From thouis at graphics.csail.mit.edu Mon Dec 1 08:12:38 2003 From: thouis at graphics.csail.mit.edu (Ray Jones) Date: Mon Jan 9 13:41:12 2006 Subject: Relative Distance Cartogram algorithm question In-Reply-To: <20031201025138.17278.qmail@web60310.mail.yahoo.com> References: <20031201025138.17278.qmail@web60310.mail.yahoo.com> Message-ID: Boris Dev writes: > If we have a distance matix can we put points on a 2 > diminsional x, y coordinate grid so that they are > postioned relative to one another according to the > distance matrix elements. Search for "multidimensional scaling". Or follow the links and references from this site and the paper it refers to: http://isomap.stanford.edu/ Ray Jones ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From michael.aupetit at cea.fr Mon Dec 1 13:25:57 2003 From: michael.aupetit at cea.fr (aupetit) Date: Mon Jan 9 13:41:12 2006 Subject: Relative Distance Cartogram algorithm question References: <20031201025138.17278.qmail@web60310.mail.yahoo.com> Message-ID: <200312011226.NAA29388@tupai.bruyeres.cea.fr> Try these methods or key-words Multi-Dimensional Scaling (MDS) or Sammon's Non-Linear Mapping and efficient variations of it such as Curvilinear Components Analysis (Demartines, Herault) Hope this helps Michael Boris Dev wrote: > I hope this is a comp geom problem: > > If we have a distance matix can we put points on a 2 > diminsional x, y coordinate grid so that they are > postioned relative to one another according to the > distance matrix elements. > > - what if distance was defined in some non-euclidian > terms based on say correlation coeffients between > composite units of an aggregate (say as a function of > USA states' > comovements). In this case all restrictions based on > data might not be met with 2 dim coordinate plane. So > will > 3dimensions suffice? > > Is there an algorithm out there? > > Any advice? > > Ultimately, I want to make a graph/cartogram based on > different relative measures of distance. > > Thanks much for all your time. > borisdev@yahoo.com > > ------------- > The compgeom mailing lists: see > http://netlib.bell-labs.com/netlib/compgeom/readme.html > or send mail to compgeom-request@research.bell-labs.com with the line: > send readme > Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. -------------- next part -------------- A non-text attachment was scrubbed... Name: aupetit.vcf Type: text/x-vcard Size: 272 bytes Desc: Card for aupetit Url : http://compgeom.poly.edu/pipermail/compgeom-announce/attachments/20031201/99338414/aupetit.vcf From large at cs.duke.edu Tue Dec 2 20:47:26 2003 From: large at cs.duke.edu (Lars Arge) Date: Mon Jan 9 13:41:12 2006 Subject: ALENEX'04 accepted papers Message-ID: <3FCD40AE.3090600@cs.duke.edu> Papers accepted for presentation at the 6th Workshop on Algorithm Engineering and Experiments (ALENEX'04). January 10, 2004, Astor Crown Plaza Hotel, New Orleans, Louisiana. http://www.siam.org/meetings/alenex04. --- Engineering a Cache-Oblivious Sorting Algorithm Gerth Brodal, Rolf Fagerberg and Kristoffer Vinther The Robustness of the Sum-of-Squares Algorithm for Bin Packing M. Bender, B. Bradley, G. Jagannathan and K. Pillaipakkamnatt Practical Aspects of Compressed Suffix Arrays and FM-index in Searching DNA Sequences Wing-Kai Hon, Tak-Wah Lam, Wing-Kin Sung, Wai-Leuk Tse, Chi-Kwong Wong and Siu-Ming Yiu Faster placement of hydrogens in protein structures by dynamic programming Andrew Leaver-Fay, Yuanxin Liu and Jack Snoeyink An Experimental Analysis of a Compact Graph Representation Dan Blandford, Guy Blelloch and Ian Kash Kernelization Algorithms for the Vertex Cover Problem: Theory and Experiments Faisal N. Abu-Khzam, Rebecca L. Collins, Michael R. Fellows and Michael A. Langston Safe Separators for Treewidth Hans L. Bodlaender and Arie M.C.A. Koster Efficient Implementation of a Hotlink Assignment Algorithm for Web Sites Artur Alves Pessoa, Eduardo Sany Laber and Cr?ston de Souza Experimental Comparison of Shortest Path Approaches for Timetable Information Evangelia Pyrga, Frank Schulz, Dorothea Wagner and Christos Zaroliagis Reach-based Routing: A New Approach to Shortest Path Algorithms Optimized for Road Networks Ron Gutman Lazy Algorithms for Dynamic Closest Pair with Arbitrary Distance Measures Jean Cardinal and David Eppstein Approximating the Visible Region of a Point on a Terrain Boaz Ben-Moshe, Paz Carmi and Matthew J. Katz A computation framework for handling motion Leo Guibas, Menelaos Karavelas and Daniel Russel Engineering a Sorted List Data Structure for 32 Bit Keys Roman Dementiev, Lutz Kettner, Jens Mehnert and Peter Sanders ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From h.j.gudmundsson at tue.nl Fri Dec 5 15:16:29 2003 From: h.j.gudmundsson at tue.nl (Joachim Gudmundsson) Date: Mon Jan 9 13:41:12 2006 Subject: CG models of computation? Message-ID: <000301c3bb3a$60ea4910$84449b83@campus.tue.nl> Dear Colleagues, I have a question about which models of computation that are accepted in the computational geometry community. In many of the papers I have co-authored we have strived to use the algebraic decision tree model of computation (sometimes extended with indirect addressing), but sometimes also using the real RAM. Recently, I read an excellent paper where the authors add the power of the floor function to the standard model of computation. The running time of their algorithm is almost linear and beats the lower bound in the comparison model. Somewhat puzzled and skeptical I asked my colleagues about their opinion on this topic, only to find out that this model was, according to my colleagues, unofficially accepted. One of my colleagues even claimed that it was so widely accepted that it is not even necessary to explicitly point out in a paper if the floor function is used or not. Amazed about this information I went back to my office and looked at a paper I'm currently working on. Adding the floor function would trivially improve the running time of the algorithm from O((m+n) log n) to O(m+n log n), maybe even more. My question is, what is "unofficially" allowed? One could claim that the use of floor function should be accepted since it is used in practice and very fast. How about bit manipulation? But then we should measure the complexity in the number of input bits, right? Anyway, I would be very happy if anyone could help remove my obvious ignorance on this topic. Sincerely, Joachim Gudmundsson ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From jeffe at cs.uiuc.edu Sun Dec 7 04:16:10 2003 From: jeffe at cs.uiuc.edu (Jeff Erickson) Date: Mon Jan 9 13:41:12 2006 Subject: CG models of computation? In-Reply-To: <000301c3bb3a$60ea4910$84449b83@campus.tue.nl> References: <000301c3bb3a$60ea4910$84449b83@campus.tue.nl> Message-ID: <20031207101610.GI9674@granmapa.cs.uiuc.edu> Joachim Gudmundsson wrote: | Recently, I read an excellent paper where the authors add the power | of the floor function to the standard model of computation. The | running time of their algorithm is almost linear and beats the lower | bound in the comparison model. | | Somewhat puzzled and skeptical I asked my colleagues about their | opinion on this topic, only to find out that this model was, | according to my colleagues, unofficially accepted. | | My question is, what is "unofficially" allowed? One could claim | that the use of floor function should be accepted since it is used | in practice and very fast. How about bit manipulation? But then we | should measure the complexity in the number of input bits, right? This is actually a pretty big can of worms! The most common model of geometric computation seems to be the unit-cost real RAM, but it is fairly common to add the floor function to permit bucketing or hashing, in many cases beating lower bounds in the algebraic decision tree model. The two classical examples are Gonzalez's algorithm for MAX GAP [g-asrp-75] and Rabin's randomized algorithm for closest pairs [r-pa-76]. However, despite its general acceptance, the unit-cost real RAM with the floor function is NOT a reasonable model of computation, because it allows any problem in PSPACE or #P to be solved in polynomial time! In 1979, Sch\"onhage [s-pram-79] described an algorithm to solve the PSPACE-complete problem QBF---deciding if a given arbitrarily quantified boolean formula is true or false---using a polynomial number of integer arithmetic operations: z=x+y, z=x-y, z=xy, and z=floor(x/y). The trick is to encode the entire formula into a single integer and then use arithmetic to process different parts of the encoded forumla in parallel. His algorithm just removes the quantifiers, by replacing each ExF(x) with F(0)vF(1) and each AxF(x) with F(0)^F(1), and then simplifies the resulting quantifier-free formula to either 0 or 1. Hartmanis and Simon [hs-pmram-74] did the same thing in 1974, only using bit-wise Boolean operations instead of integer division. A few years later, Bertoni et al. [bms-scram-85] generalized the same approach to the #P-complete problem #SAT: How many satisfying assignments does this boolean formula have? Peter van Emde Boas has a great discussion of "the unreasonable power of integer multiplication" in his survey of models of computation [e-mms-90]. Partly as a result of the Hartmanis-Simon result, there are now two essentially standard integer RAM models: (1) Logarithmic-cost (or "bit-level") RAM: Each memory location can store an arbitrary integer. The cost of each arithmetic operation is proportional to the total number of BITS involved. (2) Word-level RAM: Each memory location can store a single word consisting of Theta(log n) bits. Arithmetic and boolean operations on words take constant time, presumably because of hardware parallelism. Arithmetic on larger integers must be simulated. Complexity theorists prefer the bit-level RAM, but it's rarely used by anyone else. Almost all integer-RAM algorithms are implicitly developed and analyzed on the word-level RAM. Maybe it would be more accurate to say that most algorithms are analyzed on the unrestricted unit-cost integer RAM, but since the integers they create have only O(log n) bits, they might as well be using the word-level RAM. Essentially the same ideas as the Hartmanis-Simon-Sch\"onhage QBF algorithm lead to "unreasonably efficient" algorithms and data structures on the word-level RAM, starting with Fredman and Willard's fusion trees [fw-sitbf-93]. Anyway... since a unit-cost integer RAM can be trivially simulated using a unit-cost real RAM with the floor function, we can solve QBF or #SAT in polynomial time in that model as well. The most obvious way to avoid this mess is simply to never combine exact real arithmetic with the floor function, but it's too late for that; the bits are already out of the bag. A more reasonable approach might be to allow the use of the floor function, but only if the resulting integers have O(log n) bits. Most realRAM+floor algorithms (that I know about) obey this restriction. Allowing an operation that computes the O(log n) most significant bits of a real number might also be reasonable. Alternately, if you prefer the logarithmic-cost model, you could let the cost of the floor operation be the number of bits of the result. Even without the floor function, the real RAM is not necessarily a "reasonable" model of computation. For example, despite the existence of linear-time real RAM algorithms to compute minimum-link paths, Kahan and Snoeyink [ks-bcmlp-96] constructed examples of polygons with O(log n)-bit integer coordinates, such that some minimum link paths require Omega(n^2 log n) bits of precision. Real-RAM algorithms that compare sums of distances are also questionable, since it is open whether sums of square roots of integers can be compared in polynomial time on an integer RAM. (But see [b-csrpt-91]!) -- Jeff (Any references not listed here are in geom.bib.) @inproceedings{hs-pmram-74 , author = "Juris Hartmanis and Janos Simon" , title = "On the power of multiplciation in random-access machines" , booktitle = "Proc. 15th Annu. IEEE Sympos. Switching Automata Theory" , year = 1974 , pages = "13--23" } @inproceedings{s-pram-79 , author = "Arnold Sch{\"o}nhage" , title = "On the power of random access machines" , booktitle = "Proc. 6th Internat. Colloq. Automata Lang. Program." , series = "Lecture Notes Comput. Sci." , volume = 71 , publisher = "Springer-Verlag" , year = 1979 , pages = "520--529" } @article{bms-scram-85 , author = "A. Bertoni and G. Mauri and N. Sabadini" , title = "Simulations among classes of random access machines and equivalence among numbers succinctly represented" , journal = "Ann. Discrete Math." , volume = 25 , year = 1985 , pages = "65--90" } @incollection{e-mms-90 , author = "Peter van {Emde Boas}" , title = "Machine models and simulation" , editor = "Jan van Leeuwen" , booktitle = "Handbook of Theoretical Computer Science" , volume = "A" , publisher = "Elsevier" , address = "Amsterdam" , year = 1990 , pages = "1--66" } ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From Andreas.Fabri at sophia.inria.fr Mon Dec 8 22:09:23 2003 From: Andreas.Fabri at sophia.inria.fr (andreas) Date: Mon Jan 9 13:41:13 2006 Subject: Approximation of a function wth piecewise constant functions Message-ID: <3FD4E883.4030505@sophia.inria.fr> Hello, I have 100 values between 0 and 255. I want to approximate this function with 10 non-overlapping intervals, where the degree of freedom is * the start and endpoint * the value associated to the interval. This is probably a classical problem but I got no reply on sci.op-research. Thanks in advance, andreas -------------- next part -------------- An HTML attachment was scrubbed... URL: http://compgeom.poly.edu/pipermail/compgeom-announce/attachments/20031208/e1b9859f/attachment.htm From suresh at research.att.com Mon Dec 8 17:23:44 2003 From: suresh at research.att.com (Suresh Venkatasubramanian) Date: Mon Jan 9 13:41:13 2006 Subject: Approximation of a function wth piecewise constant functions In-Reply-To: <3FD4E883.4030505@sophia.inria.fr> References: <3FD4E883.4030505@sophia.inria.fr> Message-ID: On Mon, 8 Dec 2003, andreas wrote: > Hello, > > I have 100 values between 0 and 255. > I want to approximate this function > with 10 non-overlapping intervals, > where the degree of freedom is > * the start and endpoint > * the value associated to the interval. > > This is probably a classical problem > but I got no reply on sci.op-research. > > Thanks in advance, > > andreas > > You didn't mention the error function: assuming it is some kind of least squares, what you want a k-median solution (k=10 in this case). The k-median problem in R^n with metric d is Find k centers c_1, ... c_k such that the cost \sum d(p_i, c_n(i)) is minimized, where c_n(i) is the center closest to p_i. In your case, you are looking to solve k-median on the line. If your error metric is more of an l_infty kind of thing (i.e minimize the max error), then this boils down to the k-center problem: same as the above, except that you want to minimize the max error, rather than the sum of errors. There are a variety of algorithms for this problem depending on the metric, so a search for k-median/k-center results should help narrow things down a bit. Suresh Venkatasubramanian, Ph: 973 360 8951 (o) Member, Technical Staff Web: http://www.research.att.com/~suresh/ AT&T Shannon Labs "The guitar is the ideal instrument for anyone who is able to love loneliness." --Angelo Gilardino ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From rraman at cs.uiowa.edu Tue Dec 9 22:00:38 2003 From: rraman at cs.uiowa.edu (Rajiv Raman) Date: Mon Jan 9 13:41:13 2006 Subject: Intersecting rectangles. In-Reply-To: <20031207101610.GI9674@granmapa.cs.uiuc.edu> Message-ID: Hi, I'm experimenting with some coloring algorithms for intersection graphs of (isothetic) rectangles (primarily in the plane, but want to experiment with these techniques for higher dimensional rectangles also). In this context, rectangles are said to intersect only if the area of intersection is non-zero. In order to test these algorithms, I want to write a program that would take as parameters, (n,k), where n is the number of rectangles, and k is the maximum number of rectangles that share a point in their interior. (And hence, the corresponding graph has a clique of size atmost k). The program would generate n rectangles at random with the desired intersection property. I was wondering if there were known efficient algorithms/data-structures for this problem, or what would be a simple way to implement this. All techniques I could think of involved generating a random rectangle, and then testing if it satisifies the intersection constraint. If it doesn't, then I throw the rectangle away and generate another, and continue till I have generated n rectangles. However, this doesn't seem to work well for large values of n and small values of k. I would be grateful if anyone could provide pointers in this regard. Thanks, Rajiv ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From casa2004 at miralab.unige.ch Wed Dec 10 14:29:29 2003 From: casa2004 at miralab.unige.ch (Casa2004) Date: Mon Jan 9 13:41:13 2006 Subject: CfP - CASA2004 / Computer Animation and Social Agents 2004 Message-ID: <033501c3bf21$a39d8020$a444c281@miralabnt.unige.ch> [Apologies if you receive this CfP more than once] -------- Call for Participation ---------- ---------------- CASA2004 ---------------- Computer Animation and Social Agents 2004 http://casa2004.miralab.unige.ch/ -------------- next part -------------- An HTML attachment was scrubbed... URL: http://compgeom.poly.edu/pipermail/compgeom-announce/attachments/20031210/c2bd535d/attachment.htm From bender at cs.sunysb.edu Tue Dec 9 12:36:50 2003 From: bender at cs.sunysb.edu (Michael Bender) Date: Mon Jan 9 13:41:13 2006 Subject: SPAA '04 Message-ID: <200312091736.MAA06319@compserv4.cs.sunysb.edu> ======================================================================== CALL FOR PAPERS Sixteenth Annual ACM Symposium on Parallelism in Algorithms and Architectures SPAA '04 June 27-30, 2004 Barcelona, Spain http://www.spaa-conference.org ======================================================================== SCOPE: Contributed papers are sought in ALL areas of parallel algorithms and architectures. SPAA defines the term "parallel" broadly, encompassing any computational system that can perform multiple operations or tasks simultaneously. Thus, this call for papers covers both traditional parallel and distributed algorithms and architectures, as well as the Internet, the web, sensor networks, quantum and DNA computing, etc. Topics of interest include, but are not limited to: PARALLEL COMPUTING MASSIVE PARALLELISM Parallel Algorithms Cluster Computing and Grid Computing Parallel Complexity Theory Mobile and Wireless Computing Parallel Computing and Applications The Internet and the World Wide Web Models for Parallel Sensor Networks and Distributed Computing Instruction Level Parallelism and VLSI Satellite and Radio Networks Routing and Information Dissemination Other Large Networks Parallel Data Structures Pricing and Equilibria in Networks Compilers and Tools Supercomputer Architecture for Parallel Computation and Computing Memory-Aware Algorithms Quantum and DNA Computing Metacomputing Parallel Data Bases and Data Mining CONFERENCE PRESENTATION: Regular presentations will be allotted a 25-minute talk and up to 10 pages in the proceedings. This format is intended for contributions reporting original research, submitted exclusively to this conference. Presentation at the SPAA Revue will be allotted a 10-minute talk and up to 2 pages in the proceedings. This format is a forum for brief communications, which may be published later in other conferences. SUBMISSIONS: Authors of contributed papers are encouraged to submit their manuscript electronically. To submit electronically, visit http://sigact.cs.unlv.edu/~spaa2004/SPAA2004.html for instructions. This is the preferred method of submission. The deadline for electronic submissions is February 4, 2004, 5 p.m. EST. The submissions server can be turned off anytime after this point. Authors who are unable to submit electronically should contact the program chair, Micah Adler, at micah@cs.umass.edu to receive instructions. Do not send electronic submissions to this email address. The cover page should include (1) title, (2) authors and affiliation, (3) postal and email address of the contact author, (4) a brief abstract describing the content of the paper, and (5) an indication if this is a regular presentation or a SPAA Revue presentation. If requested by the authors, an extended abstract that is not selected for a regular presentation will also be considered for the SPAA Revue. Such a request will not affect the consideration of the paper for a regular presentation. Submissions for regular presentations should include an introduction understandable to a nonspecialist including motivation and previous work, and a technical exposition directed to a specialist. It should not exceed 10 printed pages in 11-point type or larger (excluding cover, figures, and references). More details may be supplied in a clearly marked appendix to be read at the discretion of the program committee. A camera-ready copy of each accepted paper must be prepared according to ACM guidelines for inclusion in the conference proceedings. A submission for the SPAA Revue should consist of a 2-page abstract for each proposed presentation. A camera-ready copy of each accepted abstract will have to be prepared according to ACM guidelines for inclusion in the proceedings of the conference. NOTIFICATION Authors will be sent notification of acceptance or rejection by e-mail or letter mailed on or before March 15, 2004. A camera-ready copy of each accepted paper, prepared according to ACM guidelines, must be received by April 6, 2004. ========================================================================== Program Chair Micah Adler, U. Massachusetts Program Committee Micah Adler, U. Massachusetts John Byers, Boston U. Tom Cormen, Dartmouth College Bruce Hendrickson, Sandia National Laboratories Maurice Herlihy, Brown U. Christos Kaklamanis, U. Patras Christian Lengauer, U. Passau Geppino Pucci, U. Padova Satish Rao, U.C. Berkeley Yves Robert, ENS Lyon Peter Sanders, MPI Saarbrucken Daniel Sorin, Duke U. Aravind Srinivasan, U. Maryland Berthold Vocking, U. Dortmund SPAA Local Arrangements Chair Eulalia Barriere, Technical U. of Catalonia SPAA General Chair Phil Gibbons, Intel Research SPAA Secretary Cynthia A. Phillips, Sandia National Laboratories SPAA Treasurer Rajmohan Rajaraman, Northeastern U. Publicity Chair Michael Bender, SUNY Stony Brook ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From shlomo.anglister at intel.com Thu Dec 11 15:26:04 2003 From: shlomo.anglister at intel.com (Anglister, Shlomo) Date: Mon Jan 9 13:41:13 2006 Subject: Intersecting rectangles. Message-ID: <30B8853201F31F4283E8B901EFE8B5AB029AE711@hasmsx401.iil.intel.com> Hi, Consider the following algorithms: 1) Generate a random rectangular cover of the plane. 2) Shift all rectangles at random until you satisfy the clique condition. This is a naive approach with bad complexity that will do the job. 1) Generate flowers (cliques) built from rectangles with the desired clique size. 2) Spread them in the plane. Hope it helps. Shlomo -----Original Message----- From: Rajiv Raman [mailto:rraman@cs.uiowa.edu] Sent: Wednesday, December 10, 2003 6:01 AM To: compgeom-discuss@research.bell-labs.com Subject: Intersecting rectangles. Hi, I'm experimenting with some coloring algorithms for intersection graphs of (isothetic) rectangles (primarily in the plane, but want to experiment with these techniques for higher dimensional rectangles also). In this context, rectangles are said to intersect only if the area of intersection is non-zero. In order to test these algorithms, I want to write a program that would take as parameters, (n,k), where n is the number of rectangles, and k is the maximum number of rectangles that share a point in their interior. (And hence, the corresponding graph has a clique of size atmost k). The program would generate n rectangles at random with the desired intersection property. I was wondering if there were known efficient algorithms/data-structures for this problem, or what would be a simple way to implement this. All techniques I could think of involved generating a random rectangle, and then testing if it satisifies the intersection constraint. If it doesn't, then I throw the rectangle away and generate another, and continue till I have generated n rectangles. However, this doesn't seem to work well for large values of n and small values of k. I would be grateful if anyone could provide pointers in this regard. Thanks, Rajiv ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From tsimos at mail.ariadne-t.gr Tue Dec 16 23:10:47 2003 From: tsimos at mail.ariadne-t.gr (Theodore Simos) Date: Mon Jan 9 13:41:13 2006 Subject: ICNAAM 2004 Message-ID: <3FDF74D7.FBC1119B@mail.ariadne-t.gr> FIRST ANNOUNCEMENT AND CALL FOR PAPERS INTERNATIONAL CONFERENCE OF NUMERICAL ANALYSIS AND APPLIED MATHEMATICS 2004 (ICNAAM 2004), CHALKIS , GREECE , 10-14 SEPTEMBER 2004. URL address: http://www.uop.gr/~icnaam/ The aim of ICNAAM 2004 is to bring together leading scientists of the international Numerical & Applied Mathematics community and to attract original research papers of very high quality. The topics to be covered include (but are not limited to): All the research areas of Numerical Analysis and Computational Mathematics and all the research areas of Applied Mathematics (see http://www.uop.gr/~icnaam/res8/aimscope.htm). Chairmen and Organisers Dr. T.E. Simos, Active Member of the European Academy of Sciences and Arts and Corresponding Member of the European Academy of Sciences, Department of Computer Science and Technology, Faculty of Sciences and Technology, University of Peloponnese, Greece and Dr. Ch. Tsitouras , Technological Educational Institute of Chalkis, Greece . Vice-Chairman: Dr. G. Psihoyios, Anglia Polytechnic University , Cambridge , UK . Scientific Committee Prof. G. vanden Berghe, Belgium, Prof. P. E. Bjorstad, Norway, Prof. J. Cash, UK, Prof. R. Cools, Belgium, Prof. A. Cuyt, Belgium, Prof. B. Fischer, Germany, Prof. R. W. Freund, USA, Prof. I. Gladwell, USA, Prof. B. Hendrickson, USA, Prof. A. Klar, Germany, Prof. W. F. Mitchell, USA, Dr. T.E. Simos, Greece, Prof. W.Sproessig, Germany, Dr. Ch. Tsitouras, Greece, Prof. G. Alistair Watson, UK. Proceedings: Extended abstracts will be published in a Special Volume of Wiley-VCH. The journals in which selected Proceedings of ICNAAM 2004 will be published are: (i) Applied Numerical Analysis and Computational Mathematics (ANACM) (Wiley-VCH). This is the official journal of European Academy of Computational Methods in Sciences and Engineering and (ii) Mathematical Methods in the Applied Sciences (Wiley & Sons). Call for Sessions Workshops and Minisymposia: We invite proposals for Sessions, Workshops or Minisymposia. Each session should have at least 6 paper presentations. For this session the organiser or his team can have at most 2 papers. Each workshop or minisymposium should have at least 8 paper presentations. For this workshop or minisymposium the organiser or his team can have at most 2 papers. The Session, Workshop or Minisymposium organizer will be responsible for advertising the workshop, reviewing and selecting the papers. The Session organisers will have free registration in ICNAAM 2004. The Workshop or Minisymposium organizers will have free registration and a participation in the Accommodation. Papers accepted for Sessions, Workshops or Minisymposia will be published in the Proceedings of ICNAAM 2004. After the Conference the papers presented at the Sessions, Workshops or Minisymposia will be considered for publication in the appropriate journals. Submission of Proposals Proposals to organize Sessions, Workshops or Minisymposia should include the following information: Title of the workshop name, affiliation, mailing address and e-mail address of the proposer(s) description of the topic of the session (not exceeding 100 words) a short description on how the session will be advertised. The deadline for proposal submission is January 15, 2004. Please send your proposal to icnaam@uop.gr Contact information: Secretary ICNAAM, E-mail: icnaam@uop.gr, Postal Address: 26 Menelaou Street, Amfithea Paleon Faliron, GR-175 64, Athens, Greece, Fax: +30210 94 20 091 -- Dr. T.E. Simos Active Member of the European Academy of Sciences and Arts Corresponding Member of the European Academy of Sciences Editor-in-Chief and Founder: Journal of Computational Methods in Sciences and Engineering (JCMSE) (Cambridge International Sciences Publishing) Applied Numerical Analysis and Computational Mathematics (ANACM) (Wiley-VCH) Computing Letters (COMPULETT) (Cambridge International Sciences Publishing) Editor of the Book Series: Computational, Numerical and Mathematical Methods in Sciences and Engineering (Imperial College Press) ------------------------------------------------------------------------------------------------------- Office Address: Department of Computer Science and Technology School of Sciences and Technology University of Peloponnese GR-22100 Tripolis Greece ------------------------------------------------------------------------------------------------------- Postal Address 26 Menelaou Street, Amfithea ? Paleon Faliron, GR-175 64 Athens, Greece ------------------------------------------------------------------------------------------------------- Conferences: International Conference of Computational Methods in Sciences and Engineering 2004 (ICCMSE 2004). We will provide information soon. For previous International Conferences of Computational Methods in Sciences and Engineering see at: www.uop.gr/~iccmse/ International Conference of Numerical Analysis and Applied Mathematics 2004 (ICNAAM 2004). URL address: www.uop.gr/~icnaam/ ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From vavasis at cs.cornell.edu Wed Dec 17 12:33:36 2003 From: vavasis at cs.cornell.edu (Stephen Vavasis) Date: Mon Jan 9 13:41:13 2006 Subject: trees inside delaunay triangulation Message-ID: <40E631F174C41E4DBE52727E137AF9277317F2@EXCHVS1.cs.cornell.edu> Dear colleagues, I have the following conjecture based on trying some examples. I'm wondering if anyone knows whether it is true. Conjecture. Let S be a set of n points in general position in the plane. Let T be the Delaunay triangulation of these points. Then there exists a subset T_1,...,T_{n-2} of n-2 triangles from T such that (1) These triangles form a tree in the dual graph of the Delaunay triangulation and (2) Every one of the n original points is adjacent to at least one of the n-2 triangles. Remark 1. This conjecture is obviously true if the n points are in convex position, since in this case the DT has exact n-2 triangles and they form a tree. Remark 2. The assumption of general position is necessary, since I thought of a counterexample for points not in general position. Specifically, consider a 3-by-3 evenly spaced rectangular lattice of nine points. There are many DT's for these points, but select the one in which the central point is adjacent to only four edges. This triangulation does not have the conjectured subtree. Thanks, Steve Vavasis ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From rseidel at stone.cs.uni-sb.de Wed Dec 17 21:00:45 2003 From: rseidel at stone.cs.uni-sb.de (Raimund Seidel) Date: Mon Jan 9 13:41:13 2006 Subject: trees inside delaunay triangulation In-Reply-To: <40E631F174C41E4DBE52727E137AF9277317F2@EXCHVS1.cs.cornell.edu> Message-ID: If I am not mistaken, then this is not true in general. If it were true, the boundary of the tree triangles would form a hamiltonian circuit. If I remember correctly Mike Dillencourt showed that there are Delaunay triangulations that are not Hamiltonian. RS On Wed, 17 Dec 2003, Stephen Vavasis wrote: > Dear colleagues, > > I have the following conjecture based on trying some examples. I'm wondering if anyone knows whether it is true. > > Conjecture. Let S be a set of n points in general position in the plane. Let T be the Delaunay triangulation of these points. Then there exists a subset T_1,...,T_{n-2} of n-2 triangles from T such that > (1) These triangles form a tree in the dual graph of the Delaunay triangulation > and > (2) Every one of the n original points is adjacent to at least one of the n-2 triangles. > > Remark 1. This conjecture is obviously true if the n points are in convex position, since in this case the DT has exact n-2 triangles and they form a tree. > > Remark 2. The assumption of general position is necessary, since I thought of a counterexample for points not in general position. Specifically, consider a 3-by-3 evenly spaced rectangular lattice of nine points. There are many DT's for these points, but select the one in which the central point is adjacent to only four edges. This triangulation does not have the conjectured subtree. > > Thanks, > Steve Vavasis > > ------------- > The compgeom mailing lists: see > http://netlib.bell-labs.com/netlib/compgeom/readme.html > or send mail to compgeom-request@research.bell-labs.com with the line: > send readme > Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. > ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From orourke at turing.csc.smith.edu Wed Dec 17 15:26:45 2003 From: orourke at turing.csc.smith.edu (Joseph O'Rourke) Date: Mon Jan 9 13:41:13 2006 Subject: trees inside delaunay triangulation In-Reply-To: Message-ID: On Wed, 17 Dec 2003, Raimund Seidel wrote: > If I am not mistaken, then this is not true in general. > If it were true, the boundary of the tree triangles would > form a hamiltonian circuit. > If I remember correctly Mike Dillencourt showed that there > are Delaunay triangulations that are not Hamiltonian. Raimund is correct. I raised this question in an old paper, and Dillencourt resolved it negatively. References below. :-j @article{obw-cdnh-87 , author = "J. O'Rourke and H. Booth and R. Washington" , title = "Connect-the-dots: {A} new heuristic" , journal = "Comput. Vision Graph. Image Process." , volume = 39 , year = 1987 , pages = "258--266" , keywords = "pattern recognition, Delaunay triangulations, Hamiltonian cycles " } @article{d-nhndt-87 , author = "M. B. Dillencourt" , title = "A non-{Hamiltonian}, nondegenerate {Delaunay} triangulation" , journal = "Inform. Process. Lett." , volume = 25 , year = 1987 , pages = "149--151" } ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html. From statistics at hicstatistics.org Fri Dec 19 09:20:09 2003 From: statistics at hicstatistics.org (Hawaii International Conference on Statistics) Date: Mon Jan 9 13:41:13 2006 Subject: Call for Papers Message-ID: Call for Papers/Abstracts/Submissions Hawaii International Conference on Statistics, Mathematics and Related Fields June 9 - 12, 2004 Sheraton Waikiki Hotel, Honolulu Hawaii, USA Submission Deadline: January 21, 2004 Sponsored by: East West Council for Education Center of Asian Pacific Studies of Peking University Web address: http://www.hicstatistics.org Email address: statistics@hicstatistics.org The 2004 Hawaii International Conference on Statistics, Mathematics and Related Fields will be held from June 9 (Wednesday) to June 12 (Saturday), 2004 at the Sheraton Waikiki Hotel in Honolulu, Hawaii. The conference will provide many opportunities for academicians and professionals from statistics and/or mathematics related fields to interact with members inside and outside their own particular disciplines. Cross-disciplinary submissions with other fields are welcome. Topic Areas (All Areas of Statistics and/or Mathematics are Invited): Statistics Topics: Agricultural Statistics, Applied Statistics, Bayesian Statistics, Biostatistics, Business Statistics, Computational Statistics, Computer Simulations, Econometrics, Educational Statistics, Environmental Statistics, Epidemiology, Industrial Statistics, Management Science, Mathematical Statistics, Medical Statistics, Non-Parametric Statistics, Operations Research, Probability, Psychological Measurement, Quantitative Methods, Statistical Modeling, Statistics Education, Cross-disciplinary areas of Statistics, Other Areas of Statistics. Mathematics Topics: Algebra, Applied Mathematics, Calculus, Computational Mathematics, Discrete Mathematics, Foundations of Mathematics, Financial Mathematics, Finite Mathematics, Fractals, Geometry, History of Mathematics, Logic, Mathematics Education, Number Analysis, Number Theory, Pre-Algebra, Pre-Calculus, Probability, Topology, Cross-disciplinary areas of Mathematics, Other Areas of Mathematics. The Hawaii International Conference on Statistics, Mathematics and Related Fields encourages the following types of papers/abstracts/submissions for any of the listed areas: Research Papers - Completed papers. Abstracts - Abstracts of completed or proposed research. Student Papers - Research by students. Work-in-Progress Reports or Proposals for future projects. Reports on issues related to teaching. For more information about submissions see: http://www.hicstatistics.org/cfp_stats.htm Format of Presentations: -Paper sessions will have three to four papers presented in each 90 minute session, giving each presenter 20 ? 30 minutes. -Workshop presentations will be given a full 90 minute session. -Panel sessions will provide an opportunity for three or more presenters to speak in a more open and conversational setting with conference attendees. Submissions for these 90 minute sessions should include the name, department, affiliation, and email address of each panelist in addition to a description of the presentation and the title page. -Poster sessions will last 90 minutes and consist of a large number of presenters. Poster sessions allow attendees to speak with the presenters on a one-to-one basis. Submitting a Proposal: 1. Create a title page for your submission. The title page should include: a. title of the submission b. topic area of the submission (chooses from above list) c. presentation format (choose from above list) d. name(s) of the author(s) e. department(s) and affiliation(s) f. mailing address(es) g. e-mail address(es) h. phone number(s) i. fax number(s) j. corresponding author if different than lead author 2. Email your abstract and/or paper, along with a title page, to statistics@hicstatistics.org Receipt of submissions will be acknowledged via email within 48 hours. If you do not wish to email your submission, you may send it via regular mail or fax to: Hawaii International Conference on Statistics, Mathematics and Related Fields P.O. Box 75023 Honolulu, HI, 96836, USA 808-947-2420 (Fax) ***If submitting via regular mail, please supply two copies of your submission*** There is a limit of two contributed submissions per lead author. 3. Submissions will only be published in the conference proceedings if at least one of the authors registers and attends the conference. More information will be provided upon acceptance. 4. If you wish to be a session chair, please e-mail your request to statistics@hicstatistics.org and indicate the topic area in which you are interested. Registration for the conference is required to be a session chair. To be removed from this list, please reply to this e-mail with the word "Remove" in the subject heading. Hawaii International Conference on Statistics, Mathematics and Related Fields P.O. Box 75023 Honolulu, HI 96836 USA Telephone: (808) 946-9927 Fax: (808) 947-2420 E-mail: statistics@hicstatistics.org Website: www.hicstatistics.org -------------- next part -------------- An HTML attachment was scrubbed... URL: http://compgeom.poly.edu/pipermail/compgeom-announce/attachments/20031219/01acf7c2/attachment.htm From bender at cs.sunysb.edu Tue Dec 30 12:03:50 2003 From: bender at cs.sunysb.edu (Michael Bender) Date: Mon Jan 9 13:41:13 2006 Subject: SPAA '04 Extended Deadline Message-ID: <200312301703.MAA19171@compserv4.cs.sunysb.edu> Please note that the deadline has been extended to February 6, 2004. It is now after the notification date of STOC. ======================================================================== CALL FOR PAPERS Sixteenth Annual ACM Symposium on Parallelism in Algorithms and Architectures SPAA '04 June 27-30, 2004 Barcelona, Spain http://www.spaa-conference.org ======================================================================== SCOPE: Contributed papers are sought in ALL areas of parallel algorithms and architectures. SPAA defines the term "parallel" broadly, encompassing any computational system that can perform multiple operations or tasks simultaneously. Thus, this call for papers covers both traditional parallel and distributed algorithms and architectures, as well as the Internet, the web, sensor networks, quantum and DNA computing, etc. Topics of interest include, but are not limited to: PARALLEL COMPUTING MASSIVE PARALLELISM Parallel Algorithms Cluster Computing and Grid Computing Parallel Complexity Theory Mobile and Wireless Computing Parallel Computing and Applications The Internet and the World Wide Web Models for Parallel Sensor Networks and Distributed Computing Instruction Level Parallelism and VLSI Satellite and Radio Networks Routing and Information Dissemination Other Large Networks Parallel Data Structures Pricing and Equilibria in Networks Compilers and Tools Supercomputer Architecture for Parallel Computation and Computing Memory-Aware Algorithms Quantum and DNA Computing Metacomputing Parallel Data Bases and Data Mining CONFERENCE PRESENTATION: Regular presentations will be allotted a 25-minute talk and up to 10 pages in the proceedings. This format is intended for contributions reporting original research, submitted exclusively to this conference. Presentation at the SPAA Revue will be allotted a 10-minute talk and up to 2 pages in the proceedings. This format is a forum for brief communications, which may be published later in other conferences. SUBMISSIONS: Authors of contributed papers are encouraged to submit their manuscript electronically. To submit electronically, visit http://sigact.cs.unlv.edu/~spaa2004/SPAA2004.html for instructions. This is the preferred method of submission. The deadline for electronic submissions is February 6, 2004, 5 p.m. EST. The submissions server can be turned off anytime after this point. Authors who are unable to submit electronically should contact the program chair, Micah Adler, at micah@cs.umass.edu to receive instructions. Do not send electronic submissions to this email address. The cover page should include (1) title, (2) authors and affiliation, (3) postal and email address of the contact author, (4) a brief abstract describing the content of the paper, and (5) an indication if this is a regular presentation or a SPAA Revue presentation. If requested by the authors, an extended abstract that is not selected for a regular presentation will also be considered for the SPAA Revue. Such a request will not affect the consideration of the paper for a regular presentation. Submissions for regular presentations should include an introduction understandable to a nonspecialist including motivation and previous work, and a technical exposition directed to a specialist. It should not exceed 10 printed pages in 11-point type or larger (excluding cover, figures, and references). More details may be supplied in a clearly marked appendix to be read at the discretion of the program committee. A camera-ready copy of each accepted paper must be prepared according to ACM guidelines for inclusion in the conference proceedings. A submission for the SPAA Revue should consist of a 2-page abstract for each proposed presentation. A camera-ready copy of each accepted abstract will have to be prepared according to ACM guidelines for inclusion in the proceedings of the conference. NOTIFICATION Authors will be sent notification of acceptance or rejection by e-mail or letter mailed on or before March 15, 2004. A camera-ready copy of each accepted paper, prepared according to ACM guidelines, must be received by April 6, 2004. ========================================================================== Program Chair Micah Adler, U. Massachusetts Program Committee Micah Adler, U. Massachusetts John Byers, Boston U. Tom Cormen, Dartmouth College Bruce Hendrickson, Sandia National Laboratories Maurice Herlihy, Brown U. Christos Kaklamanis, U. Patras Christian Lengauer, U. Passau Geppino Pucci, U. Padova Satish Rao, U.C. Berkeley Yves Robert, ENS Lyon Peter Sanders, MPI Saarbrucken Daniel Sorin, Duke U. Aravind Srinivasan, U. Maryland Berthold Vocking, U. Dortmund SPAA Local Arrangements Chair Eulalia Barriere, Technical U. of Catalonia SPAA General Chair Phil Gibbons, Intel Research SPAA Secretary Cynthia A. Phillips, Sandia National Laboratories SPAA Treasurer Rajmohan Rajaraman, Northeastern U. Publicity Chair Michael Bender, SUNY Stony Brook ------------- The compgeom mailing lists: see http://netlib.bell-labs.com/netlib/compgeom/readme.html or send mail to compgeom-request@research.bell-labs.com with the line: send readme Now archived at http://www.uiuc.edu/~sariel/CG/compgeom/maillist.html.