** Teaser!! ** This is kind of a private post!
When I was a teen and the Internet was only know to a very special circle, the world got interconnected by dial-up modem connections via POT (plain old telephone) -lines and bulletin board systems (Fido, ...) the buzzword was "the global village".
The spirit of that time with "Netiquette", which was a guideline to all newcomers to the global net, was openness. So like google books today, the IMHO most/only philanthropically google service, the credo was global knowledge.
It is impressive to note the equal distribution of drop ins to my blog (according to the statistics) from all over the world. Clearly significant US-Americans and Europeans but also people (students, fellow PH.D students?) from the whole world: China, India, Pakistan, Marocco, Iran, Thailand, Vietnam, Puerto Rico, Columbia, Romania, Finland, ..., ....
Sunday, 14 February 2010
Friday, 12 February 2010
Paper about piezoelectric self-penalization submitted
End of January we submitted a second paper entitled:
Wein, M. Kaltenbacher, Leugering, Bänsch, Schury; Self-Penalizing Topology Optimization of Piezoelectric Composite; 2010
to SMO.
It is devoted to the phenomenon that there is no penalization necessary performing SIMP topology optimization (let's stick to 'SIMP' even if the special feature of SIMP, the P which stands for penalization is omitted ... :) ). Hence there is also no filtering or other regularization or any other kind of constraint necessary (for the configurations where self-penalization occurs!).
Imagine the optimization strategy: As there is also no volume constraint one can just follow the gradient to add or remove material. I used a simple move limit and after 5 iterations you have a black and white design ... at least for the best working case which is static displacement maximization. Normally I use a 'grown up' optimizer which is SCPIP from Ch. Zillober, a MMA implementation with all the features which make life easier:) (see my frontend C++SCPIP)
At WCSMO-8 I was really surprised to find that Cory Rupp had the same observation (and to some extend als Maria Dühring) but this is the first paper entierely devoted to self-penalization.
Again the cosmos of topology optimizaton is a Danish centric system :) Self-penalization itself has been first (and as far as I know almost limited to) reported by Ole Sigmund and Jakob S. Jensen: Sigmund, Jensen; Systematic design of phononic band-gap materials and structures by topology optimization; 2003. They did not use the term 'self-penalization' yet and actually I could not google any corresponding reference to the term. At WCSMO-8 I talked with Ole Sigmund about my observation and I was told the term 'self-penalization' and the references from him. The best I came up by myself up to then was 'intrinsic avoidance of intermediate material' :( I just want to emphasis that the credits for the term belong to Ole (or maybe Jakob?)!
In the paper a whole range of objective functions is applied to my standard system, by heart I know only of single further objective function meaningful for piezoelectric topology optimization (the one of Maria Dühring but it is quite special). So the paper is also kind of a little review :) The objective functions are:
Wein, M. Kaltenbacher, Leugering, Bänsch, Schury; Self-Penalizing Topology Optimization of Piezoelectric Composite; 2010
to SMO.
It is devoted to the phenomenon that there is no penalization necessary performing SIMP topology optimization (let's stick to 'SIMP' even if the special feature of SIMP, the P which stands for penalization is omitted ... :) ). Hence there is also no filtering or other regularization or any other kind of constraint necessary (for the configurations where self-penalization occurs!).
Imagine the optimization strategy: As there is also no volume constraint one can just follow the gradient to add or remove material. I used a simple move limit and after 5 iterations you have a black and white design ... at least for the best working case which is static displacement maximization. Normally I use a 'grown up' optimizer which is SCPIP from Ch. Zillober, a MMA implementation with all the features which make life easier:) (see my frontend C++SCPIP)
At WCSMO-8 I was really surprised to find that Cory Rupp had the same observation (and to some extend als Maria Dühring) but this is the first paper entierely devoted to self-penalization.
Again the cosmos of topology optimizaton is a Danish centric system :) Self-penalization itself has been first (and as far as I know almost limited to) reported by Ole Sigmund and Jakob S. Jensen: Sigmund, Jensen; Systematic design of phononic band-gap materials and structures by topology optimization; 2003. They did not use the term 'self-penalization' yet and actually I could not google any corresponding reference to the term. At WCSMO-8 I talked with Ole Sigmund about my observation and I was told the term 'self-penalization' and the references from him. The best I came up by myself up to then was 'intrinsic avoidance of intermediate material' :( I just want to emphasis that the credits for the term belong to Ole (or maybe Jakob?)!
In the paper a whole range of objective functions is applied to my standard system, by heart I know only of single further objective function meaningful for piezoelectric topology optimization (the one of Maria Dühring but it is quite special). So the paper is also kind of a little review :) The objective functions are:
- mean transduction
- displacement
- sound radiation
- electric potential
- electric energy
- energy conversion
- electric power
Monday, 4 January 2010
ECCM 2010 in Paris
I'll be on ECCM 2010, the IVth European Conference on Computational Mechanics - Solids, Structures and Coupled Problems in Engineering.
I'm accepted for the minisymposium Topology Optimization for Multiphysics Problems by Ole Sigmund and Kurt Maute.
The title for my talk is "Acoustic Near Field Topology Optimization of a Piezoelectric Loudspeaker". I (hope) it is cool stuff - at least it drives the computational costs back to "normal". Having a 3D Helmholtz Equation with a discretization driven by acoustic far field conditions is very expensive - too expensive to do experiments with broad frequency range optimization. It is difficult stuff for the optimizer requiring a hell of iterations and one has to take care to be not only left with colorful pictures ...
I'm very proud that I got invited (by Ole Sigmund) and according to professors its an honour. So I'm simply happy and will do my best! :)
The conference is in Paris from May 16 to 21 in 2010. A lot of colleagues from Erlangen will also come - we are a really big structural optimization group there! I hope it's not too expensive - Lisbon was cool! Tube for 80 cents, a beer in a Cafe 1,10 Euros and probably the most appealing capital in Europe to me. I haven't been to Paris for a very long time - and always camped then.
I'm accepted for the minisymposium Topology Optimization for Multiphysics Problems by Ole Sigmund and Kurt Maute.
The title for my talk is "Acoustic Near Field Topology Optimization of a Piezoelectric Loudspeaker". I (hope) it is cool stuff - at least it drives the computational costs back to "normal". Having a 3D Helmholtz Equation with a discretization driven by acoustic far field conditions is very expensive - too expensive to do experiments with broad frequency range optimization. It is difficult stuff for the optimizer requiring a hell of iterations and one has to take care to be not only left with colorful pictures ...
I'm very proud that I got invited (by Ole Sigmund) and according to professors its an honour. So I'm simply happy and will do my best! :)
The conference is in Paris from May 16 to 21 in 2010. A lot of colleagues from Erlangen will also come - we are a really big structural optimization group there! I hope it's not too expensive - Lisbon was cool! Tube for 80 cents, a beer in a Cafe 1,10 Euros and probably the most appealing capital in Europe to me. I haven't been to Paris for a very long time - and always camped then.
Blog blogging
A year has passed since I added my blog to feedjit.com to control who's reading my blog (beside google). You can see the data on the right sidebar in the lower region - a world-map and an detailed access list. When people google me I can even see what the googled for.
Well, now I know at least that some people read me - even when they actually searched for something different. Here comes a short list of common stuff people search for:
Actually I like to blog but it is time consuming and I blog only at night. I don't write as open as I would like. I would like to share some remarks about my community - but not in public. It's no good style and you never know hows reviewing you. I also have no private blog and I believe there is often a 'private' side in some of my posts. I'll have to do more on my facebook account to 'satisfy' this. :)
I'm happy about comments or mails - even more if you start a own blog - just let me know :)
Happy new year!
Well, now I know at least that some people read me - even when they actually searched for something different. Here comes a short list of common stuff people search for:
- "piezo matlab" - sorry I use a complex C++ FEM code
- "math riddle" - I have only a single one.
- "topology optimization" - in some countries I'm quite high in google ?!
- "topology optimization book" - some read my review - and with feedjit I can see which amazon link the followed.
- "piezoelectric loudspeaker" - yeah - some new stuff! :)
- paper - a few times people searched for my paper - once from South Korea. Now, please cite me! :)
Actually I like to blog but it is time consuming and I blog only at night. I don't write as open as I would like. I would like to share some remarks about my community - but not in public. It's no good style and you never know hows reviewing you. I also have no private blog and I believe there is often a 'private' side in some of my posts. I'll have to do more on my facebook account to 'satisfy' this. :)
I'm happy about comments or mails - even more if you start a own blog - just let me know :)
Happy new year!
Wednesday, 23 September 2009
First paper in print
Nothing special for most of the people I cite, but the first time for me:
My (our) first paper exists in "real world" with the current issue of
IJAEM "International Journal of Applied Electromagnetics and Mechanics".
Topology optimization of a piezoelectric-mechanical actuator with single- and multiple-frequency excitation
It's part of a OIPE 2008
special issue with 17 selected papers out of 68 full paper submissions.
Contact me if you have no access to the journal :)
I'm 2/3 finished with another paper: "Self-Penalizing Topology Optimization of Piezoelectric Composite" - I hope it works out. It is kind of a "baby-review" paper
where the cited algorithms are implemented for the same model.
My (our) first paper exists in "real world" with the current issue of
IJAEM "International Journal of Applied Electromagnetics and Mechanics".
Topology optimization of a piezoelectric-mechanical actuator with single- and multiple-frequency excitation
It's part of a OIPE 2008
special issue with 17 selected papers out of 68 full paper submissions.
Contact me if you have no access to the journal :)
I'm 2/3 finished with another paper: "Self-Penalizing Topology Optimization of Piezoelectric Composite" - I hope it works out. It is kind of a "baby-review" paper
where the cited algorithms are implemented for the same model.
Monday, 27 July 2009
About my new job
I have been financend for three years by the DFG (the main German research fond) within the priority program SPP 1253 which is about the optimization of partial differential equations. This support and the possibility to work on the research project Optimization of Electro-Mechanical Smart Structures is grateful acknowledged. As a fourth year to finish my Ph.D. was planned, we applied for a second funding period which was unfortunately refused - it turned out, that actually all engineers were cut off this mathematical program.
Fortunately I got an offer by Prof. Michael Stingl for a full time position. I now work within the Excellence Cluster Engineering of Adcanced Materials. My tasks are closely related to what I am already doing (including the software basis CFS++) and after concurrently finishing my PhD I will continue as a postdoc. Formally I am now employed by the Chair of Applied Mathematics II of Prof. Leugering who was also one of the project leaders of the funded project.
Nevertheless, my PhD advisors have not changed. This is Prof. Manfred Kaltenbacher now in Klagenfurt/ Austria (check the first link - this is a real Austrian title concatenation :) ) and Prof. Eberhard Bänsch, head of the Chair for Applied Mathematics III. So in some sense I am also still a member of this chair.
Furthermore I did no loose my ties to the Chair of Sensor Technology as Prof. Lerch offered me to keep my desk there and I want to be there once a week.
So I am rather split/ networked/ ... and somehow more "mathematically oriented" - but note that I am still an engineer (having even two of such degrees) :)
Fortunately I got an offer by Prof. Michael Stingl for a full time position. I now work within the Excellence Cluster Engineering of Adcanced Materials. My tasks are closely related to what I am already doing (including the software basis CFS++) and after concurrently finishing my PhD I will continue as a postdoc. Formally I am now employed by the Chair of Applied Mathematics II of Prof. Leugering who was also one of the project leaders of the funded project.
Nevertheless, my PhD advisors have not changed. This is Prof. Manfred Kaltenbacher now in Klagenfurt/ Austria (check the first link - this is a real Austrian title concatenation :) ) and Prof. Eberhard Bänsch, head of the Chair for Applied Mathematics III. So in some sense I am also still a member of this chair.
Furthermore I did no loose my ties to the Chair of Sensor Technology as Prof. Lerch offered me to keep my desk there and I want to be there once a week.
So I am rather split/ networked/ ... and somehow more "mathematically oriented" - but note that I am still an engineer (having even two of such degrees) :)
Friday, 5 June 2009
WCSMO-8 is over
WCSMO-8 ist almost over. For me it was my first congress and I was looking forward to finally "become part of the community". It turned out, that DCAMM 07 was actually a real good introduction to it as I know already Martin Bendsoe, Ole Sigmund, Jakob Jensen and several of their PhD students. I got some answers and ideas from them - that will bring me a good step forward.
A very big surprise was actually to meet Cory Rupp, of whom I never heard of. He did his PhD on the topology optmization of a piezoelectric plate energy harvester. It turned out, that our work has very much in common - escpcially our observations in the dynamic case and the self-penalization effect of piezoelectric-mechanical laminates (I take the term "self-penalization" from Ole Sigmund, who made this observation in another context before). It gave me a real push to find someone who shares my experiences. His paper is "Topology Optimization of Piezoelectric Energy Harvesting Structures And Circuits" (#1594) by Cory Rupp, Martin Dunn and Kurt Maute.
I found that also Maria Duehring is doing now cool piezoelectric stuff. I liked her older paper about acoustic optimization and used it for a paper seminar. Before that conference I knew only of Emilio Silva and Alberto Donoso/ Jose Bellido doing piezoelectric topology optimization.
The highligts of the conference? Both Martin Bendsoe and Ole Sigmund pointed out a paper where the topology optimization of the head equation is used to find the best path for a robot within a room of obstacles - actually really cool and innovative. That's cross-thinking! It's entitled "Novel Mobile Robot Path Planning Algorithm by Equivalent Conduction Heat Flow Topology Optimization" (#1327) by Jae Chun Ryu, Yoon Young Kim and Chongwoo Park from South-Korea.
I liked most the talk of Ole Sigmund, where he presented an "engineering solution" (simple, robust, effective) to generate more robust designs. The idea is to perfom the
optimization also on a thickened (dilation) and thinned (erosion) variant and perfom a min max optimization. He pointed out, that the level-set method has a big natural advance here, as you get arbitrary variants of your design easily - simply by shifting the level-set. The paper is "Manufacturing Tolerant Topolog Optimization" (# 1535)
The most touching moment was, when an aircraft designer asked us in his talk to stand up in silence in memory to the people who died at the Air France Airbus crash this week.
A very big surprise was actually to meet Cory Rupp, of whom I never heard of. He did his PhD on the topology optmization of a piezoelectric plate energy harvester. It turned out, that our work has very much in common - escpcially our observations in the dynamic case and the self-penalization effect of piezoelectric-mechanical laminates (I take the term "self-penalization" from Ole Sigmund, who made this observation in another context before). It gave me a real push to find someone who shares my experiences. His paper is "Topology Optimization of Piezoelectric Energy Harvesting Structures And Circuits" (#1594) by Cory Rupp, Martin Dunn and Kurt Maute.
I found that also Maria Duehring is doing now cool piezoelectric stuff. I liked her older paper about acoustic optimization and used it for a paper seminar. Before that conference I knew only of Emilio Silva and Alberto Donoso/ Jose Bellido doing piezoelectric topology optimization.
The highligts of the conference? Both Martin Bendsoe and Ole Sigmund pointed out a paper where the topology optimization of the head equation is used to find the best path for a robot within a room of obstacles - actually really cool and innovative. That's cross-thinking! It's entitled "Novel Mobile Robot Path Planning Algorithm by Equivalent Conduction Heat Flow Topology Optimization" (#1327) by Jae Chun Ryu, Yoon Young Kim and Chongwoo Park from South-Korea.
I liked most the talk of Ole Sigmund, where he presented an "engineering solution" (simple, robust, effective) to generate more robust designs. The idea is to perfom the
optimization also on a thickened (dilation) and thinned (erosion) variant and perfom a min max optimization. He pointed out, that the level-set method has a big natural advance here, as you get arbitrary variants of your design easily - simply by shifting the level-set. The paper is "Manufacturing Tolerant Topolog Optimization" (# 1535)
The most touching moment was, when an aircraft designer asked us in his talk to stand up in silence in memory to the people who died at the Air France Airbus crash this week.
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