• 제목/요약/키워드: Locality

검색결과 867건 처리시간 0.03초

하드디스크 대용을 위한 공간적 스마트 버퍼 플래시 메모리 시스템 (Flash memory system with spatial smart buffer for the substitution of a hard-disk)

  • 정보성;이정훈
    • 한국컴퓨터정보학회논문지
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    • 제14권3호
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    • pp.41-49
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    • 2009
  • 플래시 메모리는 저전력, 저렴한 가격, 그리고 대용량저장매체로 그 중요성 및 수요에 대한 요구가 증대되고 있다. 이 연구는 하드디스크 대용을 위한 플래시 메모리 시스템을 구현하기 위하여 공간적 스마트 버퍼시스템을 통한 적극적인 공간적 지역성의 동적 페칭으로 고성능 플래시 메모리 설계에 목적이 있다. 제안된 플래시 메모리 시스템은 시간적 지역성을 위한 희생 버퍼, 공간적 지역성을 위한 공간적 버퍼 그리고 동적 페칭 유닛으로 이루어져 있다. 우리는 적극적인 동적 페칭을 위해 새로운 페칭 알고리즘을 제안한다. 즉, 새로운 구조와 새로운 알고리즘을 통하여 하드디스크 대용의 플래시 메모리 사용시 고려되어져 야 할 플래시 메모리의 단점을 줄여 범용 및 미디어 응용군에서 모두 고성능 효과를 이룰 수 있었다. 시뮬레이션 결과평균 접근실패율의 경우 미디어 응용군에 대해 기존의 스마트 버퍼시스템에 비해 25%감소 효과를 얻을 수 있었고, 평균 메모리 접근 시간의 경우스마트 버퍼시스템에 비해 35% 감소 효과를 얻을 수 있었다. 일반 범용 응용군에서도 30% 이상의 향상된 평균 메모리 접근 시간을 보였다.

A Note on Locality in Ellipsis

  • 박범식
    • 한국언어정보학회:학술대회논문집
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    • 한국언어정보학회 2006년도 제7회 정기학술대회
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    • pp.247-257
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    • 2006
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Morphological Characteristics of Brown Alga Spatoglossum crassum Tanaka (Dictyotaceae, Dictyotales), New to Korea

  • Hwang, Il-Ki;Kim, Hyung-Seop;Lee, Wook-Jae
    • ALGAE
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    • 제19권3호
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    • pp.191-199
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    • 2004
  • Morphological and phonological characteristics of brown alga Spatoglossum crassum Tanaka new to Korea were described based on the field and the indoor cultured plants. The taxonomic characteristics of the plants were agreed to those from the type locality-submerged reproductive organs in cortex, anatomical features, and absence of phaeophycean hairs on the surface. But they have rudimentary midrib on lower portion of thallus. We can observe the young plants on November, adult ones in June, and senile ones in August. This species has an annual life-cycle in the field, starting with germ lings in early November. The differentiation of thallus is quite different from other species of genera in tribe Zonarieae, e.g. Zonaria and Homoeostrichus. Three different tissues, meristoderm, cortex and medulla are discerned. The outmost cortical one celled layer as a meristoderm produce cortex by unequal periclinal division. In the apical cell division, the primary inner cells are developed into 3-4 cell layered medulla of thallus. The distribution of this species extends from Korea to Shizuoka Peninsula (34°40'N) Japan, which is the type locality of this species.

A Study of Efficient Access Method based upon the Spatial Locality of Multi-Dimensional Data

  • Yoon, Seong-young;Joo, In-hak;Choy, Yoon-chul
    • 한국데이타베이스학회:학술대회논문집
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    • 한국데이타베이스학회 1997년도 International Conference MULTIMEDIA DATABASES on INTERNET
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    • pp.472-482
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    • 1997
  • Multi-dimensional data play a crucial role in various fields, as like computer graphics, geographical information system, and multimedia applications. Indexing method fur multi-dimensional data Is a very Important factor in overall system performance. What is proposed in this paper is a new dynamic access method for spatial objects called HL-CIF(Hierarchically Layered Caltech Intermediate Form) tree which requires small amount of storage space and facilitates efficient query processing. HL-CIF tree is a combination of hierarchical management of spatial objects and CIF tree in which spatial objects and sub-regions are associated with representative points. HL-CIF tree adopts "centroid" of spatial objects as the representative point. By reflecting objects′sizes and positions in its structure, HL-CIF tree guarantees the high spatial locality of objects grouped in a sub-region rendering query processing more efficient.

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A Review of Web Cache Prefetching

  • Deng, YuFeng;Manoharan, Sathiamoorthy
    • Journal of information and communication convergence engineering
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    • 제12권3호
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    • pp.161-167
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    • 2014
  • Web caches help to reduce latencies arising from slow networks through storing and reusing what was used before. Repeat access to a cached resource does not incur network latencies. However, resources that have never been used will not be found in the cache. Cache prefetching is a technique that helps to fill a cache with still-unused resources in anticipation that these resources will be used in the near future. Typically these unused resources are related to the resources that have been accessed in the recent past. While web caching exploits temporal locality, prefetching attempts to exploit spatial locality. Access to the prefetched resources will be cache hits, and therefore reduces the latency as perceived by the user. This paper reviews the cache infrastructure supported by the hypertext transfer protocol and discusses web cache prefetching in general, including Mozilla's prefetching infrastructure. It then classifies and reviews some prefetching techniques.

Mitigating Cache Pollution Attack in Information Centric Mobile Internet

  • Chen, Jia;Yue, Liang;Chen, Jing
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제13권11호
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    • pp.5673-5691
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    • 2019
  • Information centric mobile network can significantly improve the data retrieving efficiency by caching contents at mobile edge. However, the cache pollution attack can affect the data obtaining process severely by requiring unpopular contents deliberately. To tackle the problem, we design an algorithm of mitigating cache pollution attacks in information centric mobile network. Particularly, the content popularity distribution statistic is proposed to detect abnormal behavior. Then a probabilistic caching strategy based on abnormal behavior is applied to dynamically maintain the steady-state distribution for content visiting probability and achieve the purpose of defense. The experimental results show that the proposed scheme can achieve higher request hit ratio and smaller latency for false locality content pollution attack than the CacheShield approach and the baseline approach where no mitigation approach is applied.

데이터의 지역성을 이용한 빈발구간 항목집합 생성방법 (A Method for Generating Large-Interval Itemset using Locality of Data)

  • 박원환;박두순
    • 한국멀티미디어학회논문지
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    • 제4권5호
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    • pp.465-475
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    • 2001
  • 최근에 대용량의 데이터베이스로부터 연관규칙을 발견하고자 하는 연구가 활발하며, 수량항목에도 적용할 수 있도록 이들 방법을 확장하는 연구도 소개되고 있다. 본 논문에서는 수량항목을 이진 항목으로 변환하기 위하여 빈발구간 항목집합을 생성할 때, 수량 항목의 정의 영역 내에서 특정 영역에 집중하여 발생하는 특성인 지역성을 이용하는 방법을 제안한다. 이 방법은 기존의 방법보다 많은 수의 세밀한 빈발구간 항목들을 생성할 수 있을 뿐만 아니라 세밀도를 판단하여 활용할 수 있는 생성순서 정보도 포함하고 있어, 원 데이터가 가지고 있는 특성의 손실을 최소화할 수 있는 특징이 있다. 인구센서스 등 실 데이터를 사용한 성능평가를 통하여 기존의 방법보다 우수함을 보였다.

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Rediscovery of Zubovskya morii(Bey-Bienko, 1931)(Orthoptera: Acrididae), the nearly forgotten endemic grasshopper in North Korea with revised checklist from its type locality, Mount Baekdusan

  • Kim, Taewoo;Chobanov, Dragan P.;Seo, Hongyul
    • Journal of Species Research
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    • 제6권2호
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    • pp.195-205
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    • 2017
  • Zubovskya morii (Bey-Bienko, 1931) was rediscovered from its type locality, Mount Baekdusan, from materials collected by Bulgarian zoological expeditions to North Korea in the 1970s. This grasshopper species is endemic to North Korea and for the past 85 years was known only from a single holotype male. In the present study we describe the female Z. morii for the first time. A revised checklist of Orthoptera at Mount Baekdusan (also known as Changbaishan in China) is also provided. A new synonymy, Zubovskya longifurcula (Jin et al., 2011), syn. nov. for Zubovskya koreana Mistshenko, 1952 is proposed here.