as out-place update, garbage collection, and wear-leveling are important, the performance, memory usage, and fast mount issues of flash memory file system are becoming much more important than ever because flash memory capacity is rapidly increasing. In this paper, we address the problems of the existing log-based flash memory file systems analytically and propose an efficient log-based file system, which produces higher performance, less memory usage and mount time than the existing log-based file systems. Our ideas are applied to a well-known log-based flash memory file system (YAFFS2) and the performance tests are conducted by comparing our prototype with YAFFS2. The experimental results show that our prototype achieves higher performance, less system memory usage, and faster mounting than YAFFS2, which is better than JFFS2.

• International Journal of Internet, Broadcasting and Communication
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• 제12권1호
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• pp.90-94
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• 2020

Artificial intelligence (AI) is software that learns large amounts of data and provides the desired results for certain patterns. In other words, learning a large amount of data is very important, and the role of memory in terms of computing systems is important. Massive data means wider bandwidth, and the design of the memory system that can provide it becomes even more important. Providing wide bandwidth in AI systems is also related to power consumption. AlphaGo, for example, consumes 170 kW of power using 1202 CPUs and 176 GPUs. Since more than 50% of the consumption of memory is usually used by system chips, a lot of investment is being made in memory technology for AI chips. MRAM, PRAM, ReRAM and Hybrid RAM are mainly studied. This study presents various memory technologies that are being studied in artificial intelligence chip design. Especially, MRAM and PRAM are commerciallized for the next generation memory. They have two significant advantages that are ultra low power consumption and nearly zero leakage power. This paper describes a comparative analysis of the four representative new memory technologies.

• Journal of Microbiology and Biotechnology
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• 제23권12호
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• pp.1779-1784
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• 2013

Although enzyme-hydrolyzed silk fibroin has been reported to enhance cognitive function before, it has been still unknown which peptides can improve memory. Here we report that amino acid sequences of three novel peptides were identified from fibroin hydrolysate. Fibroin hydrolysate was obtained by hydrolysis with protease after partial hydrolysis with 5M $CaCl_2$. Synthesized peptides derived from these sequences improved scopolamine-induced memory impairments in mice. We confirmed this hydrolysate had effects that improved learning and memory abilities by performing the Rey-Kim test. From this hydrolysate of silk fibroin, amino acid sequences of eight peptides were identified by LC-MS/MS. Three peptides (GAGAGTGSSGFGPY, GAGAGSGAGSGAGAGSGAGAGY, and SGAGSGAGAGSGAGAGSGA) were synthesized to investigate whether they could improve memory. Passive avoidance test and Morris water maze test were performed, and all peptides showed memory-enhancing abilities on scopolamine-induced memory impairments in mice. In this study, we identified three novel peptides that could improve memory, and that silk fibroin hydrolysate was a mixture of various active peptides that could enhance memory.

• 대한전기학회논문지:시스템및제어부문D
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• 제55권10호
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• pp.446-451
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• 2006

In this paper, we propose an implementation of JPEG2000 codec on the ARM9 Processor which includes independent memory management facility. The codec and memory management facility together can control the encoding and the decoding process effectively within available memory area. Embedded appliances like cellular phones have very limited internal memory which can't be expanded easily. However, they should provide various applications and services using restricted memory resources. The proposed codec with memory management can provide image quality that is identical to the original image on embedded platform. The implemented codec has no memory conflict with other applications. It shows that the proposed codec can manage memory resources efficiently.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.672-674
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• 1998

Java virtual machine has the garbage collector that automate memory management. Mark-compact algorithm is one of the garbage collection algorithm that operating in 2 phases, marking and sweeping. One is Marking is marking live objects reachable from root object set. Sweeping is sweeping unmarked object from memory(return to free memory pool). This algorithm is easy to implement but cause a memory fragmentation. So compacting memory, before memory defragmentation become serious. When compacting memory, all other processes are suspended. It is critical for embedded system that must guarantee real-time processing. This paper introduce enhanced mark-compact garbage collection algorithm. Grouping the objects by their size that minimize memory fragmentation. Then apply smart algorithm to the grouped objects when allocating objects and compacting memory.

• 인문언어
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• 제1권2호
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• pp.67-90
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• 2001

In the past few years, a trend has emerged emphasizing the interdisciplinary relationship between cultural and literary studies, and "memory" has been suggested as the central theme in this trend. According to Aleida and Jan Assmann, "memory" as collective memory (not individual recollection) has various functions and forms, of which communicative memory and cultural memory occupy opposite poles of a central axis. Whereas communicative memory relates to the living past shared among contemporaries, cultural memory relates to "recollected history" rather than factual history. Cultural memory finds transmission through symbolic media such as myths, festivities, and literary works. Literary works preserve critical and living memories as opposed to forgotten memories. In other words, literature should be better read as "criticism and memory" than "imitation and preservation." Works of literature are characterized by a turning away from repetition toward representation-the process of "making present" of what is past.