SyncWiki-GoogleNotebookPlanets.txt

[Notebook%20-%20Planets_files/en_notebook_150x55.gif][1] 
Planets Last edited May 22, 2008

[More by
anj »][2]  Sections: - [Inbox

](#SDQaSQgoQqMmxwZwj) - [Meeting Notes

](#SDShxQwoQ77Do5ZQj) - [Data Types

](#SDQ2NQgoQ9fzo5ZQj) - [Data Pipes

](#SDSIKQgoQx6_05ZQj) - [Data Sources

](#SDSHDQwoQvO7y5ZQj) - [Render Pipes

](#SDQcKQgoQ9brf6ZQj) - [Ensuring Data Integrity

](#SDQxVQwoQjqzw5ZQj) - [The Testbed

](#SDQGMQgoQuZG525cj)

Inbox Ideas -

Use a XML gui language to map a rich gui to a command-line argument
system. - Retrieve and assign roles in the User Manager? - IF
Localization Support?  User.getPreferredLocale? -
Dioscuri Emulation system. - Directory as a container type? - Find
data sources? - Mound drives RO? - Find out about job scheduler
code - anything we can use? - Execute a PPlan against a TB corpus,
FileSet to FileSet. - Lucene Service? -

*TYPES*: Functional types (image, movie, editable?) and physical
types (jpeg, jpeg/2000?).  'conforms-to' == any of A is
also an instance of B. -

Utility that just sends the first few bytes over the wire for
analysis? -

The BL has trust.  It's copies can be considered
authoritative.

Meeting Notes Testbed Meeting Notes

 

Open Topics: - Feedback - BM Goals integration - Project Wide - How
to use TB for emulation. - Use it as a pro-forma? - Manual
Service?  Any service can be marked as 'Manual'. - Need
manual metadata and exec information. - Define BMG by service or by
DO - Look up pronom IDs in the TB.

Features Required - Export? Data loss otherwise. - Defaults to
manual/auto by BMG. - PC Reg tools and formats, we need properties.
- Search - Lucene integration? - Services + data . outputs! -
Webdav will be available. - CORPUS: Test suites? - DELOS data? -
Mount RO?

Service Registry - Allows non-Planets Services? 
[What does that mean?]

POST an invocation request, get ticket back?

Intermediate data?

IF Message System

Sig Properties became evaluation criteria based on experiment

Measurable properties based on Experiment type.

Basic props: # pages, Character ests pages, Measure checks pages
kept.

TCC: Proposal for Service Types. See document in dev. 
*ACTION?*

Terms should be neutral.

Layering, DM and parameters.

25th for Proposal.

Lucene? *ACTION?*

ID experiments, compare three tools.

Char Exp, compare properties.

Migration, build on property comparison.

Experiment types needed to define 'things'. Science!

Plato have PP template.

Execute a pplan on a copora/other files.

Execute a PPlan workflow on filesets, get out filesets? *???*

Execute assessment of plan.

Test a tool?

Test a plan?

Execute a plan against a corpus?  *PLAN
ASSESSMENT?*

Semantic checking, validation.

Test plan on a hard FileSet.

Preservation Pla n evaluation is not clear. 
Interpretations. Refining and evaluating.

Data?

User pages - Provocative but ok. ???

Scribd

Roadmap

-Experiments TBA.

-Comparison Services?

-Testing Service Implementation.

-Internal Users In BC?

-Users and the Horse issue.

Implementation Plan

-Exp type dropdown

-Search by goals

-Data Registry lazy and search.

-Better selection UI.

VMWare by AL

Hook for 'large' exps.

Hook for message-to-user.

Hook for user locale?

Server remote status for infrastructure?

Edit Stages.

Provide hostinfo over EJB?

IF Service Invocation Data.  Wallclock,
invocation.

- + No images.

- Read timeline.

- Test running without a net connection? *???*

- 2xNetWork get BL to provide NetWork access. Cable + WiFi. Sig
Prop Conference Notes

*JISC Intro

*How do we determine the most important properties of digital
objects that we want to keep.  Representation
information. Discover, access, understand, ?

*Andrew Wilson, NAA

*[ Can we expect continued media fragility? ]

[ Seems that folks do use the phrase Digital Object, and generally
keen on OAIS]

[ Do nothing is dangerous?  Emulation is
improving.]

[ Authenticity is Important!  And perhaps inpossible
under migration.

 Bible has been preserved through refreshes and
migrations.]

Approaches

 - techno-centric

   - maintain the hw/sw

 - data-centric

   - maintain using current data formats,
changing the object

 - process-centric

   - new render streams

 - post-hoc

   - digital archeology, forensic, cf
Seamus Ross.

Authenticity important?

Migration

 - At obscelecence.

 - Normalization.

 - Migration on request.

[Is obscelete well-defined.]

NAA has supported formats.

[This is always true, as set of formats is not strictly finite. The
question of 'which formats' still looms large.]

Authenticity

 - integrity/accuracy - no unauthorised changes.

 - reliability - it is what is says it is.

 - useability - retrieve, render.

[Are 'signed diffs' possible?]

Authentic, meaning

 - appearance

 - content

 - context

 - structure

 - behaviour

[Authenticity?]

[Idea of Essence.  But if Essense is enough to define
the DO, then no DO is needed anymore!]

Lyneh, canonicalisation.

[Underlying assumption that we can estimate SP ahead of
time?]

[SP are needed for delivery, may depend].

[No way to check without the original.]

Useable as evidence.

Are SP absolutely definable.  Can we meaningfully
define them by 'type' or 'use'. c.f. INSPEC paper?

*Stephen Grace - Centre for eResearch

*INSPECT project.

SP as weighted measurable identifiers.

Weights are with repsect to a performance.

[May want to work with Planets]

[www.significantproperties.co.uk][3] 


Works with JHOVE.

[Lack of finite forimates rends sig prop pointless. ???]

[ Characterising loss of info, can we introduce a useful entropy
measure.]

[SP depend on corpus too?]

*Vectors - SSL

*- Restrict scope, static images on finite boards with closed
bounds.

[General theme of only being able to SP by limiting scope?]

- Compare CGM (CGRM), SVG, PDF/A.

- You can generate a set of properties for 'vectors'

- concepts like 'differentiable'?  That this can curves
be told apart?

- but depends on how you clip your examination.

- mapping SVG to a subset vial XSLT ==? Sig Prop?

[ Take art, reduce it to 'contains waterlillies', where'd that
doggy come from!]

[ Artist preferred their new version, some liked the old plotter
one, surely this is effectively a new work.!?!?!]

[Sig Prop model useful for comparing formats that 'do the same
thing?']

- Importance of Test Suites!

- Importance of w3c metadata now included in PDF/A.

*Moving Images - Mike Stapelton

*Â - All 'boxes' are somewhat arbitrary.

 - Source, process, preformance.

[Coulour may be a good example, as it remains slippery even when
defined.]

 - Pixels not always square, but should all video meta
data say pixel=square?

 - Sig Prop of encoding useful for delivery.

[SW to beat a human expr differ]

 - interlacing means a 50th/second gap.

 - MXF is a useful wrapper format.

 - Migration, transcoding, format shift.

 - BCC using JPEG2000 frames in an MXF wrapper.

 - even if SP can be defined, what are the SP of future
use?

[Q: Can we builk ans in any way? can re really id all use cases.
Video diffs automate tolerable?]

Most significant to least is the important thing.  Text
is critical?  Image pixels critical?

[ Vector stills can be pinned down by domain
knowledge.  i.e. get uses to tell you what is
important. ]

*e-Science - Sig Prop SW

*- Large, diverse ussues in software preservation. 'need to limit
scope'.

- Code that is 'known right' - authenticity.

- Boot-strapping issue if all sw considered 'at risk'?

- sw preferred for reproducibility, algorithm

- preserve the data by preserving the sw.

- Spec only has no test.

- Spec + SC is a test suite basis.

- Exec creation + running on data -> test suite.

  - ok whilever the 'exe' paradigm persists.'

- 'Good SW Preservation === Good SW Engineering'

*Richard Davis - eLearning Objects

*[ Unholy confusion of data and purpose, noun and verb ]

'Objects used for learning'

Please, differentiate between generic objects, being used in a
learning context, and objects designed to be used in a learning
context. The latter are digital object types related to
learning.

SCORM standard?  for ELO?

Classes by size, content type, purpose.

What are these categories for?

JORUM?

Assessment object are important, raise questions of
authenticity/integrity.  e.g. exam papers.

*Adrian Brown - Characterization in Planets*

Identification, Validation and Property Extraction (good
good)

Representation Properties - how to interpret the bitstream to get
to human form.

Significant Properties

They are in Plato team. No TB in diagram.

Planets Char Reg = PRONOM + Tool Info + Char of Sig Prop
<<<<<<<<


XCDL is on the way.  Is this enough for sig prop.

JHOVE, DROID, NZ one.

Q: Important notion of Intent. e.g. for a numerical recipe this
includes the Algorithm.

Q: Does Planets offer a platform for holders to discover what they
have?  Yein. Strong characterization.

Q: What about things like one work 'Gettysburg address' and all
it's forms, or references?  More like a tag?

*Roger Lloyd - Barclays Wealth*

As user /'skipper'. ick.

Comparison to migration to new tech.  Monitoring.

*Colin Neilson - DCC, SCARP*

Universe is analogue shocker.

Tacit knowledge, experience etc.
<<<<<<<<???


Necessary v sufficient???

Context-driven approach

Finite scope of defined types reflect lack of context.

MACE is a potential client.  Needs plugins for
accessing files.

Computs of 10 or less, but short lived, so personal data is.

BMI info pack transferred to drive?!

DB approach users get different slices/views.

DP purposes+roles.

*Stephen Rankin DCC*

SP, is it self-describing.

Check OAIS, IO, DO and RI.

Emulation may not cover >>>> network
<<<< or performance issues.

RI is infiinite?

Semantics tend to be ignored.

Context is not finite.

Raw data and interpretations.

States ' Transform does not alter sematics' - we hope.

'Semantics is the hard part'Â  but Structure is needed
first!

*Callec UNL*

Email

SIGPROPS project

Supported, Observed, Measured (auto),

Intended effect.

"No Computation Without Representation!"

Large variation.  Long tails.

71% Word docs!  Next one was 4%.

Original Bitstream might have problems.  Viriuses,
wierd filenames, embedded hidden info/issues. 
QA.

Interested in probing SigProp - e.g. Does this Word document use
Macros?

Designated Community Evolves, i.e. Users Change.

>>>>>>

Rederated Repositories as a scalable model.  Get
businesses to host storage and services, and BL archives
them.

<<<<<<

*Andrew Wilson*

Clear that Complexity is high, concerning SP.

Clear that minimising human effort is important.

AIP important, flexible, kept forever.

DIP flexible, SP are AP.

Research required into the relationship between SP and
RI.  RI produces the performance, and are
SP.  SP may include abstractions of the
performance.

Analysing needs of users is v important.

Q1: Do the users needs influence our decisions on Sig Prop (AIP I
think he means).

Q2: What level of granularity do we make decisions about
SP?  Object, File?  - Use &
Context?

How much to preserve?  Which document to
preserve?  We can't keep everything, apparently.

So, justify why we discard it. Should not be a decision based
primarily on format.

Publishing is about selecting significant properties, someone
says.  Interpreting the Scientist work for the
Audience.

There will always be changes.  Loss too.

Different definitions in the talks.

Sig Props are Sig no matter what the migration.

AIP maximises options, maxes information.  Preserve as
much as you can afford to.

What about the preservation of objects that are under
change?  This is called versioning?

What about preserving relations.

DB migration/ change control

   - Store everything, listen to users,
have good techs or tech.

Meta data that cannot be mechanically inferred from the bits is
actually data.  Some metadata may be too expensive to
generate mechanically, so should be considered data too.

Automate general science curation in collaboration with
scientists.  Niether is the best at doing
it!  e.g. automatically generated metadata.

'Performance Properties'Â  - I like that.

Technical Metadata - Portico - Only collect the MD we need to make
Tech  Decision.  Assumed that all could be
generated from the data.

More studies by object type?

Automatic tools.

Analysis of DO preservation schmemes

QA on ingest? Repair automatically? Let us not assume that received
files are ok.

Primary v. secondary/manufactured.

Trusted Repo, Trusted Obj.

Is there a central website? [www.dponline.org][4] .

Presentations up soon... Data Types Planetary Notions

The full conceptual data model addresses a number of complex,
high-level issues concerning the preservation issues that an
archive or repository must deal with. However, the level of detail
within this metadata will depend on the priorities and needs of the
individual institutions, at least in the near term.  To
enable different repositories with different data to interact, we
must build up lower-level data standards capable of embodying the
data and metadata required for communication between
institutions.  This should focus on simple operations
at first, but be built in an 'atomic' fashion to make it as easy as
possible to build more advanced services later on.  At
each stage, the set of different data types we are able to define
will reflect the data concepts that the institutions involved are
able to agree on.

Files and Digital Objects

Relationships as meta data, not embodied in the structure. PREMIS:
Preservation Metadata Maintenance Activity (Library of
Congress)

[www.loc.gov/standards/premis/][5] 
The PREMIS maintenance activity is responsible for maintaining,
supporting, and coordinating future revisions to the PREMIS data
dictionary. The Fine Free File Command

[www.darwinsys.com/file/][6]  The
file command is "a file type guesser", that is, a command-line tool
that tells you _in words_ what kind of data a file contains. Unlike
most GUI systems, command-line UNIX systems - with this program
leading the charge - don't rely on filename extentions to tell you
the type of a file, but look at the file's actual contents. This
is, of course, more reliable, but requires a bit of I/O. file

[
www.opengroup.org/onlinepubs/009695399/utilities/f...][7]  The Open
Group Base Specifications Issue 6

IEEE Std 1003.1, 2004 Edition

Copyright © 2001-2004 The IEEE and The Open Group, All
Rights reserved.

----------


[http://www.opengroup.org/onlinepubs/009695399/utilities/][8] NAME



  file - determine file type




Uniform Type Identifier - Wikipedia, the free encyclopedia

[en.wikipedia.org/wiki/Uniform_Type_Identifier][9] 
A *Uniform Type Identifier* (*UTI*) is a string defined by [Apple Inc.][10]  that
uniquely identifies the type of a class of items. Added in Apple's
[Mac OS X][11] 
[10.4][12] 
operating system, UTIs are used to identify the type of files and
folders, clipboard data, bundles, aliases and symlinks, and
streaming data. [Mac
OS X][13] 's desktop search technology, [Spotlight][14] ,
uses UTIs to categorize
documents.[<sup>1</sup>|#fn1]([http://www.google.com/notebook/onpage?client=gnotesff&v=1.0.0.19&zx=1210070431913#cite_note-ars-0][15] )^
One of the primary design goals of UTIs was to eliminate the
ambiguities and problems associated with inferring a file's content
from its MIME type, [filename
extension][16] , or [type][17]  or [creator
code][18] .[<sup>2</sup>|#fn2]([http://www.google.com/notebook/onpage?client=gnotesff&v=1.0.0.19&zx=1210070431913#cite_note-ars-0][19] )<sup>[<sup>3</sup>|#fn3]([http://www.google.com/notebook/onpage?client=gnotesff&v=1.0.0.19&zx=1210070431913#cite_note-adc-1][20] )</sup>
ffident — Java metadata extraction / file format
identification library

[schmidt.devlib.org/ffident/index.html][21] 
This is the first version of a Java library to extract information
from files and identify their formats. Most operating systems
encode the format of a file in the file name extension. However,
there are problems with this approach: Uniform Type Identifiers
Overview: What Is a Uniform Type Identifier?

[
developer.apple.com/documentation/Carbon/Conceptua...][22]  A uniform
type identifier is a string that uniquely identifies a class of
entities considered to have a
“type.†For example, for a file or
other stream of bytes, “type†refers
to the format of the data. For entities such as packages and
bundles, “type†refers to the
internal structure of the directory hierarchy. Most commonly, a UTI
provides a consistent identifier for data that all applications and
services can recognize and rely upon, eliminating the need to keep
track of all the existing methods of tagging data. Currently, for
example, a JPEG file might be identified by any of the following
methods: Wotsit.org

[www.wotsit.org/][23]  Welcome to
Wotsit.org, the programmer's file and data format resource. This
site contains information on hundreds of different file types, data
types, hardware interface details and all sorts of other useful
programming information; algorithms, source code, specifications,
etc. File format - Wikipedia, the free encyclopedia

[en.wikipedia.org/wiki/File_format][24] 
### From Wikipedia, the free encyclopedia

Jump to: [navigation][25] ,
[search][26]  A
*file format* is a particular way to encode information for storage
in a [computer
file][27] .

TZX File Extension - Open .TZX files

[www.fileinfo.net/extension/tzx][28] 
Exact copy of a cassette for the Sinclair ZX Spectrum, a home
computer released in the UK in 1982; used primarily for basic word
processing, graphics programs, and video games; can be run on a PC
using a Spectrum emulation program. Format Description
Categories

[
www.digitalpreservation.gov/formats/fdd/descriptio...][29]  The
digital content format descriptions accessible here provide
specific information about individual formats and their
characteristics. Each description provides moderately detailed
information and citations. Planned for inclusion are a wide variety
of formats: file formats, file-format classes, bitstream structures
and encodings, and the mechanisms used to compress files or
bitstreams. Inclusion of a description for a format does not imply
that the format is preferred or acceptable for Library of Congress
collections. File Signatures - Filesig - Forensic Computing
Resource...

[www.filesig.co.uk/][30] 

Established 2001, [Filesig.co.uk][31]  aims to improve
techniques in researching, identifying and recovering file data
with the forensic computer examiner, data recovery or eDiscovery
techician in mind.

GDFR - Global Digital Format Registry

[collaborate.oclc.org/wiki/gdfr/about.html][32] 
The Global Digital Format Registry (GDFR) will provide sustainable
distributed services to store, discover, and deliver representation
information about digital formats. RFC 2046 - Multipurpose Internet
Mail Extensions (MIME) Part Two: Media Types

[tools.ietf.org/html/rfc2046][33] 
In general, the top-level media type is used to declare the general
type of data, while the subtype specifies a specific format for
that type of data. Data Pipes AccessPDF - Pdftk

[www.accesspdf.com/pdftk/][34]  If
PDF is electronic paper, then pdftk is an electronic
staple-remover, hole-punch, binder, secret-decoder-ring, and
X-Ray-glasses. Pdftk is a command-line tool for doing everyday
things with PDF documents. Keep one in the top drawer of your
desktop and use it to:


 - Merge PDF Documents
 - Split PDF Pages into a New Document
 - Decrypt Input as Necessary (Password Required)
 - Encrypt Output as Desired
 - Fill PDF Forms with FDF Data and/or Flatten Forms
 - Apply a Background Watermark


Report on PDF Metrics such as Metadata, Bookmarks, and Page
Labels - Update PDF Metadata - Attach Files to PDF Pages or the PDF
Document - Unpack PDF Attachments - Burst a PDF Document into
Single Pages - Uncompress and Re-Compress Page Streams - Repair
Corrupted PDF (Where Possible) HTML Parser - HTML Parser [htmlparser.sourceforge.net/][35] 
Labels: web, datapipes HTML Parser - HTML Parser [htmlparser.sourceforge.net/][36] 
HTML Parser is a Java library used to parse HTML in either a linear
or nested fashion. Primarily used for transformation or extraction,
it features filters, visitors, custom tags and easy to use
JavaBeans. It is a fast, robust and well tested package. Welcome to
the homepage of HTMLParser - a super-fast real-time parser for
real-world HTML. What has attracted most developers to HTMLParser
has been its simplicity in design, speed and ability to handle
streaming real-world html. Labels: web, datapipes Apache POI - Java
API To Access Microsoft Format Files [poi.apache.org/][37]  Labels: msoffice,
datapipes Office Formats - Â  Untitled Document [www.textmining.org/][38]  The
tm-extractors library is a pure java library for extracting text
from Word documents. Notable improvements in this release: -
Support for fast-saved Word documents - Many misc bug fixes -
Removal of dependencies on legacy HWPF code Support for older
versions of Word for Windows (1.0, 2.0, and 4.0) - Unit tests added
- Build file added - Source moved to public subversion repository
Labels: msoffice Comparitors - Differencing - [http://imagediff.tigris.org/][39]  -
[Perceptual Image Diff][40]  -
Text diffs and object diffs? Comparitors - Infomational Content
<pre><code>[Shannon Entropy]([http://www.bearcave.com/misl/misl_tech/wavelets/compression/shannon.html][41] )
</code></pre>

rapidxml.sourceforge.net/

[rapidxml.sourceforge.net/][42] 
RapidXml is an attempt to create the fastest XML parser possible,
while retaining useability, portability and reasonable W3C
compatibility. It is an _in-situ_ parser written in modern C++,
with parsing speed approaching that of
<code>strlen</code> function executed on the same data.
The Scripting Of Services

Services should simply be mapped onto classes, as I've done
already.  If the Service Registry is used to create a
set of classes backed by WS, then any scripting language can be
used to invoke them.  On it's own, this does not allow
much in the way of concurrency.  The 80% of the need,
batch processing of sets of items, can be dealt with by a single
Batch.invoke service or special command, that takes the list and
the service class and runs each in it's own thread. 
Again, this is all pretty easy and would still allow any scripting
language to be used.  This batcher would probably need
to be created from a factory to allow the approach to work, via
Generics to give the output array the right type.

NB. Given a dedicated workflow language, concurrency can be
inferred!  All potentially sequential pipes can be
determined by looking for dependencies in the variables (state, as
all pipes are stateless).  The only exception is the
'Session Variables' required to maintain state, and these can be
tracked as local variables that cannot be *read* concurrently -
maps to BPEL Correlation Sets.

Therefore, in this model, the service description must note any
variables that are used as session identifiers.  This
might be a good idea anyway.

*Interface Idea*

Given one can programmatically build Java classes from WSDL*, one
could create a simple service registry based on it and provide an
environment where these services are mapped onto instances of
classes.  A simple web interface could be used to edit
scripts that use these services and run on a server, which posts
back the feed-back and Console info.

*Programmatically creating classes is not so easy.  You
need to invoke 'org.apache.axis.wsdl.toJava.Emitter' to output a
set of Java class files into a directory.  Then,
inspect them to work out the class name, probably. 
Next, wrap as a JAR and then add to the classpath. 
After this point, it should be possible to inspect the classes via
reflection, use them from the JVM, and export them to a
script.

*Special Objects* - Console could be a special object to allow
logging output. - Batch/Process could be used to fork or 'flow'.
-

Perhaps we can create Async versions and callbacks
automatically?

Labels: dop pdftk - the pdf toolkit

[www.pdfhacks.com/pdftk/][43]  If PDF
is electronic paper, then pdftk is an electronic staple-remover,
hole-punch, binder, secret-decoder-ring, and X-Ray-glasses. Pdftk
is a simple tool for doing everyday things with PDF documents. Keep
one in the top drawer of your desktop and use it to:


 - Merge PDF Documents
 - Split PDF Pages into a New Document
 - Rotate PDF Pages or Documents
 - Decrypt Input as Necessary (Password Required)
 - Encrypt Output as Desired
 - Fill PDF Forms with FDF Data or XFDF Data and/or Flatten
Forms
 - Apply a Background Watermark or a Foreground Stamp


-

Report on PDF Metrics such as Metadata, Bookmarks, and Page
Labels


 - Update PDF Metadata
 - Attach Files to PDF Pages or the PDF Document
 - Unpack PDF Attachments
 - Burst a PDF Document into Single Pages
 - Uncompress and Re-Compress Page Streams
 - Repair Corrupted PDF (Where Possible)


Pdftk allows you to manipulate PDF easily and freely. It does
not require Acrobat, and it runs on Windows, Linux, Mac
OSÂ X, FreeBSD and Solaris.

Data Sources Where to Find Open Data on the Web -
ReadWriteWeb

[
www.readwriteweb.com/archives/where_to_find_open_d...][44]  So what
did everyone come up with? A lot of data sources are already freely
available on the net, as it turns out, if you just know where to
look. Here's a summary, do you have anything to add? Pages tagged
with "publicdata" on del.icio.us

[del.icio.us/tag/publicdata][45] 
Render Pipes World of Spectrum - Emulators

[www.worldofspectrum.org/emulators.html#java][46] 
  >  There are a range of Spectrum
emulators we could plug in. > Might avoid issue with
Dioscuri.

Dioscuri - the modular emulator for digital preservation

[dioscuri.sourceforge.net/][47] 
Dioscuri is an x86 computer hardware emulator written in Java. It
is designed by the digital preservation community to ensure
documents and programs from the past can still be accessed in the
future.

The Dioscuri emulator has two key features: it is durable and
flexible. Because it is implemented in Java, it can be ported to
any computer platform which supports the Java Virtual Machine
(JVM), without any extra effort. This reduces the risk that
emulation will fail to work on a single architecture in the future,
as it will continue to work on another architecture.

Dioscuri is flexible because it is completely component-based. Each
hardware component is emulated by a software surrogate called a
module. Combining several modules allows the user to configure any
computer system, as long as these modules are compatible. New or
upgraded modules can be added to the software library, giving the
emulator the capability to run these. Dioscuri is the best choice
to retain access to your old documents, games and other
applications!

JPC - Computer Virtualization in Java

[www-jpc.physics.ox.ac.uk/][48]  #
What is JPC?

JPC is an x86 PC [emulator][49] 
written entirely in [Java][50] .

alphaWorks : Digital Asset Preservation Tool : Overview

[www.alphaworks.ibm.com/tech/uvc][51] 
Digital Asset Preservation Tool is a "proof-of-concept"
demonstration of the Universal Virtual Computer (UVC) solution,
which was developed at IBM Almaden Research by Raymond Lorie to
provide long-term access to JPEG and GIF87a files. The concept,
which entails several components, has been developed at IBM Almaden
Research to ensure future use of digital objects. The UVC for
images

[www.kb.nl/hrd/dd/dd_onderzoek/uvc_voor_images-en.h...][52] 
The KB’s e-Depot guarantees secure long-term
storage of digital material. However, long-term
accessibility is another matter. Research has shown that the
storage format in particular – the structure in
which the data of a digital object is stored on the
carrier – is a point of concern. Formats are
complex and not based on open standards or specifications. As the
KB aims to preserve the original object, only a limited number of
strategies can be applied.

Together with IBM Netherlands, the KB has developed a new
preservation strategy, based on the Universal Virtual Computer
(UVC). With the UVC it is possible to read files without adapting
them and without the original hardware or software. JPEG images can
now be viewed independent of changes in technology.
Afterwards, the method was extended for GIF images as well. The UVC
project took place between September 2003 and April 2004. Ensuring
Data Integrity In Storing 1’s and
0’s, the Question Is $ - New York Times

[
www.nytimes.com/2008/04/09/technology/techspecial/...][53]  LISTEN.
Do you hear it? The bits are dying. Failing the fixity check - Adam
Farquhar - BL Wiki

[
intranet.bl.uk:8080/confluence/display/~adam+farqu...][54]  We can
learn some important lessons from this: (1) best data-centre
practice calls for independent backups and uninterruptible power
supplies (UPS); (2) modern storage systems are complex and may
violate some assumptions; (3) because of the caching that takes
place in the storage architecture, computing a digest and doing an
integrity check directly after writing may be misleading
– it can report what is in the cache, not what
is on the disk; (4) routine integrity checking is essential; (5) it
is important to perform integrity checks on recent content
– but not too promptly. 14.1.3 File Descriptor
Operations

[docs.python.org/lib/os-fd-ops.html][55] 
Force write of file with filedescriptor fd to disk. On Unix, this
calls the native fsync() function; on Windows, the MS _commit()
function. If you're starting with a Python file object f, first do
<code><var>f</var>.flush()</code>,
and then do
<code>os.fsync(<var>f</var>.fileno())</code>,
to ensure that all internal buffers associated with f are written
to disk. Availability: Macintosh, Unix, and Windows starting in
[2.2.3.][56] 

----------


[#WWJ-113] WWIO needs to flush data to disk - NASA World Wind
Issues

[issues.worldwind.arc.nasa.gov/browse/WWJ-113][57] 
fileChannel.force(true); sata raid & write cache
state

[
lists.freebsd.org/pipermail/freebsd-hardware/2004-...][58]  Write
ahead logging - Wikipedia, the free encyclopedia

[en.wikipedia.org/wiki/Write_ahead_logging][59] 
tdbm - a simple, high-performance database with nested atomic
transactions

[tdbm.dss.ca/][60]  The Testbed Testbed
Architecture - Google Docs

[docs.google.com/Doc?docid=dwngn8z_16gx6swcch&hl=en...][61] 
The content on this page is provided by a [Google Notebook][62]  user, and
Google assumes no responsibility for this content.

----------



 1. [1] [↩|#fnref1]
 2. [1] [↩|#fnref2]
 3. [2] [↩|#fnref3]




  [1]: http://www.google.com/notebook/
  [2]: http://www.google.com/notebook/user/01548586005453060515
  [3]: http://www.significantproperties.co.uk/
  [4]: http://www.dponline.org/
  [5]: http://www.loc.gov/standards/premis/
  [6]: http://www.darwinsys.com/file/
  [7]: http://www.opengroup.org/onlinepubs/009695399/utilities/file.html
  [8]: http://www.opengroup.org/onlinepubs/009695399/utilities/
  [9]: http://en.wikipedia.org/wiki/Uniform_Type_Identifier
  [10]: http://en.wikipedia.org/wiki/Apple_Inc.
  [11]: http://en.wikipedia.org/wiki/Mac_OS_X
  [12]: http://en.wikipedia.org/wiki/Mac_OS_X_v10.4
  [13]: http://en.wikipedia.org/wiki/Mac_OS_X
  [14]: http://en.wikipedia.org/wiki/Spotlight_%28software%29
  [15]: http://www.google.com/notebook/onpage?client=gnotesff&v=1.0.0.19&zx=1210070431913#cite_note-ars-0
  [16]: http://en.wikipedia.org/wiki/Filename_extension
  [17]: http://en.wikipedia.org/wiki/Type_code
  [18]: http://en.wikipedia.org/wiki/Creator_code
  [19]: http://www.google.com/notebook/onpage?client=gnotesff&v=1.0.0.19&zx=1210070431913#cite_note-ars-0
  [20]: http://www.google.com/notebook/onpage?client=gnotesff&v=1.0.0.19&zx=1210070431913#cite_note-adc-1
  [21]: http://schmidt.devlib.org/ffident/index.html
  [22]: http://developer.apple.com/documentation/Carbon/Conceptual/understanding_utis/understand_utis_conc/chapter_2_section_2.html#//apple_ref/doc/uid/TP40001319-CH202-SW1
  [23]: http://www.wotsit.org/
  [24]: http://en.wikipedia.org/wiki/File_format
  [25]: http://en.wikipedia.org/wiki/File_format#column-one
  [26]: http://en.wikipedia.org/wiki/File_format#searchInput
  [27]: http://en.wikipedia.org/wiki/Computer_file
  [28]: http://www.fileinfo.net/extension/tzx
  [29]: http://www.digitalpreservation.gov/formats/fdd/descriptions.shtml
  [30]: http://www.filesig.co.uk/
  [31]: http://filesig.co.uk/
  [32]: https://collaborate.oclc.org/wiki/gdfr/about.html
  [33]: http://tools.ietf.org/html/rfc2046
  [34]: http://www.accesspdf.com/pdftk/
  [35]: http://htmlparser.sourceforge.net/
  [36]: http://htmlparser.sourceforge.net/
  [37]: http://poi.apache.org/
  [38]: http://www.textmining.org/
  [39]: http://imagediff.tigris.org/
  [40]: http://pdiff.sourceforge.net/
  [41]: http://www.bearcave.com/misl/misl_tech/wavelets/compression/shannon.html
  [42]: http://rapidxml.sourceforge.net/
  [43]: http://www.pdfhacks.com/pdftk/
  [44]: http://www.readwriteweb.com/archives/where_to_find_open_data_on_the.php
  [45]: http://del.icio.us/tag/publicdata
  [46]: http://www.worldofspectrum.org/emulators.html#java
  [47]: http://dioscuri.sourceforge.net/
  [48]: http://www-jpc.physics.ox.ac.uk/
  [49]: http://www-jpc.physics.ox.ac.uk/Emulation.html
  [50]: http://java.sun.com/
  [51]: http://www.alphaworks.ibm.com/tech/uvc
  [52]: http://www.kb.nl/hrd/dd/dd_onderzoek/uvc_voor_images-en.html
  [53]: http://www.nytimes.com/2008/04/09/technology/techspecial/09store.html?em&ex=1208059200&en=b00d6fe51d934cb3&ei=5087%0A
  [54]: http://intranet.bl.uk:8080/confluence/display/%7Eadam+farquhar/2008/04/10/Failing+the+fixity+check
  [55]: http://docs.python.org/lib/os-fd-ops.html
  [56]: http://2.2.3./
  [57]: http://issues.worldwind.arc.nasa.gov/browse/WWJ-113
  [58]: http://lists.freebsd.org/pipermail/freebsd-hardware/2004-October/001991.html
  [59]: http://en.wikipedia.org/wiki/Write_ahead_logging
  [60]: http://tdbm.dss.ca/
  [61]: http://docs.google.com/Doc?docid=dwngn8z_16gx6swcch&hl=en_GB
  [62]: http://www.google.com/notebook/