This presentation provides updated technical information regarding the Memento framework to support time travel on the Web. Its technical content overrides the first Memento presentation (http://www.slideshare.net/hvdsomp/memento-time-travel-for-the-web). More Memento information is available at http://www.mementoweb.org.
Time travel is one of my favorite topics! I wrote some time travel stories in junior high school that used a machine of my own invention to travel backwards in time, and I have continued to study this fascinating concept as the years have gone by. We all travel in time. During the last year, I've moved forward one year and so have you. Another way to say that is that we travel in time at the rate of 1 hour per hour.
But the question is, can we travel in time faster or slower than "1 hour per hour"? Or can we actually travel backward in time, going back, say 2 hours per hour, or 10 or 100 years per hour?
It is mind-boggling to think about time travel. What if you went back in time and prevented your father and mother from meeting? You would prevent yourself from ever having been born! But then if you hadn't been born, you could not have gone back in time to prevent them from meeting.
Designing for Time Travel: When Responsive Design Is Not EnoughBurin Asavesna
I'm going to talk about time travel.
Responsive Web Design is an approach to optimizing your experience depending on what *device* you're using, but what approaches do we have for when websites get crazy and need to adapt to what *time* you are viewing it? This talk will discuss challenges faced when designing sites that need to respond to time. We will also discuss tools and techniques to use that help websites become more dynamic (is there such a thing as a media query for time?). The case study for this talk will be a wedding website. As the date for the wedding approaches and passes, visitors will care about different pieces of information. 6 months out, 3 months out, a week before, the night before, the day of, a week after, and way-way after. Another example that will be used is how the Olympics website would've been designed using these techniques.
Powerpoint Search Engine has collection of slides related to specific topics. Write the required keyword in the search box and it fetches you the related results.
Time travel is one of my favorite topics! I wrote some time travel stories in junior high school that used a machine of my own invention to travel backwards in time, and I have continued to study this fascinating concept as the years have gone by. We all travel in time. During the last year, I've moved forward one year and so have you. Another way to say that is that we travel in time at the rate of 1 hour per hour.
But the question is, can we travel in time faster or slower than "1 hour per hour"? Or can we actually travel backward in time, going back, say 2 hours per hour, or 10 or 100 years per hour?
It is mind-boggling to think about time travel. What if you went back in time and prevented your father and mother from meeting? You would prevent yourself from ever having been born! But then if you hadn't been born, you could not have gone back in time to prevent them from meeting.
Designing for Time Travel: When Responsive Design Is Not EnoughBurin Asavesna
I'm going to talk about time travel.
Responsive Web Design is an approach to optimizing your experience depending on what *device* you're using, but what approaches do we have for when websites get crazy and need to adapt to what *time* you are viewing it? This talk will discuss challenges faced when designing sites that need to respond to time. We will also discuss tools and techniques to use that help websites become more dynamic (is there such a thing as a media query for time?). The case study for this talk will be a wedding website. As the date for the wedding approaches and passes, visitors will care about different pieces of information. 6 months out, 3 months out, a week before, the night before, the day of, a week after, and way-way after. Another example that will be used is how the Olympics website would've been designed using these techniques.
Powerpoint Search Engine has collection of slides related to specific topics. Write the required keyword in the search box and it fetches you the related results.
Presentation about reference rot given at the Complexity Science Hub in Vienna, November 2021.
Links to web resources frequently break (link rot), and linked content can change at unpredictable rates (content drift). These dynamics of the Web are detrimental when references to web resources provide evidence or supporting information.
This presentation will report on research that assessed the extent of these problems for links to web resources in scholarly literature, by using three vast corpora of publications and a range of public web archives. It will also describe the Robust Link approach that offers a proactive, uniform, and machine-actionable way to combat link rot and content drift. Finally, it will introduce the Robustify web service and API that was devised to generate links that remain functional over time, paying special attention to challenges related to deploying infrastructure that is required to be long lasting.
Researcher Pod: Scholarly Communication Using the Decentralized WebHerbert Van de Sompel
The presentation provides an overview of the motivation and direction of the Mellon-funded Researcher Pod project that investigates technical aspects of scholarly communication in a decentralized web setting.
Presentation for a workshop about persistent identifiers organized by the Royal Library of The Netherlands and DANS. Highlights the non-trivial commitments required of all parties involved in persistent identifier systems to actually keep links based on persistent identifiers ... err ... persistent.
Various FAIR criteria pertaining to machine interaction with scholarly artifacts can commonly be addressed by means of repository-wide affordances that are uniformly provided for all hosted artifacts rather than through artifact-specific interventions. If various repository platforms provide such affordances in an interoperable manner, devising tools - for both human and machine use - that leverage them becomes easier.
My involvement, over the years, in a range of interoperability efforts has brought the insight that two factors strongly influence adoption: addressing a burning issue and delivering a KISS solution to tackle it. Undoubtedly, FAIR and FAIR DOs are burning issues. FAIR Signposting <https://signposting.org/FAIR/> is an ad-hoc repository interoperability effort that squarely fits in this problem space and that purposely specifies a KISS solution, hoping to inspire wide adoption.
Registration / Certification Interoperability Architecture (overlay peer-review)Herbert Van de Sompel
Presentation for the COAR meeting on Overlay Peer-Review held at INRIA, Paris, France. It provides overall context regarding a scholarly communication system in which the core functions of scholarly communication (registration, certification, awareness, archiving) are implemented in a decoupled manner and whereby each function can simultaneously be fulfilled by different parties, potentially in different ways. It shows how notifications can be used to achieve loosely coupled, point-to-point interoperability in such an environment, zooming in on interoperability between registration and certification aka interoperability between repositories and overlay peer-review services.
Slides used for a keynote presentation at the VIVO 2019 Conference in Podgorica, Montenegro.
Abstract: The invitation to present a keynote at the VIVO Conference and the goal of the VIVO platform, as stated on the DuraSpace site, to create an integrated record of the scholarly work of an organisation reminded me of various efforts that I have been involved in over the past years that had similar goals. EgoSystem (2014) attempted to gather information about postdocs that had left the organisation, leaving little or no contact details behind. Autoload (2017), an operational service, discovers papers by organisational researchers in order to upload them in the institutional repository. myresearch.institute (2018), an experiment that is still in progress, discovers artefacts that researchers deposit in web productivity portals and subsequently archives them. More recently, I have been involved in thinking about the future of NARCIS, a portal that provides an overview of research productivity in The Netherlands. The approach taken in all these efforts share a characteristic motivated by a desire to devise scalable and sustainable solutions: let machines rather than humans do the work. In this talk, I will provide an overview of these efforts, their motivations, the challenges involved, and the nature of success (if any).
Presentation for PIDapalooza 2019, Dublin, Ireland.
The Scholarly Orphans project, funded by the Andrew W. Mellon Foundation, explores technical approaches aimed at capturing and archiving scholarly artifacts that researchers deposit in web productivity portals as a means to collaborate and communicate with their peers. These artifacts are not collected by other frameworks aimed at archiving the scholarly record (e.g., LOCKSS, Portico, Institutional Repositories) and are only incidentally captured by web archives. The project explores an institution-driven approach inspired by web archiving. To demonstrate the ongoing thinking, the project has devised an experimental automated pipeline that continuously discovers, captures, and archives artifacts. These are created by actual researchers who, for the purpose of the experiment, were virtually enlisted in a fictive research institution. A portal at myresearch.institute provides an overview of the artifacts that were discovered and provides access to archived versions stored in both an institutional and a cross-institutional archive. The set-up leverages a range of technologies that share a flavor of persistence: Memento, Memento Tracer, Robust Links, Signposting.
As a memento of my last week of working at LANL, I put together a slide deck that provides an overview of major efforts conducted during the time I was there.
Presentation given at EuropeanaTech 2018 in Rotterdam, The Netherlands. Provides a summary of insights gained from working for about a decade on challenges related to temporal aspects of the web, persistence.
"Scholarly Communication: Deconstruct and Decentralize" was presented at the Fall 2017 Meeting of the Coalition for Networked Information. It explores working towards a Scholarly Commons by applying decentralized web ideas to scholarly communication.
Looks at hyperlinks from the perspective of a managed collection of resources for which link persistence/integrity is considered a quality of service concern. Distinguishes between links into other managed collections and to the web at large. Considers link rot and content drift.
This slide deck provides an overview of proposals to use HTTP Links as a means to address some long standing problems related to scholarly resources on the web.
This slide deck provides an overview of proposals to use HTTP Links as a means to address some long standing problems related to scholarly resources on the web.
Presentation for PIDapalooza 2016. PIDs need to be used to achieve their intended persistence. Our research (reported at WWW2016, see http://arxiv.org/1602.09102) found that a disturbing percentage of references to papers that have DOIs actually use the landing page HTTP URI instead of the DOI HTTP URI. The problem is likely related to tools used for collecting references such as bookmarks and reference managers. These select the landing page URI instead of the DOI URI because the former is what's available in the address bar. It can safely be assumed that the same problem exists for other types of PIDs. The net result is that the true potential of PIDs is not realized. In order to ameliorate this problem we propose a Signposting pattern for PIDs (http://signposting.org/identifier/). It consists of adding a Link header to HTTP HEAD/GET responses for all resources identified by a DOI, including the landing page and content resources such as "the PDF" and "the dataset". The Link header contains a link, which points with the "identifier" relation type to the DOI HTTP URI. When such a link is available, tools can automatically discover and use the DOI URI instead of the other URIs (landing page, PDF, dataset) associated with the DOI-identified object.
DBpedia Archive using Memento, Triple Pattern Fragments, and HDTHerbert Van de Sompel
DBpedia is the Linked Data version of Wikipedia. Starting in 2007, several DBpedia dumps have been made available for download. In 2010, the Research Library at the Los Alamos National Laboratory used these dumps to deploy a Memento-compliant DBpedia Archive, in order to demonstrate the applicability and appeal of accessing temporal versions of Linked Data sets using the Memento “Time Travel for the Web” protocol. The archive supported datetime negotiation to access various temporal versions of RDF descriptions of DBpedia subject URIs.
In a recent collaboration with the iMinds Group of Ghent University, the DBpedia Archive received a major overhaul. The initial MongoDB storage approach, which was unable to handle increasingly large DBpedia dumps, was replaced by HDT, the Binary RDF Representation for Publication and Exchange. And, in addition to the existing subject URI access point, Triple Pattern Fragments access, as proposed by the Linked Data Fragments project, was added. This allows datetime negotiation for URIs that identify RDF triples that match subject/predicate/object patterns. To add this powerful capability, native Memento support was added to the Linked Data Fragments Server of Ghent University.
In this talk, we will include a brief refresher of Memento, and will cover Linked Data Fragments, Triple Pattern Fragments, and HDT in more detail. We will share lessons learned from this effort and demo the new DBpedia Archive, which, at this point, holds over 5 billion RDF triples.
These slides go with the paper "Reminiscing About 15 Years of Interoperability Efforts" which is available at http://dx.doi.org/10.1045/november2015-vandesompel
Slides were used for a presentation at the Fall 2015 Membership Meeting of the Coalition for Networked Information.
This presentation looks back at several efforts, conducted in the past fifteen years, aimed at establishing interoperability for web-based scholarly communication. It tries to characterize the perspectives/approaches taken by these efforts and, based upon that, proposes an HATEOS-based approach to interlink scholarly nodes on the web. This was first presented at the Research Data Alliance meeting in Paris, France, September 22 2015.
Extended version of slides presented at the "404/File Not Found" symposium held at Georgetown University on October 24 2014, see http://www.law.georgetown.edu/library/404/ . The presentation provides a brief overview of the link/reference rot problem and then discusses three complimentary strategies to combat it: Pro-actively capturing web resources that are linked from a seed collection; Referencing the captures by means of annotated links; Accessing the captures using Memento infrastructure.
This presentation introduces ResourceSync, a specification aimed to enable web-based synchronization of resources. The specification is the result of a collaboration between NISO and the Open Archives Initiative funded by the Sloan Foundation and JISC. The proposed resource synchronization approach is based on several existing specifications (e.g. Sitemaps, PubSubHubbub, well-known URI) and is aligned with common architectural principles (e.g. REST, follow your nose).
A 15 minute video version of these slides is available at https://www.youtube.com/watch?v=ASQ4jMYytsA
This presentation provides an overview of the Memento "Time Travel for the Web" framework that is aligned with the stable version of the Memento protocol, specified in RFC 7089.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Presentation about reference rot given at the Complexity Science Hub in Vienna, November 2021.
Links to web resources frequently break (link rot), and linked content can change at unpredictable rates (content drift). These dynamics of the Web are detrimental when references to web resources provide evidence or supporting information.
This presentation will report on research that assessed the extent of these problems for links to web resources in scholarly literature, by using three vast corpora of publications and a range of public web archives. It will also describe the Robust Link approach that offers a proactive, uniform, and machine-actionable way to combat link rot and content drift. Finally, it will introduce the Robustify web service and API that was devised to generate links that remain functional over time, paying special attention to challenges related to deploying infrastructure that is required to be long lasting.
Researcher Pod: Scholarly Communication Using the Decentralized WebHerbert Van de Sompel
The presentation provides an overview of the motivation and direction of the Mellon-funded Researcher Pod project that investigates technical aspects of scholarly communication in a decentralized web setting.
Presentation for a workshop about persistent identifiers organized by the Royal Library of The Netherlands and DANS. Highlights the non-trivial commitments required of all parties involved in persistent identifier systems to actually keep links based on persistent identifiers ... err ... persistent.
Various FAIR criteria pertaining to machine interaction with scholarly artifacts can commonly be addressed by means of repository-wide affordances that are uniformly provided for all hosted artifacts rather than through artifact-specific interventions. If various repository platforms provide such affordances in an interoperable manner, devising tools - for both human and machine use - that leverage them becomes easier.
My involvement, over the years, in a range of interoperability efforts has brought the insight that two factors strongly influence adoption: addressing a burning issue and delivering a KISS solution to tackle it. Undoubtedly, FAIR and FAIR DOs are burning issues. FAIR Signposting <https://signposting.org/FAIR/> is an ad-hoc repository interoperability effort that squarely fits in this problem space and that purposely specifies a KISS solution, hoping to inspire wide adoption.
Registration / Certification Interoperability Architecture (overlay peer-review)Herbert Van de Sompel
Presentation for the COAR meeting on Overlay Peer-Review held at INRIA, Paris, France. It provides overall context regarding a scholarly communication system in which the core functions of scholarly communication (registration, certification, awareness, archiving) are implemented in a decoupled manner and whereby each function can simultaneously be fulfilled by different parties, potentially in different ways. It shows how notifications can be used to achieve loosely coupled, point-to-point interoperability in such an environment, zooming in on interoperability between registration and certification aka interoperability between repositories and overlay peer-review services.
Slides used for a keynote presentation at the VIVO 2019 Conference in Podgorica, Montenegro.
Abstract: The invitation to present a keynote at the VIVO Conference and the goal of the VIVO platform, as stated on the DuraSpace site, to create an integrated record of the scholarly work of an organisation reminded me of various efforts that I have been involved in over the past years that had similar goals. EgoSystem (2014) attempted to gather information about postdocs that had left the organisation, leaving little or no contact details behind. Autoload (2017), an operational service, discovers papers by organisational researchers in order to upload them in the institutional repository. myresearch.institute (2018), an experiment that is still in progress, discovers artefacts that researchers deposit in web productivity portals and subsequently archives them. More recently, I have been involved in thinking about the future of NARCIS, a portal that provides an overview of research productivity in The Netherlands. The approach taken in all these efforts share a characteristic motivated by a desire to devise scalable and sustainable solutions: let machines rather than humans do the work. In this talk, I will provide an overview of these efforts, their motivations, the challenges involved, and the nature of success (if any).
Presentation for PIDapalooza 2019, Dublin, Ireland.
The Scholarly Orphans project, funded by the Andrew W. Mellon Foundation, explores technical approaches aimed at capturing and archiving scholarly artifacts that researchers deposit in web productivity portals as a means to collaborate and communicate with their peers. These artifacts are not collected by other frameworks aimed at archiving the scholarly record (e.g., LOCKSS, Portico, Institutional Repositories) and are only incidentally captured by web archives. The project explores an institution-driven approach inspired by web archiving. To demonstrate the ongoing thinking, the project has devised an experimental automated pipeline that continuously discovers, captures, and archives artifacts. These are created by actual researchers who, for the purpose of the experiment, were virtually enlisted in a fictive research institution. A portal at myresearch.institute provides an overview of the artifacts that were discovered and provides access to archived versions stored in both an institutional and a cross-institutional archive. The set-up leverages a range of technologies that share a flavor of persistence: Memento, Memento Tracer, Robust Links, Signposting.
As a memento of my last week of working at LANL, I put together a slide deck that provides an overview of major efforts conducted during the time I was there.
Presentation given at EuropeanaTech 2018 in Rotterdam, The Netherlands. Provides a summary of insights gained from working for about a decade on challenges related to temporal aspects of the web, persistence.
"Scholarly Communication: Deconstruct and Decentralize" was presented at the Fall 2017 Meeting of the Coalition for Networked Information. It explores working towards a Scholarly Commons by applying decentralized web ideas to scholarly communication.
Looks at hyperlinks from the perspective of a managed collection of resources for which link persistence/integrity is considered a quality of service concern. Distinguishes between links into other managed collections and to the web at large. Considers link rot and content drift.
This slide deck provides an overview of proposals to use HTTP Links as a means to address some long standing problems related to scholarly resources on the web.
This slide deck provides an overview of proposals to use HTTP Links as a means to address some long standing problems related to scholarly resources on the web.
Presentation for PIDapalooza 2016. PIDs need to be used to achieve their intended persistence. Our research (reported at WWW2016, see http://arxiv.org/1602.09102) found that a disturbing percentage of references to papers that have DOIs actually use the landing page HTTP URI instead of the DOI HTTP URI. The problem is likely related to tools used for collecting references such as bookmarks and reference managers. These select the landing page URI instead of the DOI URI because the former is what's available in the address bar. It can safely be assumed that the same problem exists for other types of PIDs. The net result is that the true potential of PIDs is not realized. In order to ameliorate this problem we propose a Signposting pattern for PIDs (http://signposting.org/identifier/). It consists of adding a Link header to HTTP HEAD/GET responses for all resources identified by a DOI, including the landing page and content resources such as "the PDF" and "the dataset". The Link header contains a link, which points with the "identifier" relation type to the DOI HTTP URI. When such a link is available, tools can automatically discover and use the DOI URI instead of the other URIs (landing page, PDF, dataset) associated with the DOI-identified object.
DBpedia Archive using Memento, Triple Pattern Fragments, and HDTHerbert Van de Sompel
DBpedia is the Linked Data version of Wikipedia. Starting in 2007, several DBpedia dumps have been made available for download. In 2010, the Research Library at the Los Alamos National Laboratory used these dumps to deploy a Memento-compliant DBpedia Archive, in order to demonstrate the applicability and appeal of accessing temporal versions of Linked Data sets using the Memento “Time Travel for the Web” protocol. The archive supported datetime negotiation to access various temporal versions of RDF descriptions of DBpedia subject URIs.
In a recent collaboration with the iMinds Group of Ghent University, the DBpedia Archive received a major overhaul. The initial MongoDB storage approach, which was unable to handle increasingly large DBpedia dumps, was replaced by HDT, the Binary RDF Representation for Publication and Exchange. And, in addition to the existing subject URI access point, Triple Pattern Fragments access, as proposed by the Linked Data Fragments project, was added. This allows datetime negotiation for URIs that identify RDF triples that match subject/predicate/object patterns. To add this powerful capability, native Memento support was added to the Linked Data Fragments Server of Ghent University.
In this talk, we will include a brief refresher of Memento, and will cover Linked Data Fragments, Triple Pattern Fragments, and HDT in more detail. We will share lessons learned from this effort and demo the new DBpedia Archive, which, at this point, holds over 5 billion RDF triples.
These slides go with the paper "Reminiscing About 15 Years of Interoperability Efforts" which is available at http://dx.doi.org/10.1045/november2015-vandesompel
Slides were used for a presentation at the Fall 2015 Membership Meeting of the Coalition for Networked Information.
This presentation looks back at several efforts, conducted in the past fifteen years, aimed at establishing interoperability for web-based scholarly communication. It tries to characterize the perspectives/approaches taken by these efforts and, based upon that, proposes an HATEOS-based approach to interlink scholarly nodes on the web. This was first presented at the Research Data Alliance meeting in Paris, France, September 22 2015.
Extended version of slides presented at the "404/File Not Found" symposium held at Georgetown University on October 24 2014, see http://www.law.georgetown.edu/library/404/ . The presentation provides a brief overview of the link/reference rot problem and then discusses three complimentary strategies to combat it: Pro-actively capturing web resources that are linked from a seed collection; Referencing the captures by means of annotated links; Accessing the captures using Memento infrastructure.
This presentation introduces ResourceSync, a specification aimed to enable web-based synchronization of resources. The specification is the result of a collaboration between NISO and the Open Archives Initiative funded by the Sloan Foundation and JISC. The proposed resource synchronization approach is based on several existing specifications (e.g. Sitemaps, PubSubHubbub, well-known URI) and is aligned with common architectural principles (e.g. REST, follow your nose).
A 15 minute video version of these slides is available at https://www.youtube.com/watch?v=ASQ4jMYytsA
This presentation provides an overview of the Memento "Time Travel for the Web" framework that is aligned with the stable version of the Memento protocol, specified in RFC 7089.
Software Delivery At the Speed of AI: Inflectra Invests In AI-Powered QualityInflectra
In this insightful webinar, Inflectra explores how artificial intelligence (AI) is transforming software development and testing. Discover how AI-powered tools are revolutionizing every stage of the software development lifecycle (SDLC), from design and prototyping to testing, deployment, and monitoring.
Learn about:
• The Future of Testing: How AI is shifting testing towards verification, analysis, and higher-level skills, while reducing repetitive tasks.
• Test Automation: How AI-powered test case generation, optimization, and self-healing tests are making testing more efficient and effective.
• Visual Testing: Explore the emerging capabilities of AI in visual testing and how it's set to revolutionize UI verification.
• Inflectra's AI Solutions: See demonstrations of Inflectra's cutting-edge AI tools like the ChatGPT plugin and Azure Open AI platform, designed to streamline your testing process.
Whether you're a developer, tester, or QA professional, this webinar will give you valuable insights into how AI is shaping the future of software delivery.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
Encryption in Microsoft 365 - ExpertsLive Netherlands 2024Albert Hoitingh
In this session I delve into the encryption technology used in Microsoft 365 and Microsoft Purview. Including the concepts of Customer Key and Double Key Encryption.
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
The Art of the Pitch: WordPress Relationships and SalesLaura Byrne
Clients don’t know what they don’t know. What web solutions are right for them? How does WordPress come into the picture? How do you make sure you understand scope and timeline? What do you do if sometime changes?
All these questions and more will be explored as we talk about matching clients’ needs with what your agency offers without pulling teeth or pulling your hair out. Practical tips, and strategies for successful relationship building that leads to closing the deal.
Kubernetes & AI - Beauty and the Beast !?! @KCD Istanbul 2024Tobias Schneck
As AI technology is pushing into IT I was wondering myself, as an “infrastructure container kubernetes guy”, how get this fancy AI technology get managed from an infrastructure operational view? Is it possible to apply our lovely cloud native principals as well? What benefit’s both technologies could bring to each other?
Let me take this questions and provide you a short journey through existing deployment models and use cases for AI software. On practical examples, we discuss what cloud/on-premise strategy we may need for applying it to our own infrastructure to get it to work from an enterprise perspective. I want to give an overview about infrastructure requirements and technologies, what could be beneficial or limiting your AI use cases in an enterprise environment. An interactive Demo will give you some insides, what approaches I got already working for real.
Elevating Tactical DDD Patterns Through Object CalisthenicsDorra BARTAGUIZ
After immersing yourself in the blue book and its red counterpart, attending DDD-focused conferences, and applying tactical patterns, you're left with a crucial question: How do I ensure my design is effective? Tactical patterns within Domain-Driven Design (DDD) serve as guiding principles for creating clear and manageable domain models. However, achieving success with these patterns requires additional guidance. Interestingly, we've observed that a set of constraints initially designed for training purposes remarkably aligns with effective pattern implementation, offering a more ‘mechanical’ approach. Let's explore together how Object Calisthenics can elevate the design of your tactical DDD patterns, offering concrete help for those venturing into DDD for the first time!
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
Dev Dives: Train smarter, not harder – active learning and UiPath LLMs for do...UiPathCommunity
💥 Speed, accuracy, and scaling – discover the superpowers of GenAI in action with UiPath Document Understanding and Communications Mining™:
See how to accelerate model training and optimize model performance with active learning
Learn about the latest enhancements to out-of-the-box document processing – with little to no training required
Get an exclusive demo of the new family of UiPath LLMs – GenAI models specialized for processing different types of documents and messages
This is a hands-on session specifically designed for automation developers and AI enthusiasts seeking to enhance their knowledge in leveraging the latest intelligent document processing capabilities offered by UiPath.
Speakers:
👨🏫 Andras Palfi, Senior Product Manager, UiPath
👩🏫 Lenka Dulovicova, Product Program Manager, UiPath
Designing Great Products: The Power of Design and Leadership by Chief Designe...
Memento: Updated Technical Details (March 2010)
1. Memento: Time Travel for the Web
The Memento Team
Herbert Van de Sompel
Michael L. Nelson
Robert Sanderson
Lyudmila Balakireva
Scott Ainsworth
Harihar Shankar
Memento is partially funded by the
Library of Congress
Updated Technical Details (March 2010)
Memento: Time Travel for the Web
Updated Technical Details (03/2010)
2. Memento wants to make navigating the Web’s Past Easy
http://www.mementoweb.org
http://groups.google.com/group/memento-dev
Memento: Time Travel for the Web
2
Updated Technical Details (03/2010)
3. Recap of the Basics …
Memento: Time Travel for the Web
3
Updated Technical Details (03/2010)
4. W3C Web Architecture: Resource – URI - Representation
dereference
URI
Identifies
Resource
Represents
Representation
Memento: Time Travel for the Web
4
Updated Technical Details (03/2010)
5. W3C Web Architecture: Resource – URI - Representation
dereference content negotiation
URI
Identifies
Resource
Represents
Representation 1
Represents Representation 2
Memento: Time Travel for the Web
5
Updated Technical Details (03/2010)
6. Problem Statement …
Memento: Time Travel for the Web
6
Updated Technical Details (03/2010)
9. Resources have Representations that Change over Time
Memento: Time Travel for the Web
9
Updated Technical Details (03/2010)
10. Only the Current Representation is Available from a Resource
Memento: Time Travel for the Web
10
Updated Technical Details (03/2010)
11. Old Representations are Lost Forever
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11
Updated Technical Details (03/2010)
12. Archived Resources Exist
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Updated Technical Details (03/2010)
13. Sep 11 2001, 20:36:10 UTC Dec 20 2001, 4:51:00 UTC
Archived Resources
http://en.wikipedia.org/w/index.php?
http://web.archive.org/web/20010911203610/http:// title=September_11_attacks&oldid=282333 archived
www.cnn.com/ archived resource for http://cnn.com resource for http://en.wikipedia.org/wiki/
September_11_attacks
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Updated Technical Details (03/2010) 13
14. Finding Archived Resources
Go to http://www.archive.org/ and search On http://web.archive.org/web/*/http://cnn.com, select
http://cnn.com desired datetime
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Updated Technical Details (03/2010)
15. Finding Archived Resources
Go to
http://en.wikipedia.org/wiki/September_11_attacks Browse History
and click History
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15
Updated Technical Details (03/2010)
16. Dec 20 2001, 4:51:00 UTC current
Navigating Archived Resources
Pentagon
http://en.wikipedia.org/w/index.php?
title=September_11_attacks&oldid=282333 archived
http://en.wikipedia.org/wiki/The_Pentagon
resource for http://en.wikipedia.org/wiki/
September_11_attacks3
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17. Sep 11 2001, 20:36:10 UTC Sep 11 2001, 21:38:55 UTC
Navigating Archived Resources
SPACE
http://web.archive.org/web/20010911203610/http:// http://web.archive.org/web/20010911213855/
www.cnn.com/ archived resource for http://cnn.com www.cnn.com/TECH/space/
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Updated Technical Details (03/2010)
18. Current and Past Web are Not Integrated
• Current and Past Web
based on same technology.
• But, going from Current to
Past Web is a matter of
(manual) discovery.
• Memento wants to make
going from Current to Past
Web a (HTTP) protocol
matter.
• Memento wants to integrate
Current And Past Web.
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Updated Technical Details (03/2010)
19. The Memento Approach …
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19
Updated Technical Details (03/2010)
20. Navigate the Web of the Past
http://en.wikipedea.org/wiki/
Web_Archiving
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Updated Technical Details (03/2010)
21. Navigate the Web of the Past
http://en.wikipedea.org/wiki/
Web_Archiving
Oct 11 2009, 05:30:33 UTC
Set browser time dial to …
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21
Updated Technical Details (03/2010)
22. Navigate the Web of the Past
http://en.wikipedea.org/wiki/ From Wikipedia History
Web_Archiving
Oct 11 2009, 05:30:33 UTC Oct 01 2009, 16:30:00 UTC
Set browser time dial to …
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22
Updated Technical Details (03/2010)
23. Navigate the Web of the Past
http://en.wikipedea.org/wiki/ From Wikipedia History
Web_Archiving
Oct 11 2009, 05:30:33 UTC Oct 01 2009, 16:30:00 UTC
Set browser time dial to …
Robots Exclusion Protocol Oct 11 2009, 05:30:33 UTC
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23
Updated Technical Details (03/2010)
24. Navigate the Web of the Past
http://en.wikipedea.org/wiki/
Robots_exclusion_protocol
Oct 11 2009, 05:30:33 UTC
Browser time dial still at …
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24
Updated Technical Details (03/2010)
25. Navigate the Web of the Past
http://en.wikipedea.org/wiki/ From Wikipedia History
Robots_exclusion_protocol
Oct 11 2009, 05:30:33 UTC Sep 15 2009, 20:49:00 UTC
Browser time dial still at …
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25
Updated Technical Details (03/2010)
26. Navigate the Web of the Past
http://en.wikipedea.org/wiki/ From Wikipedia History
Robots_exclusion_protocol
Oct 11 2009, 05:30:33 UTC Sep 15 2009, 20:49:00 UTC
Browser time dial still at …
Robots Exclusion Oct 11 2009, 05:30:33 UTC
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26
Updated Technical Details (03/2010)
27. Navigate the Web of the Past
http://www.robotstxt.org/
Oct 11 2009, 05:30:33 UTC
Browser time dial still at …
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27
Updated Technical Details (03/2010)
28. Navigate the Web of the Past
http://www.robotstxt.org/ From Internet Archive
Oct 11 2009, 05:30:33 UTC Nov 09 2007, 06:21:04 UTC
Browser time dial still at …
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Updated Technical Details (03/2010)
29. How does Memento achieve this?
There are two components to the Memento Solution:
• Component 1: Navigation towards an archived
resource via its original resource, by leveraging
content negotiation.
• Component 2: A discovery API for archives that
allows requesting a list of all archived versions it
holds for a resource with a given URI.
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29
Updated Technical Details (03/2010)
30. How does Memento achieve this?
• Component 1: Navigation towards an archived
resource via its original resource, by leveraging
content negotiation.
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30
Updated Technical Details (03/2010)
31. The Web without a Time Dimension
Memento: Time Travel for the Web
31
Updated Technical Details (03/2010)
32. The Web without a Time Dimension
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32
Updated Technical Details (03/2010)
33. The Web without a Time Dimension
Need to use a different URI to access archived versions of a resource and its current version
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33
Updated Technical Details (03/2010)
34. The Web with Time Dimension added by Memento
In Memento: use URI of the current version to access archived versions, but qualify it with datetime
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34
Updated Technical Details (03/2010)
35. The Web with Time Dimension added by Memento
… and magically arrive at an archived version
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35
Updated Technical Details (03/2010)
36. How does Memento achieve this?
In order to fully understand how Memento introduces
a time dimension to the Web, we present a brief
recap of Transparent Content Negotiation (conneg)
in HTTP.
RFC 2295. Transparent Content Negotiation in HTTP,
http://www.ietf.org/rfc/rfc2295.txt
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Updated Technical Details (03/2010)
37. HTTP GET on URI A
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37
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38. GET with conneg on URI T – Server Choice – 302 Found – Step 1
transparently
negotiable
resource
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Updated Technical Details (03/2010)
39. GET with conneg on URI T – Server Choice – 302 Found – Step 2
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39
Updated Technical Details (03/2010)
40. GET with conneg on URI T – Server List – 406 Not Acceptable
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40
Updated Technical Details (03/2010)
41. How does Memento do This?
• Component 1: Navigation towards an archived
resource via its original resource, by leveraging
content negotiation.
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41
Updated Technical Details (03/2010)
42. Terminology Intermission
We introduce the term Memento to refer to an
archived version of a resource.
A Memento for a resource URI-R (as it existed)
at time ti is a resource URI-Mi [URI-R@ti] for
which the representation at any moment
past its creation time tc is the same as the
representation that was available from URI-
R at time ti, with tc >= ti. Implicit in this
definition is the notion that, once created, a
Memento always keeps the same
representation.
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Updated Technical Details (03/2010)
43. DT-conneg: Content Negotiation in the datetime dimension
• RFC 2295 introduces conneg in the following dimensions: media type,
language, compression, character set, e.g.:
- HTTP Request:
o Accept-Language: en-US
o HTTP Response:
o Content-Language: en-US
• Inspired by RFC 2295, Memento introduces datetime conneg:
- HTTP Request:
o Accept-Datetime: Mon, 12 Oct 2009 14:20:33
GMT
o HTTP Response:
o Content-Datetime: Sun, 11 Oct 2009 11:18:05
GMT
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44. DT-conneg: Content Negotiation in the datetime dimension
• This means that somewhere, we will need transparently negotiable
resources (cf. slides 38-40) that supports the datetime dimension to
get to appropriate Mementos.
• This will be discussed for 2 classes of servers:
o Web servers without internal archival capabilities;
o Web servers with internal archival capabilities.
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Updated Technical Details (03/2010)
45. Servers Without Internal Archival Capabilities
• This type includes:
o Servers that are crawled by a web archive, such as the
Internet Archive
o Servers with an associated transactional archive
• These servers are not aware of the details of Mementos of their
resources held by external archives.
• These servers do not have the essential information (URI-Ms,
and associated datetimes) to respond to a DT-conneg request.
• But they can be constructive by pointing (HTTP Link) a client to
an archive that can respond to the DT-conneg request.
o Unconditionally do this for resources for which Mementos are
conceivably available in the archive.
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Updated Technical Details (03/2010)
46. Oct 04 2009, 12:00:01 UTC
current
Oct 10 2009, 12:00:03 UTC
http://lanlsource.lanl.gov/
hello
Oct 21 2009, 12:00:01 UTC
http://mementoarchive.lanl.gov/store/ta/
20091021120001/http://lanlsource.lanl.gov/hello
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46
Updated Technical Details (03/2010)
47. original
resource Mementos
original server archival server
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47
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48. DT-conneg with URI-G to get URI-M
original
resource Mementos
transparently variant
negotiable resources
resource
original server archival server
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Updated Technical Details (03/2010)
49. HTTP
DT-conneg with URI-G to get URI-M
Link
original
resource Mementos
transparently variant
negotiable resources
resource
original server archival server
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Updated Technical Details (03/2010)
50. Terminology Intermission
We introduce the term TimeGate to refer to a
transparently negotiable resource that supports the
datetime dimension.
A TimeGate for an original resource URI-R is a
transparently negotiable resource URI-
G[URI-R] for which all variant resources are
Mementos URI-Mi[URI-R@ti] of the resource
URI-R. Since multiple archives may host
versions of URI-R, multiple TimeGates may
exist for any given resource, i.e. one per
archive.
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51. HTTP
Link DT-conneg with URI-G to get URI-M
original
resource TimeGate Mementos
transparently variant
negotiable resources
resource
original server archival server
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Updated Technical Details (03/2010)
52. How to redirect from Original Resource to its (external) TimeGate
• Q1: Which archive to HTTP Link to?
o The archive with the best coverage for the server at hand.
o Always redirect to an Aggregator (see slides 110-139)
o No redirection by server: client takes control, accessing its
preferred TimeGate, bypassing Original Resource.
• Q2: What is the TimeGate URI-G for URI-R on the chosen
archive?
o Convention for syntax of URI-G as function of URI-R.
- http://web.archive.org/web/timegate/http://cnn.com
o Always redirect to an Aggregator (see slides 110-139)
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Updated Technical Details (03/2010)
53. Servers With Internal Archival Capabilities
• This type includes:
o Content Management Systems
o Version Control Systems
o Servers that archive resource representations in the cloud
and keep track of the URIs and datetimes of remotely
archived resources.
• These servers have all the essential information (URI-Ms, and
associated datetimes) to respond to a DT-conneg request.
• The previous architectural solution is maintained to enforce strict
distinction between handling requests for current and past
representations.
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Updated Technical Details (03/2010)
54. Dec 20 2001, 4:51:00 UTC
Dec 31 2004, 20:46:00 UTC
current
http://en.wikipedia.org/wiki/
September_11_attacks
Dec 20 2008, 22:21:00 UTC
http://en.wikipedia.org/w/index.php?
title=September_11_attacks&oldid=259237305
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54
Updated Technical Details (03/2010)
55. original
Mementos
resource
original server
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Updated Technical Details (03/2010)
56. HTTP
Link DT-conneg with URI-G to get URI-M
original TimeGate Mementos
resource
transparently
negotiable
resource
variant
resources
original server
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Updated Technical Details (03/2010)
57. How to redirect from Original Resource to its (internal) TimeGate
• Q1: Which archive to HTTP Link to?
o No problem as the archive and the original server coincide:
Original Resources, TimeGates, Mementos are on same server.
• Q2: What is the TimeGate URI-G for URI-R on the chosen archive?
o Can be internal convention for syntax of URI-G as function of
URI-R.
- For example, MediaWiki:
http://a.wiki.org/wiki/Special:TimeGate/http://a.wiki.org/wiki/the_title
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57
Updated Technical Details (03/2010)
58. HTTP Headers in Memento
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59. The HTTP Headers used in Memento …
• Define two new headers:
– request: Accept-Datetime:
– response: Content-Datetime:
• Introduce new content for two existing headers:
– response: Vary: ; Link:
• Use one existing headers without modification:
– response: Location:, TCN:
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60. HTTP Request Headers for DT-conneg
• Accept-Datetime:
o Issued against TimeGate, (Original Resource), (Memento)
o Header content: desired datetime of Memento
Accept-Datetime: Mon, 12 Oct 2009 14:20:33 GMT
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61. HTTP Response Headers for DT-conneg
• Content-Datetime:
o Returned by Mementos
- Even when not as a result of DT-conneg.
o Symmetrical with regular conneg e.g. Content-Type, Content-
Language, …
o Header content: archival datetime of the Memento that is being
returned.
• Note: This header is crucial to allow a client to understand it has
arrived at a Memento.
Content-Datetime: Mon, 12 Oct 2009 14:20:33 GMT
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62. HTTP Response Headers for DT-conneg
• TCN:
o Returned by TimeGate
o Same use as in regular conneg
o Header content:
- Choice:
– 302 response
– Chosen Memento in Location header
– Alternative Mementos listed in Link header
- List:
– 406, 300 response
– Possible Mementos listed in Link header (and
optionally in body as HTML)
TCN: choice
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63. HTTP Response Headers for DT-conneg
• Vary:
o Returned by TimeGate
o Similar to regular conneg
o Header content:
- negotiate, accept-datetime
• Note: accept-datetime content in Vary header is crucial to
allow a client to understand it has arrived at a TimeGate.
Vary: negotiate, accept-datetime
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64. HTTP Response Headers for DT-conneg
• Location:
o Returned by TimeGate
o Similar to regular conneg
o Header content: Location of Memento
Location: http://web.archive.org/web/20010911223004/
http://cnn.com
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65. HTTP Response Headers for DT-conneg
• Link:
o Returned by Original Resource, TimeGate and Mementos
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66. HTTP Response Headers for DT-conneg
• Link header content for Original Resource:
o Recommended: URI-G of TimeGate
- rel="timegate"
Link: <http://web.archive.org/web/timegate/http://
cnn.com/>; rel="timegate"
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67. HTTP Response Headers for DT-conneg
• Link header content for TimeGate, Mementos:
o Required: URI-R of Original Resource
- rel="original" . Note: even when not as part of DT-conneg.
o Required: URI-M of first and last available Mementos;
- rel="first-memento"; datetime="…"
- rel="last-memento"; datetime="…"
o Recommended: URI-M of time-adjacent Mementos;
- rel="prev-memento"; datetime="…"
- rel="next-memento"; datetime="…"
o Recommended: URI-B of TimeBundle
- rel="timebundle"
o Optional: URI-M of other Mementos
- rel="memento"; datetime="…"
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68. HTTP Response Headers for DT-conneg
• Link header content for TimeGate, Mementos:
Link: <http://cnn.com/>; rel="original",
<http://web.archive.org/web/timebundle/http://cnn.com/>;
rel="timebundle",
<http://web.archive.org/web/20000915112826/http://
www.cnn.com>; rel="first-memento"; datetime="Tue, 15 Sep 2000
11:28:26 GMT",
<http://web.archive.org/web/20080708093433/http://
www.cnn.com>; rel="last-memento"; datetime="Tue, 08 Jul 2008
09:34:33 GMT",
<http://web.archive.org/web/20010911203610/http://
www.cnn.com>; rel="prev-memento"; datetime="Tue, 11 Sep 2001
20:30:51 GMT",
<http://web.archive.org/web/20010911203610/http://
www.cnn.com>; rel="next-memento"; datetime="Tue, 11 Sep 2001
20:47:33 GMT"
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69. Two Memento HTTP Navigations
Details at http://www.mementoweb.org/guide/http/
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70. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
71. Memento HTTP Flow: Notes (1)
GET G, Accept-Datetime
• Accept-Datetime header only essential when communication with
URI-G. Not necessary when communicating with URI-R, URI-M.
• GET G can be optimized to HEAD G
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72. Memento HTTP Flow: Notes (2)
LinkG
• Link header pointing at URI-G only essential when server of URI-R has
its special-purpose of preferred archive(s) for its own resources.
• If Link is missing, HTTP client can resort to its preferred TimeGates.
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73. Memento HTTP Flow: Notes (3)
Three aspects of the Memento HTTP flow ensure maximal leverage of
established Web caching infrastructure:
• URI-R separate from URI-G: Coinciding URI-R and URI-G would cause
problems because caching regimes for regular resources and negotiable
resources are different.
• Link header pointing from URI-R to URI-G (as opposed to HTTP 302
used in prior Memento design) allows for caching of responses from URI-R
(many thanks to Erik Hetzner of California Digital Library).
• URI-G separate from URI-M: Allows for caching of Mementos.
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74. Two Memento HTTP Navigations
Scenario 1
• cnn.com includes Link to TimeGate at Internet Archive
• URI-R on one server, URI-G & URI-M on another
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75. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
76. Memento HTTP Flow: URI-R
HEAD R, Accept-Datetime
HEAD http://cnn.com/ HTTP/1.1
Host: cnn.com
Accept-Datetime: Tue, 11 Sep 2001 20:35:00 GMT
Connection: close
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77. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
78. Memento HTTP Flow: Success – URI-R
LinkG
HTTP/1.1 200 OK
Date: Thu, 21 Jan 2010 00:02:12 GMT
Server: Apache
Link: <http://web.archive.org/web/timegate/http://cnn.com>; rel="timegate"
Content-Length: 255
Connection: close
Content-Type: text/html; charset=iso-8859-1
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79. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
80. Memento HTTP Flow: URI-G
GET G, Accept-Datetime
GET http://web.archive.org/web/timegate/http://cnn.com HTTP/1.1
Host: web.archive.org
Accept-Datetime: Tue, 11 Sep 2001 20:35:00 GMT
Connection: close
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81. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
83. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
84. Memento HTTP Flow: URI-M
GET M, Accept-Datetime
GET http://web.archive.org/web/20010911203610/http://www.cnn.com HTTP/1.1
Host: web.archive.org
Accept-Datetime: Tue, 11 Sep 2001 20:35:00 GMT
Connection: close
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85. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
87. Two Memento HTTP Navigations
Scenario 2
• wikipedia.org natively supports Memento
• URI-R, URI-G & URI-M on one server
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88. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
89. Memento HTTP Flow: URI-R
HEAD R, Accept-Datetime
HEAD /wiki/DJ_Shadow HTTP/1.1
Host: en.wikipedia.org
Accept-Datetime: Thu, 05 Nov 2009 00:00:00 GMT
Connection: close
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90. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
91. Memento HTTP Flow: Success – URI-R
LinkG
HTTP/1.1 200 OK
Date: Thu, 21 Jan 2010 00:02:12 GMT
Server: Apache
Link:
<http://en.wikipedia.org/Special:TimeGate/http://en.wikipedia.org/wiki/DJ_Shadow>;
rel="timegate"
Content-Length: 1462
Connection: close
Content-Type: text/plain; charset=UTF-8
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92. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
93. Memento HTTP Flow: URI-G
GET G, Accept-Datetime
GET /Special:TimeGate/http://en.wikipedia.org/wiki/DJ_Shadow HTTP/1.1
Host: en.wikipedia.org
Accept-Datetime: Thu, 05 Nov 2009 00:00:00 GMT
Connection: close
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94. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
96. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
97. Memento HTTP Flow: URI-M
GET M, Accept-Datetime
GET /w/index.php?title=DJ_Shadow&oldid=324178040 HTTP/1.1
Host: en.wikipedia.org
Accept-Datetime: Thu, 05 Nov 2009 00:00:00 GMT
Connection: close
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98. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
100. Memento HTTP Navigations involving codes other than 200, 302
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101. 300 Multiple Choices
• Two scenarios that generate a 300 at the TimeGate:
– A client requests a 300 using the "Negotiate: 1.0" request header
– An archive has two or more Mementos with the same Datetime (HTTP
only supports second-level granularity)
HTTP/1.1 300 Multiple Choices
Server: Apache
Content-Length: 705
Content-Type: text/html; charset=utf-8
Date: Thu, 21 Jan 2010 00:09:40 GMT
TCN: list
Vary: negotiate, accept-datetime
Link: <http://en.wikipedia.org/Special:TimeBundle/http://en.wikipedia.org/wiki/
DJ_Shadow>; rel="timebundle",
<http://en.wikipedia.org/wiki/DJ_Shadow>; rel="original",
<http://en.wikipedia.org/w/index.php?title=DJ_Shadow&oldid=1493688>;
rel="first-memento"; datetime="Sun, 28 Sep 2003 01:42:00 GMT",
<http://en.wikipedia.org/w/index.php?title=DJ_Shadow&oldid=337446696>;
rel="last-memento"; datetime="Tue, 12 Jan 2010 19:55:00 GMT",
<http://en.wikipedia.org/w/index.php?title=DJ_Shadow&oldid=322586071>;
rel=”memento"; datetime="Sun, 31 May 2009 15:43:00 GMT",
<http://en.wikipedia.org/w/index.php?title=DJ_Shadow&oldid=326164283> ;
rel=”memento"; datetime="Sun, 31 May 2009 15:43:00 GMT"
Connection: close 101
102. 406 Not Acceptable
• A client request for a Memento with a datetime outside the first and
last values will generate a 406
• For example a request in Wikipedia with:
Accept-DateTime: Mon, 31 May 1999 00:00:00 GMT
HTTP/1.1 406 Not Acceptable
Server: Apache
Content-Length: 709
Content-Type: text/html; charset=utf-8
Date: Thu, 21 Jan 2010 00:09:40 GMT
Vary: negotiate, accept-datetime
TCN: list
Link: <http://en.wikipedia.org/Special:TimeBundle/http://en.wikipedia.org/wiki/
DJ_Shadow>; rel="timebundle",
<http://en.wikipedia.org/wiki/DJ_Shadow>; rel="original",
<http://en.wikipedia.org/w/index.php?title=DJ_Shadow&oldid=1493688>;
rel="first-memento"; datetime="Sun, 28 Sep 2003 01:42:00 GMT",
<http://en.wikipedia.org/w/index.php?title=DJ_Shadow&oldid=337446696>;
rel="last-memento"; datetime="Tue, 12 Jan 2010 19:55:00 GMT",
Connection: close 102
103. The Web with Time Dimension added by Memento
Memento: Time Travel for the Web
103
Updated Technical Details (03/2010)
104. How does Memento do This?
There are two components to the Memento Solution:
• Component 1: Navigation towards an archived
resource via its original resource, by leveraging
Done
content negotiation.
• Component 2: A discovery API for archives that
allows requesting a list of all archived versions it
holds for a resource with a given URI.
Memento: Time Travel for the Web
104
Updated Technical Details (03/2010)
105. How does Memento do This?
• Component 2: A discovery API for archives that
allows requesting a list of all archived versions it
holds for a resource with a given URI.
Memento: Time Travel for the Web
105
Updated Technical Details (03/2010)
106. Why an API?
• Mementos for any given
URI-R are distributed
across archives.
• In order to get a correct
perspective of available
Mementos, different
archives need to be
consulted.
• Can do so in distributed
consultation mode
(slooow), or by
consulting an
aggregator.
107. Terminology Intermission
We introduce the term TimeBundle to refer to a
resource via which an overview of all Mementos for
an original resource URI-R is available.
A TimeBundle for a resource URI-R, is a
resource URI-B[URI-R] that is an
aggregation of:
(a) All Mementos URI-Mi [URI-R@ti] available
from an archive,
(b) The archive's TimeGate URI-G for URI-R,
(c) The original resource URI-R itself.
Memento: Time Travel for the Web
107
Updated Technical Details (03/2010)
108. URI-
M1
URI-
URI-R M2
URI-
M3
Original
Memento
resource
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108
Updated Technical Details (03/2010)
109. HTTP LINK HEADER
timegate
URI-
M1
DT-conneg URI-
URI-R URI-G M2
URI-
M3
Original
TimeGate Memento
resource
Memento DT-conneg component
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109
Updated Technical Details (03/2010)
110. See OAI-ORE: http://www.openarchives.org/ore/1.0/toc/
ore:aggregates
URI-
M1
ore:aggregates
URI-
URI-R URI-G M2 URI-B
ore:aggregates
URI-
ore:aggregates M3
ore:aggregates
Original
TimeGate Memento TimeBundle
resource
Memento DT-conneg component
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110
Updated Technical Details (03/2010)
111. HTTP LINK HEADER
timebundle
ore:aggregates
TimeMap
URI-
M1
ore:aggregates
HTTP
URI- 303
URI-R URI-G M2 URI-B URI-T
ore:aggregates
URI-
ore:aggregates M3
ore:aggregates
Original
TimeGate Memento TimeBundle TimeMap
resource
Memento DT-conneg component Memento discovery component
Memento: Time Travel for the Web
111
Updated Technical Details (03/2010)
112. The Aggregator: A Service using the TimeBundle API
Memento: Time Travel for the Web
112
Updated Technical Details (03/2010)
113. TimeBundle API: For Discovery, Cross-Archive Services
• Archive uses common approaches to make TimeBundles/
TimeMaps discoverable:
o SiteMaps,
o Atom Feeds,
o OAI-PMH.
• Aggregator harvests and merges TimeMaps. Based on this
information, the Aggregator exposes its own TimeGates.
o Cross-archive
o Finer datetime granularity
o Better chances of matching a client’s datetime preference.
o Can become a shared target for redirection for many web
servers.
Memento: Time Travel for the Web
113
Updated Technical Details (03/2010)
114. Aggregatorusing TimeBundle API
Aggregator Conceptualization
Accept-Datetime
Original TimeMap
HTTP LINK
rel="timegate" server
TimeMap
Aggregator
datetime
browser content TimeMap
negotiation
HTTP LINK rel="original"
HTTP Link rel="timegate"
Content-Datetime
Memento TimeMap
server servers
Memento: Time Travel for the Web
114
Updated Technical Details (03/2010)
115. Two Memento HTTP Navigations involving an Aggregator
Memento: Time Travel for the Web
115
Updated Technical Details (03/2010)
116. A Memento HTTP Navigation involving an Aggregator
Scenario 3
• www.digitalpreservation.gov points at TimeGate provided by
an Aggregator
• URI-R, URI-G, URI-M on different servers
Memento: Time Travel for the Web
116
Updated Technical Details (03/2010)
117. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
118. Memento HTTP Flow: URI-R
HEAD R, Accept-Datetime
HEAD / HTTP/1.1
Host: www.digitalpreservation.gov
Accept-Datetime: Sat, 10 Oct 2009 00:00:00 GMT
Connection: close
Memento: Time Travel for the Web
118
Updated Technical Details (03/2010)
119. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
120. Memento HTTP Flow: Success – URI-R
LinkG
HTTP/1.1 200 OK
Date: Thu, 21 Jan 2010 00:02:12 GMT
Server: Apache
Link:
<http://mementoproxy.lanl.gov/aggr/timegate/http://www.digitalpreservation.gov/> ;
rel="timegate"
Content-Length: 255
Connection: close
Content-Type: text/html; charset=iso-8859-1
Memento: Time Travel for the Web
120
Updated Technical Details (03/2010)
121. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
122. Memento HTTP Flow: URI-G
GET G, Accept-Datetime
GET /aggr/timegate/http://www.digitalpreservation.gov/ HTTP/1.1
Host: mementoproxy.lanl.gov
Accept-Datetime: Sat, 10 Oct 2009 00:00:00 GMT
Connection: close
Memento: Time Travel for the Web
122
Updated Technical Details (03/2010)
123. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
125. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
126. Memento HTTP Flow: URI-M
GET M, Accept-Datetime
GET /1610/20090928171405/http://www.digitalpreservation.gov/ HTTP/1.1
Host: wayback.archive-it.org
Accept-Datetime: Sat, 10 Oct 2009 00:00:00 GMT
Connection: close
Memento: Time Travel for the Web
126
Updated Technical Details (03/2010)
127. Memento HTTP Flow
HEAD R, Accept-Datetime
LinkG
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
128. Memento HTTP Flow: Success – URI-M
200, Content-Datetime, LinkR,B,M
HTTP/1.1 200 OK
Server: Apache-Coyote/1.1 Link header values are local
X-Archive-Orig-Accept-Ranges: bytes
… to wayback.archive-it.org
Content-Type: text/html;charset=utf-8 and different than those
Content-Length: 23364 provided by URI-G
Date: Thu, 21 Jan 2010 00:09:40 GMT
Content-Datetime: Mon, 28 Sep 2009 17:14:05 GMT
Link: <http://www.digitalpreservation.gov/>; rel="original",
<http://wayback.archive-it.org/web/timebundle/http://www.digitalpreservation.gov/>;
rel="timebundle",
<http://wayback.archive
-it.org/256/20051108162921/http://www.digitalpreservation.gov/>;
rel="first-memento"; datetime="Tue, 08 Nov 2005 00:00:00 GMT",
<http://wayback.archive
-it.org/256/20100120102000/http://www.digitalpreservation.gov/>;
rel="last-memento"; datetime="Wed, 20 Jan 2010 10:20:00 GMT"
Connection: close
Memento: Time Travel for the Web
128
Updated Technical Details (03/2010)
129. A Memento HTTP Navigation involving an Aggregator
Scenario 4
• cnn.com does not include a Link to a TimeGate
• client takes control by directly contacting its preferred
Aggregator
• URI-R, URI-G, URI-M on different servers
Memento: Time Travel for the Web
129
Updated Technical Details (03/2010)
130. Memento HTTP Flow
HEAD R, Accept-Datetime
200
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
131. Memento HTTP Flow: URI-R
HEAD R, Accept-Datetime
HEAD http://cnn.com/ HTTP/1.1
Host: cnn.com
Accept-Datetime: Tue, 11 Sep 2001 20:35:00 GMT
Connection: close
Memento: Time Travel for the Web
131
Updated Technical Details (03/2010)
132. Memento HTTP Flow
HEAD R, Accept-Datetime
200
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
133. Memento HTTP Flow: No Success – URI-R
200
HTTP/1.1 200 OK
Date: Thu, 21 Jan 2010 00:02:12 GMT
Server: Apache
Content-Length: 255
Connection: close
Content-Type: text/html; charset=iso-8859-1
Memento: Time Travel for the Web
133
Updated Technical Details (03/2010)
134. Memento HTTP Flow
HEAD R, Accept-Datetime
200
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
135. Memento HTTP Flow: URI-G
GET G, Accept-Datetime
GET /aggr/timegate/http://cnn.com/ HTTP/1.1
Host: mementoproxy.lanl.gov
Accept-Datetime: Tue, 11 Sep 2001 20:35:00 GMT
Connection: close
Memento: Time Travel for the Web
135
Updated Technical Details (03/2010)
136. Memento HTTP Flow
HEAD R, Accept-Datetime
200
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
138. Memento HTTP Flow
HEAD R, Accept-Datetime
200
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
139. Memento HTTP Flow: URI-M
GET M, Accept-Datetime
GET http://web.archive.org/web/20010911203610/http://www.cnn.com HTTP/1.1
Host: web.archive.org
Accept-Datetime: Tue, 11 Sep 2001 20:35:00 GMT
Connection: close
Memento: Time Travel for the Web
139
Updated Technical Details (03/2010)
140. Memento HTTP Flow
HEAD R, Accept-Datetime
200
GET G, Accept-Datetime
302M, Vary, TCN, LinkR,B,M
GET M, Accept-Datetime
200, Content-Datetime, LinkR,B,M
141. Memento HTTP Flow: Success – URI-M
200, Content-Datetime, LinkR,B,M
HTTP/1.1 200 OK
Server: Apache-Coyote/1.1 note: Link header values are
X-Archive-Orig-Accept-Ranges: bytes
… local to web.archive.org
Content-Type: text/html;charset=utf-8 and different than those
Content-Length: 23364 provided by URI-G
Date: Thu, 21 Jan 2010 00:09:40 GMT
Content-Datetime: Tue, 11 Sep 2001 20:36:10 GMT
Link: <http://cnn.com/>; rel="original",
<http://web.archive.org/web/timebundle/http://cnn.com/>; rel="timebundle",
<http://web.archive.org/web/20000915112826/http://www.cnn.com>;
rel="first-memento"; datetime="Tue, 15 Sep 2000 11:28:26 GMT",
<http://web.archive.org/web/20080708093433/http://www.cnn.com>;
rel="last-memento"; datetime="Tue, 08 Jul 2008 09:34:33 GMT",
<http://web.archive.org/web/20010911203610/http://www.cnn.com>;
rel="prev-memento"; datetime="Tue, 11 Sep 2001 20:30:51 GMT",
<http://web.archive.org/web/20010911203610/http://www.cnn.com>;
rel="next-memento"; datetime="Tue, 11 Sep 2001 20:47:33 GMT"
Connection: close
141
142. The Memento Profile of OAI-ORE
Memento: Time Travel for the Web
142
Updated Technical Details (03/2010)
143. Memento Profile of OAI-ORE
URI-G TimeGate ORE Aggregated Resource
ore:aggregates
URI-R
Original ORE Aggregated Resource
ore:aggregates resource
ore:describes
ore:aggregates
URI-
URI-T URI-B M1 Memento ORE Aggregated Resource
ore:aggregates
URI-
TimeMap TimeBundle M2 Memento ORE Aggregated Resource
ORE Resource Map ORE Aggregation
Memento: Time Travel for the Web
143
Updated Technical Details (03/2010)
144. Information in the TimeMap about the TimeGate
• Coverage Period the TimeGate has Mementos for
Predicate: mem:covers
Object: mem:TimeSpan
• Which Original Resource it is a TimeGate for
Predicate: mem:timeGateFor
Object: mem:OriginalResource
• TimeSpan Class:
• mem:start datestamp
• mem:end datestamp
Memento: Time Travel for the Web
144
Updated Technical Details (03/2010)
145. Information in the TimeMap about the TimeGate
mem:covers
URI-G
mem:start
mem:timeGateFor datetime
ore:aggregates
URI-R
ore:aggregates
ore:describes datetime
mem:end
URI-
URI-T URI-B M1
ore:aggregates
Memento: Time Travel for the Web
145
Updated Technical Details (03/2010)
146. Information in the TimeMap about Mementos
• The representation's mime-type:
dc:format
• The representation's byte size:
dc:extent
• Over what period was the representation observed as the current
representation of the Original Resource::
Predicate: mem:observedOver
Object: mem:TimeSpan
• Or over what period was the representation known to be active as the
current representation of the Original Resource:
Predicate: mem:validOver
Object: mem:TimeSpan
• The number of observations of the representation in the given time period:
mem:observations integer
• Any further information that is available about Mementos
Memento: Time Travel for the Web
146
Updated Technical Details (03/2010)
147. Information in the TimeMap about Mementos
integer
URI-G mem:observations
mem:start datetime
ore:aggregates
URI-R
ore:aggregates
mem:
ore:describes datetime
mementoFor mem:end
URI-
URI-T URI-B M1
mem:
ore:aggregates observedOver
integer
dc:extent
dc:format
string
Memento: Time Travel for the Web
147
Updated Technical Details (03/2010)
148. Memento Ontology: Classes
• TimeMap SubClassOf ore:ResourceMap
• TimeBundle SubClassOf ore:Aggregation
• OriginalResource SubClassOf gen:TimeGenericResource
• TimeGate SubClassOf irw:WebResource
• Memento SubClassOf gen:TimeSpecificResource
• TimeSpan Typed Blank Node
Memento: Time Travel for the Web
148
Updated Technical Details (03/2010)
153. How does Memento do This?
There are two components to the Memento Solution:
• Component 1: Navigation towards an archived
resource via its original resource, by leveraging
Done
content negotiation.
• Component 2: A discovery API for archives that
allows requesting a list of all archived versions it
Done
holds for a resource with a given URI.
Memento: Time Travel for the Web
153
Updated Technical Details (03/2010)
154. Memento in a non-Memento Web …
Memento: Time Travel for the Web
154
Updated Technical Details (03/2010)
155. Memento and Client Development
• Browser plug-in must use different HTTP request/response cycle
when in time travel mode.
• Browser plug-in needs to be more or less aware of its state in the
chain Original Resource => TimeGate => Memento
• Interesting user interface challenges, among others related to
time-distribution of Mementos embedded in encompassing
Memento, e.g. images in HTML page.
Memento: Time Travel for the Web
155
Updated Technical Details (03/2010)
156. Memento and Web Archives
• Web Archives rewrite URLs in archived pages, in order to avoid:
o Serving current representations of embedded resources;
o Linking to current representations of resources
• The upside: Archived pages are self-contained.
• The downside:
o Cannot navigate beyond the archive’s content;
o Other servers (archives or original) may have appropriate
version of (missing) embedded or linked resource.
• Memento does not require URL-rewriting.
Memento: Time Travel for the Web
156
Updated Technical Details (03/2010)
157. BBC home page from Internet Archive; URL rewriting
Memento: Time Travel for the Web
157
Updated Technical Details (03/2010)
158. Embedded & linked resources still available at BBC site
Memento: Time Travel for the Web
158
Updated Technical Details (03/2010)
159. BBC home page from Internet Archive; no URL-rewriting
Memento: Time Travel for the Web
159
Updated Technical Details (03/2010)
160. Standardization
• Link relationships original, timegate, timebundle,
memento, first-memento, last-memento, prev-memento,
next-memento will be registered as per upcoming HTTP Link
header RFC.
• Headers Accept-Datetime, Content-Datetime will be registered
in the provisional registry for Message Header Fields as per RFC
3864.
• A process will be initiated aimed at publishing an RFC specifying the
Memento solution.
• TimeGate URI syntax convention for Web archives will be discussed
in the context of International Internet Preservation Consortium.
Memento: Time Travel for the Web
160
Updated Technical Details (03/2010)
161. Towards Acceptance …
Memento: Time Travel for the Web
161
Updated Technical Details (03/2010)
163. Towards Acceptance: Discussing
http://efoundations.typepad.com/
efoundations/2009/11/memento-and-
negotiating-on-time.html
Is the Memento proposal OK from the
perspective of the Architecture of the World
Wide Web, and REST?
Resulted in some adjustments to the
proposed framework.
Memento: Time Travel for the Web
163
Updated Technical Details (03/2010)
164. Towards Acceptance: Discussing
http://www.mementoweb.org/events/
IA201002/
Two day discussion with Internet Archive,
California Digital Library, LoCKSS, Library
of Congress about Memento.
Resulted in some adjustments to the
proposed framework.
Resulted in commitment by all represented
archives to deploy experimental Memento
support.
Memento: Time Travel for the Web
164
Updated Technical Details (03/2010)
165. Towards Acceptance: Discussing
http://groups.google.com/group/memento-
dev
Discussion list regarding Memento
Resulted in some adjustments to the
proposed framework.
Memento: Time Travel for the Web
165
Updated Technical Details (03/2010)
166. Towards Acceptance: Thinking
http://www.open.ac.uk/blogs/telstar/
2009/11/24/the-when-of-the-web/
Use Memento to go from formal citation
of Web page (URL, datetime) to
appropriate archival version of the Web
page.
Memento: Time Travel for the Web
166
Updated Technical Details (03/2010)
167. Towards Acceptance: Developing
• Apache plug-in rule that adds Link header to TimeGate on HTTP
HEAD/GET requests to Original Resources.
• http://mementoweb.org/tools/apache
• Memento plug-in for the MediaWiki platform.
o http://www.mediawiki.org/wiki/Extension:Memento
o Working towards community acceptance.
o Started similar process for Drupal.
Memento: Time Travel for the Web
167
Updated Technical Details (03/2010)
168. Towards Acceptance: Developing
• Created demonstration client:
o FireFox plug-in: http://www.mementoweb.org/tools/ (many
thanks to Sam Adams, Cambridge University)
o Currently working on plug-in for Internet Explorer
Memento: Time Travel for the Web
168
Updated Technical Details (03/2010)
169. Towards Acceptance: Ongoing
• JISC funded developer contest for the creation of Memento-
based prototype demonstrators: http://wiki.2010.dev8d.org/w/
Talk_5
• The Memento Team will engage in a funded, collaborative
agreement with the Library of Congress for:
o Standardization (I-D => RFC).
o Outreach.
o Research.
o Software development.
Memento: Time Travel for the Web
169
Updated Technical Details (03/2010)
170. Some Interesting Consequences of Memento …
Memento: Time Travel for the Web
170
Updated Technical Details (03/2010)
171. Memento and Resource Persistence (1)
• URI-R vanishes, but the server that used to serve it is still
operational:
o The server should still include a HTTP Link header with
rel="timegate" pointing at a TimeGate for URI-R,
irrespective of whether the client issues a DT-conneg request
or not. This allows seamless access to a Memento of URI-R,
even if the server no longer hosts the original.
o If the server does not include a HTTP Link header pointing
at a TimeGate for URI-R, the client resorts to interaction with
archives (or with an Aggregator) and arrives at the most
recent Memento of the resource.
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171
Updated Technical Details (03/2010)
172. Memento and Resource Persistence (2)
• A domain vanishes:
o The client is looking for a current representation of URI-R that
was hosted by the domain, but fails.
o The client resorts to interaction with archives (or with an
Aggregator) and arrives at the most recent Memento of the
resource.
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172
Updated Technical Details (03/2010)
173. Memento and Resource Persistence (3)
• A domain is taken over by a new custodian:
o The new custodian adheres to other policies regarding which
archive to redirect a DT-conneg request.
o The client understands from the first-memento/last-
memento HTTP Link header of that archive of choice, that
it does not cover the time range in which the previous
custodian operated the domain.
o The client resorts to interaction with other archives (or with an
Aggregator) and arrives at an appropriate Memento.
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173
Updated Technical Details (03/2010)
174. Memento and Resource Versioning (1)
Resource state may evolve over time. Requiring a
URI owner to publish a new URI for each change in
resource state would lead to a significant number
of broken references. For robustness, Web
architecture promotes independence between an
identifier and the state of the identified resource.
From: The Architecture of the World Wide Web, http://
www.w3.org/TR/webarch/
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174
Updated Technical Details (03/2010)
175. Memento and Resource Versioning (2)
But there are many use cases that require resource
versioning, including community-based content
creation, scientific communication, open
government, etc.
How does resource versioning work currently? How
can it work in a Memento Web?
Paper at http://arxiv.org/abs/1003.3661
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175
Updated Technical Details (03/2010)
176. Current Resource Versioning (3)
• Version Identification: HTTP
URIs
• Versioning Strategy: new
URI for new version
• Version Relationships: RDF
or HTTP Links
• Version Datetime: RDF
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176
Updated Technical Details (03/2010)
177. Memento and Resource Versioning (4)
• Version Identification: HTTP
URIs
• Versioning Strategy: stable ,
cool URI for "current" version;
new URI for old version
• Version Relationships:
HTTP Links, HTTP datetime
conneg
• Version Datetime: HTTP
Content-Datetime response
header
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177
Updated Technical Details (03/2010)
178. Memento and Non-Information Resources (1)
Current
description
of URI-R
HTTP
Non-Information URI-R 303 URI-S
Information
resource resource
Paper at http://arxiv.org/abs/1003.3661
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178
Updated Technical Details (03/2010)
179. Memento and Non-Information Resources (2)
Current
description
of URI-R
HTTP
Non-Information URI-R 303 URI-S
Information
resource resource
HTTP LINK HEADER Past
timegate Description
of URI-R
DT-conneg
TimeGate URI-G URI-M Memento
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179
Updated Technical Details (03/2010)
180. Memento and Non-Information Resources (3)
• DBpedia subject URI e.g. http://dbpedia.org/resource/France
leads to current description of the subject.
• Archive of prior descriptions of DBpedia subject URIs
implemented at LANL:
o Archive exposes a TimeGate per DBpedia subject URI e.g.
http://mementoarchive.lanl.gov/dbpedia/timegate/http://
dbpedia.org/resource/France
o These TimeGates support DT-conneg.
• DBpedia provides HTTP Link header with rel="timegate"
pointing at these TimeGates.
• Result: Clients can access current and prior descriptions using
"follow your nose" HTTP navigation.
• Proof-of-Concept: "follow your nose" time-series analysis across
DBpedia versions.
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180
Updated Technical Details (03/2010)
181. Memento and Non-Information Resources (4)
Time-Series analysis across DBpedia versions
Memento: Time Travel for the Web
181
Updated Technical Details (03/2010)
182. Memento and Time-Persistent Web Annotations
Paper at http://arxiv.org/abs/1003.2643
Memento: Time Travel for the Web
182
Updated Technical Details (03/2010)
183. Memento wants to make navigating the Web’s Past Easy
http://www.mementoweb.org
http://groups.google.com/group/memento-dev
Memento: Time Travel for the Web
183
Updated Technical Details (03/2010)