• Title/Summary/Keyword: Data Locality

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Taxonomic assessment of North American species of the genera Cumathamnion, Delesseria, Membranoptera and Pantoneura (Delesseriaceae, Rhodophyta) using molecular data

  • Wynne, Michael J.;Saunders, Gary W.
    • ALGAE
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    • v.27 no.3
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    • pp.155-173
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    • 2012
  • Evidence from molecular data supports the close taxonomic relationship of the two North Pacific species Delesseria decipiens and D. serrulata with Cumathamnion, up to now a monotypic genus known only from northern California, rather than with D. sanguinea, the type of the genus Delesseria and known only from the northeastern North Atlantic. The transfers of D. decipiens and D. serrulata into Cumathamnion are effected. Molecular data also reveal that what has passed as Membranoptera alata in the northwestern North Atlantic is distinct at the species level from northeastern North Atlantic (European) material; M. alata has a type locality in England. Multiple collections of Membranoptera and Pantoneura fabriciana on the North American coast of the North Atlantic prove to be identical for the three markers that have been sequenced, and the name Membranoptera fabriciana (Lyngbye) comb. nov. is proposed for them. Many collections of Membranoptera from the northeastern North Pacific (predominantly British Columbia), although representing the morphologies of several species that have been previously recognized, are genetically assignable to a single group for which the oldest name applicable is M. platyphylla.

A Novel Memory Hierarchy for Flash Memory Based Storage Systems

  • Yim, Keno-Soo
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.5 no.4
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    • pp.262-269
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    • 2005
  • Semiconductor scientists and engineers ideally desire the faster but the cheaper non-volatile memory devices. In practice, no single device satisfies this desire because a faster device is expensive and a cheaper is slow. Therefore, in this paper, we use heterogeneous non-volatile memories and construct an efficient hierarchy for them. First, a small RAM device (e.g., MRAM, FRAM, and PRAM) is used as a write buffer of flash memory devices. Since the buffer is faster and does not have an erase operation, write can be done quickly in the buffer, making the write latency short. Also, if a write is requested to a data stored in the buffer, the write is directly processed in the buffer, reducing one write operation to flash storages. Second, we use many types of flash memories (e.g., SLC and MLC flash memories) in order to reduce the overall storage cost. Specifically, write requests are classified into two types, hot and cold, where hot data is vulnerable to be modified in the near future. Only hot data is stored in the faster SLC flash, while the cold is kept in slower MLC flash or NOR flash. The evaluation results show that the proposed hierarchy is effective at improving the access time of flash memory storages in a cost-effective manner thanks to the locality in memory accesses.

A Novel Node Management in Hadoop Cluster by using DNA

  • Balaraju. J;PVRD. Prasada Rao
    • International Journal of Computer Science & Network Security
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    • v.23 no.9
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    • pp.134-140
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    • 2023
  • The distributed system is playing a vital role in storing and processing big data and data generation is speedily increasing from various sources every second. Hadoop has a scalable, and efficient distributed system supporting commodity hardware by combining different networks in the topographical locality. Node support in the Hadoop cluster is rapidly increasing in different versions which are facing difficulty to manage clusters. Hadoop does not provide Node management, adding and deletion node futures. Node identification in a cluster completely depends on DHCP servers which managing IP addresses, hostname based on the physical address (MAC) address of each Node. There is a scope to the hacker to theft the data using IP or Hostname and creating a disturbance in a distributed system by adding a malicious node, assigning duplicate IP. This paper proposing novel node management for the distributed system using DNA hiding and generating a unique key using a unique physical address (MAC) of each node and hostname. The proposed mechanism is providing better node management for the Hadoop cluster providing adding and deletion node mechanism by using limited computations and providing better node security from hackers. The main target of this paper is to propose an algorithm to implement Node information hiding in DNA sequences to increase and provide security to the node from hackers.

Efficient Implementation of SVM-Based Speech/Music Classifier by Utilizing Temporal Locality (시간적 근접성 향상을 통한 효율적인 SVM 기반 음성/음악 분류기의 구현 방법)

  • Lim, Chung-Soo;Chang, Joon-Hyuk
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.49 no.2
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    • pp.149-156
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    • 2012
  • Support vector machines (SVMs) are well known for their pattern recognition capability, but proper care should be taken to alleviate their inherent implementation cost resulting from high computational intensity and memory requirement, especially in embedded systems where only limited resources are available. Since the memory requirement determined by the dimensionality and the number of support vectors is generally too high for a cache in embedded systems to accomodate, frequent accesses to the main memory occur inevitably whenever the cache is not able to provide requested data to the processor. These frequent accesses to the main memory result in overall performance degradation and increased energy consumption because a memory access typically takes longer and consumes more energy than a cache access or a register access. In this paper, we propose a technique that reduces the number of main memory accesses by optimizing the data access pattern of the SVM-based classifier in such a way that the temporal locality of the accesses increases, fully utilizing data loaded into the processor chip. With experiments, we confirm the enhancement made by the proposed technique in terms of the number of memory accesses, overall execution time, and energy consumption.

Observing Changes of Data Locality as Unrolling Factors Increase in Outer Loop Unrolling (외부 루프 펼침에서 펼침 인자 증가에 따른 데이터 지역성 변화 관찰)

  • 우덕균;표창우
    • Proceedings of the Korean Information Science Society Conference
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    • 1998.10b
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    • pp.407-409
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    • 1998
  • 루프 몸체를 복제하는 루프 펼침을 외부 루프에 대하여 적용하면, 루프 내포체의 데이터 지역성이 개선된다. 펼침 횟수 증가에 따른 루프 내포체의 데이터 지역성 변화를 예측하였고, 예측 결과를 행렬 곱셈 프로그램에 대하여 실행 시간과 개시 미스 변화를 측정하여 검증하였다. 펼침 횟수는 증가함에 따라, 초반에는 실행 시간과 캐시 미스가 급격히 감소하다 점점 감소폭이 줄어드는 기하급수적 변화를 보였다. 이 결과는 데이터 지역성 개선을 위한 외부 루프 펼침 변환을 적용 할 때, 작은 값(최대 405회)의 펼침으로 프로그램 성능 향상을 기대할 수 있음을 의미한다. 한편, 컴파일러에 의한 루프 펼침을 적용할 때, 불필요하게 많은 펼침 횟수의 펼침 효과에 대하여 분석 할 필요가 없음을 나타낸다

A Study on Modular Min (Modular MIN에 관한 연구)

  • 장창수;최창훈;유창하
    • The Journal of the Korea Contents Association
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    • v.2 no.2
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    • pp.103-111
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    • 2002
  • In parallel application programs with a localized communication, even if the MINs have lour diameters, overall system performance degrades when compared to the hypercube and tree structure. The reason is that it is impossible for MINs to provide some mechanisms for clustering to exploit the locality of reference. However proposed MIN can be constructed suitable for localized communication by providing the shortcut path and multiple paths inside the processor-memory duster which has frequent data communications. Therefore proposed MIN achieves enhanced performance in parallel application program with a localized communication.

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Review of the Shell-bearing Gastropods in the Russian Waters of the East Sea (Sea of Japan). IV. Heterobranchia

  • Gulbin, Vladimir V.;Chaban, Elena M.
    • The Korean Journal of Malacology
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    • v.25 no.1
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    • pp.71-79
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    • 2009
  • Based on investigation of archive collections of A.V. Zhirmunsky Institute of Marine Biology of the Far-Eastern Branch of the Russian Academy of Sciences (Vladivostok) and O.A. Scarlato Zoological Institute of the Russian Academy of Sciences (Saint Petersburg), as well as on the analysis of published data, the species composition of shell-bearing gastropod mollusks of the Russian waters of the East Sea (Sea of Japan), consisting of 331 species and subspecies, has been identified. The fourth part of the Review includes 46 species of Heterobranchia (Allogastropoda, Opistobranchia, and Pulmonata). Each species is assigned to a biogeographic grouping in the study area. Its type locality and habitat (depth and substrate) are also documented.

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Review of the Shell-bearing Gastropods in the Russian Waters of the East Sea (Sea of Japan). III. Caenogastropoda: Neogastropoda

  • Gulbin, Vladimir V.
    • The Korean Journal of Malacology
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    • v.25 no.1
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    • pp.51-70
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    • 2009
  • Based on investigation of collections at the A.V. Zhirmunsky Institute of Marine Biology of the Far-Eastern Branch of the Russian Academy of Sciences (Vladivostok) and Zoological Institute of the Russian Academy of Sciences (Saint Petersburg), as well as on the analysis of published data, the species composition of shell-bearing gastropod mollusks of the Russian waters of the East Sea (Sea of Japan), consisting of 331 species and subspecies, has been identified. Each species is assigned to a biogeographic grouping in the study area. Its type locality and habitat (depth and substrate) are also documented. The third part of this review includes 129 species in Neogastropoda (Caenogastropoda).

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The conspecificity of Pterosiphonia spinifera and P. arenosa (Rhodomelaceae, Ceramiales) inferred from morphological and molecular analyses

  • Bustamante, Danilo E.;Won, Boo Yeon;Cho, Tae Oh
    • ALGAE
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    • v.31 no.2
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    • pp.105-115
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    • 2016
  • The genus Pterosiphonia includes twenty-one currently described species of red algae that occur in temperate to tropical regions of the Atlantic and Pacific Oceans. Pterosiphonia spinifera was originally described as Polysiphonia spinifera from Peru and later transferred to Pterosiphonia. Pterosiphonia spinifera has been reported from Peru as Pterosiphonia pennata, which was originally described from the Mediterranean Sea. Recently, Pterosiphonia arenosa was described based on specimens of P. pennata from Korea. We collected P. spinifera along the coast of Peru and P. arenosa near the type locality in Korea. We compared them with the isotype specimens of P. arenosa using both morphological and molecular data. Our morphological observations and our phylogenetic analysis of rbcL sequences demonstrate that P. spinifera and P. arenosa are conspecific and indicate that P. arenosa is a later synonym of P. spinifera. Our study confirms the wide occurrence of P. spinifera in the western and eastern Pacific Ocean.

Re-description of Chrysaora pacifica (Goette, 1886) (Cnidaria, Scyphozoa) from Korean Coastal Waters: Morphology and Molecular Comparisons

  • Lee, Hye Eun;Yoon, Won Duk;Chae, Jinho;Ki, Jang-Seu
    • Ocean and Polar Research
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    • v.38 no.4
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    • pp.295-301
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    • 2016
  • The nomenclature of the sea nettle jellyfish from Korea was initially described as Dactylometra quinquecirrha Agassiz, 1862. However its identity has been questioned on the basis of its local distribution and molecular data. Here, we examined morphology and DNA sequences of nuclear rDNA using specimens collected from southern Korean waters in August 2014. Based on morphological characteristics (bell size, umbrella pattern, number of tentacles and lappets) and distribution locality, we reassign the Korean D. quinquecirrha to Chrysaora pacifica (Goette, 1886), and provide a re-description accordingly. The molecular identity of C. pacifica was further confirmed by comparison of nuclear ribosomal DNA sequences.