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Marcelo Antonio Da ,silva - One of the best experts on this subject based on the ideXlab platform.
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Use of distributed computing for Storage and indexing of forensic data
2012Co-Authors: Marcelo Antonio Da ,silvaAbstract:Este trabalho apresenta um sistema distribuído construído para realizar o armazenamento e a indexação dos dados resultantes de uma análise forense em dispositivo de armazenamento computacional. Com o passar dos anos, a quantidade de dados forenses a analisar vem se tornando cada vez maior. Isto é decorrente tanto do constante crescimento da capacidade dos dispositivos de armazenamento computacional quanto da maior popularização destes equipamentos. Em um caso que envolva dezenas de dispositivos de armazenamento secundário, realizar a análise forense torna-se uma tarefa com alto custo computacional de processamento, devido ao processo de geração dos índices e a necessidade de um espaço de armazenamento adequado para os dados. A indexação é fundamental para uma posterior análise nos dados forenses. A solução apresentada neste trabalho utiliza um sistema de arquivos distribuído para prover um espaço de armazenamento para os dados forenses com escalabilidade, disponibilidade e tolerância a falhas. Também, realiza a indexação dos dados forenses, através de um eficiente método de distribuição de processamento em grade. Neste trabalho são apresentados os cenários que foram elaborados e utilizados para testar o comportamento do sistema de armazenamento e indexação distribuída de dados forenses. _________________________________________________________________________________ ABSTRACTThis thesis presents a distributed system built to perform Storage and indexing of data resulting from a forensic analysis of Computer Storage device. Over the years, the amount of forensic data to analyze is becoming ever greater. This is due to both the growing capacity of Computer Storage Devices and the increased popularity of these Devices. In a case involving dozens of secondary Storage Devices, perform forensic analysis becomes a task with high computational cost of processing, due to the index generation process and the need for adequate Storage space for data. The indexing is fundamental for further forensics analysis in these data. The solution presented here uses a distributed file system to provide a Storage space for forensic data with scalability, availability and fault tolerance. Also, performs the indexing of forensic data, through an efficient distribution method with grid processing. This paper presents the scenarios that were developed and used to test the behavior of the system of distributed Storage and indexing of forensic data
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Use of distributed computing for Storage and indexing of forensic data
2012Co-Authors: Marcelo Antonio Da ,silvaAbstract:Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2012.Este trabalho apresenta um sistema distribuído construído para realizar o armazenamento e a indexação dos dados resultantes de uma análise forense em dispositivo de armazenamento computacional. Com o passar dos anos, a quantidade de dados forenses a analisar vem se tornando cada vez maior. Isto é decorrente tanto do constante crescimento da capacidade dos dispositivos de armazenamento computacional quanto da maior popularização destes equipamentos. Em um caso que envolva dezenas de dispositivos de armazenamento secundário, realizar a análise forense torna-se uma tarefa com alto custo computacional de processamento, devido ao processo de geração dos índices e a necessidade de um espaço de armazenamento adequado para os dados. A indexação é fundamental para uma posterior análise nos dados forenses. A solução apresentada neste trabalho utiliza um sistema de arquivos distribuído para prover um espaço de armazenamento para os dados forenses com escalabilidade, disponibilidade e tolerância a falhas. Também, realiza a indexação dos dados forenses, através de um eficiente método de distribuição de processamento em grade. Neste trabalho são apresentados os cenários que foram elaborados e utilizados para testar o comportamento do sistema de armazenamento e indexação distribuída de dados forenses. _________________________________________________________________________________ ABSTRACTThis thesis presents a distributed system built to perform Storage and indexing of data resulting from a forensic analysis of Computer Storage device. Over the years, the amount of forensic data to analyze is becoming ever greater. This is due to both the growing capacity of Computer Storage Devices and the increased popularity of these Devices. In a case involving dozens of secondary Storage Devices, perform forensic analysis becomes a task with high computational cost of processing, due to the index generation process and the need for adequate Storage space for data. The indexing is fundamental for further forensics analysis in these data. The solution presented here uses a distributed file system to provide a Storage space for forensic data with scalability, availability and fault tolerance. Also, performs the indexing of forensic data, through an efficient distribution method with grid processing. This paper presents the scenarios that were developed and used to test the behavior of the system of distributed Storage and indexing of forensic data
William Saffady - One of the best experts on this subject based on the ideXlab platform.
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digital library concepts and technologies for the management of library collections an analysis of methods and costs
Library technology reports, 1995Co-Authors: William SaffadyAbstract:CONTENTS INTRODUCTION Definitions History Digital Library Projects Motives for Digital Libraries The Cost Issue TEXT-BASED IMPLEMENTATIONS Hardware and Software Requirements Storage Requirements Document Conversion In-House Key-Entry Offshore Data-Entry OCR Conversion Cost Comparisons Calculating Implementation Costs Worksheet 1. An Example of a Text-Based Implementation IMAGE-BASED IMPLEMENTATIONS Hardware and Software Requirements Storage Requirements Document Conversion Calculating Implementation Costs Worksheet 2. An Example of an Image-Based Implementation REFERENCES TABLES 1. Storage capacities of selected optical disk autochangers 2. Data-entry time per 1,000 characters at various keystroking rates 3. Data-entry costs per 1,000 characters without verification and error correction 4. Data-entry cost per 1,000 characters including keystroke verification and correction 5. Data-entry cost per 1,000 characters including sight verification and correction 6. Comparison of document conversion costs: Example 1 7. Comparison of document conversion costs: Example 2 8. Comparison of document conversion costs: Example 3 9. Comparison of document conversion costs: Example 4 10. Image Storage requirements for test documents scanned at 200 dpi 11. Image Storage requirements for test documents scanned at 300 dpi 12. Storage capacities of selected optical disk autochangers for documents scanned at 200 dpi 13. Storage capacities of selected optical disk autochangers for documents scanned at 300 dpi 14. Comparison of costs for document conversion by in-house scanning and service bureaus INTRODUCTION DEFINITIONS Broadly defined, a digital library is a collection of Computer-processible information or a repository for such information. In nonlibrary applications, the phrase has been widely applied to centralized repositories of Computer programs or machine-readable data. That usage has a long history, particularly in scientific and technical applications. Gerstenberg (1977), for example, describes a digital library of photonuclear data maintained by the National Bureau of Standards. More recently, Schatz (1991, 1994) has discussed a digital library of scientific information about C elegans, a nematode worm that serves as a model organism in molecular biology. Allen (1993) describes a similar application in botany. Coyne and Hulen (1993) and Coyne et al. (1994) discuss the role of the National Storage System Foundation (NSSF) in promoting digital libraries as repositories of the nation's information assets. Information management specialists, policy makers, and politicians increasingly view such repositories as important components of an emerging National Information Infrastructure (NII), a concept discussed by Altinkemer et al. (1994), Baron (1994), Doctor (1994), Doty and Bishop (1994), Forcht and Oeare (1994), Galbreath and Andreotta (1994), Hayashi and Sueyoshi (1994), McKeown (1994), Pelton (1994), Radack (1994), Shuler (1993), and Williams (1994), among others. Other publications that equate digital libraries with large information repositories include Berleant and Berghel (1994), Drapeau et al. (1994), and Gladney (1993). Various online databases and CD-ROM information products, particularly those with multimedia or interactive video components, are characterized by their producers as "digital libraries." Alternatively, the phrase "digital libraries" may denote the Computer Storage Devices on which information repositories reside; optical disk jukeboxes and magnetic tape autoloaders, for example, are sometimes characterized as digital libraries. Definitions employed in library literature are comparably broad. Citing various congressional bills and national policy documents, Fox (1993) and Fox and Lunin (1993) equate digital libraries with Computerized, networked library systems. Garrett (1993), Garrett and Lyons (1993), and Lynch (1991) use the phrase to describe databases, including library catalogs, that are accessible through the Internet or the emerging National Research and Education Network (NREN). …
Stanley G Hutton - One of the best experts on this subject based on the ideXlab platform.
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A STABILITY ANALYSIS OF CONSTRAINED ROTATING DISKS WITH DIFFERENT BOUNDARY CONDITIONS
2020Co-Authors: Ramin M H Khorasany, Stanley G HuttonAbstract:ABSTRACT The vibration behavior of constrained high speed rotating disks is of interest in industries as diverse as: aerospace, Computer disk manufacture and saw design and usage. The purpose of this study is to investigate the stability behavior of guided circular disks with different boundary conditions. The equations of motion are developed for circular rotating disks constrained by space fixed linear, mass, spring, damper systems. The resulting equation of motion is a two dimensional fourth order partial differential equation that requires numerical solution. The Galerkin Method is employed using the eigenfunctions of the stationary non-constrained disk as approximation functions. Of interest is the effect on stability of conditions at the inner boundary. In particular the difference in behavior for centrally clamped, and splined disks (those disks that run on a spline arbor) is investigated. Also discussed is the effect of constraints on the flutter and divergence instability boundaries. Preliminary experimental results are presented for constrained splined disks, and these results are compared with the analytical predictions. INTRODUCTION Spinning disks can be found in many engineering applications. Applications include turbine rotors, saws and Computer Storage Devices. Therefore, the vibration behavior of spinning disks has attracted research interest for some time. In the past three decades, numerous papers have been published on the dynamics of the rotating disks. Most of the work reported has dealt the dynamic behavior of clamped disks and little attention has been paid to the dynamics of disks that can freely move on the arbor, so called "splined disks". In wood machining applications it has been found that guided splined saws exhibit higher level of stability at hig
Ramin M H Khorasany - One of the best experts on this subject based on the ideXlab platform.
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A STABILITY ANALYSIS OF CONSTRAINED ROTATING DISKS WITH DIFFERENT BOUNDARY CONDITIONS
2020Co-Authors: Ramin M H Khorasany, Stanley G HuttonAbstract:ABSTRACT The vibration behavior of constrained high speed rotating disks is of interest in industries as diverse as: aerospace, Computer disk manufacture and saw design and usage. The purpose of this study is to investigate the stability behavior of guided circular disks with different boundary conditions. The equations of motion are developed for circular rotating disks constrained by space fixed linear, mass, spring, damper systems. The resulting equation of motion is a two dimensional fourth order partial differential equation that requires numerical solution. The Galerkin Method is employed using the eigenfunctions of the stationary non-constrained disk as approximation functions. Of interest is the effect on stability of conditions at the inner boundary. In particular the difference in behavior for centrally clamped, and splined disks (those disks that run on a spline arbor) is investigated. Also discussed is the effect of constraints on the flutter and divergence instability boundaries. Preliminary experimental results are presented for constrained splined disks, and these results are compared with the analytical predictions. INTRODUCTION Spinning disks can be found in many engineering applications. Applications include turbine rotors, saws and Computer Storage Devices. Therefore, the vibration behavior of spinning disks has attracted research interest for some time. In the past three decades, numerous papers have been published on the dynamics of the rotating disks. Most of the work reported has dealt the dynamic behavior of clamped disks and little attention has been paid to the dynamics of disks that can freely move on the arbor, so called "splined disks". In wood machining applications it has been found that guided splined saws exhibit higher level of stability at hig
K Komvopoulos - One of the best experts on this subject based on the ideXlab platform.
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a molecular dynamics study of the oxidation mechanism nanostructure evolution and friction characteristics of ultrathin amorphous carbon films in vacuum and oxygen atmosphere
Scientific Reports, 2021Co-Authors: Shengxi Wang, K KomvopoulosAbstract:Amorphous carbon (a-C) films are characterized by extraordinary chemical inertness and unique thermophysical properties that are critical to applications requiring oxidation-resistant, low-friction, and durable overcoats. However, the increasing demands for ultrathin (a few nanometers thick) a-C films in various emerging technologies, such as Computer Storage Devices, microelectronics, microdynamic systems, and photonics, make experimental evaluation of the structural stability and tribomechanical properties at the atomic level cumbersome and expensive. Consequently, the central objective of this study was to develop comprehensive MD models that can provide insight into the oxidation behavior and friction characteristics of ultrathin a-C films exhibiting layered through-thickness structure. MD simulations were performed for a-C films characterized by relatively low and high sp3 contents subjected to energetic oxygen atom bombardment or undergoing normal and sliding contact against each other in vacuum and oxygen atmosphere. The effect of energetic oxygen atoms on the oxidation behavior of a-C films, the dependence of contact deformation and surface attractive forces (adhesion) on surface interference, and the evolution of friction and structural changes (rehybridization) in the former a-C films during sliding are interpreted in the context of simulations performed in vacuum and oxidizing environments. The present study provides insight into the oxidation mechanism and friction behavior of ultrathin a-C films and introduces a computational framework for performing oxidation/tribo-oxidation MD simulations that can guide experimental investigations.