Johannes Meinecke's Blog

PhD Defended

2009-05-20T23:47:00.000-07:00

On 20.05.2009 I defended my Dissertation at Chemnitz. The last 5 years have been quite an experience for me: new technologies, new ideas, new personal challanges, new places, new research groups, ... I would like to thank all the great people I had the honour to work with and who supported me during this time.

Moved to a New Lab

2008-11-09T08:04:00.000-08:00

In November 2008, I left the DSS group and joined SAP Research to work at the Campus-based Engineering Center in Dresden. If you want to contact me, please use my TU Chemnitz email address which remains valid.

The problem with URIs

2008-08-15T07:18:00.000-07:00

... is that they are extremely useful to pin down the meaning of something for a machine, but they are not easy to handle for a human user. Unless you have the right Web Engineering tools :-). Today, I wrote a component that assists users in entering meaningful values (URIs) by offering autocomplete to a list of given choices. The choices originate from a configured Linked Data source, like a SPARQL endpoint or a DataGridService.

News from WAM

2008-08-08T09:30:00.000-07:00

The WebComposition Architecture Model finally has a homepage: http://webcomposition.net/wam (Thanks to Andreas Heil's initiative). The page summarizes project-relevant links, papers, examples, downloadable hands-on material and a demo for future reference. Currently, one of our student projects applies WAM in an interesting domain: visualizing security architectures in the context of IP telephony.

PhD thesis submitted

2008-07-30T22:42:00.000-07:00

After a long phase of reviewing and reworking, I officially submitted my PhD thesis yesterday. Following now will be the process of the faculty for Informatics, which includes expert reports, an examination and the defense. This also marks the end of my time at VSR, as I will leave the group at the end of September.

Underwater Laboratory

2008-07-25T02:01:00.000-07:00

Earlier this week, we had to discover that a part of the ceiling had collapsed in the student laboratory next to our room and that water was dripping on our hardware. Luckily, there was nobody in the room when it happened, so no casualties except a keyboard. The cause of the accident was a leak in the air conditioning system, which apparently seems to happen here once in a while.

Summer Semester 2008 – Lessons Learned

2008-07-17T23:44:00.000-07:00

Today marks the end of another lecture period at Chemnitz University. The joined seminar / pro-seminar on Semantic Web turned out to be quite a challenge for the participating students. It is interesting to see how the Semantic Web, after being around for about 10 years, is still confusing newcomers. Lessons learned from the improved feedback marks of the lecture-related tutorial on protocols of distributed systems (6.4/7 points): students love to actually see and experience the technologies mentioned on the slides in demos and exercises.

ICWE 2008

2008-07-11T07:43:00.000-07:00

Next week, the Eighth International Conference on Web Engineering (ICWE2008) will be held in Yorktown Heights, New York, USA. Unfortunately, I won't be able to attend this year, after having visited all conferences of the last four years (Munich, Sydney, Palo Alto, Como). However, some of the tools we have been building recently will be used, like the idFS-enabled Wiki for the car sharing site and the WebComposition/DGS for managing a list of the published papers.

Site updates

2008-06-09T05:42:00.001-07:00

The reengineering of our homepage is advancing. Recently, we have setup a publicly readable version of the Data Grid Service at our VSR-DATA site to publish the content in multiple machine-readable formats. A new list has been added for student research projects, forming the base for future tools to manage the advising process. On my own homepage, I have added a Links section from del.ico.us.

Generation W

2008-05-23T04:43:00.000-07:00

Chemnitz University of Technology and the Computer science faculty are currently conducting a number of programs to attract more pupils from schools. Yesterday, I was giving a lecture on Web internals to a group of 10th grade students. All born after the invention of the Web, they have been growing up with it and already knew a lot. Most of them had experience in writing their own Web sites, many of them had also programmed Web applications.

idFS Homepage online

2008-05-15T07:36:00.000-07:00

The idFS homepage is now online. The site offers a downloadable version of idFS, current idFS-related news, documentation and related papers. Moreover, there is an online demo available that illustrates, how federated single sign on can be achieved through browser redirects.

Site updates

2008-05-09T06:34:00.000-07:00

After the recent visual changes, the VSR web site is now becoming a) "more English" and b) "more semantic". During the next weeks, we plan to translate most of the up-front pages to reflect the international orientation of our research. Yesterday, I extended the publication list with an RDF view, linking papers with our FOAF files. Furthermore, we have added a new DGS list for projects.

The new (old) design

2008-05-02T04:08:00.001-07:00

As the eye of the careful observer might have noticed, Chemnitz University has switched to a new Web design, which is slightly more pastel-greenish than the old one. The real progress is however even more subtle: the style template is now proper XHTML, i.e. much more friendly for machine-readable markup (microformats, RDFa etc). I still remember the hassle with the last version of my homepage when I manually adjusted a copy of the PHP template.

UDDI over SOAP over HTTP over TCP over IP over Ethernet over SOAP over ...

2008-04-25T04:41:00.000-07:00

The first exercise session of the lecture on protocols for distributed systems starts today. During the last few weeks, I have written a lot of sample programs that partially implement or use most of the covered protocols on top of TCP sockets. Apart from some unpleasant experiences with COM, it was good fun, largely due to the simplicity of the technologies. The exercise later in the semester will also feature some of our own research products.

DGS List Manager complete

2008-04-18T01:20:00.001-07:00

The first version of the DGS List Manager is now complete and in productive use for the VSR homepage. The programs serves as a front-end to the Data Grid Service (DGS), a Web-service for creating and managing lists of aribtrary XML content in an ad-hoc fashion via an easy to consume interface.

PhD Talk

2008-04-03T07:15:00.000-07:00

Yesterday, I held a presentation on my PhD area of research at an internal group meeting. While it was quite challenging to pack the most important things in 30 minutes, I got some valuable feedback for further improvements of the talk. As the thesis itself is currently under my supervisor’s review, I’m now more occupied with the upcoming semster than with my PhD.

Web forms for arbitrary XML content

2008-03-19T08:54:00.000-07:00

Last week, we looked at an easy way to generate online forms for editing arbitrary data (i.e., XML defined by an XML schema). With the help of an MSDN article, the InfoPath application and a lot of patience, we finally managed to get a generic data managing application online that can be extended with new forms semi-automatically generated from XML schemas. It is not particularly efficient in the browser, but it saves the headache of having to develop the form manually.

Preparations for the new Semester

2008-03-12T09:29:00.000-07:00

The lecture period of the summer semester starts in 4 weeks. This time, I’ll be conducting a joined seminar / pro-seminar on Semantic Web, and a lecture-related tutorial on protocols of distributed systems. Following the feedback from last semester, the next tutorial will contain a lot of practical, hands-on exercises which I am currently preparing. The registration form for the seminar is now available online at the TUC registration service.

WAM Architecture Manager

2008-03-06T05:02:00.000-08:00

During the last few days, I started working on a new tool to keep track all the applications and services we have deployed. The WAM architecture manager can be used to manage a distributed architecture of Web applications, Web services and Federation infrastructure services, based on the WebComposition Architecture Model (WAM). Its public functionality of the browser can be seen online, while logged in administrators can also register new components or modify existing entries.

More invisible site changes

2008-02-29T06:26:00.000-08:00

As I started building this personal homepage last year, I used a lot of XML and XSLT to provide its content in a manageable way. The XML is transformed on the server site, which is why this internal site structure cannot be seen from the outside. As one step further, the content (e.g. the publication list) now comes from a data-managing Web service, which my colleague Andreas Heil is working on. One of many advantages here is that gradually, we will be able to reuse our content in more places across the whole VSR site.

Application integration

2008-02-21T08:27:00.000-08:00

This week, I evaluated some open source wiki and blog engines based on ASP.NET in combination with idFS. I turned out that idFS is pretty straightforward to integrate with existing code, especially in cases where the application already makes use of the standard ASP.NET mechanisms for application security. In some cases, it was even possible to link the applications built-in roles with idFS roles without touching the code. I finally chose screwturn wiki and blogengine.net, which will be used for supplying a blog and a wiki for the ISWE site.

ICWE Paper Deadline extended

2008-02-15T04:14:00.000-08:00

The deadline for this year’s ICWE conference is approaching. It has been extended to February 22, 2008. The Eighth International Conference on Web Engineering (ICWE2008) will be held in July 2008 in Yorktown Heights, New York, USA. ICWE2008 aims at promoting research and scientific excellence on Web Engineering and at bringing together practitioners, scientists, and researchers interested in technologies, methodologies, tools, and techniques used to develop and maintain Web-based applications.

idFS Version 2.3

2008-02-08T06:32:00.000-08:00

idFS Version 2.3 is complete and available for download. It includes some minor fixes and is adjusted to .NET 3.5 / Visual Studio 2008. In addition, I have installed updated online demo on a public web server. The case study in the Web Engineering practical course worked out well. All groups were able to integrate their application, although one group needed some help for configuring advanced features.

End of lecture period in Chemnitz

2008-02-01T06:03:00.001-08:00

After 15 weeks of teaching, it’s the end of the lecture period in Chemnitz, and I’m staring into another golden period of two month of quality research time. The results from this semester’s student feedback reviews were good, but improvable. The students in the practical course rated the interestingness of their project with 5.75 / 7, generally stating that they would prefer a longer project phase and shorter exercise phase. The students in the lecture-related tutorial gave an average of 5 / 7 points, with several requests for more practical, programming-related exercises and less reading homework.

ISWE Site Developments

2008-01-25T05:46:00.001-08:00

The ISWE site is currently undergoing redevelopment behind the scenes, as we add new management features. We switched over to .NET 3.5 to take advantage of the improved XML handling capabilities (LINQ), which has already proven to be quite useful. idFS is now also used to manage activity memberships by integrating its Identity Management Web services directly into the main application. This will hopefully give us some insights with respect to possible new idFS features.

New toys

2008-01-16T08:42:00.000-08:00

Finally, after several delays and smashed hopes, our new laptops have arrived. Slightly bigger than my old one, but also much more powerful. The battery looks like a close assault weapon and will hopefully not cause too much trouble at the airport.

idFS on .NET 3.5

2008-01-11T00:14:00.001-08:00

idFS is compatible with the .NET Framework 3.5. Although the latest version of the framework is additive, this was not self-evident, as some aspects of idFS depend on rather deep, technical layers. This week, I upgraded it using Visual Studio 2008. Meanwhile, we are now using idFS within the project phase of this semester’s practical course on Web Engineering.

Piled the 6th chapter

2007-12-20T07:42:00.000-08:00

Today, I finished my 6th chapter of my PhD thesis. This makes the draft 111 pages long, giving me a good excuse to actually celebrate Christmas this year and not be in office until 01.01.2008.

ICWE 2008 Website online

2007-12-07T07:35:00.000-08:00

The Eighth International Conference on Web Engineering (ICWE2008) will be held in July 2008 in Yorktown Heights, New York, USA. ICWE2008 aims at promoting research and scientific excellence on Web Engineering and at bringing together practitioners, scientists, and researchers interested in technologies, methodologies, tools, and techniques used to develop and maintain Web-based applications. The ICWE 2008 website is now online, featuring the Call For Papers and first information about the event.

New Book on Web Engineering

2007-11-28T08:24:00.000-08:00

A new book on Web Engineering has recently been published at Springer London. "Web Engineering: Modelling and Implementing Web Applications" presents the state of the art of approaches for obtaining a correct and complete Web software product from conceptual schemas, represented via well-known design notations. We contributed the section "The Web as an Application Platform", in which we highlight the specific challenges of distributed Web-based systems.

Cooperation with LIFIA

2007-11-23T03:37:00.000-08:00

Triggered by the research visit at LIFIA a few weeks ago, a cooperative project has now been initiated between the two groups. This involves a student thesis conducted at La Plata in the area of composition with respect to business processes, workflows and data integration.

Student projects with idFS underway

2007-11-16T04:38:00.000-08:00

The reengineering of idFS V2.2 is paying off again, as it is now being used within two student projects at the DSS group. One is using it for the protection of a Web application, possibly extending idFS with a new identity provider to authenticate against the university-wide account system. The other one is concerned with building a more capable and flexible identity store, adding more interfaces and management features.

Joining the Force

2007-11-09T00:17:00.000-08:00

We recently managed to recruit some new members for the DSS. Ronny Jahn has joined us as a student assistant and has already started to help us with the reconstruction of our homepage. He will be accompanied by a second student assistant, Sebastian Brandt.

Trip to LA-WEB / LIFIA - Resumé

2007-11-03T04:33:00.000-07:00

While the LA-WEB conference felt quite short, it gave some interesting insights, especially in the direction of search and advertisement. One interesting point was for example to see the new developments of Yahoo, who now has some semi-structured search features that almost look like semantic search. Moreover, I got some feedback for our own presented work on change propagation in distributed Web-based systems, e.g. the idea to put more effort in pro-active change announcement via the notion of deprecation etc.

Trip to LA-WEB / LIFIA

2007-10-25T05:47:00.000-07:00

Tomorrow, I will be leaving to La Plata, Argentina for a short research visit at LIFIA group of the National University of La Plata, who is also working in the field of Web Engineering. The program includes a joined Seminar, where I will give a talk about the WebComposition Architecture Model. Directly after that, I will attend the LA-Web 2007 conference in Santiago de Chile to present our work on architecture changes in distributed Web applications.

ISWE Activities

2007-10-18T04:38:00.001-07:00

During the past months, the International Society for Web Engineering (ISWE) has attracted several more members. We now have about 30 members from 13 countries. Moreover, the societies work is now organized in sub-groups called Activities, as can be seen on the ISWE homepage. This includes MDWEnet, an initiative started by a group of researchers that have been working on model-driven Web Engineering for the past few years.

New developments at DSS

2007-10-11T08:32:00.000-07:00

At the beginning of the month, our group leader Martin Gaedke acquired his full professorship. The group has also been reinforced by a new member, Andreas Heil, who I have been working with before at the University of Karlsruhe. On the technical site, our homepage is just in the process of a major update, including the establishment of a consistent URL convention.

The new Semester

2007-10-05T08:27:00.000-07:00

I’m back in office, just in time before the start of the new Semester. This time, I’ll be conducting a practical course on Web Engineering technologies, a joined seminar / pro-seminar on Web 2.0, and a lecture-related tutorial on the design of distributed systems. All courses will start in the second week of the semester.

Off to visit uncle Ho

2007-08-31T08:38:00.000-07:00

It is finally time for this year's holidays. I will be out of office for most of September, and not be able to answer any email. Meanwhile, please contact the other group members in case of any urgent requests.

idFS Version 2.2

2007-08-20T04:29:00.000-07:00

The next version of Identity Federation System (idFS) is complete and deployed for the webengineering.org and iswe-ev.de web sites. idFS V2.2 core component is now a standalone library (formerly it was integrated into the WebComposition Service Linking System, WSLS). This makes it much easier to deploy, not requiring any sort of programming to secure an application. Additionally, idFS has been extended with the AuthorizationManager, a Web application to manage the access control policy for idFS-secured applications and services.

Piled Higher and Deeper

2007-08-09T03:41:00.000-07:00

A few weeks ago, I started to work on my PhD thesis, which since then has been growing slowly but consistently. With the semester break and nearly the entire remaining group on holiday, it's currently an excellent time to get things started. If all works according to plan, I should be able to finish it by spring 2008.

Paper presentation at LA-WEB 2007

2007-07-31T05:47:00.000-07:00

LA-Web 2007 is the fifth of a series of refereed conferences aimed at providing a venue in Latin America for researchers and technologists from around the world to present, demonstrate and discuss the latest Web developments. LA-Web 2007 will be held in Santiago de Chile. DSS has submitted a paper on "Enabling Architecture Changes in Distributed Web-Applications", which we will present in October.

Seventh International Conference on Web Engineering - Resumé

2007-07-23T04:28:00.000-07:00

This year’s ICWE conference took place in Como, Italy. As during the last years, I enjoyed very much the open atmosphere and the many interesting discussions both in and outside the sessions. Moreover, the Web Engineering community seems to advance in terms of common activities: The society (ISWE) won many new members, while at the same time more and more groups cooperate on a working level, as e.g. in the context of the MDWEnet initiative.

Real-life testbed for Federation research

2007-07-13T01:52:00.000-07:00

Within the last few days, several Web sites have gone online, where I am involved in the development and operation process: a relaunch of the community portal webengineering.org, the official Web site of the International Society for Web Engineering e.V. (iswe-ev.de), and a homepage for the Hanoi research project. This is a nice opportunity for applying our Federation-related research approaches and systems. Currently, all sites already use idFS for access control.

OpenID

2007-07-04T05:26:00.000-07:00

Still following up on all the exiting new developments that could be seen at the World Wide Web conference, I gave a group-internal presentation today on OpenID. OpenID is an open, decentralized, free framework for user-centric digital identity. Web sites supporting OpenId let users identity by entering their URL (e.g. of their homepage) and delegate the authentication process to arbitrary identity providers. As a result, users can access many different sites using the same account, which has a lot of interesting implications on how data can be used across multiple applications.

ISWE Meeting in Karlsruhe

2007-06-27T04:15:00.000-07:00

The next meeting of the members of the International Society for Web Engineering e.V. will take place in Karlsruhe, on Fri, 6 July 2007. The society promotes science and research in the entire field of Web Engineering, i.e. the systematic engineering of Web applications. Among other issues, we will discuss last preparations for the society’s appearance on this year’s Web Engineering conference (ICWE 2007).

idFS Version 2.1

2007-06-21T04:19:00.000-07:00

After a longer period of work related to other things, I have recently found the time to continue working on my research prototype, the Identity Federation System (idFS). idFS is a system that can be used to secure Web applications and Web services with security tokens, based on Federation specifications. Today, I completed version 2.1, which solves some technical difficulties with certificates and is now compatible with the latest specifications.

More Semantics

2007-06-15T05:45:00.000-07:00

Continuing my private experiments with machine-readable information on the Web, I have recently added some semantic mark-up directly into the page. Today’s browsers cannot see this, but you can make it visible by using plug-ins, like for example Operator and Tails (for the Firefox browser) or by entering my homepage URL into the Tabulator. Technically, the markup is extracted by using a new W3C draft called GRDDL. Adding semantics into Web pages is actually not very difficult. The challenging part is to transform your legacy HTML files into an XHTML-compliant format, which is the precondition for extraction mechanism to work.

FOAF-games

2007-06-04T12:01:00.000-07:00

FOAF (Friend of a Friend) is a project for machine-readable modelling of homepage-like profiles and social networks with the means of the Semantic Web. Last week, I experimented a bit with my own profile and some Semantic Web tools, which become increasingly available (e.g. the Tabulator or the FOAF explorer). Hopefully, there will be some more data to link to in the near future.

Paper presentation at ICWE 2007

2007-05-29T12:12:00.000-07:00

The Seventh International Conference on Web Engineering (ICWE2007) will be held in July 2007 in Como, Italy. ICWE2007 aims at promoting research and scientific excellence on Web Engineering and at bringing together practitioners, scientists, and researchers interested in technologies, methodologies, tools, and techniques used to develop and maintain Web-based applications. DSS has submitted a paper on "Component-Based Content Linking Beyond the Application", which we will present in July.

Homepage online

2007-05-24T12:22:00.000-07:00

After 2 months at my new office in Chemnitz, I finally got around to set up my homepage. Inspired by all the new fancy ideas around Web 2.0 and Linked Data, this site also servers as a playground for experimenting with FOAF, microformats, external REST-services, etc.