---
_id: '1841'
abstract:
- lang: eng
text: We propose a new family of message passing techniques for MAP estimation in
graphical models which we call Sequential Reweighted Message Passing (SRMP). Special
cases include well-known techniques such as Min-Sum Diffusion (MSD) and a faster
Sequential Tree-Reweighted Message Passing (TRW-S). Importantly, our derivation
is simpler than the original derivation of TRW-S, and does not involve a decomposition
into trees. This allows easy generalizations. The new family of algorithms can
be viewed as a generalization of TRW-S from pairwise to higher-order graphical
models. We test SRMP on several real-world problems with promising results.
author:
- first_name: Vladimir
full_name: Kolmogorov, Vladimir
id: 3D50B0BA-F248-11E8-B48F-1D18A9856A87
last_name: Kolmogorov
citation:
ama: Kolmogorov V. A new look at reweighted message passing. IEEE Transactions
on Pattern Analysis and Machine Intelligence. 2015;37(5):919-930. doi:10.1109/TPAMI.2014.2363465
apa: Kolmogorov, V. (2015). A new look at reweighted message passing. IEEE Transactions
on Pattern Analysis and Machine Intelligence. IEEE. https://doi.org/10.1109/TPAMI.2014.2363465
chicago: Kolmogorov, Vladimir. “A New Look at Reweighted Message Passing.” IEEE
Transactions on Pattern Analysis and Machine Intelligence. IEEE, 2015. https://doi.org/10.1109/TPAMI.2014.2363465.
ieee: V. Kolmogorov, “A new look at reweighted message passing,” IEEE Transactions
on Pattern Analysis and Machine Intelligence, vol. 37, no. 5. IEEE, pp. 919–930,
2015.
ista: Kolmogorov V. 2015. A new look at reweighted message passing. IEEE Transactions
on Pattern Analysis and Machine Intelligence. 37(5), 919–930.
mla: Kolmogorov, Vladimir. “A New Look at Reweighted Message Passing.” IEEE Transactions
on Pattern Analysis and Machine Intelligence, vol. 37, no. 5, IEEE, 2015,
pp. 919–30, doi:10.1109/TPAMI.2014.2363465.
short: V. Kolmogorov, IEEE Transactions on Pattern Analysis and Machine Intelligence
37 (2015) 919–930.
date_created: 2018-12-11T11:54:18Z
date_published: 2015-05-01T00:00:00Z
date_updated: 2021-01-12T06:53:33Z
day: '01'
department:
- _id: VlKo
doi: 10.1109/TPAMI.2014.2363465
ec_funded: 1
intvolume: ' 37'
issue: '5'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: http://arxiv.org/abs/1309.5655
month: '05'
oa: 1
oa_version: Preprint
page: 919 - 930
project:
- _id: 25FBA906-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '616160'
name: 'Discrete Optimization in Computer Vision: Theory and Practice'
publication: IEEE Transactions on Pattern Analysis and Machine Intelligence
publication_status: published
publisher: IEEE
publist_id: '5261'
quality_controlled: '1'
scopus_import: 1
status: public
title: A new look at reweighted message passing
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 37
year: '2015'
...
---
_id: '1859'
abstract:
- lang: eng
text: "Structural support vector machines (SSVMs) are amongst the best performing
models for structured computer vision tasks, such as semantic image segmentation
or human pose estimation. Training SSVMs, however, is computationally costly,
because it requires repeated calls to a structured prediction subroutine (called
\\emph{max-oracle}), which has to solve an optimization problem itself, e.g. a
graph cut.\r\nIn this work, we introduce a new algorithm for SSVM training that
is more efficient than earlier techniques when the max-oracle is computationally
expensive, as it is frequently the case in computer vision tasks. The main idea
is to (i) combine the recent stochastic Block-Coordinate Frank-Wolfe algorithm
with efficient hyperplane caching, and (ii) use an automatic selection rule for
deciding whether to call the exact max-oracle or to rely on an approximate one
based on the cached hyperplanes.\r\nWe show experimentally that this strategy
leads to faster convergence to the optimum with respect to the number of requires
oracle calls, and that this translates into faster convergence with respect to
the total runtime when the max-oracle is slow compared to the other steps of the
algorithm. "
author:
- first_name: Neel
full_name: Shah, Neel
id: 31ABAF80-F248-11E8-B48F-1D18A9856A87
last_name: Shah
- first_name: Vladimir
full_name: Kolmogorov, Vladimir
id: 3D50B0BA-F248-11E8-B48F-1D18A9856A87
last_name: Kolmogorov
- first_name: Christoph
full_name: Lampert, Christoph
id: 40C20FD2-F248-11E8-B48F-1D18A9856A87
last_name: Lampert
orcid: 0000-0001-8622-7887
citation:
ama: 'Shah N, Kolmogorov V, Lampert C. A multi-plane block-coordinate Frank-Wolfe
algorithm for training structural SVMs with a costly max-oracle. In: IEEE; 2015:2737-2745.
doi:10.1109/CVPR.2015.7298890'
apa: 'Shah, N., Kolmogorov, V., & Lampert, C. (2015). A multi-plane block-coordinate
Frank-Wolfe algorithm for training structural SVMs with a costly max-oracle (pp.
2737–2745). Presented at the CVPR: Computer Vision and Pattern Recognition, Boston,
MA, USA: IEEE. https://doi.org/10.1109/CVPR.2015.7298890'
chicago: Shah, Neel, Vladimir Kolmogorov, and Christoph Lampert. “A Multi-Plane
Block-Coordinate Frank-Wolfe Algorithm for Training Structural SVMs with a Costly
Max-Oracle,” 2737–45. IEEE, 2015. https://doi.org/10.1109/CVPR.2015.7298890.
ieee: 'N. Shah, V. Kolmogorov, and C. Lampert, “A multi-plane block-coordinate Frank-Wolfe
algorithm for training structural SVMs with a costly max-oracle,” presented at
the CVPR: Computer Vision and Pattern Recognition, Boston, MA, USA, 2015, pp.
2737–2745.'
ista: 'Shah N, Kolmogorov V, Lampert C. 2015. A multi-plane block-coordinate Frank-Wolfe
algorithm for training structural SVMs with a costly max-oracle. CVPR: Computer
Vision and Pattern Recognition, 2737–2745.'
mla: Shah, Neel, et al. A Multi-Plane Block-Coordinate Frank-Wolfe Algorithm
for Training Structural SVMs with a Costly Max-Oracle. IEEE, 2015, pp. 2737–45,
doi:10.1109/CVPR.2015.7298890.
short: N. Shah, V. Kolmogorov, C. Lampert, in:, IEEE, 2015, pp. 2737–2745.
conference:
end_date: 2015-06-12
location: Boston, MA, USA
name: 'CVPR: Computer Vision and Pattern Recognition'
start_date: 2015-06-07
date_created: 2018-12-11T11:54:24Z
date_published: 2015-06-01T00:00:00Z
date_updated: 2021-01-12T06:53:40Z
day: '01'
department:
- _id: VlKo
- _id: ChLa
doi: 10.1109/CVPR.2015.7298890
ec_funded: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: http://arxiv.org/abs/1408.6804
month: '06'
oa: 1
oa_version: Preprint
page: 2737 - 2745
project:
- _id: 2532554C-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '308036'
name: Lifelong Learning of Visual Scene Understanding
- _id: 25FBA906-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '616160'
name: 'Discrete Optimization in Computer Vision: Theory and Practice'
publication_status: published
publisher: IEEE
publist_id: '5240'
quality_controlled: '1'
scopus_import: 1
status: public
title: A multi-plane block-coordinate Frank-Wolfe algorithm for training structural
SVMs with a costly max-oracle
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2015'
...
---
_id: '2271'
abstract:
- lang: eng
text: "A class of valued constraint satisfaction problems (VCSPs) is characterised
by a valued constraint language, a fixed set of cost functions on a finite domain.
Finite-valued constraint languages contain functions that take on rational costs
and general-valued constraint languages contain functions that take on rational
or infinite costs. An instance of the problem is specified by a sum of functions
from the language with the goal to minimise the sum. This framework includes and
generalises well-studied constraint satisfaction problems (CSPs) and maximum constraint
satisfaction problems (Max-CSPs).\r\nOur main result is a precise algebraic characterisation
of valued constraint languages whose instances can be solved exactly by the basic
linear programming relaxation (BLP). For a general-valued constraint language
Γ, BLP is a decision procedure for Γ if and only if Γ admits a symmetric fractional
polymorphism of every arity. For a finite-valued constraint language Γ, BLP is
a decision procedure if and only if Γ admits a symmetric fractional polymorphism
of some arity, or equivalently, if Γ admits a symmetric fractional polymorphism
of arity 2.\r\nUsing these results, we obtain tractability of several novel and
previously widely-open classes of VCSPs, including problems over valued constraint
languages that are: (1) submodular on arbitrary lattices; (2) bisubmodular (also
known as k-submodular) on arbitrary finite domains; (3) weakly (and hence strongly)
tree-submodular on arbitrary trees. "
author:
- first_name: Vladimir
full_name: Kolmogorov, Vladimir
id: 3D50B0BA-F248-11E8-B48F-1D18A9856A87
last_name: Kolmogorov
- first_name: Johan
full_name: Thapper, Johan
last_name: Thapper
- first_name: Stanislav
full_name: Živný, Stanislav
last_name: Živný
citation:
ama: Kolmogorov V, Thapper J, Živný S. The power of linear programming for general-valued
CSPs. SIAM Journal on Computing. 2015;44(1):1-36. doi:10.1137/130945648
apa: Kolmogorov, V., Thapper, J., & Živný, S. (2015). The power of linear programming
for general-valued CSPs. SIAM Journal on Computing. SIAM. https://doi.org/10.1137/130945648
chicago: Kolmogorov, Vladimir, Johan Thapper, and Stanislav Živný. “The Power of
Linear Programming for General-Valued CSPs.” SIAM Journal on Computing.
SIAM, 2015. https://doi.org/10.1137/130945648.
ieee: V. Kolmogorov, J. Thapper, and S. Živný, “The power of linear programming
for general-valued CSPs,” SIAM Journal on Computing, vol. 44, no. 1. SIAM,
pp. 1–36, 2015.
ista: Kolmogorov V, Thapper J, Živný S. 2015. The power of linear programming for
general-valued CSPs. SIAM Journal on Computing. 44(1), 1–36.
mla: Kolmogorov, Vladimir, et al. “The Power of Linear Programming for General-Valued
CSPs.” SIAM Journal on Computing, vol. 44, no. 1, SIAM, 2015, pp. 1–36,
doi:10.1137/130945648.
short: V. Kolmogorov, J. Thapper, S. Živný, SIAM Journal on Computing 44 (2015)
1–36.
date_created: 2018-12-11T11:56:41Z
date_published: 2015-02-01T00:00:00Z
date_updated: 2023-02-23T10:46:30Z
day: '01'
department:
- _id: VlKo
doi: 10.1137/130945648
external_id:
arxiv:
- '1311.4219'
intvolume: ' 44'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: http://arxiv.org/abs/1311.4219
month: '02'
oa: 1
oa_version: Preprint
page: 1 - 36
publication: SIAM Journal on Computing
publication_status: published
publisher: SIAM
publist_id: '4673'
quality_controlled: '1'
related_material:
record:
- id: '2518'
relation: earlier_version
status: public
scopus_import: 1
status: public
title: The power of linear programming for general-valued CSPs
type: journal_article
user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87
volume: 44
year: '2015'
...
---
_id: '1637'
abstract:
- lang: eng
text: An instance of the Valued Constraint Satisfaction Problem (VCSP) is given
by a finite set of variables, a finite domain of labels, and a sum of functions,
each function depending on a subset of the variables. Each function can take finite
values specifying costs of assignments of labels to its variables or the infinite
value, which indicates an infeasible assignment. The goal is to find an assignment
of labels to the variables that minimizes the sum. We study, assuming that P ≠
NP, how the complexity of this very general problem depends on the set of functions
allowed in the instances, the so-called constraint language. The case when all
allowed functions take values in {0, ∞} corresponds to ordinary CSPs, where one
deals only with the feasibility issue and there is no optimization. This case
is the subject of the Algebraic CSP Dichotomy Conjecture predicting for which
constraint languages CSPs are tractable (i.e. solvable in polynomial time) and
for which NP-hard. The case when all allowed functions take only finite values
corresponds to finite-valued CSP, where the feasibility aspect is trivial and
one deals only with the optimization issue. The complexity of finite-valued CSPs
was fully classified by Thapper and Zivny. An algebraic necessary condition for
tractability of a general-valued CSP with a fixed constraint language was recently
given by Kozik and Ochremiak. As our main result, we prove that if a constraint
language satisfies this algebraic necessary condition, and the feasibility CSP
(i.e. the problem of deciding whether a given instance has a feasible solution)
corresponding to the VCSP with this language is tractable, then the VCSP is tractable.
The algorithm is a simple combination of the assumed algorithm for the feasibility
CSP and the standard LP relaxation. As a corollary, we obtain that a dichotomy
for ordinary CSPs would imply a dichotomy for general-valued CSPs.
alternative_title:
- 56th Annual Symposium on Foundations of Computer Science
author:
- first_name: Vladimir
full_name: Kolmogorov, Vladimir
id: 3D50B0BA-F248-11E8-B48F-1D18A9856A87
last_name: Kolmogorov
- first_name: Andrei
full_name: Krokhin, Andrei
last_name: Krokhin
- first_name: Michal
full_name: Rolinek, Michal
id: 3CB3BC06-F248-11E8-B48F-1D18A9856A87
last_name: Rolinek
citation:
ama: 'Kolmogorov V, Krokhin A, Rolinek M. The complexity of general-valued CSPs.
In: IEEE; 2015:1246-1258. doi:10.1109/FOCS.2015.80'
apa: 'Kolmogorov, V., Krokhin, A., & Rolinek, M. (2015). The complexity of general-valued
CSPs (pp. 1246–1258). Presented at the FOCS: Foundations of Computer Science,
Berkeley, CA, United States: IEEE. https://doi.org/10.1109/FOCS.2015.80'
chicago: Kolmogorov, Vladimir, Andrei Krokhin, and Michal Rolinek. “The Complexity
of General-Valued CSPs,” 1246–58. IEEE, 2015. https://doi.org/10.1109/FOCS.2015.80.
ieee: 'V. Kolmogorov, A. Krokhin, and M. Rolinek, “The complexity of general-valued
CSPs,” presented at the FOCS: Foundations of Computer Science, Berkeley, CA, United
States, 2015, pp. 1246–1258.'
ista: 'Kolmogorov V, Krokhin A, Rolinek M. 2015. The complexity of general-valued
CSPs. FOCS: Foundations of Computer Science, 56th Annual Symposium on Foundations
of Computer Science, , 1246–1258.'
mla: Kolmogorov, Vladimir, et al. The Complexity of General-Valued CSPs.
IEEE, 2015, pp. 1246–58, doi:10.1109/FOCS.2015.80.
short: V. Kolmogorov, A. Krokhin, M. Rolinek, in:, IEEE, 2015, pp. 1246–1258.
conference:
end_date: 2015-10-20
location: Berkeley, CA, United States
name: 'FOCS: Foundations of Computer Science'
start_date: 2015-10-18
date_created: 2018-12-11T11:53:10Z
date_published: 2015-12-01T00:00:00Z
date_updated: 2023-02-23T12:44:26Z
day: '01'
department:
- _id: VlKo
doi: 10.1109/FOCS.2015.80
ec_funded: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: http://arxiv.org/abs/1502.07327
month: '12'
oa: 1
oa_version: Preprint
page: 1246 - 1258
project:
- _id: 25FBA906-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '616160'
name: 'Discrete Optimization in Computer Vision: Theory and Practice'
publication_status: published
publisher: IEEE
publist_id: '5518'
quality_controlled: '1'
related_material:
record:
- id: '644'
relation: other
status: public
scopus_import: 1
status: public
title: The complexity of general-valued CSPs
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2015'
...
---
_id: '1675'
abstract:
- lang: eng
text: Proofs of work (PoW) have been suggested by Dwork and Naor (Crypto’92) as
protection to a shared resource. The basic idea is to ask the service requestor
to dedicate some non-trivial amount of computational work to every request. The
original applications included prevention of spam and protection against denial
of service attacks. More recently, PoWs have been used to prevent double spending
in the Bitcoin digital currency system. In this work, we put forward an alternative
concept for PoWs - so-called proofs of space (PoS), where a service requestor
must dedicate a significant amount of disk space as opposed to computation. We
construct secure PoS schemes in the random oracle model (with one additional mild
assumption required for the proof to go through), using graphs with high “pebbling
complexity” and Merkle hash-trees. We discuss some applications, including follow-up
work where a decentralized digital currency scheme called Spacecoin is constructed
that uses PoS (instead of wasteful PoW like in Bitcoin) to prevent double spending.
The main technical contribution of this work is the construction of (directed,
loop-free) graphs on N vertices with in-degree O(log logN) such that even if one
places Θ(N) pebbles on the nodes of the graph, there’s a constant fraction of
nodes that needs Θ(N) steps to be pebbled (where in every step one can put a pebble
on a node if all its parents have a pebble).
alternative_title:
- LNCS
article_processing_charge: No
author:
- first_name: Stefan
full_name: Dziembowski, Stefan
last_name: Dziembowski
- first_name: Sebastian
full_name: Faust, Sebastian
last_name: Faust
- first_name: Vladimir
full_name: Kolmogorov, Vladimir
id: 3D50B0BA-F248-11E8-B48F-1D18A9856A87
last_name: Kolmogorov
- first_name: Krzysztof Z
full_name: Pietrzak, Krzysztof Z
id: 3E04A7AA-F248-11E8-B48F-1D18A9856A87
last_name: Pietrzak
orcid: 0000-0002-9139-1654
citation:
ama: 'Dziembowski S, Faust S, Kolmogorov V, Pietrzak KZ. Proofs of space. In: 35th
Annual Cryptology Conference. Vol 9216. Springer; 2015:585-605. doi:10.1007/978-3-662-48000-7_29'
apa: 'Dziembowski, S., Faust, S., Kolmogorov, V., & Pietrzak, K. Z. (2015).
Proofs of space. In 35th Annual Cryptology Conference (Vol. 9216, pp. 585–605).
Santa Barbara, CA, United States: Springer. https://doi.org/10.1007/978-3-662-48000-7_29'
chicago: Dziembowski, Stefan, Sebastian Faust, Vladimir Kolmogorov, and Krzysztof
Z Pietrzak. “Proofs of Space.” In 35th Annual Cryptology Conference, 9216:585–605.
Springer, 2015. https://doi.org/10.1007/978-3-662-48000-7_29.
ieee: S. Dziembowski, S. Faust, V. Kolmogorov, and K. Z. Pietrzak, “Proofs of space,”
in 35th Annual Cryptology Conference, Santa Barbara, CA, United States,
2015, vol. 9216, pp. 585–605.
ista: 'Dziembowski S, Faust S, Kolmogorov V, Pietrzak KZ. 2015. Proofs of space.
35th Annual Cryptology Conference. CRYPTO: International Cryptology Conference,
LNCS, vol. 9216, 585–605.'
mla: Dziembowski, Stefan, et al. “Proofs of Space.” 35th Annual Cryptology Conference,
vol. 9216, Springer, 2015, pp. 585–605, doi:10.1007/978-3-662-48000-7_29.
short: S. Dziembowski, S. Faust, V. Kolmogorov, K.Z. Pietrzak, in:, 35th Annual
Cryptology Conference, Springer, 2015, pp. 585–605.
conference:
end_date: 2015-08-20
location: Santa Barbara, CA, United States
name: 'CRYPTO: International Cryptology Conference'
start_date: 2015-08-16
date_created: 2018-12-11T11:53:24Z
date_published: 2015-08-01T00:00:00Z
date_updated: 2024-03-20T08:31:49Z
day: '01'
department:
- _id: VlKo
- _id: KrPi
doi: 10.1007/978-3-662-48000-7_29
ec_funded: 1
intvolume: ' 9216'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://eprint.iacr.org/2013/796.pdf
month: '08'
oa: 1
oa_version: Preprint
page: 585 - 605
project:
- _id: 25FBA906-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '616160'
name: 'Discrete Optimization in Computer Vision: Theory and Practice'
- _id: 258C570E-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '259668'
name: Provable Security for Physical Cryptography
publication: 35th Annual Cryptology Conference
publication_identifier:
isbn:
- '9783662479995'
issn:
- 0302-9743
publication_status: published
publisher: Springer
publist_id: '5474'
pubrep_id: '671'
quality_controlled: '1'
related_material:
record:
- id: '2274'
relation: earlier_version
status: public
scopus_import: '1'
status: public
title: Proofs of space
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 9216
year: '2015'
...