Tesi: "File" – Grafiati

1

Rivera, Gabrio. "From file pathnames to file objects /". Zürich, 2001. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=14377.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

2

Yarovyi, O. "File system". Thesis, Sumy State University, 2015. http://essuir.sumdu.edu.ua/handle/123456789/40511.

Testo completo

Abstract (sommario):

Nowadays, many people use electronic devices. For example, it is can be cameras, mobile phones, computers and others. The file system is a very important component of any device that works with the file.

Gli stili APA, Harvard, Vancouver, ISO e altri

3

García, Moral Daniel Jesús. "Remote File Access System for Generic Ericsson Processor Boards : File transfer service, Random Access Memory-based file system and secure file transfer solution research". Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-53448.

Testo completo

Abstract (sommario):

Generic Ericsson Processor boards are general purpose hardware platforms which provide generic processing services. They support the Unified Extensible Firmware Interface Specification. They have several network interfaces available and they are connected to Ericsson’s laboratory network. Several servers are also connected to this network. These boards require periodic firmware upgrades. They also require acquiring new firmware components and data files. Currently, an application to download or upload files from and to Ericsson’s laboratory servers when an Operating System has not already been booted does not exist. Therefore, the files have to be transferred to USB drives which are connected later to the boards in order to transfer the files. This is a time consuming operation which decreases Ericsson’s productivity. In addition, although Generic Ericsson Processor boards have an optional solid-state drive as secondary storage, Ericsson wants to be able to operate without it. This is because this secondary storage is not always available and Ericsson does not want to use it when the Generic Ericsson Processor boards are operating before an Operating System has been loaded. They prefer to use Random Access Memory storage. This project is focused on studying possible solutions for those two problems. Several file transfer protocols are analyzed. Several file system solutions mounted on Random Access Memory are also explored. A Trivial File Transfer Protocol client application and a Random Access Memory Disk driver prototype are designed, implemented and tested. They are tailored to work on a pre-boot environment, when the boards have not booted an Operating System yet, in Ericsson’s laboratory network. Finally, a secure file transfer protocols’ study is developed. This study will be used to assess Ericsson on the optimal secure file transfer protocol choice in order to implement possible secure future versions of the system.

Gli stili APA, Harvard, Vancouver, ISO e altri

4

Ordulu, Nizameddin (Nizameddin H. ). "A file system for accessing MySQL tables as CSV files". Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/62664.

Testo completo

Abstract (sommario):

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 49-50).
In this thesis, we describe the design and implementation of a userspace file system that represents MySQL tables as comma-separated values (CSV) files. The users can access and modify the data through both the file system and MySQL's query interface. In order to transform read and write operations to SQL queries, we maintain a reverse index from file offsets to line numbers. Changes to the database outside of the file system are reflected on the file system by means of MySQL's master-slave replication feature. We evaluate our system by comparing its performance to a regular file system's performance using popular command line tools(grep, sed, awk) and user applications (OpenOffice.org spreadsheets). The choice of the database for this system was MySQL because of its popularity and the availability of its source code, however, the same ideas can be applied to any relational database with replication to create a similar system.
by Nizameddin Ordulu.
M.Eng.

Gli stili APA, Harvard, Vancouver, ISO e altri

5

Zhang, Irene Y. (Irene Yun). "Efficient file distribution in a flexible,wide-area file system". Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/53188.

Testo completo

Abstract (sommario):

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2009.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 63-65).
WheelFS is a wide-area distributed file system designed to help applications cope with the challenges of sharing data over the wide-area network. A wide range of applications can use WheelFS as a storage layer because applications can control various trade-offs in WheelFS, such as consistency versus availability, using semantic cues. One key feature that many applications require from any storage system is efficient file distribution. The storage system needs to be able to serve files quickly, even large or popular ones, and allow users and applications to quickly browse files. Wide-area links with high latency and low throughput make achieving these goals difficult for most distributed storage systems. This thesis explores using pre fetching, a traditional file system optimization technique, in wide-area file systems for more efficient file distribution. This thesis focuses on Tread, a pref etcher for WheelFS. Tread includes several types of pre fetching to improve the performance of reading files and directories in WheelFS: read-ahead pre fetching, whole file prefetching, directory prefetching and a prefetching optimization for WheelFS's built-in cooperative caching. To makes the best use of scarce wide-area resources, Tread adaptively rate-limits prefetching and gives applications control over what and how prefetching is done using WheelFS's semantic cues. Experiments show that Tread can reduce the time to read a 10MB file in WheelFS by 40% and the time to list a directory with 100 entries by more than 80%.
(cont.) In addition, experiments on Planetlab show that using prefetching with cooperative caching to distribute a 10MB file to 270 clients reduces the average latency for each client to read the file by almost 45%.
by Irene Y. Zhang.
M.Eng.

Gli stili APA, Harvard, Vancouver, ISO e altri

6

Purdin, Titus Douglas Mahlon. "ENHANCING FILE AVAILABILITY IN DISTRIBUTED SYSTEMS (THE SAGUARO FILE SYSTEM)". Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184161.

Testo completo

Abstract (sommario):

This dissertation describes the design and implementation of the file system component of the Saguaro operating system for computers connected by a local-area network. Systems constructed on such an architecture have the potential advantage of increased file availability due to their inherent redundancy. In Saguaro, this advantage is made available through two mechanisms that support semi-automatic file replication and access: reproduction sets and metafiles. A reproduction set is a collection of files that the system attempts to keep identical on a "best effort" basis, relying on the user to handle unusual situations that may arise. A metafile is a special file that contains symbolic path names of other files; when a metafile is opened, the system selects an available constituent file and opens it instead. These mechanisms are especially appropriate for situations that do not require guaranteed consistency or a large number of copies. Other interesting aspects of the Saguaro file system design are also described. The logical file system forms a single tree, yet any file can be placed in any of the physical file systems. This organization allows the creation of a logical association among files that is quite different from their physical association. In addition, the broken path algorithm is described. This algorithm makes it possible to bypass elements in a path name that are on inaccessible physical file systems. Thus, any accessible file can be made available, regardless of the availability of directories in its path. Details are provided on the implementation of the Saguaro file system. The servers of which the system is composed are described individually and a comprehensive operational example is supplied to illustrate their interation. The underlying data structures of the file system are presented. The virtual roots, which contain information used by the broken path algorithm, are the most novel of these. Finally, an implementation of reproduction sets and metafiles for interconnected networks running Berkeley UNIX is described. This implementation demonstrates the broad applicability of these mechanisms. It also provides insight into the way in which mechanisms to facilitate user controlled replication of files can be inexpensively added to existing file systems. Performance measurements for this implementation are also presented.

Gli stili APA, Harvard, Vancouver, ISO e altri

7

Alsowail, Rakan. "Secure file sharing". Thesis, University of Sussex, 2016. http://sro.sussex.ac.uk/id/eprint/63551/.

Testo completo

Abstract (sommario):

File sharing has become an indispensable part of our daily lives. The shared files might be sensitive, thus, their confidentially, integrity and availability should be protected. Such protection might be against external threats that are initiated by unauthorised users or insider threats that are initiated by authorised users. Our main interest in this thesis is with insider threats. Protecting shared files against insiders is a challenging problem. Insiders enjoy various characteristics such as being trusted and authorised, in addition to being inside the network perimeter and having knowledge of information systems. This makes it difficult to prevent or detect policy violation for these users. The goal of this thesis is to protect shared files from the perspective of insider security with language-based techniques. In the first part of the thesis, we define what we mean by an insider and the insider problem precisely, and propose an approach to classify the insider problem into different categories. We then define and focus on one category that is related to file sharing. Namely, protecting the confidentiality and integrity of the shared files against accidental misuse by insiders. Furthermore, we classify the activity of file sharing into different categories that describe all possible ways of performing the activity of file sharing. These categories represent policies that describe how files should be propagated and accessed by insiders. We show that enforcing these policies can protect the files against accidental misuse by insiders while allowing the activity of sharing to be performed as desired. Thus our interest can be summarised as keeping honest users safe. In the second part of the thesis, we develop a security type system that statically enforces information flow and access control policies in a file system. Files are associated with security types that represent security policies, and programs are sets of operations to be performed on files such as read, copy, move, etc. A type checker, therefore, will statically check each operation to be performed on a file and determine whether the operation satisfies the policy of the file. We prove that our type system is sound and develop a type reconstruction algorithm and prove its soundness and completeness. The type system we developed in this thesis protects the files against accidental misuse by insiders.

Gli stili APA, Harvard, Vancouver, ISO e altri

8

Motara, Yusuf Moosa. "File integrity checking". Thesis, Rhodes University, 2006. http://hdl.handle.net/10962/d1007701.

Testo completo

Abstract (sommario):

This thesis looks at file execution as an attack vector that leads to the execution of unauthorized code. File integrity checking is examined as a means of removing this attack vector, and the design, implementation, and evaluation of a best-of-breed file integrity checker for the Linux operating system is undertaken. We conclude that the resultant file integrity checker does succeed in removing file execution as an attack vector, does so at a computational cost that is negligible, and displays innovative and useful features that are not currently found in any other Linux file integrity checker.

Gli stili APA, Harvard, Vancouver, ISO e altri

9

Lee, Hojin. "S1_Scrambled_siRNA [Digital file]". Diss., Temple University Libraries, 2008. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/254229.

Testo completo

Abstract (sommario):

Microbiology and Immunology;
Ph.D.;
c-Cbl functions as a multifunctional adaptor and an E3 ubiquitin protein ligase. Several studies have shown that c-Cbl is involved in cytoskeleton-mediated events, but the molecular mechanisms linking c-Cbl to cytoskeletal rearrangements remain to be elucidated. Our previous results indicated that c-Cbl facilitates spreading and migration of v-Abl-transformed NIH 3T3 fibroblasts and suggested that small GTPases play important roles in the cytoskeletal effects of c-Cbl in this system. To elucidate the individual contributions of small GTPases to these effects, we assessed the roles of endogenous Rac1, RhoA and Rap1 in the c-Cbl-dependent spreading and migration of v-Abl-transformed fibroblasts overexpressing c-Cbl, using RNAi. Furthermore, since it has been shown that Rap1 can act as an upstream regulator of Rac1 in inducing cell spreading, we analyzed the interplay between Rap1 and Rac1 in the signaling pathways connecting c-Cbl to the cytoskeletal events. Our results indicate that Rac1 is essential for cell migration and spreading, whereas activation of RhoA exerts a negative effect. We have also shown that Rap1 is essential for cell spreading, although not for migration in our experimental system. Furthermore, we provide evidence that Rap1 is located upstream of Rac1 in one of the signaling pathways that regulate c-Cbl-facilitated cell spreading. Overall, our findings are consistent with the model describing the connection of c-Cbl to the cytoskeletal rearrangements via two pathways, one of which is mediated by PI3K and Rac1, and the other, by CrkL/C3G, Rap1 and Rac1. A major biological feature of glioma is the ability to invade normal brain tissue. The molecular mechanisms of glioma invasion are involved in multiple biological processes which are primarily associated with cytoskeleton-mediated events including adhesion, migration, degradation of extra cellular matrix (ECM). Biological functions of c-Cbl in glioma have not been elucidated. In this study, we examined biological roles of c-Cbl using RNAi-mediated depletion of endogenous c-Cbl and stably c-Cbl expressing glioma cells generated by lentiviral transduction and showed that c-Cbl increases invasion through degradation of ECM by upregulation of MMP2 but not through migration, adhesion, or growth of SNB19, a grade IV glioblastoma cell line.
Temple University--Theses

Gli stili APA, Harvard, Vancouver, ISO e altri

10

Lee, Hojin. "S2_RhoA_siRNA [Digital file]". Diss., Temple University Libraries, 2008. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/254230.

Testo completo

Abstract (sommario):

Microbiology and Immunology;
Ph.D.;
c-Cbl functions as a multifunctional adaptor and an E3 ubiquitin protein ligase. Several studies have shown that c-Cbl is involved in cytoskeleton-mediated events, but the molecular mechanisms linking c-Cbl to cytoskeletal rearrangements remain to be elucidated. Our previous results indicated that c-Cbl facilitates spreading and migration of v-Abl-transformed NIH 3T3 fibroblasts and suggested that small GTPases play important roles in the cytoskeletal effects of c-Cbl in this system. To elucidate the individual contributions of small GTPases to these effects, we assessed the roles of endogenous Rac1, RhoA and Rap1 in the c-Cbl-dependent spreading and migration of v-Abl-transformed fibroblasts overexpressing c-Cbl, using RNAi. Furthermore, since it has been shown that Rap1 can act as an upstream regulator of Rac1 in inducing cell spreading, we analyzed the interplay between Rap1 and Rac1 in the signaling pathways connecting c-Cbl to the cytoskeletal events. Our results indicate that Rac1 is essential for cell migration and spreading, whereas activation of RhoA exerts a negative effect. We have also shown that Rap1 is essential for cell spreading, although not for migration in our experimental system. Furthermore, we provide evidence that Rap1 is located upstream of Rac1 in one of the signaling pathways that regulate c-Cbl-facilitated cell spreading. Overall, our findings are consistent with the model describing the connection of c-Cbl to the cytoskeletal rearrangements via two pathways, one of which is mediated by PI3K and Rac1, and the other, by CrkL/C3G, Rap1 and Rac1. A major biological feature of glioma is the ability to invade normal brain tissue. The molecular mechanisms of glioma invasion are involved in multiple biological processes which are primarily associated with cytoskeleton-mediated events including adhesion, migration, degradation of extra cellular matrix (ECM). Biological functions of c-Cbl in glioma have not been elucidated. In this study, we examined biological roles of c-Cbl using RNAi-mediated depletion of endogenous c-Cbl and stably c-Cbl expressing glioma cells generated by lentiviral transduction and showed that c-Cbl increases invasion through degradation of ECM by upregulation of MMP2 but not through migration, adhesion, or growth of SNB19, a grade IV glioblastoma cell line.
Temple University--Theses

Gli stili APA, Harvard, Vancouver, ISO e altri

11

Lee, Hojin. "S3_Rac1_siRNA [Digital file]". Diss., Temple University Libraries, 2008. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/254231.

Testo completo

Abstract (sommario):

Microbiology and Immunology;
Ph.D.;
c-Cbl functions as a multifunctional adaptor and an E3 ubiquitin protein ligase. Several studies have shown that c-Cbl is involved in cytoskeleton-mediated events, but the molecular mechanisms linking c-Cbl to cytoskeletal rearrangements remain to be elucidated. Our previous results indicated that c-Cbl facilitates spreading and migration of v-Abl-transformed NIH 3T3 fibroblasts and suggested that small GTPases play important roles in the cytoskeletal effects of c-Cbl in this system. To elucidate the individual contributions of small GTPases to these effects, we assessed the roles of endogenous Rac1, RhoA and Rap1 in the c-Cbl-dependent spreading and migration of v-Abl-transformed fibroblasts overexpressing c-Cbl, using RNAi. Furthermore, since it has been shown that Rap1 can act as an upstream regulator of Rac1 in inducing cell spreading, we analyzed the interplay between Rap1 and Rac1 in the signaling pathways connecting c-Cbl to the cytoskeletal events. Our results indicate that Rac1 is essential for cell migration and spreading, whereas activation of RhoA exerts a negative effect. We have also shown that Rap1 is essential for cell spreading, although not for migration in our experimental system. Furthermore, we provide evidence that Rap1 is located upstream of Rac1 in one of the signaling pathways that regulate c-Cbl-facilitated cell spreading. Overall, our findings are consistent with the model describing the connection of c-Cbl to the cytoskeletal rearrangements via two pathways, one of which is mediated by PI3K and Rac1, and the other, by CrkL/C3G, Rap1 and Rac1. A major biological feature of glioma is the ability to invade normal brain tissue. The molecular mechanisms of glioma invasion are involved in multiple biological processes which are primarily associated with cytoskeleton-mediated events including adhesion, migration, degradation of extra cellular matrix (ECM). Biological functions of c-Cbl in glioma have not been elucidated. In this study, we examined biological roles of c-Cbl using RNAi-mediated depletion of endogenous c-Cbl and stably c-Cbl expressing glioma cells generated by lentiviral transduction and showed that c-Cbl increases invasion through degradation of ECM by upregulation of MMP2 but not through migration, adhesion, or growth of SNB19, a grade IV glioblastoma cell line.
Temple University--Theses

Gli stili APA, Harvard, Vancouver, ISO e altri

12

Malkus, Amy J. "Test Item File". Digital Commons @ East Tennessee State University, 2010. https://dc.etsu.edu/etsu-works/4590.

Testo completo

Abstract (sommario):

Book Summary: Through this book's accessible, active, and applied approach, users determine whether their learning style strengths are verbal/linguistic, logical/mathematical, visual/spatial, or interpersonal. Throughout the text, personalized content-specific study tips are correlated to these specific styles allowing the student to focus on learning style strengths and weaknesses. By studying according to their own personal learning style, Psychology helps students become more effective and efficient learners. Up-to-date research and a seamless narrative keeps students engaged in the study of Psychology.

Gli stili APA, Harvard, Vancouver, ISO e altri

13

Anne, Aditya. "A WEB BASED MACHINE LEARNING UTILITY". University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1196644291.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

14

Fang, Xin. "Reliable file transfer on the Internet using distributed file transfer, DFT". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ57539.pdf.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

15

Grusecki, Travis R. "Improving block sharing in the Write Anywhere File Layout file system". Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/76818.

Testo completo

Abstract (sommario):

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 41).
It is often useful in modern file systems for several files to share one or more data blocks. Block sharing is used to improve storage utilization by storing only one copy of a block shared by multiple files or volumes. This thesis proposes an approach, called Space Maker, which uses garbage collection techniques to simplify the up-front cost of file system operations, moving some of the more difficult block tracking work, such as the work required to clean-up after a file delete, to a back-end garbage collector. Space Maker was developed on top of the WAFL file system used in NetApp hardware. The Space Maker is shown to have fast scan performance, while decreasing the front-end time to delete files. Other operations, like file creates and writes have similar performance to a baseline system. Under Space Maker, block sharing is simplified, making a possible for new file system features that rely on sharing to be implemented more quickly with good performance.
by Travis R. Grusecki.
M.Eng.

Gli stili APA, Harvard, Vancouver, ISO e altri

16

Leal, Anamary. "Exploring the effectiveness of 3D file browsing techniques for file searching tasks". Honors in the Major Thesis, University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/1285.

Testo completo

Abstract (sommario):

This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf.edu/Systems/DigitalInitiatives/DigitalCollections/InternetDistributionConsentAgreementForm.pdf You may also contact the project coordinator, Kerri Bottorff, at kerri.bottorff@ucf.edu for more information.
Bachelors
Engineering and Computer Science
Early Childhood Education

Gli stili APA, Harvard, Vancouver, ISO e altri

17

Artiaga, Amouroux Ernest. "File system metadata virtualization". Doctoral thesis, Universitat Politècnica de Catalunya, 2014. http://hdl.handle.net/10803/133489.

Testo completo

Abstract (sommario):

The advance of computing systems has brought new ways to use and access the stored data that push the architecture of traditional file systems to its limits, making them inadequate to handle the new needs. Current challenges affect both the performance of high-end computing systems and its usability from the applications perspective. On one side, high-performance computing equipment is rapidly developing into large-scale aggregations of computing elements in the form of clusters, grids or clouds. On the other side, there is a widening range of scientific and commercial applications that seek to exploit these new computing facilities. The requirements of such applications are also heterogeneous, leading to dissimilar patterns of use of the underlying file systems. Data centres have tried to compensate this situation by providing several file systems to fulfil distinct requirements. Typically, the different file systems are mounted on different branches of a directory tree, and the preferred use of each branch is publicised to users. A similar approach is being used in personal computing devices. Typically, in a personal computer, there is a visible and clear distinction between the portion of the file system name space dedicated to local storage, the part corresponding to remote file systems and, recently, the areas linked to cloud services as, for example, directories to keep data synchronized across devices, to be shared with other users, or to be remotely backed-up. In practice, this approach compromises the usability of the file systems and the possibility of exploiting all the potential benefits. We consider that this burden can be alleviated by determining applicable features on a per-file basis, and not associating them to the location in a static, rigid name space. Moreover, usability would be further increased by providing multiple dynamic name spaces that could be adapted to specific application needs. This thesis contributes to this goal by proposing a mechanism to decouple the user view of the storage from its underlying structure. The mechanism consists in the virtualization of file system metadata (including both the name space and the object attributes) and the interposition of a sensible layer to take decisions on where and how the files should be stored in order to benefit from the underlying file system features, without incurring on usability or performance penalties due to inadequate usage. This technique allows to present multiple, simultaneous virtual views of the name space and the file system object attributes that can be adapted to specific application needs without altering the underlying storage configuration. The first contribution of the thesis introduces the design of a metadata virtualization framework that makes possible the above-mentioned decoupling; the second contribution consists in a method to improve file system performance in large-scale systems by using such metadata virtualization framework; finally, the third contribution consists in a technique to improve the usability of cloud-based storage systems in personal computing devices.

Gli stili APA, Harvard, Vancouver, ISO e altri

18

Conroy, Tracy Michael Buxton Winslow Hurlburt. "Secure distributed file systems /". Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1994. http://handle.dtic.mil/100.2/ADA285525.

Testo completo

Abstract (sommario):

Thesis (M.S. in Information Technology Management) Naval Postgraduate School, September 1994.
Thesis advisor(s): Roger Stemp, Kishore Sengupta. "September 1994." Bibliography: p. 106-108. Also available online.

Gli stili APA, Harvard, Vancouver, ISO e altri

19

Nadeem, Ashraf Muhammad. "Forensic Multimedia File Carving". Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-119998.

Testo completo

Abstract (sommario):

Distribution of video contents over the Internet has increased drastically over the past few years. With technological advancements and emergence of social media services, video content sharing has grown exponentially. An increased number of cyber crimes today belong to possession or distribution of illegal video contents over the Internet. Therefore, it is crucial for forensic examiners to have the capability of recovering and analyzing illegal video contents from seized storage devices. File carving is an advanced forensic technique used to recover deleted contents from a storage device even when there is no file system present. After recovering a deleted video file, its contents have to be analyzed manually in order to classify them. This is not only very stressful but also takes a large amount of time. In this thesis we propose a carving approach for streaming multimedia formats that allows forensic examiners to recover individual frames of a video file as images. The contents of these images then can be classified using existing techniques for forensic analysis of image sets. A carving tool based on this approach is developed for MPEG-1 video files. A number of experiments are conducted to evaluate performance of the tool. For each experiment an MPEG-1 file with different encoding parameters is used. Moreover, each experiment contains 18 runs and with each run chunk size of the input MPEG-1 file is varied in order to create different amount of disk fragmentation For video only MPEG-1 files, 87.802 % frames are fully recovered when the chunk size is equal to 124 KB. Where as in the case of MPEG-1 files containing both audio and video data 90.55 % frames are fully recovered when the chunk size is 132 KB.

Gli stili APA, Harvard, Vancouver, ISO e altri

20

Conroy, Tracy Michael, e Winslow Hurlburt Buxton. "Secure distributed file systems". Thesis, Monterey, California. Naval Postgraduate School, 1994. http://hdl.handle.net/10945/30928.

Testo completo

Abstract (sommario):

Secure information distribution is a strategic capability as significant as weapons systems and tactics to military operations. The Department of Defense has recognized the importance of establishing and maintaining secure distributed file systems and explores the practicality and applicability of one such system, Trusted Ficus File System (TRUFFLES), in the DoD infrastructure. Integrated into this research are discussions of Privacy Enhanced Mail (PEM), which is currently an integral part of the TRUFFLES implementation. This thesis concludes with a discussion of the actual installation of a PEM reference implementation, and future requirements for the TRUFFLES installation at the Naval Postgraduate School.

Gli stili APA, Harvard, Vancouver, ISO e altri

21

Dumitran, Octavian-Daniel. "Fixing file descriptor leaks". Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/41645.

Testo completo

Abstract (sommario):

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2007.
Includes bibliographical references (p. 89).
We design, implement and test a tool for eliminating file descriptor (FD) leaks in programs at run-time. Our tool monitors FD allocation and use. When the allocation of a new FD would fail because a process's entire pool of FDs is already in use, our tool "recycles" (forcibly closes) an FD. The FD to be recycled is chosen according to three simple rules: 1) do not recycle FDs used within the last second, 2) do not recycle "persistent" FDs (FDs allocated at sites that allocate few FDs) and 3) recycle the FD that was least recently used. We tested our tool with nine applications (HTTP/FTP servers, proxies and clients) that make extensive use of FDs. We first simulated massive leaks by disabling all calls to close. Without recycling (and in the presence of leaks), all applications malfunctioned. With FD recycling, applications continued to execute normally despite massive FD leakage. Throughout our tests, our tool has never attempted to close an FD that was still in use.
by Octavian-Daniel Dumitran.
M.Eng.

Gli stili APA, Harvard, Vancouver, ISO e altri

22

Dabek, Frank (Frank Edward) 1977. "A cooperative file system". Thesis, Massachusetts Institute of Technology, 2001. http://hdl.handle.net/1721.1/86811.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

23

Mazières, David (David Folkman) 1972. "Self-certifying file system". Thesis, Massachusetts Institute of Technology, 2000. http://hdl.handle.net/1721.1/86610.

Testo completo

Abstract (sommario):

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.
Includes bibliographical references (p. 137-141) and index.
by David Mazières.
Ph.D.

Gli stili APA, Harvard, Vancouver, ISO e altri

24

Vogelsang, Stefan. "Monitoring Tools File Specification". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-199034.

Testo completo

Abstract (sommario):

This paper describes the format of monitoring data files that are collected for external measuring sites and at laboratory experiments at the Institute for Building Climatology (IBK). The Monitoring Data Files are containers for storing time series or event driven data collected as input for transient heat and moisture transport simulations. Further applications are the documentation of real world behaviour, laboratory experiments or the collection of validation data sets for simulation results ( whole building / energy consumption / HAM ). The article also discusses the application interface towards measurement data verification tools as well as data storage solutions that can be used to archive measurement data files conveniently and efficiently.

Gli stili APA, Harvard, Vancouver, ISO e altri

25

Soares, João Paulo da Conceição. "FEW phone file system". Master's thesis, FCT - UNL, 2009. http://hdl.handle.net/10362/2229.

Testo completo

Abstract (sommario):

Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial para obtenção do grau de Mestre em Engenharia Informática
The evolution of mobile phones has made these devices more than just simple mobile communication devices. Current mobile phones include such features as built-in digital cameras, the ability to play and record multimedia contents and also the possibility of playing games. Most of these devices have support for Java developed applications, as well as multiple wireless technologies (e.g. GSM/GPRS, UMTS, Bluetooth, and Wi-Fi). All these features have been made possible due to technological evolution that led to the improvement of computational power, storage capacity, and communication capabilities of these devices. This thesis presents a distributed data management system, based on optimistic replication,named FEW Phone File System. This system takes advantage of the storage capacity and wireless communication capabilities of current mobile phones, by allowing users to carry their personal data “in” their mobile phones, and to access it in any workstation, as if they were files in the local file system. The FEW Phone File System is based on a hybrid architecture that merges the client/server model with peer-to-peer replication, that relies on periodic reconciliation to maintain consistency between replicas. The system’s server side runs on the mobile phone, and the client on a workstation. The communication between the client and the server can be supported by one of multiple network technologies, allowing the FEW Phone File System to dynamically adapt to the available network connectivity. The presented system addresses the mobile phone’s storage and power limitations by allowing multimedia contents to be adapted to the device’s specifications, thus reducing the volume of data transferred to the mobile phone, allowing for more user’s data to be stored. The FEW Phone File System also integrates mechanisms that maintain information about the existence of other copies of the stored files (e.g. WWW), avoiding the transfer of those files from the mobile device whenever accessing those copies is advantageous. Due to the increasing number of on-line storage resources (e.g. CVS/SVN, Picasa), this approach allows for those resources to be used by the FEW Phone File System to obtain the stored copies of the user’s files.

Gli stili APA, Harvard, Vancouver, ISO e altri

26

Vidiksis, Adam. "Vidiksis-Transfigurations [Digital File]". Diss., Temple University Libraries, 2013. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/253842.

Testo completo

Abstract (sommario):

Music Composition
D.M.A.
Transfigurations is a symphonic work in one movement for orchestra and live computer processing utilizing the graphical audio programming language Pure Data. The score and patch for this piece are accompanied by an essay describing the audio processing techniques and the compositional processes employed in this work. Programming methods discussed include strategies for data capture, patch structure, user interface, and processor management. All audio processing in the work is realized in realtime. These sounds are derived directly from the orchestra in performance, except for the last. The processes involved in Transfigurations include pitch and amplitude tracking, pitch-shifting, filtering, frequency and amplitude modulation, granular synthesis, delay, and convolution. The final sounds from the computer employ stochastic processes for synthesis which are derived from the germinal materials of the piece. The essay also discusses the aesthetic philosophy and formal structure of the work, principle themes and motives, and formative pitch materials, as well as the compositional processes in each section. The final discourse of the essay considers microphone and loudspeaker setups, patch preparation and leveling, and strategies for rehearsal and performance.
Temple University--Theses

Gli stili APA, Harvard, Vancouver, ISO e altri

27

Bourget, Jean Paul. "Role-based file archiving /". Online version of thesis, 2008. http://hdl.handle.net/1850/8045.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

28

Menon, Prasad. "Ubiquitous file system protocol". [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0000867.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

29

Rao, Herman Chung-Hwa. "The Jade File System". Diss., The University of Arizona, 1991. http://hdl.handle.net/10150/185569.

Testo completo

Abstract (sommario):

File systems have long been the most important and most widely used form of shared permanent storage. File systems in traditional time-sharing systems such as Unix support a coherent sharing model for multiple users. Distributed file systems implement this sharing model in local area networks. However, most distributed file systems fail to scale from local area networks to an internet. This thesis recognizes four characteristics of scalability: size, wide area, autonomy, and heterogeneity. Owing to size and wide area, techniques such as broadcasting, central control, and central resources, which are widely adopted by local area network file systems, are not adequate for an internet file system. An internet file system must also support the notion of autonomy because an internet is made up by a collection of independent organizations. Finally, heterogeneity is the nature of an internet file system, not only because of its size, but also because of the autonomy of the organizations in an internet. This thesis introduces the Jade File System, which provides a uniform way to name and access files in the internet environment. Jade is a logical system that integrates a heterogeneous collection of existing file systems, where heterogeneous means that the underlying file systems support different file access protocols. Because of autonomy, Jade is designed under the restriction that the underlying file systems may not be modified. In order to avoid the complexity of maintaining an internet-wide, global name space, Jade permits each user to define a private name space. In Jade's design, we pay careful attention to avoiding unnecessary network messages between clients and file servers in order to achieve acceptable performance. Jade's name space supports two novel features: It allows multiple file systems to be mounted under one directory, and it permits one logical name space to mount other logical name spaces. A prototype of Jade has been implemented to examine and validate its design. The prototype consists of interfaces to the Unix File System, the Sun Network File System, and the File Transfer Protocol.

Gli stili APA, Harvard, Vancouver, ISO e altri

30

Buonviri, Nathan. "Audio-OnlyTest [Digital File]". Diss., Temple University Libraries, 2010. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/254227.

Testo completo

Abstract (sommario):

Music Education
Ph.D.
The purpose of this study was to determine how pitch and rhythm aspects of melodic memory are affected by aural distractions when melodic stimuli are presented both visually and aurally, as compared to aurally only. The rationale for this research is centered on the need for improved melodic memory skills of students taking melodic dictation, and the possibility that temporary visual imagery storage of target melodies might enhance those skills. The participants in this study were undergraduate and graduate music majors (n=41) at a large northeastern university. All participants had successfully completed the first two semesters of college-level music theory, and none had perfect pitch. Participants progressed through two self-contained experimental tests at the computer. Identical target melodies were presented: 1) aurally only on one test; and 2) aurally, with visual presentation of the matching notation, on the other test. After the target melody, a distraction melody sounded, during which time participants were to maintain the original target melody in memory. Participants then chose which of two aural options matched the original target, with a third choice of "neither." The incorrect answer choice in each item contained either a pitch or rhythm discrepancy. The 2x2 factorial design of this experiment was based on independent variables of test presentation format and answer discrepancy type. The dependent variable was experimental test scores. Each participant took both parts of both tests, yielding 164 total observations. Additional data were collected for exploratory analysis: the order in which each participant took the tests, the major instrument of each participant, and the educational status of each participant (undergraduate or graduate). Results of a 2x2 ANOVA revealed no significant differences in test scores, based on either test format or answer discrepancy type, and no interaction between the factors. The exploratory analyses revealed no significant differences in test scores, based on test order, major instrument, or student status. Results suggest that visual reinforcement of melodies does not affect aural memory for those melodies, in terms of either pitch or rhythm. Suggestions for further research include an aural-visual melodic memory test paired with a learning modalities survey, a longitudinal study of visual imagery applied to aural skills study, and a detailed survey of strategies used by successful and unsuccessful dictation students.
Temple University--Theses

Gli stili APA, Harvard, Vancouver, ISO e altri

31

Buonviri, Nathan. "Audio-VisualTest [Digital File]". Diss., Temple University Libraries, 2010. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/254228.

Testo completo

Abstract (sommario):

Music Education
Ph.D.
The purpose of this study was to determine how pitch and rhythm aspects of melodic memory are affected by aural distractions when melodic stimuli are presented both visually and aurally, as compared to aurally only. The rationale for this research is centered on the need for improved melodic memory skills of students taking melodic dictation, and the possibility that temporary visual imagery storage of target melodies might enhance those skills. The participants in this study were undergraduate and graduate music majors (n=41) at a large northeastern university. All participants had successfully completed the first two semesters of college-level music theory, and none had perfect pitch. Participants progressed through two self-contained experimental tests at the computer. Identical target melodies were presented: 1) aurally only on one test; and 2) aurally, with visual presentation of the matching notation, on the other test. After the target melody, a distraction melody sounded, during which time participants were to maintain the original target melody in memory. Participants then chose which of two aural options matched the original target, with a third choice of "neither." The incorrect answer choice in each item contained either a pitch or rhythm discrepancy. The 2x2 factorial design of this experiment was based on independent variables of test presentation format and answer discrepancy type. The dependent variable was experimental test scores. Each participant took both parts of both tests, yielding 164 total observations. Additional data were collected for exploratory analysis: the order in which each participant took the tests, the major instrument of each participant, and the educational status of each participant (undergraduate or graduate). Results of a 2x2 ANOVA revealed no significant differences in test scores, based on either test format or answer discrepancy type, and no interaction between the factors. The exploratory analyses revealed no significant differences in test scores, based on test order, major instrument, or student status. Results suggest that visual reinforcement of melodies does not affect aural memory for those melodies, in terms of either pitch or rhythm. Suggestions for further research include an aural-visual melodic memory test paired with a learning modalities survey, a longitudinal study of visual imagery applied to aural skills study, and a detailed survey of strategies used by successful and unsuccessful dictation students.
Temple University--Theses

Gli stili APA, Harvard, Vancouver, ISO e altri

32

Frank, Wiewandt Edward. "ARCHIVING THE DIGITAL IMAGE: TODAY'S BEST PRACTICES OF FILE PREPARATION". Bowling Green State University / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1131398443.

Testo completo

Gli stili APA, Harvard, Vancouver, ISO e altri

33

Fricker, Christine. "File d'attente à serveur autonome et insensibilité en théorie des files d'attente". Paris 7, 1985. http://www.theses.fr/1985PA07F130.

Testo completo

Abstract (sommario):

L'objet de cette thèse est deux applications des probabilités à l'étude des files d'attente. La rédaction comprend deux parties indépendantes. La première partie consiste en un article intitulé Etude d'une file GI/GI/1 à service autonome (avec vacances du serveur). La deuxième partie est un travail original sur l'insensibilité en théorie des files d'attente. Ces deux parties seront introduites séparément.

Gli stili APA, Harvard, Vancouver, ISO e altri

34

Kukkadapu, Sowmya. "Android application for file storage and retrieval over secured and distributed file servers". Kansas State University, 2012. http://hdl.handle.net/2097/13959.

Testo completo

Abstract (sommario):

Master of Science
Department of Computing and Information Sciences
Daniel A. Andresen
Recently, the world has been trending toward the use of Smartphone. Today, almost each and every individual is using Smartphone for various purposes benefited by the availability of large number of applications. The memory on the SD (Secure Digital) memory card is going to be a constraint for the usage of the Smartphone for the user. Memory is used for storing large amounts of data, which include various files and important document. Besides having many applications to fill the free space, we hardly have an application that manages the free memory according to the user’s choice. In order to manage the free space on the SD card, we need an application to be developed. All the important files stored on the Android device cannot be retrieved if we lose the Android device. Targeting the problem of handling the memory issues, we developed an application that can be used to provide the security to the important documents and also store unnecessary files on the distributed file servers and retrieve them back on request.

Gli stili APA, Harvard, Vancouver, ISO e altri

35

Wennergren, Oscar, Mattias Vidhall e Jimmy Sörensen. "Transparency analysis of Distributed file systems : With a focus on InterPlanetary File System". Thesis, Högskolan i Skövde, Institutionen för informationsteknologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-15727.

Testo completo

Abstract (sommario):

IPFS claims to be the replacement of HTTP and aims to be used globally. However, our study shows that in terms of scalability, performance and security, IPFS is inadequate. This is a result from our experimental and qualitative study of transparency of IPFS version 0.4.13. Moreover, since IPFS is a distributed file system, it should fulfill all aspects of transparency, but according to our study, this is not the case. From our small-scale analysis, we speculate that nested files appear to be the main cause of the performance issues and replication amplifies these problems even further.

Gli stili APA, Harvard, Vancouver, ISO e altri

36

Paleker, Farzana. "Comparison of canal transportation and centering ability of K-files the ProGlider file and G-file : a micro-computed tomography study of curved canals". Diss., University of Pretoria, 2015. http://hdl.handle.net/2263/53037.

Testo completo

Abstract (sommario):

The aim of this in vitro study was to investigate the canal centering ability and apical root canal transportation of pre-curved stainless steel K-files, the ProGlider file and GFiles after glide path enlargement in curved root canals of extracted human mandibular molars using micro-CT scanning. The working times for the different glide path enlargement methods were also recorded. Ninety untreated curved root canals from extracted molars were randomly divided into three groups (n = 30). Group 1: manual glide path preparation with size 0.10 Kfile and enlargement with size 0.15 and 0.20 hand K-files; Group 2: manual glide path preparation with size 0.10 K-file and enlargement with NiTi rotary G-Files; and Group 3: manual glide path preparation with size 0.10 K-file and enlargement with the NiTi rotary ProGlider file (ISO tip size 16). Micro-computed tomography was used to scan the teeth before and after glide path enlargement. Three-dimensional images were reconstructed from the pre- and post-instrumentation scans to enable a comparison of the centring ability at three selected levels: 1 mm from the apical foramen (D1), at the point of maximum root curvature (Dmc) and 7 mm from the apical foramen (D7). Canal transportation was assessed at 1 mm from the apical foramen in eight directions (MB, B, DB, D, DL, L, ML, M). The time it took to enlarge the glide paths for each group was also calculated. One-way Analysis of Variance was performed to assess if significant differences existed between the three groups for the variables being compared (p<0.05). A Bonferroni adjusted p value of 0.016 was used for pairwise comparisons of centring ability. K-files displayed statistically significantly higher centering ratios than G-Files at D1. At all levels the ProGlider file exhibited statistically significantly lower centering ratios than K-files. At Dmc, the ProGlider file demonstrated statistically significantly lower centering ratios than G-Files. Ratios were significantly similar between K-files and GFiles at D7 as well as between G-Files and the ProGlider file at D7 (p<0.016). Apical canal transportation for K-files was significantly more than G-Files in five directions and the ProGlider file in six directions (p<0.05). Glide path enlargement time for Kfiles was significantly slower (74.92 s ± 2.60 s) than G-Files (41.87 s ± 20.19 s) and the ProGlider file (27.95 s ± 8.55 s)(p<0.05). There was no statistically significant difference between glide path enlargement times of G-Files and the ProGlider file. Findings suggest that NiTi rotary glide path files are suitable for safe glide path enlargement because they cause less apical canal transportation than stainless steel hand K-files. Of the two NiTi rotary glide path file groups, the ProGlider file showed an overall significantly better centering ability around the entirety of the original canals, particularly at the point of maximum curvature. Glide path enlargement with the NiTi rotary glide path file groups was significantly faster than Kfiles (p<0.05).
Dissertation (MSc)--University of Pretoria, 2015.
Odontology
MSc
Unrestricted

Gli stili APA, Harvard, Vancouver, ISO e altri

37

Ledung, Gabriel, e Johan Andersson. "Darknet file sharing : application of a private peer-to-peer distributed file system concept". Thesis, Uppsala universitet, Informationssystem, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-129908.

Testo completo

Abstract (sommario):

Peer-to-peer network applications has been a tremendous success among end users and has therefore received much attention in academia and industry, as have illegal public file sharing in media. However, private peer-to-peer file sharing between family, friends and co-workers have attracted little interest from the research community. Existing approaches also limit the users by not allowing for native interaction with userspace applications. In this paper we ex- -plore how private file sharing can be made safe, fast and scalable without constraining the users in this aspect. We demonstrate the concept of a private file sharing application utilizing a decentralized peer-to-peer network overlay by creating a prototype with extreme program- ming as methodology. To maximize the freedom of users the network is accessed through a virtual file-system interface. The prototype proves this to be a valid approach and we hope readers can use this paper as a platform for further developments in this area.
Fildelningsapplikationer som använder peer-to-peer teknik har varit en enorm framgång blandslutanvändare och har därmed erhållit mycket uppmärksamhet från akademi och indus- tri, liksom olaglig fildelning fått inom media. Däremot har inte privat fildelning mellan vän- ner, arbetskamrater och kollegor tilldelats samma uppmärksamhet från forskningssamfundet. Nuvarande tillämpningar begränsar användaren genom att inte tillåta naturlig interaktion med användarapplikationer. I denna uppsats utforskar vi hur privat fildelning kan göras snabb, skalbar och säker utan att begränsa användaren ur den aspekten. Vi demonstrerar ett koncept- för privat fildelning som nyttjar decentraliserad peer-to-peer arkitektur m.h.a en prototyp som tagits fram med extreme programming som metodologi. För att maximera användarnas frihet nyttjas ett virtuellt filsystem som gränssnitt. Prototypen visar att vår tillämpning fungerar i praktiken och vi hoppas att läsaren kan använda vårt arbete som en plattform för fortsatt utveckling inom detta område.

Gli stili APA, Harvard, Vancouver, ISO e altri

38

Heger, Dominique A. "The Design of a Logarithmic File Data Allocation Algorithm for Extent Based File Systems". NSUWorks, 2001. http://nsuworks.nova.edu/gscis_etd/578.

Testo completo

Abstract (sommario):

I/O has become the major bottleneck in application performance as processor speed has skyrocket over the last few years, leaving storage hardware and file systems struggling to be competitive. This study presented a new methodology to evaluate workload-dependent file system performance. Applying the new methodology, the benchmarks conducted on the VxFS file system served as a baseline for the design of a new logarithmic file data allocation algorithm for extent based file systems. Most of the I/O performance evaluations conducted today have reached a steady state in which new developments are evolutionary, not revolutionary. The performance model that was introduced in this thesis is revolutionary, as it produces an application as well as a system characterization vector that allows researchers to conduct an in -depth analysis of a complete system environment. The constructed performance hierarchy incorporates performance dependencies at all levels of a system, which allows comparing, evaluating, and analyzing the system at any level of abstraction. When combining the performance characterization vectors, a single, application specific metric allows the analyst to conduct a sensitivity study. The characterization vectors and the resulting single metric satisfy all the potential demands for analyzing I/O performance, in particular systems evaluation, comparison, and optimization. The main argument made throughout this study is that systems performance has to be measured in the context of a particular application and a particular workload. The performance evaluation methodology presented in this thesis enables such measurements. Utilizing the methodology, the in-depth file system performance analysis conducted on different hardware and software configurations reviled that the new approach taken in this study was successful, as it was possible to rank the test systems in their proper order of relative performance measurements. The methodology allowed to normalize the results and to quantify performance in terms of performance paths that included an application, an operating system, as well as the underlying hardware subsystems. The file system benchmarks conducted on VxFS and UFS file systems respectively disclosed the strengths and weaknesses of an extent-based and a block-based file system design. In both architectures, fragmentation substantially impacts I/O performance as the file systems age. The performance measurements outlined the correlation between internal and external fragmentation, and made a strong case for a much enhanced file data allocation algorithm for extent based file systems. The second part of this research introduced a new file data allocation algorithm for extent based file systems that is unique in its approach in that it questioned established boundaries and redistributed existing responsibilities. The new allocation algorithm fulfilled the major requirements of increasing I/O performance by lowering internal fragmentation without significantly increasing the metadata overhead. The presented analytical data model, as well as the actual simulation of the new file data allocation algorithm proofed the great potential of the new design. The study concluded with the recommendation for a new I/O model that is fundamentally different from all the existing once. The vision is that a completely redesigned I/O model is necessary to provide adequate I/O performance. To be efficient, the new I/O model will have to work around the expensive memory-copy to and from user and kernel address space. Moving the data in an out of virtual address ·space is poor overhead, and if the subsystem that is moving the data does not have any virtual memory technique implemented to avoid the data copy, performance is limited to approximately 1,4 of the memory speed. The next generation I/O model envisioned in this study focuses on alleviating all unnecessary overhead in the I/O path , allowing the hardware to operate at its full potential.

Gli stili APA, Harvard, Vancouver, ISO e altri

39

Kovac, Timmy. "Jämförelse av File Carving Program och presterande vid fragmentering". Thesis, Högskolan i Halmstad, Sektionen för Informationsvetenskap, Data– och Elektroteknik (IDE), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-18998.

Testo completo

Abstract (sommario):

Idag har vi mängder av data på våra lagringsmedia vilket gör dem till en värdefull informationskälla. Om denna data raderas betyder det inte att den är borta för alltid. Data finns fortfarande kvar på lagringsmediet och går att återskapa med så kallad file carving. Att kunna återskapa data är en viktig del inom den polisiära verksamheten, men även för andra verksamheter som förlorat data. Det finns dock vissa problem som kan ställa till med besvär när data ska återskapas. När filer inte är lagrade i sammanhängande datablock blir de fragmenterade vilket innebär problem. För att ta reda på hur stort problemet egentligen är utfördes tre test med den kommersiella programvaran EnCase och open source programvarorna Foremost, PhotoRec och Scalpel. Resultatet visade tydligt att gratisprogrammet PhotoRec var bättre än de andra programmen, men kanske mest förvånande är att det kommersiella och dyra programmet EnCase inte lyckades speciellt bra. Det framgick även att samtliga program har stora problem med att återskapa fragmenterade filer, men det var återigen gratisprogramvaran PhotoRec som presterade bäst.

Gli stili APA, Harvard, Vancouver, ISO e altri

40

Owais, Fahad. "Capability File Names over HTTP". Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-26393.

Testo completo

Abstract (sommario):

File access over the Internet adds a whole new dimension to the continuously evolving World Wide Web. Considering its significance in the big picture, there exists a need to provide a completely secure and exible way to share and access content existing on a file host web server somewhere over the Internet. A number of access control mechanisms attempt to do this with moderate success with most of them lacking the ability to allow sharing of information to unauthenticated users and adequate file-based access control capabilities. Capability File Names provide a new and completely unique access control mechanism that uses file names as a means to store access control information against files on a remote location and allows a user unhindered access to his files along with the capability to delegate rights as deemed necessary. The aim of this thesis project has been to develop a prototype implementation that makes use of Capability File Names as a way to control access to files and folders placed on an HTTP Web Server over the Internet. It involves a Linux implementation on the client-side using "FUSE" (Filesystem in Userspace) with a server-side implementation using Java Server Pages (JSP). The access control features have entirely been implemented on server side with the client user only needing the Capability File Names pointing to the original files on the server to gain access to them. In addition to the server and client applications, there is a separate utility provided to the user hosting the server allowing generation of Capability File Names against files located on the server.

Gli stili APA, Harvard, Vancouver, ISO e altri

41

Vogelsang, Stefan, e Andreas Nicolai. "Delphin 6 Output File Specification". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-70337.

Testo completo

Abstract (sommario):

This paper describes the file formats of the output data and geometry files generated by the Delphin program, a simulation model for hygrothermal transport in porous media. The output data format is suitable for any kind of simulation output generated by transient transport simulation models. Implementing support for the Delphin output format enables use of the advanced post-processing functionality provided by the Delphin post- processing tool and its dedicated physical analysis functionality. The article also discusses the application programming interface of the DataIO library that can be used to read/write Delphin output data and geometry files conveniently and efficiently.

Gli stili APA, Harvard, Vancouver, ISO e altri

42

Guo, Hong. "Mobile certifying cryptographic file system". Thesis, University of Ottawa (Canada), 2006. http://hdl.handle.net/10393/27249.

Testo completo

Abstract (sommario):

This thesis describes the design and implementation of a Mobile Certifying Cryptographic File System (MCCFS), which proposes a solution that allows the mobile user access to remote resources from different locations using either the same device or nearby devices. The MCCFS is aimed to support the host mobility and user mobility in a secure environment. We separated the key management from the notion of administrative realm based on two factors authentication and certificate-based access control lists. Mobile users can certify themselves in remote domains freely. MCCFS provided transparent encryption support for accessing files not only in local machine but also across Internet on HTTP or FTP servers. Files are encrypted when they are transferred over the network and when saved on untrusted machines. The MCCFS affords mobile users more flexibility in accessing and sharing their files and does not require the assistance of the local or remote realm's system administrator.

Gli stili APA, Harvard, Vancouver, ISO e altri

43

Bladh, Thomas. "StepTree : A File System Visualizer". Thesis, Blekinge Tekniska Högskola, Institutionen för programvaruteknik och datavetenskap, 2002. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-5905.

Testo completo

Abstract (sommario):

A 3D visualization tool for file system hierarchies is presented. The visualization technique used is based on the Tree-map / nested Venn diagram concept and is capable of visualizing metrics and attributes such as size, change and file type for thousands of nodes simultaneously. Size is visualized through node base area, change is visualized through the ghosting and hiding of unchanged nodes and file type is visualized through colors. Actions such as navigation and selection are performed exclusively in 3D. Finally a method for improving the visibility of nodes through the equalization of sibling nodes is proposed.
Ett 3D visualiseringsverktyg för filsystem presenteras. Visualiseringstekniken är baserad på Tree-maps / Venn diagram och kan visualisera attribut såsom storlek, förändring och filtyp för tusentals noder samtidigt. Storlek visualiseras genom noders bas area, förändringar visualiseras genom ghosting (avfokusering) och hiding (gömning) av oförändrade noder och filtyp visualiseras med färger. Slutligen så föreslås en metod för att förbättra synligheten hos noder genom utjämning.
Tel. 0457-26310 Alt. 044-246025 (annars e-mail)

Gli stili APA, Harvard, Vancouver, ISO e altri

44

McGregor, Anthony James. "Block-Based Distributed File Systems". The University of Waikato, 1997. http://hdl.handle.net/10289/2607.

Testo completo

Abstract (sommario):

Distributed file systems have become popular because they allow information to be shared be between computers in a natural way. A distributed file system often forms a central building block in a distributed system. Currently most distributed file systems are built using a communications interface that transfers messages about files between machines. This thesis proposes a different, lower level, communications interface. This `block-based' interface exchanges information about the blocks that make up the file but not about the files themselves. No other distributed file system is built this way. By demonstrating that a distributed file system can be implemented in a block-based manner, this thesis opens the way for many advances in distributed file systems. These include a reduction of the processing required at the server, uniformity in managing file blocks and fine-grained placement and replication of data. The simple communications model also lends itself to efficient implementation both at the server and in the communications protocols that support the interface. These advantages come at the cost of a more complex client implementation and the need for a lower level consistency mechanism. A block-based distributed file system (BB-NFS) has been implemented. BB-NFS provides the Unix file system interface and demonstrates the feasibility and implementability of the block-based approach. Experience with the implementation lead to the development of a lock cache mechanism which gives a large improvement in the performance of the prototype. Although it has not been directly measured it is plausible that the prototype will perform better than the file based approach. The block-based approach has much to offer future distributed file system developers. This thesis introduces the approach and its advantages, demonstrates its feasibility and shows that it can be implemented in a way that performs well.

Gli stili APA, Harvard, Vancouver, ISO e altri

45

Roy, Catherine Karen. "File-based autobiographies after 1989". Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/38062.

Testo completo

Abstract (sommario):

This study analyzes four autobiographical accounts written after the fall of the Berlin Wall by former data subjects, i.e., by individuals who have been under the surveillance of the East German Stasi (Staatssicherheit). Following a suggestion by Cornelia Vismann, I refer to these texts as “file-based autobiographies.” The term reflects the fact that they were written in response to the opening of the Stasi archives and the passing of the Stasi Files Act, which allowed data subjects to access their files. By constructing narratives using files written and compiled by informers and secret police officials rather than relying on their own, personal memories, these data subjects challenge the traditional aesthetics of autobiographies and subvert the usual expectations of autobiographical reading. “File-based autobiographies" constitute nothing less than a new autobiographical sub-genre. Rather than offering a personal story that begins in early childhood and ends later in life, data subjects engage in a revision of their lives using files written by a hostile third party. The four case studies show how people under surveillance may need to draw on such documents, even if they are inaccurate, in order to support their claims of authenticity and thus fulfill the autobiographical pact. In this way, these autobiographers acquire and re-functionalize the hostile documents, thus challenging the original purposes for which the files were kept. They show that using their files not only results in unexpected memory processes, but is also a political and literary process that supports their personal agendas and targets particular audiences. Access to and subsequent use of their files gives them the authority to discuss their reaction to the opening of the Stasi files as well as the records themselves.

Gli stili APA, Harvard, Vancouver, ISO e altri

46

Vogelsang, Stefan, Heiko Fechner e Andreas Nicolai. "Delphin 6 Material File Specification". Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-126274.

Testo completo

Abstract (sommario):

This paper describes the format of material data files that hold parameters needed by thermal and hygrothermal simulation tools such as Delphin, Hajawee (Dynamic Room Model) and Nandrad. The Material Data Files are containers for storing parameters and functions for heat and moisture transport and storage models. The article also discusses the application programming interface of the Material library that can be used to read/write material data files conveniently and efficiently.

Gli stili APA, Harvard, Vancouver, ISO e altri

47

Su, Yang M. Eng Massachusetts Institute of Technology. "File system unification using LatticeFS". Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/53145.

Testo completo

Abstract (sommario):

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2009.
Includes bibliographical references (p. 57-58).
LatticeFS is a namespace unification system designed to merge multiple source file systems into a single working file system. atticeFS can be used to merge multiple software package directories, work with multiple file systems as if they are one, and share a single storage medium among multiple machines. On a high level, LatticeFS takes as input an arbitrary number of file system paths, and mounts a new virtual drive that will appear to the user as a union of the input file systems. Of course, attempting to combine multiple file systems will inevitably be met with conflicts. Situations in which multiple input file systems contain files/directories with the same name will be common in large systems; which file/directory should the user be exposed to in this case? Previous work such as UnionFS solved the problem by giving each input file system a strict priority value, and when a conflict occurred, the file/directory with the highest priority was the one shown to the user. In LatticeFS, we have introduced a plug-in system in which different strategies for resolving conflicts can be easily swapped in and out; additionally, handlers for special file types can also be "plugged" into the system. This paper describes and evaluates all aspects of LatticeFS in detail.
by Yang Su.
M.Eng.

Gli stili APA, Harvard, Vancouver, ISO e altri

48

Tseng, Jessica Hui-Chun 1977. "Energy-efficient register file design". Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/80219.

Testo completo

Abstract (sommario):

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2000.
Includes bibliographical references (p. 69-70).
by Jessica Hui-Chun Tseng.
S.M.

Gli stili APA, Harvard, Vancouver, ISO e altri

49

Cuevas, Genevieve T. "SloanSpace- DSpace file transfer component". Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/33118.

Testo completo

Abstract (sommario):

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2005.
Includes bibliographical references (leaf 57).
This thesis demonstrates how to use Web services to integrate course management systems with digital repositories. We present a component that provides interoperation between SloanSpace, a course management system, and DSpace, a digital repository, both developed at MIT. In particular, a file transfer component was created that enables SloanSpace users to search and retrieve DSpace documents while in SloanSpace, and submit SloanSpace documents into DSpace. DSpace's web services provided the means for interaction between the systems. The architecture of the component was designed to handle not only the metadata mappings between SloanSpace and DSpace metadata, but mappings between file metadata of SloanSpace and other systems as well. Two scenarios were then created to test the effectiveness of the component. The test results demonstrate the ability of the component to decrease the amount of time spent in performing file transfers between the two systems. Most importantly, however, the component demonstrates more generally interoperation with digital repositories. It not only integrates SloanSpace with DSpace, but also allows for a more a general integration with any other system.
by Genevieve T. Curvas.
M.Eng.

Gli stili APA, Harvard, Vancouver, ISO e altri

50

Goldman, Aaron David. "CCFS cryptographically curated file system". Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54394.

Testo completo

Abstract (sommario):

The Internet was originally designed to be a next-generation phone system that could withstand a Soviet attack. Today, we ask the Internet to perform tasks that no longer resemble phone calls in the face of threats that no longer resemble Soviet bombardment. However, we have come to rely on names that can be subverted at every level of the stack or simply be allowed to rot by their original creators. It is possible for us to build networks of content that serve the content distribution needs of today while withstanding the hostile environment that all modern systems face. This dissertation presents the Cryptographically Curated File System (CCFS), which offers five properties that we feel a modern content distribution system should provide. The first property is Strong Links, which maintains that only the owner of a link can change the content to which it points. The second property, Permissionless Distribution, allows anyone to become a curator without dependence on a naming or numbering authority. Third, Independent Validation arises from the fact that the object seeking affirmation need not choose the source of trust. Connectivity, the fourth property, allows any curator to delegate and curate the right to alter links. Each curator can delegate the control of a link and that designee can do the same, leaving a chain of trust from the original curator to the one who assigned the content. Lastly, with the property of Collective Confidence, trust does not need to come from a single source, but can instead be an aggregate affirmation. Since CCFS embodies all five of these properties, it can serve as the foundational technology for a more robust Web. CCFS can serve as the base of a web that performs the tasks of today’s Web, but also may outperform it. In the third chapter, we present a number of scenarios that demonstrate the capacity and potential of CCFS. The system can be used as a publication platform that has been re-optimized within the constraints of the modern Internet, but not the constraints of decades past. The curated links can still be organized into a hierarchical namespace (e.g., a Domain Naming System (DNS)) and de jure verifications (e.g., a Certificate Authority (CA) system), but also support social, professional, and reputational graphs. This data can be distributed, versioned, and archived more efficiently. Although communication systems were not designed for such a content-centric system, the combination of broadcasts and point-to-point communications are perfectly suited for scaling the distribution, while allowing communities to share the burdens of hosting and maintenance. CCFS even supports the privacy of friend-to-friend networks without sacrificing the ability to interoperate with the wider world. Finally, CCFS does all of this without damaging the ability to operate search engines or alert systems, providing a discovery mechanism, which is vital to a usable, useful web. To demonstrate the viability of this model, we built a research prototype. The results of these tests demonstrate that while the CCFS prototype is not ready to be used as a drop-in replacement for all file system use cases, the system is feasible. CCFS is fast enough to be usable and can be used to publish, version, archive, and search data. Even in this crude form, CCFS already demonstrates advantages over previous state-of-the-art systems. When the Internet was designed, there were relatively fewer computers that were far weaker than the computers we have now. They were largely connected to each other over reliable connections. When the Internet was first created, computing was expensive and propagation delay was negligible. Since then, the propagation delay has not improved on a Moore’s Law Curve. Now, latency has come to dominate all other costs of retrieving content; specifically, the propagation time has come to dominate the latency. In order to improve the latency, we are paying more for storage, processing, and bandwidth. The only way to improve propagation delay is to move the content closer to the destination. In order to have the content close to the demand, we store multiple copies and search multiple locations, thus trading off storage, bandwidth, and processing for lower propagation delay. The computing world should re-evaluate these trade-offs because the situation has changed. We need an Internet that is designed for the technologies used today, rather than the tools of the 20th century. CCFS, which regards the trade-off for lower propagation delay, will be better suited for 21st-century technologies. Although CCFS is not preferable in all situations, it can still offer tremendous value. Better robustness, performance, and democracy make CCFS a contribution to the field. Robustness comes from the cryptographic assurances provided by the five properties of CCFS. Performance comes from the locality of content. Democracy arises from the lack of a centralized authority that may grant the right of Free Speech only to those who espouse rhetoric compatible with their ideals. Combined, this model for a cryptographically secure, content-centric system provides a novel contribution to the state of communications technology and information security.

Gli stili APA, Harvard, Vancouver, ISO e altri

Tesi sul tema "File"

Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili