Twitter – Data Science, Data Analytics and Machine Learning Consulting in Koblenz Germany https://www.rene-pickhardt.de Extract knowledge from your data and be ahead of your competition Tue, 17 Jul 2018 12:12:43 +0000 en-US hourly 1 https://wordpress.org/?v=4.9.6 PhD proposal on distributed graph data bases https://www.rene-pickhardt.de/phd-proposal-on-distributed-graph-data-bases/ https://www.rene-pickhardt.de/phd-proposal-on-distributed-graph-data-bases/#comments Tue, 27 Mar 2012 10:19:22 +0000 http://www.rene-pickhardt.de/?p=1214 Over the last week we had our off campus meeting with a lot of communication training (very good and fruitful) as well as a special treatment for some PhD students called “massage your diss”. I was one of the lucky students who were able to discuss our research ideas with a post doc and other PhD candidates for more than 6 hours. This lead to the structure, todos and time table of my PhD proposal. This has to be finalized over the next couple days but I already want to share the structure in order to make it more real. You might also want to follow my article on a wish list of distributed graph data base technology

[TODO] 0. Find a template for the PhD proposal

That is straight forward. The task is just to look at other students PhD proposals also at some major conferences and see what kind of structure they use. A very common structure for papers is Jennifer Widom’s structure for writing a good research paper. This or a similar template will help to make the proposal readable in a good way. For this blog article I will follow Jennifer Widom more or less.

1. Write an Introduction

Here I will describe the use case(s) of a distributed graph data base. These could be

  • indexing the web graph for a general purpose search engine like Google, Bing, Baidu, Yandex…
  • running the backend of a social network like Facebook, Google+, Twitter, LinkedIn,…
  • storing web log files and click streams of users
  • doing information retrieval (recommender systems) in the above scenarios

There could also be very other use cases like graphs from

  • biology
  • finance
  • regular graphs 
  • geographic maps like road and traffic networks

2. Discuss all the related work

This is done to name all the existing approaches and challenges that come with a distributed graph data base. It is also important to set onself apart from existing frameworks like graph processing. Here I will name the at least the related work in the following fields:

  • graph processing (Signal Collect, Pregel,…)
  • graph theory (especially data structures and algorithms)
  • (dynamic/adaptive) graph partitioning
  • distributed computing / systems (MPI, Bulk Synchronous Parallel Programming, Map Reduce, P2P, distributed hash tables, distributed file systems…)
  • redundancy vs fault tolerance
  • network programming (protocols, latency vs bandwidth)
  • data bases (ACID, multiple user access, …)
  • graph data base query languages (SPARQL, Gremlin, Cypher,…)
  • Social Network and graph analysis and modelling.

3. Formalize the problem of distributed graph data bases

After describing the related work and knowing the standard terminology it makes sense to really formalize the problem. Several steps have to be taken: There needs to be notation for distributed graph data bases fixed. This has to respect two things:
a) the real – so far unknown – problems that will be solved during PhD. In this way fixing the notation and formalizing the (unknown) problem will be kind of hard.
b) The use cases: For the web use case this will probably translate to scale free small world network graphs with a very small diameter. Probably in order to respect other use cases than the web it will make sense to cite different graph models e.g. mathematical models to generate graphs with certain properties from the related work.
The important step here is that fixing a use case will also fix a notation and help to formalize the problem. The crucial part is to choose the use case still so general that all special cases and boarder line cases are included. Especially the use case should be a real extension to graph processing which should of course be possible with a distributed graph data base. 
One very important part of the formalization will lead to a first research question:

4. Graph Query languages – Graph Algebra

I think graph data bases are not really general purpose data bases. They exist to solve a certain class of problems in a certain range. They seem to be especially useful where information of a local neighborhood of data points is frequently needed. They also often seem to be useful when schemaless data is processed. This leads to the question of a query language. Obviously (?) the more general the query language the harder to have a very efficient solution. The model of a relational algebra was a very successful concept in relational data bases. I guess a similar graph algebra is needed as a mathmatical concept for distributed graph data bases as a foundation of their query languages. 
Remark that this chapter has nothing much to do with distributed graph data bases but with graph data bases in general.
The graph algebra I have in mind so far is pretty similar to neo4j and consists of some atomic CRUD operations. Once the results are known (ether as an answer from the related work or by own research) I will be able to run my first experiments in a distributed environment. 

5. Analysis of Basic graph data structures vs distribution strategies vs Basic CRUD operations

As expected the graph algebra will consist of some atomic CRUD operations those operations have to be tested against all different data structures one can think of in the different known distributed environments over several different real world data sets. This task will be rather straight forward. It will be possible to know the theoretical results of most implementations. The reason for this experiment is to collect experimental experiences in a distributed setting and to understand what is really happening and where the difficulties in a distributed setting are. Already in the evaluation of graphity I realized that there is a huge gap between theoretical predictions and the real results. In this way I am convinced that this experiment is a good step forward and the deep understanding of actually implementing all this will hopefully lead to:

6. Development of hybrid data structures (creative input)

It would be the first time in my life where I am running such an experiment without any new ideas coming up to tweak and tune. So I am expecting to have learnt a lot from the first experiment in order to have some creative ideas how to combine several data structures and distribution techniques in order to make a better (especially bigger scaling) distributed graph data base technology.

7. Analysis of multiple user access and ACID

One important fact of a distributed graph data base that was not in the focus of my research so far is the part that actually makes it a data base and sets it apart from some graph processing frame work. Even after finding a good data structure and distributed model there are new limitations coming once multiple user access and ACID  are introduced. These topics are to some degree orthogonal to the CRUD operations examined in my first planned experiment. I am pretty sure that the experiments from above and more reading on ACID in distributed computing will lead to more reasearch questions and ideas how to test several standard ACID strategies for several data structures in several distributed environments. In this sense this chapter will be an extension to the 5. paragraph.

8. Again creative input for multiple user access and ACID

After heaving learnt what the best data structures for basic query operations in a distributed setting are and also what the best methods to achieve ACID are it is time for more creative input. This will have the goal to find a solution (data structure and distribution mechanism) that respects both the speed of basic query operations and the ease for ACID. Once this done everything is straight forward again.

9. Comprehensive benchmark of my solution with existing frameworks

My own solution has to be benchmarked against all the standard technologies for distributed graph data bases and graph processing frameworks.

10. Conclusion of my PhD proposal

So the goal of my PhD is to analyse different data structures and distribution techniques for a realization of distributed graph data base. This will be done with respect to a good runtime of some basic graph queries (CRUD) respecting a standardized graph query algebra as well as muli user access and the paradigms of ACID. 

11 Timetable and mile stones

This is a rough schedual fixing some of the major mile stones.

  • 2012 / 04: hand in PhD proposal
  • 2012 / 07: graph query algebra is fixed. Maybe a paper is submitted
  • 2012 / 10: experiments of basic CRUD operations done
  • 2013 / 02: paper with results from basic CRUD operations done
  • 2013 / 07: preliminary results on ACID and multi user experiments are done and submitted to a conference
  • 2013 /08: min 3 month research internship  in a company benchmarking my system on real data
  • end of 2013: publishing the results
  • 2014: 9 months of writing my dissertation

For anyone who has input, knows of papers or can point me to similar research I am more than happy if you could contact me or start the discussion!
Thank you very much for reading so far!

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Related-work.net – Product Requirement Document released! https://www.rene-pickhardt.de/related-work-net-product-requirement-document-released/ https://www.rene-pickhardt.de/related-work-net-product-requirement-document-released/#comments Mon, 12 Mar 2012 10:26:50 +0000 http://www.rene-pickhardt.de/?p=1176 Recently I visited my friend Heinrich Hartmann in Oxford. We talked about various issues how research is done in these days and how the web could theoretically help to spread information faster and more efficiently connect people interested in the same paper / topics.
The idea of http://www.related-work.net was born. A scientific platform which is open source and open data and tries to solve those problems.
But we did not want to reinvent the wheel. So we did some research on existing online solutions and also asked people from various disciplines to name their problems. Find below our product requirement document! If you like our approach you can contact us or contribute on the source code find some starting documentation!
So the plan is to fork an open source question answer system and enrich it with the features fulfilling the needs of scientists and some social aspects (hopefully using neo4j as a supporting data base technology) which will eventually help to rank related work of a paper.
Feel free to provide us with feedback and wishes and join our effort!

Beginning of our Product Requirement Document

We propose to create a new website for the scientific community which brings together people which are reading the same paper. The basic idea is to mix the functionality of a Q&A platform (like MathOverflow) with a paper database (like arXiv). We follow a strict openness principal by making available the source code and the data we collect.
We start with an analysis how the internet is currently used in different fields and explain the shortcomings. The actual product description can be found under the section “Basic idea”. At the end we present an overview over the websites which follow a similar approach.
This document – as well as the whole project – is work in progress. We are happy about any kind of comments or other contributions.

The distribution of scientific knowledge

Every scientist hast to stay up to date with the developments in his area of research. The basic sources for finding new information are:

  • Conferences
  • Research Seminars
  • Journals
  • Preprint-servers (arXiv)
  • Review Databases (MathSciNet, Zentralblatt, …)
  • Q&A Sites (MathOverflow, StackOverflow, …)
  • Blogs
  • Social Networks (Twitter, Google+)
  • Bibliograhpic Databases (Mendeley, nNode, Medline, etc. )

Every community has found its very own way of how to use this tools.

Mathematics by Heinrich Hartmann – Oxford:

To stay up to date with recent developments I check arxiv.org on a daily basis (RSS feed) participate in mathoverflow.net and search for papers over Google Scholar or MathSciNet. Occasionally interesting work is shared by people in my Google+ circles. In general the speed of pure mathematics is very slow. New research often builds upon work which has been out for a few years. To stay reasonably up to date it is enough to go to conferences every 3-5 months.
I read many papers on myself because I am the only one at the department who does research on that particular topic. We have a reading class where we read papers/lecture notes which are relevant for more people. Usually they are concerned with introductions to certain kinds of theory. We have weekly seminars where people talk about their recently published work. There are some very active blogs by famous mathematicians, but in my area blogs play virtually no role.

Computer Science by René Pickhardt – Uni Koblenz

In Computer Science topics are evolving but also changing very quickly. It is always important to have both an overview of upcoming technologies (which you get from tech blogs) as well as access to current research trends.
Since the speed in computer science is so fast and the review process in Journals often takes much time our main source of information and papers are conferences and twitter.

  • Usually conference papers are distributed digitally to participants. If one is interested in those papers google queries like “conference name year papers” are frequently used. Sites like http://www.sciweavers.org/ host and aggregate preprints of papers and organize them by conference.
  • The general method to follow a conference that one is not attending is to follow the hashtag of the conference on Twitter. In general Twitter is the most used tool to share distribute and find information not only for papers but also for the above mentioned news about upcoming technologies.

Another rich source for computer scientists is, of course, the related work of papers and google scholar. Especially useful is the method of finding a very influential paper with more than 1000 citations and find newer papers that quote this paper containing a certain keyword which is one of the features of google scholar.
The main problem in computer science is not to find a rare paper or idea but rather to filter the huge amount of publications and also bad publications and also keep track of trends. In this way a system that ranks and summarize papers (not only by abstract and citation counts) would help me a lot to select what related work of a paper I should read!

Psychology by Elisa Scheller – Uni Freiburg

As a psychologist/neuroscientist, I receive recommendations for scientific papers via google scholar alerts or science direct alerts (http://www.sciencedirect.com/); I receive alerts regarding keywords or regarding entire journal issues. When I search for a certain publication, I use pubmed.org or scholar.google.com. This can sometimes be kind of annoying, as I receive multiple alerts from different sources; but I guess it is the best way to stay up to date regarding recent developments. This is especially important in my field, as we feel a big amount of “publication pressure”; I work on a method which is considered as “quite fancy” at the moment, so I also use the alerts to make sure nobody has published “my” experiment yet.
Sometimes a facebook friend recommends a certain publication or a colleague points me to it. Most of the time, I read articles on my own, as I am the only person working on this specific topic at my institution. Additionally, we have a weekly journal club where everyone in turn presents work which is related to our focus of research, e.g. a certain part of the human brain. There is also a weekly seminar dedicated to presentations about ongoing projects.
Blogs (e.g. mindhacks.com, http://neuroskeptic.blogspot.com/) can be a source to get an overview about recent developments, but I have to admit I use them mainly for work-related entertainment.
All in all, it is easy to stay up to date using alerts from different platforms;  the annoying part of it is the flood of emails you receive and that you are quite often alerted to articles that don’t fit your interests (no matter how exact you try to specify your keywords).

Biomedical Research by Johanna Goldmann – MIT

In the biological sciences, in research at the bench – communication is one of the most fundamental tools a scientist can have. Communication with other scientist may open up the possibilities of new collaborations, can lead to a completely new view point of a known question, the integration and expansion of methods as well as allowing a scientist to have a good understanding of what is known, what is not known and what other people have – both successfully and unsuccessfully – tried to investigate.
Yet communication is something that is currently very much lacking in academic science – lacking to the extent that most scientist will agree hinders the progress of research. Nonetheless the lack of communication and the issues it brings with it is something that most scientists will have accepted as a necessary evil – not knowing how to possibly change it.
Progress is only reported in peer-reviewed journals – many which are greatly affected not only but what is currently “sexy” in research but also by politics and connections and the “publish or perish” pressure. Due to the amount of this pressure in publishing in journals and the amount of weight the list of your publications will have upon any young scientists chances of success, scientist tend also to be very reluctant in sharing any information pre-publication.
Furthermore one of the major issues is that currently there really is no way of publishing or communicating either negative results or minor findings, which causes may questions or methods to be repeatedly investigated as well as a loss of information.
Given how much social networks and the internet has changed communication as well as the access to information over the past years – there is a need for this change to affect research and communication in the life science and transform the way we think not only about solving and approaching research questions we gather but the information and insights we gain as a whole.

Philosophy by Sascha Benjamin Fink – Uni Osnabrück

The most important source of information for philosophers is http://philpapers.org/. You can follow trends going on in your field of interest. Philpapers has a list of almost all papers together with their abstracts, keywords and categories as well as a link to the publisher. Additional information about similar papers is displayed.
Every category of papers is managed by some editor. For each category it is possible to subscribe to a newsletter. In this way once per month I will be informed about current publications in journals related to my topic of interest. Every User is able to create an account and manage his literature and the papers of his he is interested in.
Other research and information exchange methods among philosophers consist of mailing lists, reading clubs and Blogs. Have a look at David Chalmers blog list. Blogs are also becoming more and more important. Unfortunately they are usually on general topics and discussing developments of the community (e.g. Leiter’s Blog, Chalmers’ Blog and Schwitzgebel’s Blog).
But all together I still think that for me a centralized service like Philpapers is my favourite tool because it aggregates most information. If I don’t hear about it on Philpapers usually it is not that important. I think among Philosophers this platform – though incomplete – seems to be the standard for the next couple of years.

Problems

As a scientist it is crucial to be informed about the current developments in the research area. Abstracting from the reports above we divide the tasks roughly into the following stages.

1. Finding and filtering new publications:

  • What is happening right now? What are the current hot topics my area? What are current trends? (→ Check arXiv/Twitter)
  • Did a friend of mine write something? Did a “big shot” write something?
    (→ Check meta information: title, authors)
  • Are my colleagues excited about a new development? (→ Talk to them.)

2. Getting more information about a given paper:

  • What is actually done in a given paper? Is it relevant for me? Is it really new? Is it a breakthrough? (→ Read abstracts. Find a good readable summary/review.)
  • Judge the quality of a paper: Is it correct? Is it well written?
    ( → Where is it published, if at all? Skim through content.)

Finally there is a fundamental decision: Shall I read the whole paper, or not? which leads us to the next task.

3. Understanding a paper: Understanding a paper in depth can be a very time consuming and tedious process. The presentation is often very short and much knowledge is assumed from the reader. The notation choices can be bad, so that even the statements are hard to understand. In effect the paper is easily readable only for a very small circle of specialist in the area. If one is not in the lucky situation to belong to that circle, one usually applies the following strategies:

  1. Lookup references. This forces you to process a whole tree of older papers which might be hard to read, and hard to get hold of. Sometimes it is worthwhile to consult a textbook to polish up fundamentals.
  2. Finding additional resources. Is there a review? Is there a related video lecture or slides explaining the material in more detail? Is the author going to a conference in the near future, or even giving a seminar in the area?
  3. Join forces. Find people thinking about the same paper: Has somebody at my department already read the paper, so that I can ask some questions? Is there enough interest to make a reading group, or more formally, run a seminar about that paper.
  4. Contact the author. This a last resort. If you have struggled with understanding the paper for a very long time and really need/want to get it, you might eventually write an email to the author – who might respond, or not. Sometimes even errors are found! – and not published! An indeed, there is no easy way to publish “errata” anywhere on the net.

In mathematics most papers are not getting read though the end. One uses strategies 1 & 2 till one gets stuck and moves on to something more exciting. The chances of survival are much better with strategy 3 where one is committed putting a lot of effort in it over weeks.

4. Finding related work. Where to go from there? Is the paper superseded by a more recent development? Which are the relevant papers which the author builds upon? What are the historic influences? What are the founding ideas of the subject? Finding related work is very time consuming. It is easy to overlook things given that the references are often vast, and sometimes hard to get hold of. Getting information over citations requires often access to commercial databases.

Basic idea:

All researchers around the world are faced with the same problems and come up with their individual solutions. There are great synergies in bringing these people together with an online platform! Most of the addressed problems are solved with a paper centric service which allows you to…

  • …get to know other readers of the paper.
  • …exchange with the other readers: ask questions, write comments, reviews.
  • …share the gained insights with the community.
  • …ask questions about the paper.
  • …discuss the paper.
  • …review the paper.

We want to do that with a new mixture of a traditional Q&A system like StackExchange or MathOverflow with a paper database and social features. The key features of this system are as follows:

Openness: We follow a strict openness principle. The software will be developed in open source. All data generated on this site will be under a creative commons license (like Wikipedia) and will be made available to the community in form of database dumps or an API (open data).

We use two different types of content sites in our system: Papers and Discussions.

Paper sites. A paper site is dedicated to a single publication. And has the following features:

  1. Paper meta information
    – show title, author, abstract, journal, tags
    – leave a comment
    – write a review (with wiki option)
    – vote up/down
  2. Paper resources
    – show pdfs, slides, notes, video lectures, etc.
    – add a resource
  3. Related Work
    – show the reference-tree and citations in an intelligent way.
  4. Discussions:
    – show related discussions
    – start a new discussion
  5. Social features
    – bookmark
    – share on G+, twitter

The point “Related Work” deserves some further explanation. The citation graph offers a great deal more information than just a list of references. Together with the user generated content like votes and the individual paper bookmarks and social graph one has a very interesting data set which can be harvested. We want this point at least view with respect to: Popularity/Topics/Read by Friends. Later on one could add more sophisticated, even graphical views on this graph.


Discussion sites.
A discussion looks more like a traditional QA-question, with the difference, that each discussion may have related (many) papers. A discussion site contains:

  1. Discussion meta information (title, author, body)
  2. Discussion content
  3. Related papers
  4. Voting
  5. Follow/Bookmark

Besides the content sides we want to provide the following features:

News Stream. This is the start page of our website. It will be generated from the network consisting of friends, papers and authors. There should be several modes like:

  • hot: heavily discussed papers/discussions
  • new papers: list new publications (filtered by tag, like arXiv feed)
  • social: What did your friends do lately
  • default: intelligent mix of recent activity that is relevant to the logged in user


Moreover, filter by tag should be always available.

Search bar:

  • Searches contents of the site, but should also find papers on freely available databases (e.g. arXiv). Adding a paper should be very seamless process from there.
  • Search result ranking uses vote and view information.
  • Personalized search information. (Physicists usually do not want sociology results.)
  • Auto completion on paper titles, author, discussions.

Social: (hard to implement, maybe for second version!)

  • Easily refer to users by @-syntax familiar from Twitter/Google+
  • Maintain a friendship / trust graph
  • Friendship recommendations
  • Find friends from Google+ on the site

Benefits

Our proposed websites improves the above mentioned problems in the following ways.
1. Finding and filtering new publications:This step can be improved with even very little  community effort:

  • Tell other people, that you are interested in the paper. Vote it up or leave a comment if you are very excited about it.
  • Point out a paper to a colleague.

2. Getting more information about a given paper:

  • Write a summary or review about a paper you have read or skimmed through. Maybe the introduction is hard to read or some results are not clearly stated.
  • Can you recommend reading this paper? Vote it up!
  • Ask a colleague for his opinion on the paper. Maybe he can write a summary?

Many reviews of new papers are already written. E.g. MathSciNet and Zentralblatt maintain a large database of Reviews which are provided by the community and are not freely available. Many authors would be much more happy to write them to an open system!
3. Understanding a paper:Here are the mayor synergies which we want to address with our project.

  • Ask a question: Why is the author using this experimental method? How does Lemma 3.4 work? Why do I need this assumption? What is the intiution behind the “virtual truncation”? What implications does this work have?
  • Start a discussion: (might involve more than one paper.) What is the difference of these two papers? Is there a reference explaining this more clearly? What should I read in advance to understand the theory?
  • Add resources. Tell the community about related videos, notes, books etc. which are available on other sites.
  • Share your notes. If you have discussed a paper in a reading class or seminar. Collect your notes or opinions and make them available for the community.
  • Restate interesting statements. Tell the community when you have found a helpful result which is buried inside the paper. In that way Google may find it!

4. Finding related work. Having a well structured and easily navigable view on related papers simplifies the search a lot. The filtering benefits from the content generated by the users (votes) and individual information, like friends who have written/bookmarked a paper.

Similar Sites on the Web

There are several discussions in QA forum which are discussing precisely this problem:

We found three sites on the internet which follow a similar approach which we examined more carefully.
1. There is a social network which has most of our features implemented:

researchgate.net
“Connect with researchers, make your work visible, and stay current.”

The Economist has dedicated an article to them. It is essentially a facebook clone, with special features for scientist.

  • Large, fast growing community. 1.4m +50.000/m. Mainly Biology and Medicine.
    (As Daniel Mietchen points out, the size might be misleading due to institutional accounts)
  • Very professional Look and Feel. Company from Berlin, Germany, funded by VC. (48 People involved, 10 Jobs advertised)
  • Huge Feature set:
    • Profile site, Connect to friends
    • News Feed
    • Publication Database, Conference Finder, Jobmarket
    • Every Paper its own page: with
      • Voting up/down
      • Comments
      • Metadata (Title, Author, Abstract, Preveiw)
      • Social Media (Share, Bookmark, Follow author)
    • Organize Workgroups/Reading Classes.

Differences to our approach:

  • Closed Data / Closed Source
  • Very complex site which solves a lot of purposes
  • Only very basic features on paper site: vote/comment.
  • QA system is not linked well to paper database
  • No MathML
  • Mainly populated by undergraduates

2. Another website which comes reasonably close is:

http://www.sciweavers.org/

“an academic network that aggregates links to research paper preprints
then categorizes them into proceedings.”

  • Includes a large collection of online tools for various purposes
  • Have a big library of papers/software/datasets/conferences for computer science.
    Paper sites have:
    • Meta information and preview
    • Vote functionality and view statistics, tags
    • Comments
    • Related work
    • Bookmarking
    • Author information
  • User profiles (no friendships)


Differences to our approach:

  • Focus on computer science community
  • Comment and Discussions are well hidden on paper sites
  • No News stream
  • Very spacious design

 
3. Another very similar site is:

journalfire.com – beta
“Share what your read – connect to colleagues – create journal clubs.”

It has the following features:

  • Comment on Papers. Activity feed (?). Follow articles.
  • Host Journal Clubs. Create Events related to papers.
  • Powerful search box fetching papers from Arxiv and Pubmed (slow)
  • Social features on site: User profiles, friend finder (no fb/g+ integration yet)
  • News feed – from subscribed papers and friends
  • Easy paper import via Bookmarklet
  • Good usability!! (but slow loading times)
  • Private reading clubs cost money!

They are very skilled: Maintained by 3 PhD students/postdocs from Caltec and MIT.

Differences to our approach:

  • Closed Data, Closed Source
  • Also this site misses (currently) misses out ranking features
  • Very Closed model – Signup required
  • Weak Crowd sourcing: Cannot add Meta information

The site is still at its very beginning with little users. The project started in 2010 and did not gain much momentum since.

The other sites are roughly classified in the following categories:
1. Single people who are following a very similar idea:

  • annotatr.appspot.com. Combines a metadata-base with the disqus plugin. You can comment but not rate. Good usability. Nice CSS. Good search function. No MathML. No related article suggestion. Maintained by two academics in private time. Hosted on Google Apps. Closed Source – Closed Data.
  • r-Forum – a resource where mathematicians can collect record reviews, corrections of a resource (e.g. paper, talk, …). A simple Vanilla-Forum/Wiki with almost no content used by maybe 12 people in US. No automated Data import. No rating system.
  • http://math-arch.org/ – Post comments to math papers. very bad usability – get even errors. Maintained by a group of russian programmers LogicSun. Closed Source – Closed Data.

Analysis: Although the principal idea to connect people reading papers is there. The implementation is very bad in terms of usability and even basic programming. Also the voting features are missed out.

2. (Semi) Professional sites.

  • Public Libary of Science very professional, huge paper data base for mainly biology, medicine. Features full text papers, lots of interesting meta information including references. Has comment features (not very visible) and news stream on the start page.
    No QA features (+1, Ask question) on the site. Only published articles are on the site.
  • Mendeley.com – Huge Bibliographic database with bookmarking and social features. You can organize reading groups in there, with comments and notes shared among the participants. Features a news stream with papers by friends. Nice import. Impressive fulltext data and Reference features.
    No QA features for paper. No comments for paper. Requires Signup to do anything useful.
  • papercritic.com – Open review database. Connected to Mendely bibliographic libary. You can post reviews. No rating. No comments. Not open: Mendely is commercial.
  • webofknowledge.com. Commercial academic citation index.
  • zotero.org – features programm that runs inside a browser. “easy-to-use tool to help you collect, organize, cite, and share your research sources”

Analysis: The goal of all these tools is to simplify the reference management, by providing metadata like references, citations, abstracts, author profiles. Commenting features on the paper site are not there or not promoted.
3. Vaguely related sites which solve different problems:

  • citeulike.org – Social bookmarking for papers. Closed Source – Open Data.
  • http://www.scholarpedia.org. A peer reviewed open access encyclopedia.
  • Philica.com Online Journal which publishes articles from any field along with its reviews.
  • MathSciNet/Zentralblatt – Review database for math community. Closed Source – Commercial.
  • http://f1000research.com/ – Online Journal with a public, post publish review process. “Open Science – Open Data – Open Review”
  • http://altmetrics.org/manifesto/ as an emerging trend from the web-science trust community. Their goal is to revolutionize the review process and create better filters for scientific publications making use of link structures and public discussions. (Might be interesting for us).
  • http://meta.wikimedia.org/wiki/WikiScholar – one of several ideas under discussion at Wikimedia as to a central repository for references (that are cited on Wikipedias and other Wikimedia projects)

Upshot of all this:

There is not a single site featuring good Q&A features for papers.

If you like our approach you can contact us or contribute on the source code find some starting documentation!
So the plan is to fork an open source question answer system and enrich it with the features fulfilling the needs of scientists and some social aspects which will eventually help to rank related work of a paper.
Feel free to provide us with feedback and wishes and join our effort!

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Data structure for Social news streams on Graph data bases https://www.rene-pickhardt.de/data-structure-for-social-news-streams-on-graph-data-bases/ https://www.rene-pickhardt.de/data-structure-for-social-news-streams-on-graph-data-bases/#comments Mon, 05 Sep 2011 12:36:57 +0000 http://www.rene-pickhardt.de/?p=752 UPDATE: look at http://www.rene-pickhardt.de/graphity for a more scientific survey and evaluation of this data structure.
Ok you guys did not hear much from me most recently. I was on vaccation and then on summer school and I worked on my first scientific poster and on a talk which will hopefully ontribute to my PhD thesis. Well at least I can now share some ressources which include my poster and the slides from my talk. But let me first show you two pictures.
The standard graph of a social network. You see several people and attached to them content items identified by numbers which are supposed to be time stamps

My model of a social network graph. The ego network changed from a star topology to a list topology and each ego network has a certain edge type which is modeled by edge color here. This graph stores exactly the same information as the standard model but makes retrieval of news streams much faster

Poster

Feel  free to download and look at my first poster with the Title:  a model for social news streams and time indices on graph data bases
You will probably not see so many things in it without the slides from my talk. So let me explain some things. I was looking into the data structures to model social news streams.  Basically there is the approach of normalized or denormalized relational data bases which I call the twitter approach for the reason that Twitter is doing something similar with FlockDB
I also looked into the case of saving the news stream as a flat file for every user in which the events from his friends are saved for every user. For some reason I thought I had picked up somewhere that facebook is running on such a system. But right now I can’t find the resource anymore. If you can, please tell me! Anyway while studying these different approaches I realized that the flat file approach even though it seems to be primitive makes perfect sense. It scales to infinity and is very fast for reading! Even though I can’t find the resource anymore I will still call this approach the Facebook approach.
I was now wondering how you would store a social news stream in a graph data base like neo4j in a way that you get some nice properties. More specifically I wanted to combine the advantages of both the facebook and the twitter approach and try to get rid of the downfalls. And guess what! To me this seems actually possible on graph data bases. The key Idea is to store the social network and content items created by the users not only in a star topology but also in a list topology ordered by time of occuring events. The crucial part is to maintain this topology which is actually possible in O(1) while Updates occure to the graph.

Talk

As mentioned together with this poster I was giving  a talk social news streams and time indices on social network graphs. Please feel free to download the slides. Unfortunally I improved the example while making the poster so that some pictures are not consistant with those from the poster! If I find the time I will not only update the slides but also give the talk as a video lecture on youtube! I think this will be helpful to spread the idea!

Future Work

  1. I need to publish all these results in a good coference or journal
  2. relevance filtering and recommendations which is the problem I am really interested in.
  3. Implementing this stuff for my social network (see blog post)

Open Questions

  1. Is it possible in neo4j to specify edgetypes (Relationship types) on runtime rather than compiletime.
  2. If so: Is the time of accessing them O(1) with respect to the node degree?
  3. If not: is there a graph data base that is capable of doing this?

Discussion

Anyway it is great to see how much more insight you get when thinking of a problem in a scientific way and not only implement it right away!

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First privacy impressions of my new android phone https://www.rene-pickhardt.de/first-privacy-impressions-of-my-new-android-phone/ https://www.rene-pickhardt.de/first-privacy-impressions-of-my-new-android-phone/#respond Wed, 22 Jun 2011 17:29:44 +0000 http://www.rene-pickhardt.de/?p=597 My new cellphone finally arrived today. Being a fan of Google products, I was excited to test Android and get a feeling for everything. I wasn’t sure whether I would really need a smartphone or whether it was rather a time wasting but cool toy. After a bit of testing and playing around, I have to admit that I will probably use the option to retrieve feeds and read more news / blogs while being on the train or bus. I might also work on my Chinese more frequently with Anki for Android and there are some other features that will most certainly enrich my life.
One of them was that Google offered to synchronize my Gmail address book + calender with Android. The data is with Google anyway so I decided that it is not a big deal. And voilà, all my contacts, including phone numbers, are on my new phone. Amazing, considering my heart attack after my old cell broke down for which I did not have any backups.

All this comes at a very high price.

Since I started blogging and working on my PhD, I also started to use Twitter. So I wanted to download a Twitter app from the Android app market. It is incredible that the official Twitter app asks permission to access my phone’s address book. Remember, my phones address book is just a copy of my Gmail address book. I see how it helps Twitter to increase their service but to me, it became just too easy to share very sensitive data with companies that you might not (?) trust. I wonder whether the service Twitter offers to us will really improve that much if we share our private address book with the company. In my opinion, the small improvement we get does not justify their need to access my private address book. What would I have to promise someone to have a copy of his address book?

Can I escape?

I decided not to install the Twitter app. But does that really make sense? I guess most people don’t mind. After all, it is Twitter, a well known brand, that asks for the data. Additionally, Twitter is a communication service, so it makes sense to share this kind of data. However, even if I don’t share, Twitter can still guess the entries of my address book. Most of my friends who use Twitter with an android phone will probably accept the terms and condition of the Twitter app. Does not installing the app really help to protect my and my friends(!) privacy?
It is amazing that I am thinking right now about the consequences of blogging my experience of interviewing with Google when exactly this company creates structures that make us all sit in a glass house! I am very sure that this is intentionally like this. Please don’t missunderstand me. My first impression of Android is very good and I knew before that it encourages you in several ways to share data with anyone. Still, Android is probably one of the most useful tools which were brought to customers within the last ten years. I am only pointing out that things are changing very fast these days.

Which Android apps do I need?

So far I have:

  • Google Maps
  • Gmail
  • Google Search
  • Google Voice Recognition
  • Google Reader
  • Google News
  • Tweetdeck (without sharing my address book !)
  • Ankidroid
  • Google Docs
  • Google Calendar

What else would you suggest? And no, I don’t want a Facebook app. (-:

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The secrete behind Googles success revealed by Eric Schmidt https://www.rene-pickhardt.de/the-secrete-behind-googles-success-revealed-by-eric-schmidt/ https://www.rene-pickhardt.de/the-secrete-behind-googles-success-revealed-by-eric-schmidt/#comments Wed, 01 Jun 2011 13:56:34 +0000 http://www.rene-pickhardt.de/?p=485 Today Eric Schmidt was a trending topic on Twitter. The reason seems that at AllThingsD9l Walt Mossberg was interviewing Eric Schmidt the former Google CEO. Please listen to this man. He has an amazing viewpoint!
This could also fill into privacy or collective intelligence but the topic is much deeper.
While most people discuss on privacy issues almost everyone oversees the fact that it is really about internet business models. Eric Schmidt is telling everyone the “secreet” of Googles success and it seems that almost nobody is listening:

The following is taken from around 4:47 where a discussion about the app market and privacy inside it rises up.

Eric Schmidt: “What else could we do besides just informing people. ”
Walter Mossberg: “You could curate. ”
Eric Schmidt: “But we made the decission to not curate. We stay focused on open platforms. The apple model is the inverse of the Google model. And I think the competition is very healthy. The fact of the matter is that the apple model produces beautiful products of a specific market size and share with an awful lot of clever stuff going on that are entirely controlled by apple. The Google model ist just the inverse. It’s ok. Let the market decide. It’s called competition.”

Let’s try to understand what is really going on here!
Realize that google within a very short time just became market leader in the app market and take into mind that apple had several advantages in this market:

  • first mover in the phone / app market
  • superior hardware
  • fashion brand. To have an iPod iPhone was just “hip”
  • iTunes and the combination with music

We conclude:
It is all about being open and setting open standards. Just like the whole internet is!
If you are interested in more please compare for my article Why open source wins and then Jonathan Rosenberg’s post about this topic.

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Social news streams – a possible PhD research topic? https://www.rene-pickhardt.de/social-news-streams-a-possible-phd-research-topic/ https://www.rene-pickhardt.de/social-news-streams-a-possible-phd-research-topic/#comments Mon, 25 Apr 2011 22:03:08 +0000 http://www.rene-pickhardt.de/?p=351 It is two months now of reading papers since I started my PhD program. Enough time to think about possible research topics. I am more and more interested in search, social networks in general and social news streams in particular. It is obvious that it is becoming more and more important to aggregate news around a users interests and social circle and display them to the user in an efficient manner. Facebook and Twitter are doing this in an obvious way but also Google, Google News and a lot of other sites have similar products.

To much information in one’s social environment

In order to create a news stream there is the possibility to just show the most recent information to the user (as Twitter is doing it). Due to the huge amount of information created, one wants to filter the results in order to gain a higher user experience. Facebook first started to filter the news stream on their site which lead to the widely spread discussion about their ironically called EdgeRank algorithm. Many users seem to be unhappy with the user experience of Facebook’s Top News.
Also for some information such as the existence of an event in future it might not be the best moment to display the information as soon as it becomes available.

Interesting research hook points and difficulties

I observed these trends and realized that this problem can be seen as a special case of search or more general recommendation engines in information retrieval. We want to obtain the most relevant information updates around a certain time window for every specific user.
This problem seems to me algorithmically much harder than web search where the results don’t have this time component and for a long time also haven’t been personalized to the user’s interest. The time component makes it hard to decide the question for relevance. The information is new and you don’t have any votes or indicators of relevance. Consider a news source or person in someone’s environment that wasn’t important before. All of a sudden this person could provide a highly relevant and useful information to the user.

My goal and roadmap

Fortunately in the past I have created metalcon.de together with several friends. Metalcon is a social network for heavy metal fans. On metalcon users can access information (cd releases, upcoming concerts, discussions, news, reviews,…) about their favorite music bands, concerts and venues in their region and updates from their friends. These information can perfectly be displayed in a social news stream. On the other hand metalcon users share information about their taste of music, the venues they go to and the people they are friend with.
This means that I have a perfect sandbox to develop and test (with real users) some smart social news algorithms that are supposed to aggregate and filter the most relevant news to our users based on their interests.
Furthermore regional information and information about music are available as linked open data. So the news stream can easily be enriched with semantic components.
Since I am about to redesign (a lot of work) metalcon for the purpose of research and I am about to go into this direction for my PhD thesis I would be very happy to receive some feedback and thoughts about my suggestions of my future research topic. You can leave a comment or contact me.
Thanks you!

Current Achievments:

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Power of Google Homepage https://www.rene-pickhardt.de/power-of-google-homepage/ https://www.rene-pickhardt.de/power-of-google-homepage/#respond Sun, 20 Mar 2011 11:54:09 +0000 http://www.rene-pickhardt.de/?p=317 Google has put information about the Youtube Symphony Orchestra on its homepage! Whatch yourself:

After Thomas recommended reading a paper about trending topics in twitter where it was discovered that trends can be strongly influenced by external factors (media, news) I went right away to twitter looking for the #ysto. Of course I was not surprised that it was already trending on the twitter homepage. After searching for the hashtag an leaving the result page as it was for about 15 minutes Twitter told me that there where 1754 new tweets since my last search!

If I find the time I will later look a little deeper into the wave Google created by putting something on the homepage. But for now I will enjoy the concert!

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