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Showing posts with label IST. Show all posts
Showing posts with label IST. Show all posts
2011-05-23
2010-04-12
IoT@IST MScs 2010
IoT@IST (Internet of Things at Instituto Superior Técnico)
Want to study how RFID meets the Internet and sparks the next IT revolution? Come talk to me! MSc proposals deadline is April 23rd.
I will do a presentation about RFID this Wednesday, 16:00, IST (room F2). It is part of a course in my Doctoral program and it is also a good chance to get started into this exciting research topic. See you there!
Want to study how RFID meets the Internet and sparks the next IT revolution? Come talk to me! MSc proposals deadline is April 23rd.
I will do a presentation about RFID this Wednesday, 16:00, IST (room F2). It is part of a course in my Doctoral program and it is also a good chance to get started into this exciting research topic. See you there!
2009-07-09
2009-07-04
No to SQL
It appears there is a "rebellion" against relational databases, as reported in Computer World.
This is the typical problem when you just use off-the-shelf software without considering other options.
Some years ago, Prof. PMMVAS, in a class, presented a good summarization of the trade-offs in the database world:
Data structure complexity VS Query capabilities
Relational databases have simple data structures (tables) but sophisticated querying capabilities (SQL SELECT).
Hierarchical databases (e.g. XML) have more complex data structures (records) and less powerful queries.
Object databases have complex data structures (object graphs, code+data encapsulation) but poor querying capabilities.
It is an interesting discussion on how to keep our digital "bookshelves" organized...
This is the typical problem when you just use off-the-shelf software without considering other options.
Some years ago, Prof. PMMVAS, in a class, presented a good summarization of the trade-offs in the database world:
Data structure complexity VS Query capabilities
Relational databases have simple data structures (tables) but sophisticated querying capabilities (SQL SELECT).
Hierarchical databases (e.g. XML) have more complex data structures (records) and less powerful queries.
Object databases have complex data structures (object graphs, code+data encapsulation) but poor querying capabilities.
It is an interesting discussion on how to keep our digital "bookshelves" organized...
2009-05-12
Advanced Distributed Systems (ADS) - naming and file systems
I'm taking a Advanced Distributed Systems course. We read papers and we present and discuss them.
The first two topics were:
Naming
1 - The Design and Implementation of an Intentional Naming System. William Adjie-Winoto, Elliot Schwartz, Hari Balakrishnan, Jeremy Lilley, SOSP 1999.
2 - Locating Objects in Wide-Area Systems. Maarten van Steen, Franz J. Hauck, Philip Homburg, Andrew S. Tanenbaum, IEEE Communications Magazine 36(1), January 1998, pages 104–109
Adjie-Winoto99 is a seminal paper for DHTs (Distributed Hash Tables). DHTs are good for matching items using identifiers but are not so good in matching attribute value ranges.
Another interesting topic were the trade-offs between soft-state (time limited persistence, fate sharing) and hard-state (persistence until explicit deletion). Hard requires recovery, checkpoints, transactions, logs. Soft allows for much faster node recovery.
Distributed File Systems
1 - An application of a context-aware file system. Christopher K. Hess, Roy H. Campbel. Springer-Verlag, London, 2003
2- The Google File System. Sanjay Ghemawat, Howard Gobioff, Shun-Tak Leung, SOSP 2003.
There are subtle differences in consistency definitions. For instance, the Google File System uses consistent and defined.
e.g. "The sky is yellow" - it's wrong, but it's consistent if everyone sees the same statement. Consistent isn't the same as correct.
The first two topics were:
Naming
1 - The Design and Implementation of an Intentional Naming System. William Adjie-Winoto, Elliot Schwartz, Hari Balakrishnan, Jeremy Lilley, SOSP 1999.
2 - Locating Objects in Wide-Area Systems. Maarten van Steen, Franz J. Hauck, Philip Homburg, Andrew S. Tanenbaum, IEEE Communications Magazine 36(1), January 1998, pages 104–109
Adjie-Winoto99 is a seminal paper for DHTs (Distributed Hash Tables). DHTs are good for matching items using identifiers but are not so good in matching attribute value ranges.
Another interesting topic were the trade-offs between soft-state (time limited persistence, fate sharing) and hard-state (persistence until explicit deletion). Hard requires recovery, checkpoints, transactions, logs. Soft allows for much faster node recovery.
Distributed File Systems
1 - An application of a context-aware file system. Christopher K. Hess, Roy H. Campbel. Springer-Verlag, London, 2003
2- The Google File System. Sanjay Ghemawat, Howard Gobioff, Shun-Tak Leung, SOSP 2003.
There are subtle differences in consistency definitions. For instance, the Google File System uses consistent and defined.
A file region is consistent if all clients will always see the same data, regardless of which replicas they read from.
A region is defined after a file data mutation if it is consistent and clients will see what the mutation writes in its entirety.
e.g. "The sky is yellow" - it's wrong, but it's consistent if everyone sees the same statement. Consistent isn't the same as correct.
2008-10-15
SOP - Service on Process
Ramos A., "eXtended Information System Architecture for SmartTags", Instituto Superior Técnico, MSc thesis contains an interesting figure about how services can relate to an Enterprise Architecture (AE).
It's called Service On Process (SOP) and the full reference for the work is:
Almeida, J.M.; Santos, P.; Carvalho, B.; Marques, E.; Segura, J.; Vieira, A.; Sousa, P.; "BPB-SOA e SOP: uma Framework e Metodologia para SOA orientado ao negócio", Link Consulting, 2008.
It's called Service On Process (SOP) and the full reference for the work is:
Almeida, J.M.; Santos, P.; Carvalho, B.; Marques, E.; Segura, J.; Vieira, A.; Sousa, P.; "BPB-SOA e SOP: uma Framework e Metodologia para SOA orientado ao negócio", Link Consulting, 2008.
2008-10-08
Workshop Masters S.I.
A great initiative from the Information Systems group of DEI, IST to kick-start their students MSc works.
http://sites.google.com/site/mestradosi/
Highly recommended for all Computer Science students!
http://sites.google.com/site/mestradosi/
Highly recommended for all Computer Science students!
2008-08-01
AI Landscape
Leake and Gary, in "AI Magazine", Summer 2008 issue
This poster available at AAAI's site, http://www.aaai.org/Magazine/ailandscape.php, is a great way to spread the word about modern, state-of-the-art AI!
It's certainly more interesting (and eye-catching) than the IA perspective I got in my undergrad course back in 1998...
For more information on some of the most interesting IA research currently underway at IST, check Joana's page and contact her.
This poster available at AAAI's site, http://www.aaai.org/Magazine/ailandscape.php, is a great way to spread the word about modern, state-of-the-art AI!It's certainly more interesting (and eye-catching) than the IA perspective I got in my undergrad course back in 1998...
For more information on some of the most interesting IA research currently underway at IST, check Joana's page and contact her.
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