The Experts below are selected from a list of 143271 Experts worldwide ranked by ideXlab platform

Zili Shao - One of the best experts on this subject based on the ideXlab platform.

  • IEEE Real-Time and Embedded Technology and Applications Symposium - Real-Time Flash Translation Layer for NAND Flash Memory Storage Systems
    2012 IEEE 18th Real Time and Embedded Technology and Applications Symposium, 2012
    Co-Authors: Yi Wang, Zili Shao
    Abstract:

    Due to the variable garbage Collection latency, NAND flash memory storage systems may suffer long system response time, especially when the flash memory is close to be full. Most of existing flash translation layer (FTL) schemes focus on improving the average response time but ignore to provide a desirable worst case response time upper bound. This paper proposes a Real-time Flash Translation Layer (RFTL) scheme to hide the long garbage Collection latency while satisfying a worst case response time upper bound that achieves an ideal case. We achieve this by using a distributed partial garbage Collection Policy that enables RFTL to reclaim the space and to serve the write requests simultaneously. A new block-level address mapping approach is designed to guarantee enough free space to serve the write request arriving at any time period. Experimental results show that our scheme improves both the worst case system response time and the average system response time compared with previous work.

Yi Wang - One of the best experts on this subject based on the ideXlab platform.

  • IEEE Real-Time and Embedded Technology and Applications Symposium - Real-Time Flash Translation Layer for NAND Flash Memory Storage Systems
    2012 IEEE 18th Real Time and Embedded Technology and Applications Symposium, 2012
    Co-Authors: Yi Wang, Zili Shao
    Abstract:

    Due to the variable garbage Collection latency, NAND flash memory storage systems may suffer long system response time, especially when the flash memory is close to be full. Most of existing flash translation layer (FTL) schemes focus on improving the average response time but ignore to provide a desirable worst case response time upper bound. This paper proposes a Real-time Flash Translation Layer (RFTL) scheme to hide the long garbage Collection latency while satisfying a worst case response time upper bound that achieves an ideal case. We achieve this by using a distributed partial garbage Collection Policy that enables RFTL to reclaim the space and to serve the write requests simultaneously. A new block-level address mapping approach is designed to guarantee enough free space to serve the write request arriving at any time period. Experimental results show that our scheme improves both the worst case system response time and the average system response time compared with previous work.

Fred Muratori - One of the best experts on this subject based on the ideXlab platform.

Ohhoon Kwon - One of the best experts on this subject based on the ideXlab platform.

  • swap space management technique for portable consumer electronics with nand flash memory
    IEEE Transactions on Consumer Electronics, 2010
    Co-Authors: Ohhoon Kwon
    Abstract:

    Flash memory has more capacity and a lower price. It makes flash memory more suitable for portable consumer electronics. Portable consumer electronics such as table PC and smart phones use NAND flash memory as a secondary storage because it has many attractive features such as small size, fast access speeds, and light weight. The portable consumer electronics with NAND flash memory exploit a "demand paging" to run applications, and also use a "swapping" to extend a limited main memory space. However, if the portable consumer electronics use NAND flash memory as swap space, it should perform garbage Collection, which is a time-consuming operation. Therefore, in order to manage swap space efficiently, this work presents a novel garbage Collection Policy for the portable consumer electronics with a swap system. The proposed Policy has three features important in NAND flash memory based swap systems: (1) long endurance of NAND flash memory, (2) quick garbage Collection, and (3) low energy consumption.

  • swap aware garbage Collection for nand flash memory based embedded systems
    Computer and Information Technology, 2007
    Co-Authors: Ohhoon Kwon
    Abstract:

    Embedded systems use NAND flash memory as a secondary storage device because it has many attractive features such as small size, fast access speeds, shock resistance, and light weight. NAND flash memory based embedded systems exploit a "demand paging" to run applications and also use a "swapping" to extend a limited main memory space. Because the embedded systems use NAND flash memory as swap space, it should perform garbage Collection, which is a time-consuming operation. Besides, the number of the erase operations allowed to each block is also limited. In this paper, we propose a new garbage Collection Policy for embedded systems with the swap system. The proposed garbage Collection Policy focuses on minimizing the garbage Collection time and even wear-leveling. Trace-driven simulations show that the proposed Policy performs better than existing garbage Collection policies in terms of the garbage Collection time and the endurance of flash memory.

  • an efficient garbage Collection Policy for flash memory based swap systems
    International Conference on Computational Science and Its Applications, 2007
    Co-Authors: Ohhoon Kwon
    Abstract:

    Mobile computing devices use flash memory as a secondary storage because it has many attractive features such as small size, fast access speeds, shock resistance, and light weight. Mobile computing devices exploit a swap system to extend a limited main memory space and use flash memory as a swap system. Although flash memory has the attractive features, it should perform garbage Collection, which includes erase operations. The erase operations are very slow, and usually decrease the performance of the system. Besides, the number of the erase operations allowed to each block is also limited. To minimize the garbage Collection time and evenly wear out, our proposed garbage Collection Policy focuses on minimizing the garbage Collection time and wear-leveling. Trace-driven simulations show that the proposed Policy performs better than existing garbage Collection policies in terms of the number of erase operation, the garbage Collection time, total amount of energy consumption and the endurance of flash memory.

  • ICCSA (1) - An efficient garbage Collection Policy for flash memory based swap systems
    Lecture Notes in Computer Science, 2007
    Co-Authors: Ohhoon Kwon
    Abstract:

    Mobile computing devices use flash memory as a secondary storage because it has many attractive features such as small size, fast access speeds, shock resistance, and light weight. Mobile computing devices exploit a swap system to extend a limited main memory space and use flash memory as a swap system. Although flash memory has the attractive features, it should perform garbage Collection, which includes erase operations. The erase operations are very slow, and usually decrease the performance of the system. Besides, the number of the erase operations allowed to each block is also limited. To minimize the garbage Collection time and evenly wear out, our proposed garbage Collection Policy focuses on minimizing the garbage Collection time and wear-leveling. Trace-driven simulations show that the proposed Policy performs better than existing garbage Collection policies in terms of the number of erase operation, the garbage Collection time, total amount of energy consumption and the endurance of flash memory.

  • ef greedy a novel garbage Collection Policy for flash memory based embedded systems
    International Conference on Conceptual Structures, 2007
    Co-Authors: Ohhoon Kwon, Jaewoo Lee, Kern Koh
    Abstract:

    Flash memory is becoming increasingly important for embedded systems because it has many attractive features such as small size, fast access speeds, shock resistance, and light weight. Although flash memory has attractive features, it should perform garbage Collection, which includes erase operations. The erase operations are very slow, and usually decrease the performance of the system. Besides, the number of the erase operations allowed to each block is also limited. To minimize the garbage Collection time and evenly wear out, our proposed garbage Collection Policy focuses on minimizing the garbage Collection time and wear-leveling. Trace-driven simulations show that the proposed Policy performs better than existing garbage Collection policies in terms of the garbage Collection time and the endurance of flash memory. Specifically, we have shown that the performance improvement of our proposed Policy against the greedy Policy in terms of the endurance of flash memory is as much as 90.6%.

Jarmo Saarti - One of the best experts on this subject based on the ideXlab platform.

  • From the centralized national Collection Policy towards a decentralized Collection management and resource sharing co-operation – Finnish experiences
    Library Management, 2014
    Co-Authors: Ari Muhonen, Jarmo Saarti, Pentti Vattulainen
    Abstract:

    Purpose – Finland had a legislation-based centralized Collection Policy until the mid-1990s. The main components were national resource centers (selected higher education libraries) and provincial libraries (selected public libraries). This paradigm changed during the recession of the 1990s when new public management ideologies were adopted by the government. This ended the centralized model and a new Policy favoring a decentralized Collection management which demanded resource sharing. The models designated for the print-only age became obsolete also when the digital dissemination of especially scientific documents began to be the norm. The Finnish libraries have started to implement a new strategy consisting of different elements including a new model of library automation systems, the National Repository which is the hub for the resource sharing of print materials, digitization projects (to be especially implemented by the National Library) and with new policies defining the roles and responsibilities ...

  • from the centralized national Collection Policy towards a decentralized Collection management and resource sharing co operation finnish experiences
    Library Management, 2014
    Co-Authors: Ari Muhonen, Jarmo Saarti, Pentti Vattulainen
    Abstract:

    Purpose – Finland had a legislation-based centralized Collection Policy until the mid-1990s. The main components were national resource centers (selected higher education libraries) and provincial libraries (selected public libraries). This paradigm changed during the recession of the 1990s when new public management ideologies were adopted by the government. This ended the centralized model and a new Policy favoring a decentralized Collection management which demanded resource sharing. The models designated for the print-only age became obsolete also when the digital dissemination of especially scientific documents began to be the norm. The Finnish libraries have started to implement a new strategy consisting of different elements including a new model of library automation systems, the National Repository which is the hub for the resource sharing of print materials, digitization projects (to be especially implemented by the National Library) and with new policies defining the roles and responsibilities ...

  • From the centralized national Collection Policy towards a decentralized Collection management and resource sharing co-operation – Finnish experiences
    Library Management, 2014
    Co-Authors: Ari Muhonen, Jarmo Saarti, Pentti Vattulainen
    Abstract:

    Purpose – Finland had a legislation-based centralized Collection Policy until the mid-1990s. The main components were national resource centers (selected higher education libraries) and provincial libraries (selected public libraries). This paradigm changed during the recession of the 1990s when new public management ideologies were adopted by the government. This ended the centralized model and a new Policy favoring a decentralized Collection management which demanded resource sharing. The models designated for the print-only age became obsolete also when the digital dissemination of especially scientific documents began to be the norm. The Finnish libraries have started to implement a new strategy consisting of different elements including a new model of library automation systems, the National Repository which is the hub for the resource sharing of print materials, digitization projects (to be especially implemented by the National Library) and with new policies defining the roles and responsibilities of each of the libraries involved. This article aims to describe the history of the Finnish centralized Collection Policy, its shift to the modern management of the Collection as well as the philosophy and tools used in this work. Design/methodology/approach – The paper describes the evolution of the Finnish national Collection Policy and its main trends. Findings – The National Repository Library has enabled Finnish university libraries to focus their Collection policies and to make savings in the cost of premises. A new business model for the digital era is needed for document sharing between libraries. Research limitations/implications – The paper is based on Finnish experiences. Practical implications – Models for national and international Collection and preservation policies are presented. Originality/value – The paper provides proposals for the building of global division of work in the long-tail management of documents.

  • Collection Policy management for the Kuopio University and Kuopio University Hospital, Finland: Detecting the needs of users and developing high-quality Collections
    Health Information and Libraries Journal, 2006
    Co-Authors: Jukka Kananen, Tuulevi Ovaska, Jarmo Saarti
    Abstract:

    BACKGROUND: This article discusses the Collection policies of a university library in a modern digital environment. A brief description of national Collection Policy decisions in Finland is provided. The rapid evolution and growth of scientific publication places new demands on building a Collection in a health and bioscience orientated university, and it requires an evidence-based approach to support effective service processes. OBJECTIVES: The aim of the study was to identify the needs of the university's students and staff. METHODS: Usage statistics were surveyed and analysed. RESULTS: Both usage statistics and user surveys indicate that the library use is divided half-and-half between the traditional use of printed material and library premises and the modern use of digital materials via the Web. The former is mainly the way that the students and hospital staff use the library, and the latter can be viewed as the researchers' way of using the library. Librarians and information specialists act in this as service providers and/or guides and tutors to the end-users. These results, however, must be validated with a longer timescale data collation and analysis, both of which are an ongoing process within the library. CONCLUSIONS: It is important that requirements and needs of the library's users are monitored regularly and acquisition policies are updated frequently. It also seems that the needs have changed quite dramatically in response to modern ways of disseminating publications, but this supposition will require further study.

  • from printed world to a digital environment
    Library Management, 2005
    Co-Authors: Jarmo Saarti
    Abstract:

    Purpose – To determine and define the role of repository libraries in Finland for a medium‐sized university library in the digital environment.Design/methodology/approach – Literature and strategy‐based conceptual analysis and a case study of the role of different types of scientific library and information service actors in Finland.Findings – The Finnish University Libraries and Ministry of Education have made strategic solutions in order to ensure an effective national Collection Policy. Digital materials are acquired mainly via the University Libraries' consortium, FinELib. The older and less used printed materials are collected in the National Repository Library. Modern technologies and logistic solutions are used in ensuring the effective end‐user services. Thus each library can make its own strategic Collection Policy decisions based on these national services.Research limitations/implications – Based on conditions in Finland.Practical implications – Gives an example of a national Collection Policy ...