(This tribute has appeared in the special issue on Semidefinite
Programming in Mathematical Programming, volume 77, 1997.)
Svata Poljak was born in Prague on October 9, 1951. He did his training
at Charles University in Prague and received his PhD in 1980 under the
supervision of Zdenek Hedrlin. Upon completion of his PhD he first took a
position at Ceske Vysoke Uceni Technicke, the Technical University in Prague,
in the Department of Operations Research, and
next, in 1986, at Charles University in the Department of Applied Mathematics.
In April 1994 he moved to the
University of Passau to take up a position in the
Faculty of Mathematics and Computer Science.
He died on April 2, 1995 in a car accident.
Svata is survived by his wife Jana and their two sons Honza and Vitek.
Svata had a very broad interest and a wide mathematical knowledge.
This is best illustrated by his many important contributions in
diverse areas of discrete mathematics and combinatorial optimization
such as
matroid theory, matching theory, the max-cut and stable set problem,
spectral approaches to graph problems,
convex and polyhedral relaxations, semidefinite programming,
and various other integer programming related problems.
The fast approximation algorithms for finding a maximum cut
by semidefinite
programming, which are currently in the spotlight and play a major role
in the popularity of semidefinite programming,
find their root in work
of Svata on eigenvalue methods for graph problems.
In addition, Svata's early work included
pioneering contributions to the area of neural networks.
Svata was involved in a fatal car accident.
This occurred 62 kms from Prague on Sunday evening April 2, 1995.
Svata was on his way back to Prague from his summer house in Nove Hute.
This is a village in the mountains, very conveniently located
about halfway between Passau and Prague.
Svata had just bought the cottage and he was
really thrilled with it. In winter you can go skiing, starting
right from the front door. It was one of Svata's longstanding dreams
to have a place like that ...
He was in the car with Standa Tyle, one of his best friends from Prague,
two women including Standa's wife, and two children.
They were hit by a car that came the other way, but
on their side. There was no way to escape.
Svata and his friend must have been dead instantly. The
children recovered quickly from their
physical injuries, but the two women had to undergo treatment for a long
time.
Svata and Standa belonged to a group of four very good
friends, who were engaged in fencing from the age of 10.
The four of them and, later also their families, have remained inseparable
throughout the years. They shared, among other things,
a common love for hiking, canoeing, cross-country skiing,
mountain trips, biking, etc...
This tragic accident happened at a moment which may have been
among the happiest in Svata's life. Svata was indeed very happy
with his new professional activity in Passau; he liked very much
his work and the university environment,
as well as living in Passau with his family.
During the winter of 1995, he enjoyed fully
the snowy weekends in Nove Hute, where he could
happily mix work and leisure.
Svata will remain a point of reference in our community in
many respects. We regret deeply the loss of a colleague and friend.
Following are a few memories by some of his collaborators and friends.
-
from Michele Conforti:
I did not know Svata too well, but there is a story I would like to tell.
A few years ago, Svata applied for a position and he asked me
for a letter of
recommendation. He sent me his vitae together with some publications.
When I looked into his stuff, it became obvious that he was a much more
advanced and established researcher than I was. I felt quite embarrassed
to write a letter for such a strong (and versatile!) person. I think that
he had a much larger mathematical culture than the average researcher in
our area, but his low profile played (although won him some admirers, like
me) a bit against him. When he proposed strikingly innovative
research, as the use of semidefinite programming to obtain bounds for
integer programs, he had trouble getting it accepted. It is very sad
that only now we are here to recognize the value of this very honest person.
-
from Michel Goemans:
I did not know Svata well, having met him only once at an Oberwolfach
meeting. I was hoping to have the opportunity to get to know him better,
but sadly this will not happen. I remember very well the result he
presented at this Oberwolfach meeting; it was a real gem, like many of
his
results. He proved in a very elegant way that, for arbitrarily weighted
instances of maxcut on cubic graphs, local search terminates in a
polynomial number of iterations.
His work with Charles Delorme on eigenvalue bounds for the maxcut
problem
is closely related to my work with David Williamson on the worst-case
analysis of semidefinite programming relaxations for maxcut. I got
interested in this topic after a series of talks by Laci Lov\'asz in
1989,
but did not make any progress then. It was Charles Delorme and Svata
Poljak's conjecture of the 5-cycle being the worst for their eigenvalue
bound (which is still open) and Farid Alizadeh's semidefinite
programming
paper that motivated David and I to look back at the problem, and try
harder to prove a worst-case bound.
-
from Francois Jaeger:
I always enjoyed to be with Svata; to share with him the love of
mathematics and the love of mountains. He was so enthusiastic, so full of
life and so committed to everything he undertook. When we talked about
mathematics, he was never superficial. He always wanted to go as deep as
possible, either to understand fully some part of my knowledge,or to
explain to me in the greatest detail some part of his.
When we went hiking, he
always wanted to see more, to see what was on the other side of the
ridge. He was brave and would happily engage in adventurous steps
without
proper experience and equipment.
I also liked his frankness and honesty, and his lucid and open minded
vision of our job and our society........
-
from Monique Laurent:
I first met Svata in Paris in 1988 at the occasion
of the Conference Coding and Counting. We worked on the metric
polytope,
we walked around Montmartre, and so started
a strong friendship and fruitful collaboration.
This friendship was soon extended to Svata's family.
Jana and Svata always offered a warm hospitality
to friends and colleagues, which was very dear to me,
most preciously in Bonn, where we were simultaneously visiting
in 1991/92.
Our last encounter was in Amsterdam last November. This was a very
fruitful and exciting month, during which
we explored geometric questions related to
positive semidefinite programming.
Svata was a warm and kind person, very generous and helpful,
also very shy, modest, and vulnerable. He was clever,
always full of ideas and eager to share them.
Svata's patience and enthusiasm were a constant source
of inspiration for me.
I have learned a lot of mathematics from him,
and I miss very much the constant exchange of ideas we had
together.
-
from Martin Loebl:
My memory of Svata is closely associated with the Prague Combinatorial
Seminar which we both attended; Svata as one of its pillars and I as a
novice. I immediately liked Svata because of his singular friendliness, and
we became close friends and later collaborators.
The main topics of our joint work were
totally unimodular matrices and factors of graphs. Let me mention one
joint result I am particularly proud of: we classified the
algorithmic complexity of the {K_2,H} factor problem, i.e.
-
let H
be a fixed graph; for a given graph
H decide if its vertices may be
covered by vertex-disjoint edges and copies of H.
Svata made fundamental contributions in many areas of
combinatorial optimization, local optimization and
positive-semidefinite programming, his last subject which is covered
most
by this special issue.
Svata enjoyed life fully and doing mathematics played a major role in his
life. He will be
sorely missed.
-
from Jarik Nesetril:
Svata Poljak was my first diploma student which I supervised at Charles
University. We had contacts ever since and Poljak , Turzik and my
families and all our then small kids took regular summer
canoeing trips on various Bohemian
rivers. Some papers started there. And some 10 years later I was happy
to get Svata to Charles University back. I didn't expected this to
last so briefly.
-
from Franz Rendl:
My first personal meeting with Svata was at a conference
on partitioning in Grottaferrata (Italy) in 1991. We realized
very quickly that we had many common research interests.
This lead to a fruitful cooperation, but perhaps more important,
to a deep friendship.
Many of our joint results were obtained in a rather
relaxed environment, where we would combine family holidays
with mathematical discussions.
It is sad for me to see several of our papers appearing in print
only after his death.
-
from Henry Wolkowicz:
I met Svata while on sabbatical leave at DIMACS. Svata was visiting at
the same time and we were introduced by our mutual friend Franz Rendl.
Svata immediately showed me his conjecture:
-
four, seemingly unrelated, bounds for the max-cut problem are in fact
all equal.
Though I knew little about max-cut problems, the bounds involved
continuous optimization techniques, which fell into
my area of expertise. My first impression of Svata was how he never lost
patience while explaining the details of the conjecture to me.
His enthusiasm was infectious and we worked on this problem
together. Our joint effort resulted in a proof
of this conjecture. This work started our collaboration. Svata next met
me in Graz, Austria and ``took'' me by car to his new home in Passau.
Ironically, he disliked driving very much and I did all the driving from
Graz to Passau. At this time he was essentially commuting from his
family home in Prague to Passau. My lasting memory of Svata is spending
several extremely enjoyable days at Passau discussing Mathematics and
helping a very excited Svata explore his new home.
FOOTNOTES:
See also the Notice in: Opt-Net Digest v95w15
This home page, several of Svata's publications and the following
(long) list
of his publications can be found over WWW with URL:
http://orion.uwaterloo.ca/~hwolkowi/henry/software/psd_tool.d/poljak.d/
BIBLIOGRAPHY follows: (5 ps files of papers are available)
PUBLICATION LIST
Svatopluk Poljak
February 1994
-
A note on stable sets and colouring of graphs, Comment. Math.
Univ. Carolinae 15 (1974) 307-309.
MR 50#4369; Zbl 284.05105
-
(with M. Boguszak and J. Tuma) Note on homomorphism
interpolation theorem, Comment. Math. Univ. Carolinae 17
(1976) 105-109.
MR 53#12964; Zbl 335.05007
-
(with D. Turzik) On amalgamation of graphs and essential sets
of generators, Comment. Math. Univ. Carolinae 19 (1979)
359-369.
MR 80a:05171; Zbl 276.05053
-
(with D. Turzik) Some equivalent formulations of the
intersection problem of finitely generated classes of
graphs, Acta Sci. Math. 41 (1979) 357-374.
MR 81c:05035; Zbl 427.05049
-
(with V. Rödl) Orthogonal partitions and covering of graphs,
Czechoslovak Mathematical Journal 105 (1980) 475-485.
MR 82j:05088; Zbl 456.05051
-
(with D. Turzik) Weak join of matroids, Proc. 8th Winter
School on Abstract Analysis, Math. Institute Czech. Acad.
Sci. 1980, pp.130-133.
-
(with J. Nesetril) Geometric and algebraic aspects of
combinatorial optimization (in Czech), SOFSEM 1980, pp.35-77.
-
(with J. Nesetril and D. Turzik)
Amalgamation of matroids and
its applications, J. Combinatorial Theory Ser.B 31 (1981)
9-22.
MR 82k:05080; Zbl 473.05021
-
(with V. Rödl) On the arc-chromatic number of a digraph, J.
Combinatorial Theory Ser.B 31 (1981) 190-198.
MR 82j:05059; Zbl 472.05024
-
(with A. Pultr) On the dimension of trees, Discrete
Mathematics 34 (1981) 165-171.
MR 82m:05040; Zbl 476.05075
-
(with V. Rödl) On set systems determined by intersections,
Discrete Mathematics 34 (1981) 173-184.
MR 82e:05105; Zbl 474.05060
-
(with V. Rödl and D. Turzik)
Complexity of representing graphs
by set systems, Discrete Applied Mathematics 3 (1981)
301-312.
MR 83j:68054; Zbl 473.68064
-
(with A. Pultr and V. Rödl) On the dimension of Kneser
graphs, in: Algebraic Methods in Graph Theory, eds. L. Lovász
and V. T. Sós, Colloq. Math. Soc. János Bolyai 25,
North-Holland, Amsterdam 1981, pp. 631-646.
Zb 476.05077
-
(with D. Turzik) A note of dimension of
Czechoslovak Mathematical Journal 106 (1981) 484-487.
Zb 476.05076
-
(with A. Pultr) Representing graphs by means of strong and
weak products, Comment. Math. Univ. Carolinae 22 (1981)
449-466.
MR 83d:05085 Zb 476.05074
-
(with D. Turzik and P. Pudlák) Extension of k-subsets to
- existence versus constructability, Comment.
Math. Univ. Carolinae 23 (1982) 337-349.
MR 83h:68045 Zb 495.68059
-
(with D. Turzik) A polynomial algorithm for constructing a
large bipartite subgraph with an application to
satisfiability problem, Canadian Mathematical J. 24 (1982)
519-524.
MR 83j:05048; Zbl 487.68058
-
(with D. Turzik) A note on sticky matroids, Discrete
Mathematics 42 (1982) 119-123.
MR 84d:05059; Zbl 491.05020
-
(with M. Sura) An algorithm for graceful labelling of trees,
Ars Combinatoria 14 (1982) 57-66.
MR 84d:05150; Zbl 504.05029
-
(with A. Pultr and V. Rödl) On qualitatively independent
partitions and related problems, Discrete Applied Mathematics
6 (1983) 193-205.
MR 85d:05024; Zbl 515.05009
-
(with V. Rödl) On classes of graphs determined by forbidden
subgraphs, Czechoslovak Mathematical Journal 108 (1983)
27-33.
MR 84d:05129; Zbl 528.05054
-
(with M. Sura) On periodical behaviour in societies with
symmetrical relations, Combinatorica 3 (1983) 119-121.
MR 85a:90022; Zbl 561.90008
-
(with M. Sura) On a construction of graceful trees, in:
Graphs and Other Combinatorial Topics (M. Fiedler ed.), Proc.
of the Third Czech.Symp. on Graph Theory (Prague 1982),
Teubner Texte zur Math. 59, Leipzig 1983, pp. 220-222.
Zbl 528.05021
-
(with A. Pultr and V. Rödl) On a product dimension of
bipartite graphs, Journal of Graph Theory 7 (1983) 475-486.
MR 85i:05202; Zbl 531.05038
-
(with D. Turzik) On systems, periods and semipositive
mappings, Comment. Math. Univ. Carolinae 25 (1984) 597-614.
Zbl 576.05059
-
(with D. Turzik) Amalgamation over uniform matroids,
Czechoslovak Mathematical Journal 109 (1984) 239-246.
MR 85i:05075; Zbl 553.05029
-
(with D. Turzik) Amalgamation of matroids along hypergraphs,
in: Finite and Infinite Sets
( eds. A. Hajnal, L. Lovász and
V. T. Sós), Colloq. Math. Soc. Janos Bolyai 37, North-Holland,
Amsterdam 1984, pp. 607-620.
MR 87a:05048; Zbl 567.05015
-
(with J. Nesetril and D. Turzik) Some remarks on the
Ramsey
matroids, Supplemento ai Rendiconto del Circolo Matematico di
Palermo, Serie II, n.3 (1984), Proceeding of the 11th Winter
School on Abstract Analysis, pp. 185-189.
Zbl 543.05021
-
(with D. Turzik) On social influence models with ranking
alternatives and local election rules, Mathematical Social
Sciences 10 (1985) 189-198.
-
(with J. Pelant) Extensions of cyclically monotone mappings,
Supplemento ai Rendiconto del Circolo Matematico di Palermo,
Serie II, n.11 (1985), Proceeding of the 13th Winter School
on Abstract Analysis, pp. 81-88.
Zbl 586.90005
-
(with J. Nesetril) On the complexity of the subgraph problem ,
Comment. Math. Univ. Carolinae 26 (1985) 415-419.
Zbl 571.05050
-
(with J. Nesetril and D. Turzik)
Special amalgams of matroids,
in: Matroid Theory, eds. L. Lovász and A. Recski, Colloq.
Math. Soc. János Bolyai 40, North-Holland, Amsterdam 1985,
pp. 267-298.
MR 87k:05053
-
(with J. Nesetril) A note on max-cut problem with an
application to discrete-analogue convertors, Operations
Research Letters 4 (1986) 289-191.
Zbl 585.90085
-
(with D. Turzik) On an application of convexity to discrete
systems, Discrete Applied Mathematics 13 (1986) 27-32.
MR 87k:58133; Zbl 588.93048
-
(with D. Turzik) On pre-periods of discrete influence systems,
Discrete Applied Mathematics 13 (1986) 33-39.
MR 87k:58134;
-
(with D. Turzik) A polynomial heuristic for certain subgraph
optimization problems with guaranteed lower bound, Discrete
Mathematics 58 (1986) 99-104.
Zbl 585.05032
-
(with J. Pelant and D. Turzik) Limit behaviour of trajectories
involving subgradients of convex functions, Comment. Math.
Univ. Carolinae 28 (1987) 457-466.
-
(with D. Turzik)
On a facet of the balanced subgraph polytope,
Cas. pest. matem. 112 (1987) 373-380.
-
(with M. Chrobak) A generalization of Smith's Theorem,
Zastosowania Matematyki (Applic. Math.) XIX (1987) 371-374.
-
(with Zs. Tuza) Maximum bipartite subgraphs of Kneser graphs,
Graphs and Combinatorics 3 (1987) 191-199.
-
Transformations on graphs and convexity, Complex Systems 1
(1987) 1021-1033.
-
(with M. Loebl) Matroids induced by packing subgraphs, J.
Combinatorial Theory Ser.B 44 (1988) 338-354.
-
(with D. Turzik) Subgradients of convex functions and periodical
behaviour of finite automata, Proc. of Inst. Chem. Tech. (Prague),
M 2 (1988), 75-86.
-
(with M. Loebl) On the union of matching matroids,
Mathematica Slovaca 38 (1988) 301-304.
-
(with M. Loebl) Bipartite packing, in: Combinatorics, Eger
(Hungary) 1987, Colloq. Math. Soc. János Bolyai 52,
North-Holland, Amsterdam 1988, pp. 375-384.
-
(with M. Chrobak) On common edges in optimal solutions to
travelling salesman and and other optimization problems,
Discrete Applied Mathematics 20 (1988) 101-111.
-
(with V. Rödl and J. Spencer) Polynomial time algorithm for
tournament ranking that ensures the expected profit, SIAM J.
on Discrete Mathematics, 1 (1988) 372-376.
-
(with Zs. Tuza) Improved bounds for the number of
qualitatively independent partitions, J. Combinatorial Theory
Ser.A 51 (1989) 111-116.
-
Maximum rank of powers of a matrix of a given pattern,
Proceedings AMS 106 (1989) 1137-1144.
-
(with M. Loebl) A hierarchy of totally unimodular matrices,
Discrete Mathematics 76 (1989) 241-246.
-
(with P. Alles) Long induced paths and cycles in Kneser
graphs, Graphs and Combinatorics 5 (1989) 303-306.
-
On the generic dimension of controllable subspaces, IEEE
Transactions on Automatic Control, March 1990, Vol.35, No.3,
367-369.
-
(with M. Loebl) Subgraph packing - a survey. Topics in
Combinatorics and Graph Theory: Essays in Honour of Gerhard
Ringel, Physica-Verlag Heidelberg 1990, pp.491-503.
-
(with K. Murota) Note on a graph-theoretic criterion for
structural output controllability, IEEE Transactions on
Automatic Control vol. 35, No 8 August 1990, 939-942.
-
(with B.Mohar) Eigenvalues and the max-cut problem,
Czechoslovak Mathematical Journal 40(115) (1990) 343-352.
-
(with M. Kano) Graphs with the Balas-Uhry property, Journal
of Graph Theory 14 (1990) 623-628.
-
(with P. Alles and
J. Nesetril) Extendability, dimensions and
diagrams for cyclic orders, SIAM J. on Discrete Mathematics
4 (1991) 453-471.
-
(with M. Schlegel) Computing generic Jordan canonical form,
Linear and Multilinear Algebra 28 (1991) 241-249.
-
(with T. Ibaraki) Weak three-linking in Eulerian digraphs,
SIAM J. on Discrete Mathematics, 4 (1991) 84-98
-
Coloring digraphs by iterated antichains,
Comment. Math. Univ. Carolinae 32,2 (1991) 209-212.
-
Polyhedral and eigenvalue approximations of the max-cut
problem.
in: "Sets, Graphs and Numbers" (eds. G. Halász, L. Lovász,
D. Miklós and T. Szönyi),
Colloq. Math. Soc. János Bolyai 60,
North-Holland, Amsterdam 1992, pp. 569-581.
-
(with M. Loebl) Packing by families of subgraphs,
in Forth Czechoslovakian Symposium
on Combinatorics, Graph Theory and complexity,
(M. Fiedler and J. Nesetril eds.), Annals of Discrete Mathematics 51,
North-Holland 1992,
pp. 181-186.
-
(with Y. Crama and M. Loebl) On line balancing of strongly
unimodular matrices,
Discrete Applied Mathematics, 102 (1992) 143-147.
-
(with M. Deza and M. Laurent) Facets of the cut cone III:
The role of triangle facets,
Graphs and Combinatorics 8 (1992) 125-142.
-
(with M. Laurent) The metric polytope,
Proc of IPCO 1992, (eds. E. Balas, G. Cornuejols and R. Kannan),
1992, pp. 274-286.
-
Minimum spectral radius of a weighted graph,
Linear Algebra and Its Applications, 171 (1992) 53-63.
-
(with J. Kratochv´l)
Compatible two-factors, Discrete Applied
Mathematics, 36 (1992) 253-266.
-
(with D. Turzik) Maximum cut in circulant graphs,
Discrete Mathematics, 108 (1992) 379-392.
-
On the gap between structural controllability
of time-invariant and time-varying systems,
IEEE Transactions on Automatic Control, 37 (1992) 1961-1965.
- (with Ch. Delorme)
The performance of an eigenvalue bound in some classes of graphs,
in Proceedings of the Conference on Combinatorics,
Marseille 1990.
Discrete Mathematics, 111 (1993) 145-156.
-
On existence theorems,
in Proceedings of the Conference on Combinatorics,
Marseille 1990.
Discrete Mathematics, 122 (1993) 423-434.
-
(with B. Mohar) Eigenvalue methods in combinatorial optimization,
in: Combinatorial and Graph-Theoretic Problems in Linear
Algebra, (eds. R. Brualdi, S. Friedland and V. Klee), The IMA Volumes
in Mathematics and its Applications, vol. 50, Springer-Verlag 1993, pp. 107-151.
-
(with J. Bang-Jensen) Eulerian trails through a set of terminals
in specific, unique and all orders. In: "Graph Structure Theory",
Proc. AMS-IMS-SIAM Joint Summer Conf. (Seattle 1991), eds. N. Robertson
and P. Seymour, Contemporary Mathematics vol. 147, Amer. Mat. Soc. 1993,
pp. 247-258.
-
(with Ch. Delorme)
Combinatorial properties and the complexity of an eigenvalue
approximation of the max-cut problem,
Europ. J. Combinatorics 14 (1993) 313-333.
-
(with J. Rohn) Checking robust nonsingularity is NP-hard,
Mathematics of Control, Signals and Systems 6 (1993) 1-9.
- (with Ch. Helmberg, B. Mohar,
and F. Rendl) A spectral approach to bandwidth and separator
problems in graphs, Third IPCO Conference (G. Rinaldi and L. Wolsey, eds.),
1993 pp. 183-194.
-
(with M. Loebl) Efficient subgraph packing.
J. Combinatorial Theory Ser.B, 59 (1993) 106-121.
-
(with Ch. Delorme)
Laplacian eigenvalues and the maximum cut problem,
Mathematical Programming 63 (1993) 557-574.
-
(with T.Nishizeki) K-connectivity and decomposition of graphs
into forests,
Discrete Applied Mathematics, 55 (1994) 295-301.
-
(with Zs. Tuza) Bipartite subgraphs of triangle free
graphs,
SIAM J. Discrete Math. 7 (1994) 307-314.
-
(with F. Rendl) Computational experiments with node and edge relaxations
of the max-cut problem, Computing 52 (1994) 123-137.
-
(with Zs. Tuza) On the expected relative error of the polyhedral
approximation of the max-cut,
Oper. Res. Letters 16 (1994) 191-198.
-
(with F. Rendl) Computing the max-cut by eigenvalues,
to appear in a special volume of Annals of Operation Research.
- (with F. Rendl) Nonlinear relaxation of the
graph-bisection problems,
to appear in SIAM J. Opt.
- (with Ch. Helmberg, B. Mohar,
and F. Rendl) A spectral approach to bandwidth and separator
problems in graphs,
to appear in Linear and Multilinear Algebra.
-
(with G. Hahn and P. Hell) On the ultimate independence ratio
of a graph,
Report No. 91717-OR (Institut für Diskrete Mathematik,
Universität Bonn), Europ. J. Combinatorics 16 (1995). to appear.
-
(with M. Laurent)
One-third integrality in the metric polytope,
Mathematical Programming, 71 (1996) 29-50.
-
Integer linear programs and local search,
SIAM J. Comp. 24 (1995) 822-839.
- (with H. Wolkowicz) Convex relaxations of 0-1 quadratic
programming, Mathematics of Operation Research, 20:550-561, 1995.
- (with M. Laurent)
On a positive semidefinite relaxation
of the cut polytope,
Linear Algebra and Its Applications, 223/224:439-461, 1995.
- (with Zs. Tuza)
Max-cut - a survey, preprint Academia Sinica, 1993.
- (with Zs. Tuza)
Maximum cuts and largest bipartite subgraphs.
In W. Cook, L. Lovasz, and P. Seymour, editors, Combinatorial
Optimization, volume 20 of DIMACS Series in Discrete Mathematics
and Theoretical Computer Science, pages 181--244,
American Mathematical Society, 1995.
- (with M. Laurent)
On the facial structure of the correlation matrices,
SIAM J. Matrix Analysis, 17:530--547, 1996.
- (with M. Laurent and F. Rendl)
Connections between semidefinite relaxations of the max-cut
and stable set problems,
Mathematical Programming, to appear.
- (with F. Rendl and H. Wolkowicz)
A recipe for semidefinite relaxation
for (0,1)-quadratic programming, J. Global Optimization,
7:51-73, 1995.
- (with M. Laurent)
On the gap inequalities
Europ. J. Comb., 1996, to appear.
- (with D. Turzik) The probability of exact graphs, in preparation.
-
(F. Rendl and H. Wolkowicz) A semidefinite programming approach to
integer programming, Proceedings of the 4th International IPCO
Conference,
Egon Balas and Jens Clausen (Eds.),
Lecture Notes in Computer Science 920, Springer 1995, pp. 124-134.
-
Neural Networks via Convexity and Linear Programming, submitted
-
(with Ch. Delorme) Nonlinear relaxation of graph partition
problems, in preparation.
-
(with V.Rödl)
Average discrepancy of a set system, in preparation.
- (with C. DeSimone, Ch. Helmberg, F. Rendl and G. Rinaldi)
Polyhedral and semidefinite relaxations for the max-cut problem, in preparation.
Henry's
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