The Experts below are selected from a list of 75702 Experts worldwide ranked by ideXlab platform

R Jaumann - One of the best experts on this subject based on the ideXlab platform.

  • A special joint symposium of ISPRS Technical Commission IV & AutoCarto in conjunction with ASPRS/CaGIS 2010 Fall Specialty Conference MAP DESCRIPTION AND MANAGEMENT BY SPATIAL Metadata: REQUIREMENTS FOR DIGITAL MAP LEGEND FOR PLANETARY GEOLOGICAL AND GEOM
    2020
    Co-Authors: Andrea Nass, S Van Gasselt, R Jaumann
    Abstract:

    ABSTRACT: Instruments carried along on missions to, e.g., Mars, the Moon, Venus, and various Outer-Solar System objects, produce a rich variety of image data recorded in different wavelengths and some of them allow to derive additional datasets (e.g., digital terrain models). These data form the basis for geologically exploring the evolution of planetary bodies by analyzing and geoscientifically interpreting surface structures. By using modern GIS techniques the results are represented in thematic, mostly geological and geomorphological maps and allow to extract additional Information, e.g. by means of morphometric measurements. To allow for an efficient collaboration among various scientists and groups, all mapping results have to be uniformly prepared, described, managed and archived. In order to achieve this, GIS-based mapping approaches are currently underway. One of the important aspects in this context is a detailed map description and an efficient management of mapping results by using Metadata Information. Such data describe, e.g. the geometry, extent, quality, contents and conditions of source data and additionally allow detailed queries for context Information. We are currently working on the evaluation and creation of Metadata templates that deal with individually descriptive elements of planetary mapping results. Such templates then form an obligatory component to be filled in by the user/mapper after mapping conduct. The first step on the way to such a generic data-description template is the formulation of Metadata requirements which help to establish a common Information basis that can be used by the planetary science community to search and understand spatial data products on the level of input data as well as on the level of digital map products. Such a Metadata basis therefore forms a way to store Information of traditional analog map legends within a digital map product. Such Metadata Information needs to be implemented as template on two different levels: the individual (vector-based) map level data as well as the (raster-based) dataset level that was used to create the map. Such a Metadata template can then be used either in stand-alone GIS projects or it can be integrated into a more sophisticated database model using an XML-structured and standardized vocabulary. The usage of an obligatory map description template facilitates the efficient and traceable storage of spatial data and mapping results on a network level

  • map description and management by spatial Metadata requirements for digital map legend for planetary geological and geomorphological mapping
    2010
    Co-Authors: Andrea Nass, S Van Gasselt, R Jaumann
    Abstract:

    Instruments carried along on missions to, e.g., Mars, the Moon, Venus, and various Outer-Solar System objects, produce a rich variety of image data recorded in different wavelengths and some of them allow to derive additional datasets (e.g., digital terrain models). These data form the basis for geologically exploring the evolution of planetary bodies by analyzing and geoscientifically interpreting surface structures. By using modern GIS techniques the results are represented in thematic, mostly geological and geomorphological maps and allow to extract additional Information, e.g. by means of morphometric measurements. To allow for an efficient collaboration among various scientists and groups, all mapping results have to be uniformly prepared, described, managed and archived. In order to achieve this, GIS-based mapping approaches are currently underway. One of the important aspects in this context is a detailed map description and an efficient management of mapping results by using Metadata Information. Such data describe, e.g. the geometry, extent, quality, contents and conditions of source data and additionally allow detailed queries for context Information. We are currently working on the evaluation and creation of Metadata templates that deal with individually descriptive elements of planetary mapping results. Such templates then form an obligatory component to be filled in by the user/mapper after mapping conduct. The first step on the way to such a generic data-description template is the formulation of Metadata requirements which help to establish a common Information basis that can be used by the planetary science community to search and understand spatial data products on the level of input data as well as on the level of digital map products. Such a Metadata basis therefore forms a way to store Information of traditional analog map legends within a digital map product. Such Metadata Information needs to be implemented as template on two different levels: the individual (vector-based) map level data as well as the (raster-based) dataset level that was used to create the map. Such a Metadata template can then be used either in stand-alone GIS projects or it can be integrated into a more sophisticated database model using an XML-structured and standardized vocabulary. The usage of an obligatory map description template facilitates the efficient and traceable storage of spatial data and mapping results on a network level.

Muhammad Naeem Ahmed Khan - One of the best experts on this subject based on the ideXlab platform.

  • performance analysis of bayesian networks and neural networks in classification of file system activities
    Computers & Security, 2012
    Co-Authors: Muhammad Naeem Ahmed Khan
    Abstract:

    Precise comprehension of a file system state at any given time is vital for performing digital forensic analyses. To uncover evidence of the digital crime, the logical representation of file system activities helps reconstruct post-event timeline of the unauthorized or malicious accesses made on a system. This paper describes a comparative performance analysis of the Bayesian networks and neural networks techniques to classify the state of file system activities in terms of execution of applications based on the pattern of manipulation of specific files during certain period of time. In particular, this paper discusses the construction of a Bayesian networks and neural networks from the predetermined knowledge of the manipulation of file system artifacts and their corresponding Metadata Information by a set of software applications. The variability amongst the execution patterns of various applications indicate that the Bayesian network-based model is a more appropriate tool as compared to neural networks because of its ability to learn and detect patterns even from an incomplete dataset. The focus of this paper is to highlight intrinsic significance of the learning approach of Bayesian network methodology in comparison to the techniques used for supervised learning in ordinary neural networks. The paper also highlights the efficacy of Bayesian network technique to proficiently handle large volumes of datasets.

Onur Mutlu - One of the best experts on this subject based on the ideXlab platform.

  • Improving the Performance and Endurance of Persistent Memory with Loose-Ordering Consistency
    IEEE Transactions on Parallel and Distributed Systems, 2018
    Co-Authors: Jiwu Shu, Long Sun, Onur Mutlu
    Abstract:

    Persistent memory provides high-performance data persistence at main memory. Memory writes need to be performed in strict order to satisfy storage consistency requirements and enable correct recovery from system crashes. Unfortunately, adhering to such a strict order significantly degrades system performance and persistent memory endurance. This paper introduces a new mechanism, Loose-Ordering Consistency (LOC), that satisfies the ordering requirements at significantly lower performance and endurance loss. LOC consists of two key techniques. First, Eager Commit eliminates the need to perform a persistent commit record write within a transaction. We do so by ensuring that we can determine the status of all committed transactions during recovery by storing necessary Metadata Information statically with blocks of data written to memory. Second, Speculative Persistence relaxes the write ordering between transactions by allowing writes to be speculatively written to persistent memory. A speculative write is made visible to software only after its associated transaction commits. To enable this, our mechanism supports the tracking of committed transaction ID and multi-versioning in the CPU cache. Our evaluations show that LOC reduces the average performance overhead of memory persistence from 66.9% to 34.9% and the memory write traffic overhead from 17.1% to 3.4% on a variety of workloads.

  • Loose-Ordering Consistency for Persistent Memory
    2018
    Co-Authors: Jiwu Shu, Long Sun, Onur Mutlu
    Abstract:

    Emerging non-volatile memory (NVM) technologies enable data persistence at the main memory level at access speeds close to DRAM. In such persistent memories, memory writes need to be performed in strict order to satisfy storage consistency requirements and enable correct recovery from system crashes. Unfortunately, adhering to a strict order for writes to persistent memory significantly degrades system performance as it requires flushing dirty data blocks from CPU caches and waiting for their completion at the main memory in the order specified by the program. This paper introduces a new mechanism, called Loose-Ordering Consistency (LOC), that satisfies the ordering requirements of persistent memory writes at significantly lower performance degradation than state-of-the-art mechanisms. LOC consists of two key techniques. First, Eager Commit reduces the commit overhead for writes within a transaction by eliminating the need to perform a persistent commit record write at the end of a transaction. We do so by ensuring that we can determine the status of all committed transactions during recovery by storing necessary Metadata Information statically with blocks of data written to memory. Second, Speculative Persistence relaxes the ordering of writes between transactions by allowing writes to be speculatively written to persistent memory. A speculative write is made visible to software only after its associated transaction commits. To enable this, our mechanism requires the tracking of committed transaction ID and support for multi-versioning in the CPU cache. Our evaluations show that LOC reduces the average performance overhead of strict write ordering from 66.9% to 34.9% on a variety of workloads.

Yves Le Traon - One of the best experts on this subject based on the ideXlab platform.

  • Comparison of Metadata quality in open data portals using the Analytic Hierarchy Process
    Government Information Quarterly, 2018
    Co-Authors: Sylvain Kubler, Jérémy Robert, Sebastian Neumaier, Jürgen Umbrich, Yves Le Traon
    Abstract:

    The quality of Metadata in open data portals plays a crucial role for the success of open data. E-government, for example, have to manage accurate and complete Metadata Information to guarantee the reliability and foster the reputation of e-government to the public. Measuring and comparing the quality of open data is not a straightforward process because it implies to take into consideration multiple quality dimensions whose quality may vary from one another, as well as various open data stakeholders who – depending on their role/needs – may have different preferences regarding the dimensions' importance. To address this Multi-Criteria Decision Making (MCDM) problem, and since data quality is hardly considered in existing e-government models, this paper develops an Open Data Portal Quality (ODPQ) framework that enables end-users to easily and in real-time assess/rank open data portals. From a theoretical standpoint, the Analytic Hierarchy Process (AHP) is used to integrate various data quality dimensions and end-user preferences. From a practical standpoint, the proposed framework is used to compare over 250 open data portals, powered by organizations across 43 different countries. The findings of our study reveals that today's organizations do not pay sufficient heed to the management of datasets, resources and associated Metadata that they are currently publishing on their portal.

Nikos C Kyrpides - One of the best experts on this subject based on the ideXlab platform.

  • the genomes on line database gold in 2009 status of genomic and metagenomic projects and their associated Metadata
    Nucleic Acids Research, 2007
    Co-Authors: Ioanna Pagani, Konstantinos Liolios, Jakob Jansson, Imin A Chen, Tatyana Smirnova, Bahador Nosrat, Victor Markowitz, Nikos C Kyrpides
    Abstract:

    The Genomes On Line Database (GOLD) is a comprehensive resource for centralized monitoring of genome and metagenome projects worldwide. Both complete and ongoing projects, along with their associated Metadata, can be accessed in GOLD through precomputed tables and a search page. As of September 2009, GOLD contains Information for more than 5800 sequencing projects, of which 1100 have been completed and their sequence data deposited in a public repository. GOLD continues to expand, moving toward the goal of providing the most comprehensive repository of Metadata Information related to the projects and their organisms/environments in accordance with the Minimum Information about a (Meta)Genome Sequence (MIGS/MIMS) specification. GOLD is available at: http://www.genomesonline.org and has a mirror site at the Institute of Molecular Biology and Biotechnology, Crete, Greece, at: http://gold.imbb.forth.gr/