---
OA_place: publisher
_id: '992'
abstract:
- lang: eng
text: "An instance of the Constraint Satisfaction Problem (CSP) is given by a finite
set of\r\nvariables, a finite domain of labels, and a set of constraints, each
constraint acting on\r\na subset of the variables. The goal is to find an assignment
of labels to its variables\r\nthat satisfies all constraints (or decide whether
one exists). If we allow more general\r\n“soft” constraints, which come with (possibly
infinite) costs of particular assignments,\r\nwe obtain instances from a richer
class called Valued Constraint Satisfaction Problem\r\n(VCSP). There the goal
is to find an assignment with minimum total cost.\r\nIn this thesis, we focus
(assuming that P\r\n6\r\n=\r\nNP) on classifying computational com-\r\nplexity
of CSPs and VCSPs under certain restricting conditions. Two results are the core\r\ncontent
of the work. In one of them, we consider VCSPs parametrized by a constraint\r\nlanguage,
that is the set of “soft” constraints allowed to form the instances, and finish\r\nthe
complexity classification modulo (missing pieces of) complexity classification
for\r\nanalogously parametrized CSP. The other result is a generalization of Edmonds’
perfect\r\nmatching algorithm. This generalization contributes to complexity classfications
in two\r\nways. First, it gives a new (largest known) polynomial-time solvable
class of Boolean\r\nCSPs in which every variable may appear in at most two constraints
and second, it\r\nsettles full classification of Boolean CSPs with planar drawing
(again parametrized by a\r\nconstraint language)."
acknowledgement: FP7/2007-2013/ERC grant agreement no 616160
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Michal
full_name: Rolinek, Michal
id: 3CB3BC06-F248-11E8-B48F-1D18A9856A87
last_name: Rolinek
citation:
ama: Rolinek M. Complexity of constraint satisfaction. 2017. doi:10.15479/AT:ISTA:th_815
apa: Rolinek, M. (2017). Complexity of constraint satisfaction. Institute
of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:th_815
chicago: Rolinek, Michal. “Complexity of Constraint Satisfaction.” Institute of
Science and Technology Austria, 2017. https://doi.org/10.15479/AT:ISTA:th_815.
ieee: M. Rolinek, “Complexity of constraint satisfaction,” Institute of Science
and Technology Austria, 2017.
ista: Rolinek M. 2017. Complexity of constraint satisfaction. Institute of Science
and Technology Austria.
mla: Rolinek, Michal. Complexity of Constraint Satisfaction. Institute of
Science and Technology Austria, 2017, doi:10.15479/AT:ISTA:th_815.
short: M. Rolinek, Complexity of Constraint Satisfaction, Institute of Science and
Technology Austria, 2017.
corr_author: '1'
date_created: 2018-12-11T11:49:35Z
date_published: 2017-05-01T00:00:00Z
date_updated: 2026-04-08T14:17:06Z
day: '01'
ddc:
- '004'
degree_awarded: PhD
department:
- _id: VlKo
doi: 10.15479/AT:ISTA:th_815
ec_funded: 1
file:
- access_level: open_access
checksum: 81761fb939acb7585c36629f765b4373
content_type: application/pdf
creator: system
date_created: 2018-12-12T10:07:55Z
date_updated: 2020-07-14T12:48:18Z
file_id: '4654'
file_name: IST-2017-815-v1+3_final_blank_signature_maybe_pdfa.pdf
file_size: 786145
relation: main_file
- access_level: closed
checksum: 2b2d7e1d6c1c79a9795a7aa0f860baf3
content_type: application/zip
creator: dernst
date_created: 2019-04-05T08:43:24Z
date_updated: 2020-07-14T12:48:18Z
file_id: '6208'
file_name: 2017_Thesis_Rolinek_source.zip
file_size: 5936337
relation: source_file
file_date_updated: 2020-07-14T12:48:18Z
fulldoi: https://doi.org/10.15479/AT:ISTA:th_815
has_accepted_license: '1'
language:
- iso: eng
month: '05'
oa: 1
oa_version: Published Version
page: '97'
project:
- _id: 25FBA906-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '616160'
name: 'Discrete Optimization in Computer Vision: Theory and Practice'
publication_identifier:
issn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
publist_id: '6407'
pubrep_id: '815'
status: public
supervisor:
- first_name: Vladimir
full_name: Kolmogorov, Vladimir
id: 3D50B0BA-F248-11E8-B48F-1D18A9856A87
last_name: Kolmogorov
title: Complexity of constraint satisfaction
type: dissertation
user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd
year: '2017'
...
---
_id: '993'
abstract:
- lang: eng
text: In real-world applications, observations are often constrained to a small
fraction of a system. Such spatial subsampling can be caused by the inaccessibility
or the sheer size of the system, and cannot be overcome by longer sampling. Spatial
subsampling can strongly bias inferences about a system’s aggregated properties.
To overcome the bias, we derive analytically a subsampling scaling framework that
is applicable to different observables, including distributions of neuronal avalanches,
of number of people infected during an epidemic outbreak, and of node degrees.
We demonstrate how to infer the correct distributions of the underlying full system,
how to apply it to distinguish critical from subcritical systems, and how to disentangle
subsampling and finite size effects. Lastly, we apply subsampling scaling to neuronal
avalanche models and to recordings from developing neural networks. We show that
only mature, but not young networks follow power-law scaling, indicating self-organization
to criticality during development.
article_number: '15140'
article_processing_charge: Yes (in subscription journal)
author:
- first_name: Anna
full_name: Levina (Martius), Anna
id: 35AF8020-F248-11E8-B48F-1D18A9856A87
last_name: Levina (Martius)
- first_name: Viola
full_name: Priesemann, Viola
last_name: Priesemann
citation:
ama: Levina (Martius) A, Priesemann V. Subsampling scaling. Nature Communications.
2017;8. doi:10.1038/ncomms15140
apa: Levina (Martius), A., & Priesemann, V. (2017). Subsampling scaling. Nature
Communications. Nature Publishing Group. https://doi.org/10.1038/ncomms15140
chicago: Levina (Martius), Anna, and Viola Priesemann. “Subsampling Scaling.” Nature
Communications. Nature Publishing Group, 2017. https://doi.org/10.1038/ncomms15140.
ieee: A. Levina (Martius) and V. Priesemann, “Subsampling scaling,” Nature Communications,
vol. 8. Nature Publishing Group, 2017.
ista: Levina (Martius) A, Priesemann V. 2017. Subsampling scaling. Nature Communications.
8, 15140.
mla: Levina (Martius), Anna, and Viola Priesemann. “Subsampling Scaling.” Nature
Communications, vol. 8, 15140, Nature Publishing Group, 2017, doi:10.1038/ncomms15140.
short: A. Levina (Martius), V. Priesemann, Nature Communications 8 (2017).
date_created: 2018-12-11T11:49:35Z
date_published: 2017-05-04T00:00:00Z
date_updated: 2025-07-10T12:02:06Z
day: '04'
ddc:
- '005'
- '571'
department:
- _id: GaTk
- _id: JoCs
doi: 10.1038/ncomms15140
ec_funded: 1
external_id:
isi:
- '000400560700001'
file:
- access_level: open_access
checksum: 9880212f8c4c53404c7c6fbf9023c53a
content_type: application/pdf
creator: system
date_created: 2018-12-12T10:15:05Z
date_updated: 2020-07-14T12:48:19Z
file_id: '5122'
file_name: IST-2017-819-v1+1_2017_Levina_SubsamplingScaling.pdf
file_size: 746224
relation: main_file
file_date_updated: 2020-07-14T12:48:19Z
fulldoi: https://doi.org/10.1038/ncomms15140
has_accepted_license: '1'
intvolume: ' 8'
isi: 1
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '05'
oa: 1
oa_version: Published Version
project:
- _id: 25681D80-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '291734'
name: International IST Postdoc Fellowship Programme
publication: Nature Communications
publication_identifier:
issn:
- 2041-1723
publication_status: published
publisher: Nature Publishing Group
publist_id: '6406'
pubrep_id: '819'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Subsampling scaling
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 8
year: '2017'
...
---
_id: '994'
abstract:
- lang: eng
text: The formation of vortices is usually considered to be the main mechanism of
angular momentum disposal in superfluids. Recently, it was predicted that a superfluid
can acquire angular momentum via an alternative, microscopic route -- namely,
through interaction with rotating impurities, forming so-called `angulon quasiparticles'
[Phys. Rev. Lett. 114, 203001 (2015)]. The angulon instabilities correspond to
transfer of a small number of angular momentum quanta from the impurity to the
superfluid, as opposed to vortex instabilities, where angular momentum is quantized
in units of ℏ per atom. Furthermore, since conventional impurities (such as molecules)
represent three-dimensional (3D) rotors, the angular momentum transferred is intrinsically
3D as well, as opposed to a merely planar rotation which is inherent to vortices.
Herein we show that the angulon theory can explain the anomalous broadening of
the spectroscopic lines observed for CH 3 and NH 3 molecules in superfluid
helium nanodroplets, thereby providing a fingerprint of the emerging angulon instabilities
in experiment.
article_processing_charge: No
arxiv: 1
author:
- first_name: Igor
full_name: Cherepanov, Igor
id: 339C7E5A-F248-11E8-B48F-1D18A9856A87
last_name: Cherepanov
- first_name: Mikhail
full_name: Lemeshko, Mikhail
id: 37CB05FA-F248-11E8-B48F-1D18A9856A87
last_name: Lemeshko
orcid: 0000-0002-6990-7802
citation:
ama: Cherepanov I, Lemeshko M. Fingerprints of angulon instabilities in the spectra
of matrix-isolated molecules. Physical Review Materials. 2017;1(3). doi:10.1103/PhysRevMaterials.1.035602
apa: Cherepanov, I., & Lemeshko, M. (2017). Fingerprints of angulon instabilities
in the spectra of matrix-isolated molecules. Physical Review Materials.
American Physical Society. https://doi.org/10.1103/PhysRevMaterials.1.035602
chicago: Cherepanov, Igor, and Mikhail Lemeshko. “Fingerprints of Angulon Instabilities
in the Spectra of Matrix-Isolated Molecules.” Physical Review Materials.
American Physical Society, 2017. https://doi.org/10.1103/PhysRevMaterials.1.035602.
ieee: I. Cherepanov and M. Lemeshko, “Fingerprints of angulon instabilities in the
spectra of matrix-isolated molecules,” Physical Review Materials, vol.
1, no. 3. American Physical Society, 2017.
ista: Cherepanov I, Lemeshko M. 2017. Fingerprints of angulon instabilities in the
spectra of matrix-isolated molecules. Physical Review Materials. 1(3).
mla: Cherepanov, Igor, and Mikhail Lemeshko. “Fingerprints of Angulon Instabilities
in the Spectra of Matrix-Isolated Molecules.” Physical Review Materials,
vol. 1, no. 3, American Physical Society, 2017, doi:10.1103/PhysRevMaterials.1.035602.
short: I. Cherepanov, M. Lemeshko, Physical Review Materials 1 (2017).
corr_author: '1'
date_created: 2018-12-11T11:49:35Z
date_published: 2017-08-08T00:00:00Z
date_updated: 2025-06-04T10:15:04Z
day: '08'
department:
- _id: MiLe
doi: 10.1103/PhysRevMaterials.1.035602
ec_funded: 1
external_id:
arxiv:
- '1705.09220'
isi:
- '000416564000004'
fulldoi: https://doi.org/10.1103/PhysRevMaterials.1.035602
intvolume: ' 1'
isi: 1
issue: '3'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1705.09220
month: '08'
oa: 1
oa_version: Submitted Version
project:
- _id: 26031614-B435-11E9-9278-68D0E5697425
call_identifier: FWF
grant_number: P29902
name: Quantum rotations in the presence of a many-body environment
- _id: 2564DBCA-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '665385'
name: International IST Doctoral Program
publication: Physical Review Materials
publication_status: published
publisher: American Physical Society
publist_id: '6405'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Fingerprints of angulon instabilities in the spectra of matrix-isolated molecules
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 1
year: '2017'
...
---
_id: '996'
abstract:
- lang: eng
text: 'Iodine (I 2 ) molecules embedded in He nanodroplets are aligned by a 160
ps long laser pulse. The highest degree of alignment, occurring at the peak of
the pulse and quantified by ⟨cos 2 θ 2D ⟩ , is measured as a function of the laser
intensity. The results are well described by ⟨cos 2 θ 2D ⟩ calculated for a gas
of isolated molecules each with an effective rotational constant of 0.6 times
the gas-phase value, and at a temperature of 0.4 K. Theoretical analysis using
the angulon quasiparticle to describe rotating molecules in superfluid helium
rationalizes why the alignment mechanism is similar to that of isolated molecules
with an effective rotational constant. A major advantage of molecules in He droplets
is that their 0.4 K temperature leads to stronger alignment than what can generally
be achieved for gas phase molecules -- here demonstrated by a direct comparison
of the droplet results to measurements on a ∼ 1 K supersonic beam of isolated
molecules. This point is further illustrated for more complex system by measurements
on 1,4-diiodobenzene and 1,4-dibromobenzene. For all three molecular species studied
the highest values of ⟨cos 2 θ 2D ⟩ achieved in He droplets exceed 0.96. '
article_number: '013946'
article_processing_charge: No
arxiv: 1
author:
- first_name: Benjamin
full_name: Shepperson, Benjamin
last_name: Shepperson
- first_name: Adam
full_name: Chatterley, Adam
last_name: Chatterley
- first_name: Anders
full_name: Søndergaard, Anders
last_name: Søndergaard
- first_name: Lars
full_name: Christiansen, Lars
last_name: Christiansen
- first_name: Mikhail
full_name: Lemeshko, Mikhail
id: 37CB05FA-F248-11E8-B48F-1D18A9856A87
last_name: Lemeshko
orcid: 0000-0002-6990-7802
- first_name: Henrik
full_name: Stapelfeldt, Henrik
last_name: Stapelfeldt
citation:
ama: Shepperson B, Chatterley A, Søndergaard A, Christiansen L, Lemeshko M, Stapelfeldt
H. Strongly aligned molecules inside helium droplets in the near-adiabatic regime.
The Journal of Chemical Physics. 2017;147(1). doi:10.1063/1.4983703
apa: Shepperson, B., Chatterley, A., Søndergaard, A., Christiansen, L., Lemeshko,
M., & Stapelfeldt, H. (2017). Strongly aligned molecules inside helium droplets
in the near-adiabatic regime. The Journal of Chemical Physics. AIP Publishing.
https://doi.org/10.1063/1.4983703
chicago: Shepperson, Benjamin, Adam Chatterley, Anders Søndergaard, Lars Christiansen,
Mikhail Lemeshko, and Henrik Stapelfeldt. “Strongly Aligned Molecules inside Helium
Droplets in the Near-Adiabatic Regime.” The Journal of Chemical Physics.
AIP Publishing, 2017. https://doi.org/10.1063/1.4983703.
ieee: B. Shepperson, A. Chatterley, A. Søndergaard, L. Christiansen, M. Lemeshko,
and H. Stapelfeldt, “Strongly aligned molecules inside helium droplets in the
near-adiabatic regime,” The Journal of Chemical Physics, vol. 147, no.
1. AIP Publishing, 2017.
ista: Shepperson B, Chatterley A, Søndergaard A, Christiansen L, Lemeshko M, Stapelfeldt
H. 2017. Strongly aligned molecules inside helium droplets in the near-adiabatic
regime. The Journal of Chemical Physics. 147(1), 013946.
mla: Shepperson, Benjamin, et al. “Strongly Aligned Molecules inside Helium Droplets
in the Near-Adiabatic Regime.” The Journal of Chemical Physics, vol. 147,
no. 1, 013946, AIP Publishing, 2017, doi:10.1063/1.4983703.
short: B. Shepperson, A. Chatterley, A. Søndergaard, L. Christiansen, M. Lemeshko,
H. Stapelfeldt, The Journal of Chemical Physics 147 (2017).
date_created: 2018-12-11T11:49:36Z
date_published: 2017-06-01T00:00:00Z
date_updated: 2025-06-04T08:17:46Z
day: '01'
department:
- _id: MiLe
doi: 10.1063/1.4983703
external_id:
arxiv:
- '1704.03684'
isi:
- '000405089400047'
fulldoi: https://doi.org/10.1063/1.4983703
intvolume: ' 147'
isi: 1
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1704.03684
month: '06'
oa: 1
oa_version: Submitted Version
publication: The Journal of Chemical Physics
publication_identifier:
issn:
- 0021-9606
publication_status: published
publisher: AIP Publishing
publist_id: '6403'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Strongly aligned molecules inside helium droplets in the near-adiabatic regime
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 147
year: '2017'
...
---
_id: '997'
abstract:
- lang: eng
text: Recently it was shown that molecules rotating in superfluid helium can be
described in terms of the angulon quasiparticles (Phys. Rev. Lett. 118, 095301
(2017)). Here we demonstrate that in the experimentally realized regime the angulon
can be seen as a point charge on a 2-sphere interacting with a gauge field of
a non-abelian magnetic monopole. Unlike in several other settings, the gauge fields
of the angulon problem emerge in the real coordinate space, as opposed to the
momentum space or some effective parameter space. Furthermore, we find a topological
transition associated with making the monopole abelian, which takes place in the
vicinity of the previously reported angulon instabilities. These results pave
the way for studying topological phenomena in experiments on molecules trapped
in superfluid helium nanodroplets, as well as on other realizations of orbital
impurity problems.
article_number: '235301'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Enderalp
full_name: Yakaboylu, Enderalp
id: 38CB71F6-F248-11E8-B48F-1D18A9856A87
last_name: Yakaboylu
orcid: 0000-0001-5973-0874
- first_name: Andreas
full_name: Deuchert, Andreas
id: 4DA65CD0-F248-11E8-B48F-1D18A9856A87
last_name: Deuchert
orcid: 0000-0003-3146-6746
- first_name: Mikhail
full_name: Lemeshko, Mikhail
id: 37CB05FA-F248-11E8-B48F-1D18A9856A87
last_name: Lemeshko
orcid: 0000-0002-6990-7802
citation:
ama: Yakaboylu E, Deuchert A, Lemeshko M. Emergence of non-abelian magnetic monopoles
in a quantum impurity problem. Physical Review Letters. 2017;119(23). doi:10.1103/PhysRevLett.119.235301
apa: Yakaboylu, E., Deuchert, A., & Lemeshko, M. (2017). Emergence of non-abelian
magnetic monopoles in a quantum impurity problem. Physical Review Letters.
American Physical Society. https://doi.org/10.1103/PhysRevLett.119.235301
chicago: Yakaboylu, Enderalp, Andreas Deuchert, and Mikhail Lemeshko. “Emergence
of Non-Abelian Magnetic Monopoles in a Quantum Impurity Problem.” Physical
Review Letters. American Physical Society, 2017. https://doi.org/10.1103/PhysRevLett.119.235301.
ieee: E. Yakaboylu, A. Deuchert, and M. Lemeshko, “Emergence of non-abelian magnetic
monopoles in a quantum impurity problem,” Physical Review Letters, vol.
119, no. 23. American Physical Society, 2017.
ista: Yakaboylu E, Deuchert A, Lemeshko M. 2017. Emergence of non-abelian magnetic
monopoles in a quantum impurity problem. Physical Review Letters. 119(23), 235301.
mla: Yakaboylu, Enderalp, et al. “Emergence of Non-Abelian Magnetic Monopoles in
a Quantum Impurity Problem.” Physical Review Letters, vol. 119, no. 23,
235301, American Physical Society, 2017, doi:10.1103/PhysRevLett.119.235301.
short: E. Yakaboylu, A. Deuchert, M. Lemeshko, Physical Review Letters 119 (2017).
corr_author: '1'
date_created: 2018-12-11T11:49:36Z
date_published: 2017-12-06T00:00:00Z
date_updated: 2025-04-14T07:26:54Z
day: '06'
department:
- _id: MiLe
- _id: RoSe
doi: 10.1103/PhysRevLett.119.235301
ec_funded: 1
external_id:
arxiv:
- '1705.05162'
isi:
- '000417132100007'
fulldoi: https://doi.org/10.1103/PhysRevLett.119.235301
intvolume: ' 119'
isi: 1
issue: '23'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1705.05162
month: '12'
oa: 1
oa_version: Preprint
project:
- _id: 25681D80-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '291734'
name: International IST Postdoc Fellowship Programme
- _id: 25C6DC12-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '694227'
name: Analysis of quantum many-body systems
- _id: 26031614-B435-11E9-9278-68D0E5697425
call_identifier: FWF
grant_number: P29902
name: Quantum rotations in the presence of a many-body environment
publication: Physical Review Letters
publication_identifier:
issn:
- 0031-9007
publication_status: published
publisher: American Physical Society
publist_id: '6401'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Emergence of non-abelian magnetic monopoles in a quantum impurity problem
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 119
year: '2017'
...
---
_id: '998'
abstract:
- lang: eng
text: 'A major open problem on the road to artificial intelligence is the development
of incrementally learning systems that learn about more and more concepts over
time from a stream of data. In this work, we introduce a new training strategy,
iCaRL, that allows learning in such a class-incremental way: only the training
data for a small number of classes has to be present at the same time and new
classes can be added progressively. iCaRL learns strong classifiers and a data
representation simultaneously. This distinguishes it from earlier works that were
fundamentally limited to fixed data representations and therefore incompatible
with deep learning architectures. We show by experiments on CIFAR-100 and ImageNet
ILSVRC 2012 data that iCaRL can learn many classes incrementally over a long period
of time where other strategies quickly fail. '
article_processing_charge: No
arxiv: 1
author:
- first_name: Sylvestre Alvise
full_name: Rebuffi, Sylvestre Alvise
last_name: Rebuffi
- first_name: Alexander
full_name: Kolesnikov, Alexander
id: 2D157DB6-F248-11E8-B48F-1D18A9856A87
last_name: Kolesnikov
- first_name: Georg
full_name: Sperl, Georg
id: 4DD40360-F248-11E8-B48F-1D18A9856A87
last_name: Sperl
- first_name: Christoph
full_name: Lampert, Christoph
id: 40C20FD2-F248-11E8-B48F-1D18A9856A87
last_name: Lampert
orcid: 0000-0001-8622-7887
citation:
ama: 'Rebuffi SA, Kolesnikov A, Sperl G, Lampert C. iCaRL: Incremental classifier
and representation learning. In: Vol 2017. IEEE; 2017:5533-5542. doi:10.1109/CVPR.2017.587'
apa: 'Rebuffi, S. A., Kolesnikov, A., Sperl, G., & Lampert, C. (2017). iCaRL:
Incremental classifier and representation learning (Vol. 2017, pp. 5533–5542).
Presented at the CVPR: Computer Vision and Pattern Recognition, Honolulu, HA,
United States: IEEE. https://doi.org/10.1109/CVPR.2017.587'
chicago: 'Rebuffi, Sylvestre Alvise, Alexander Kolesnikov, Georg Sperl, and Christoph
Lampert. “ICaRL: Incremental Classifier and Representation Learning,” 2017:5533–42.
IEEE, 2017. https://doi.org/10.1109/CVPR.2017.587.'
ieee: 'S. A. Rebuffi, A. Kolesnikov, G. Sperl, and C. Lampert, “iCaRL: Incremental
classifier and representation learning,” presented at the CVPR: Computer Vision
and Pattern Recognition, Honolulu, HA, United States, 2017, vol. 2017, pp. 5533–5542.'
ista: 'Rebuffi SA, Kolesnikov A, Sperl G, Lampert C. 2017. iCaRL: Incremental classifier
and representation learning. CVPR: Computer Vision and Pattern Recognition vol.
2017, 5533–5542.'
mla: 'Rebuffi, Sylvestre Alvise, et al. ICaRL: Incremental Classifier and Representation
Learning. Vol. 2017, IEEE, 2017, pp. 5533–42, doi:10.1109/CVPR.2017.587.'
short: S.A. Rebuffi, A. Kolesnikov, G. Sperl, C. Lampert, in:, IEEE, 2017, pp. 5533–5542.
conference:
end_date: 2017-07-26
location: Honolulu, HA, United States
name: 'CVPR: Computer Vision and Pattern Recognition'
start_date: 2017-07-21
date_created: 2018-12-11T11:49:37Z
date_published: 2017-04-14T00:00:00Z
date_updated: 2025-06-04T08:18:32Z
day: '14'
department:
- _id: ChLa
- _id: ChWo
doi: 10.1109/CVPR.2017.587
ec_funded: 1
external_id:
arxiv:
- '1611.07725'
isi:
- '000418371405066'
fulldoi: https://doi.org/10.1109/CVPR.2017.587
intvolume: ' 2017'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1611.07725
month: '04'
oa: 1
oa_version: Submitted Version
page: 5533 - 5542
project:
- _id: 2532554C-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '308036'
name: Lifelong Learning of Visual Scene Understanding
publication_identifier:
isbn:
- 978-153860457-1
publication_status: published
publisher: IEEE
publist_id: '6400'
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'iCaRL: Incremental classifier and representation learning'
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 2017
year: '2017'
...
---
_id: '999'
abstract:
- lang: eng
text: 'In multi-task learning, a learner is given a collection of prediction tasks
and needs to solve all of them. In contrast to previous work, which required that
annotated training data must be available for all tasks, we consider a new setting,
in which for some tasks, potentially most of them, only unlabeled training data
is provided. Consequently, to solve all tasks, information must be transferred
between tasks with labels and tasks without labels. Focusing on an instance-based
transfer method we analyze two variants of this setting: when the set of labeled
tasks is fixed, and when it can be actively selected by the learner. We state
and prove a generalization bound that covers both scenarios and derive from it
an algorithm for making the choice of labeled tasks (in the active case) and for
transferring information between the tasks in a principled way. We also illustrate
the effectiveness of the algorithm on synthetic and real data. '
alternative_title:
- PMLR
article_processing_charge: No
arxiv: 1
author:
- first_name: Anastasia
full_name: Pentina, Anastasia
id: 42E87FC6-F248-11E8-B48F-1D18A9856A87
last_name: Pentina
- first_name: Christoph
full_name: Lampert, Christoph
id: 40C20FD2-F248-11E8-B48F-1D18A9856A87
last_name: Lampert
orcid: 0000-0001-8622-7887
citation:
ama: 'Pentina A, Lampert C. Multi-task learning with labeled and unlabeled tasks.
In: Vol 70. ML Research Press; 2017:2807-2816.'
apa: 'Pentina, A., & Lampert, C. (2017). Multi-task learning with labeled and
unlabeled tasks (Vol. 70, pp. 2807–2816). Presented at the ICML: International
Conference on Machine Learning, Sydney, Australia: ML Research Press.'
chicago: Pentina, Anastasia, and Christoph Lampert. “Multi-Task Learning with Labeled
and Unlabeled Tasks,” 70:2807–16. ML Research Press, 2017.
ieee: 'A. Pentina and C. Lampert, “Multi-task learning with labeled and unlabeled
tasks,” presented at the ICML: International Conference on Machine Learning, Sydney,
Australia, 2017, vol. 70, pp. 2807–2816.'
ista: 'Pentina A, Lampert C. 2017. Multi-task learning with labeled and unlabeled
tasks. ICML: International Conference on Machine Learning, PMLR, vol. 70, 2807–2816.'
mla: Pentina, Anastasia, and Christoph Lampert. Multi-Task Learning with Labeled
and Unlabeled Tasks. Vol. 70, ML Research Press, 2017, pp. 2807–16.
short: A. Pentina, C. Lampert, in:, ML Research Press, 2017, pp. 2807–2816.
conference:
end_date: 2017-08-11
location: Sydney, Australia
name: 'ICML: International Conference on Machine Learning'
start_date: 2017-08-06
corr_author: '1'
date_created: 2018-12-11T11:49:37Z
date_published: 2017-06-08T00:00:00Z
date_updated: 2025-06-04T08:19:03Z
day: '08'
department:
- _id: ChLa
ec_funded: 1
external_id:
arxiv:
- '1602.06518'
isi:
- '000683309502093'
intvolume: ' 70'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1602.06518
month: '06'
oa: 1
oa_version: Submitted Version
page: 2807 - 2816
project:
- _id: 2532554C-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '308036'
name: Lifelong Learning of Visual Scene Understanding
publication_identifier:
isbn:
- '9781510855144'
publication_status: published
publisher: ML Research Press
publist_id: '6399'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Multi-task learning with labeled and unlabeled tasks
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 70
year: '2017'
...
---
_id: '313'
abstract:
- lang: eng
text: 'Tunneling of a particle through a potential barrier remains one of the most
remarkable quantum phenomena. Owing to advances in laser technology, electric
fields comparable to those electrons experience in atoms are readily generated
and open opportunities to dynamically investigate the process of electron tunneling
through the potential barrier formed by the superposition of both laser and atomic
fields. Attosecond-time and angstrom-space resolution of the strong laser-field
technique allow to address fundamental questions related to tunneling, which are
still open and debated: Which time is spent under the barrier and what momentum
is picked up by the particle in the meantime? In this combined experimental and
theoretical study we demonstrate that for strong-field ionization the leading
quantum mechanical Wigner treatment for the time resolved description of tunneling
is valid. We achieve a high sensitivity on the tunneling barrier and unambiguously
isolate its effects by performing a differential study of two systems with almost
identical tunneling geometry. Moreover, working with a low frequency laser, we
essentially limit the non-adiabaticity of the process as a major source of uncertainty.
The agreement between experiment and theory implies two substantial corrections
with respect to the widely employed quasiclassical treatment: In addition to a
non-vanishing longitudinal momentum along the laser field-direction we provide
clear evidence for a non-zero tunneling time delay. This addresses also the fundamental
question how the transition occurs from the tunnel barrier to free space classical
evolution of the ejected electron.'
alternative_title:
- 'Journal of Physics: Conference Series'
article_number: '012004'
article_processing_charge: No
arxiv: 1
author:
- first_name: Nicolas
full_name: Camus, Nicolas
last_name: Camus
- first_name: Enderalp
full_name: Yakaboylu, Enderalp
id: 38CB71F6-F248-11E8-B48F-1D18A9856A87
last_name: Yakaboylu
orcid: 0000-0001-5973-0874
- first_name: Lutz
full_name: Fechner, Lutz
last_name: Fechner
- first_name: Michael
full_name: Klaiber, Michael
last_name: Klaiber
- first_name: Martin
full_name: Laux, Martin
last_name: Laux
- first_name: Yonghao
full_name: Mi, Yonghao
last_name: Mi
- first_name: Karen
full_name: Hatsagortsyan, Karen
last_name: Hatsagortsyan
- first_name: Thomas
full_name: Pfeifer, Thomas
last_name: Pfeifer
- first_name: Cristoph
full_name: Keitel, Cristoph
last_name: Keitel
- first_name: Robert
full_name: Moshammer, Robert
last_name: Moshammer
citation:
ama: 'Camus N, Yakaboylu E, Fechner L, et al. Experimental evidence for Wigner’s
tunneling time. In: Vol 999. American Physical Society; 2017. doi:10.1088/1742-6596/999/1/012004'
apa: 'Camus, N., Yakaboylu, E., Fechner, L., Klaiber, M., Laux, M., Mi, Y., … Moshammer,
R. (2017). Experimental evidence for Wigner’s tunneling time (Vol. 999). Presented
at the Annual International Laser Physics Workshop LPHYS, Kazan, Russian Federation:
American Physical Society. https://doi.org/10.1088/1742-6596/999/1/012004'
chicago: Camus, Nicolas, Enderalp Yakaboylu, Lutz Fechner, Michael Klaiber, Martin
Laux, Yonghao Mi, Karen Hatsagortsyan, Thomas Pfeifer, Cristoph Keitel, and Robert
Moshammer. “Experimental Evidence for Wigner’s Tunneling Time,” Vol. 999. American
Physical Society, 2017. https://doi.org/10.1088/1742-6596/999/1/012004.
ieee: N. Camus et al., “Experimental evidence for Wigner’s tunneling time,”
presented at the Annual International Laser Physics Workshop LPHYS, Kazan, Russian
Federation, 2017, vol. 999, no. 1.
ista: 'Camus N, Yakaboylu E, Fechner L, Klaiber M, Laux M, Mi Y, Hatsagortsyan K,
Pfeifer T, Keitel C, Moshammer R. 2017. Experimental evidence for Wigner’s tunneling
time. Annual International Laser Physics Workshop LPHYS, Journal of Physics: Conference
Series, vol. 999, 012004.'
mla: Camus, Nicolas, et al. Experimental Evidence for Wigner’s Tunneling Time.
Vol. 999, no. 1, 012004, American Physical Society, 2017, doi:10.1088/1742-6596/999/1/012004.
short: N. Camus, E. Yakaboylu, L. Fechner, M. Klaiber, M. Laux, Y. Mi, K. Hatsagortsyan,
T. Pfeifer, C. Keitel, R. Moshammer, in:, American Physical Society, 2017.
conference:
end_date: 2017-08-21
location: Kazan, Russian Federation
name: Annual International Laser Physics Workshop LPHYS
start_date: 2017-08-17
date_created: 2018-12-11T11:45:46Z
date_published: 2017-07-14T00:00:00Z
date_updated: 2025-09-18T10:29:07Z
day: '14'
ddc:
- '530'
department:
- _id: MiLe
doi: 10.1088/1742-6596/999/1/012004
external_id:
arxiv:
- '1611.03701'
isi:
- '000432427200004'
file:
- access_level: open_access
checksum: 6e70b525a84f6d5fb175c48e9f5cb59a
content_type: application/pdf
creator: dernst
date_created: 2019-01-22T08:34:10Z
date_updated: 2020-07-14T12:46:00Z
file_id: '5871'
file_name: 2017_Physics_Camus.pdf
file_size: 949321
relation: main_file
file_date_updated: 2020-07-14T12:46:00Z
fulldoi: https://doi.org/10.1088/1742-6596/999/1/012004
has_accepted_license: '1'
intvolume: ' 999'
isi: 1
issue: '1'
language:
- iso: eng
month: '07'
oa: 1
oa_version: Published Version
publication_identifier:
issn:
- 1742-6588
publication_status: published
publisher: American Physical Society
publist_id: '7552'
quality_controlled: '1'
related_material:
record:
- id: '6013'
relation: later_version
status: public
scopus_import: '1'
status: public
title: Experimental evidence for Wigner's tunneling time
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: conference
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 999
year: '2017'
...
---
_id: '373'
abstract:
- lang: eng
text: 'This review captures the synthesis, assembly, properties, and applications
of copper chalcogenide NCs, which have achieved significant research interest
in the last decade due to their compositional and structural versatility. The
outstanding functional properties of these materials stems from the relationship
between their band structure and defect concentration, including charge carrier
concentration and electronic conductivity character, which consequently affects
their optoelectronic, optical, and plasmonic properties. This, combined with several
metastable crystal phases and stoichiometries and the low energy of formation
of defects, makes the reproducible synthesis of these materials, with tunable
parameters, remarkable. Further to this, the review captures the progress of the
hierarchical assembly of these NCs, which bridges the link between their discrete
and collective properties. Their ubiquitous application set has cross-cut energy
conversion (photovoltaics, photocatalysis, thermoelectrics), energy storage (lithium-ion
batteries, hydrogen generation), emissive materials (plasmonics, LEDs, biolabelling),
sensors (electrochemical, biochemical), biomedical devices (magnetic resonance
imaging, X-ray computer tomography), and medical therapies (photochemothermal
therapies, immunotherapy, radiotherapy, and drug delivery). The confluence of
advances in the synthesis, assembly, and application of these NCs in the past
decade has the potential to significantly impact society, both economically and
environmentally. '
acknowledgement: C.C. and K.M.R. gratefully acknowledge support from Science Foundation
Ireland (SFI) under the Principal Investigator Program under Contract No. 11PI-1148.
This work was conducted under the framework of the Irish Government’s Programme
for Research in Third Level Institutions Cycle 5, National Development Plan 2007−2013
with the assistance of the European Regional Development Fund. A.S. gratefully acknowledges
Director’s Postdoctoral Fellowship support from the Los Alamos National Laboratory.
M.I., O.D., and A.C. gratefully acknowledge support from the European Regional Development
Funds and the Spanish MINECO Project BOOSTER (ENE2013-46624-C4-3-R). M.I. and O.D.
thank AGAUR for their Beatriu de Pinós postdoctoral grant (2013 BP-A00344) and Ph.D.
grant (2015 FI-B00810, 2016 FI-B100067), respectively.
article_processing_charge: No
article_type: review
author:
- first_name: Claudia
full_name: Coughlan, Claudia
last_name: Coughlan
- first_name: Maria
full_name: Ibanez Sabate, Maria
id: 43C61214-F248-11E8-B48F-1D18A9856A87
last_name: Ibanez Sabate
orcid: 0000-0001-5013-2843
- first_name: Oleksandr
full_name: Dobrozhan, Oleksandr
last_name: Dobrozhan
- first_name: Ajay
full_name: Singh, Ajay
last_name: Singh
- first_name: Andreu
full_name: Cabot, Andreu
last_name: Cabot
- first_name: Kevin
full_name: Ryan, Kevin
last_name: Ryan
citation:
ama: Coughlan C, Ibáñez M, Dobrozhan O, Singh A, Cabot A, Ryan K. Compound copper
chalcogenide nanocrystals. Chemical Reviews. 2017;117(9):5865-6109. doi:10.1021/acs.chemrev.6b00376
apa: Coughlan, C., Ibáñez, M., Dobrozhan, O., Singh, A., Cabot, A., & Ryan,
K. (2017). Compound copper chalcogenide nanocrystals. Chemical Reviews.
American Chemical Society. https://doi.org/10.1021/acs.chemrev.6b00376
chicago: Coughlan, Claudia, Maria Ibáñez, Oleksandr Dobrozhan, Ajay Singh, Andreu
Cabot, and Kevin Ryan. “Compound Copper Chalcogenide Nanocrystals.” Chemical
Reviews. American Chemical Society, 2017. https://doi.org/10.1021/acs.chemrev.6b00376.
ieee: C. Coughlan, M. Ibáñez, O. Dobrozhan, A. Singh, A. Cabot, and K. Ryan, “Compound
copper chalcogenide nanocrystals,” Chemical Reviews, vol. 117, no. 9. American
Chemical Society, pp. 5865–6109, 2017.
ista: Coughlan C, Ibáñez M, Dobrozhan O, Singh A, Cabot A, Ryan K. 2017. Compound
copper chalcogenide nanocrystals. Chemical Reviews. 117(9), 5865–6109.
mla: Coughlan, Claudia, et al. “Compound Copper Chalcogenide Nanocrystals.” Chemical
Reviews, vol. 117, no. 9, American Chemical Society, 2017, pp. 5865–6109,
doi:10.1021/acs.chemrev.6b00376.
short: C. Coughlan, M. Ibáñez, O. Dobrozhan, A. Singh, A. Cabot, K. Ryan, Chemical
Reviews 117 (2017) 5865–6109.
date_created: 2018-12-11T11:46:06Z
date_published: 2017-04-10T00:00:00Z
date_updated: 2024-03-05T12:17:59Z
day: '10'
doi: 10.1021/acs.chemrev.6b00376
extern: '1'
external_id:
pmid:
- '28394585'
fulldoi: https://doi.org/10.1021/acs.chemrev.6b00376
intvolume: ' 117'
issue: '9'
language:
- iso: eng
month: '04'
oa_version: None
page: 5865 - 6109
pmid: 1
publication: Chemical Reviews
publication_identifier:
eissn:
- 1520-6890
issn:
- 0009-2665
publication_status: published
publisher: American Chemical Society
publist_id: '7456'
quality_controlled: '1'
status: public
title: Compound copper chalcogenide nanocrystals
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 117
year: '2017'
...
---
_id: '374'
abstract:
- lang: eng
text: The conversion of thermal energy to electricity and vice versa by means of
solid state thermoelectric devices is extremely appealing. However, its cost-effectiveness
is seriously hampered by the relatively high production cost and low efficiency
of current thermoelectric materials and devices. To overcome present challenges
and enable a successful deployment of thermoelectric systems in their wide application
range, materials with significantly improved performance need to be developed.
Nanostructuration can help in several ways to reach the very particular group
of properties required to achieve high thermoelectric performances. Nanodomains
inserted within a crystalline matrix can provide large charge carrier concentrations
without strongly influencing their mobility, thus allowing to reach very high
electrical conductivities. Nanostructured materials contain numerous grain boundaries
that efficiently scatter mid- and long-wavelength phonons thus reducing the thermal
conductivity. Furthermore, nanocrystalline domains can enhance the Seebeck coefficient
by modifying the density of states and/or providing type- and energy-dependent
charge carrier scattering. All these advantages can only be reached when engineering
a complex type of material, nanocomposites, with exquisite control over structural
and chemical parameters at multiple length scales. Since current conventional
nanomaterial production technologies lack such level of control, alternative strategies
need to be developed and adjusted to the specifics of the field. A particularly
suitable approach to produce nanocomposites with unique level of control over
their structural and compositional parameters is their bottom-up engineering from
solution-processed nanoparticles. In this work, we review the state-of-the-art
of this technology applied to the thermoelectric field, including the synthesis
of nanoparticles of suitable materials with precisely engineered composition and
surface chemistry, their combination and consolidation into nanostructured materials,
the strategies to electronically dope such materials and the attempts to fabricate
thermoelectric devices using nanoparticle-based nanopowders and inks.
acknowledgement: This work was supported by the European Regional Development Funds,
the Spanish Ministerio de Econom?a y Competitividad through the projects BOOSTER
(ENE2013-46624-C4-3-R) and SEHTOP (ENE2016-77798-C4-3-R). S. O. thanks AGAUR her
PhD grant. Y. L. and Y. Z. thank the China Scholarship Council for scholarship support.
M. I. acknowledges financial support by ETH Carrier Seed Grant (SEED-18 16-2) and
M. V. K. acknowledges partial financial support by the European Union (EU) via FP7
ERC Starting Grant 2012 (Project NANOSOLID, GA No. 306733).
article_processing_charge: No
article_type: original
author:
- first_name: Silvia
full_name: Ortega, Silvia
last_name: Ortega
- first_name: Maria
full_name: Ibanez Sabate, Maria
id: 43C61214-F248-11E8-B48F-1D18A9856A87
last_name: Ibanez Sabate
orcid: 0000-0001-5013-2843
- first_name: Yu
full_name: Liu, Yu
id: 2A70014E-F248-11E8-B48F-1D18A9856A87
last_name: Liu
orcid: 0000-0001-7313-6740
- first_name: Yu
full_name: Zhang, Yu
last_name: Zhang
- first_name: Maksym
full_name: Kovalenko, Maksym
last_name: Kovalenko
- first_name: Doris
full_name: Cadavid, Doris
last_name: Cadavid
- first_name: Andreu
full_name: Cabot, Andreu
last_name: Cabot
citation:
ama: Ortega S, Ibáñez M, Liu Y, et al. Bottom up engineering of thermoelectric nanomaterials
and devices from solution processed nanoparticle building blocks. Chemical
Society Reviews. 2017;46(12):3510-3528. doi:10.1039/c6cs00567e
apa: Ortega, S., Ibáñez, M., Liu, Y., Zhang, Y., Kovalenko, M., Cadavid, D., &
Cabot, A. (2017). Bottom up engineering of thermoelectric nanomaterials and devices
from solution processed nanoparticle building blocks. Chemical Society Reviews.
Royal Society of Chemistry. https://doi.org/10.1039/c6cs00567e
chicago: Ortega, Silvia, Maria Ibáñez, Yu Liu, Yu Zhang, Maksym Kovalenko, Doris
Cadavid, and Andreu Cabot. “Bottom up Engineering of Thermoelectric Nanomaterials
and Devices from Solution Processed Nanoparticle Building Blocks.” Chemical
Society Reviews. Royal Society of Chemistry, 2017. https://doi.org/10.1039/c6cs00567e.
ieee: S. Ortega et al., “Bottom up engineering of thermoelectric nanomaterials
and devices from solution processed nanoparticle building blocks,” Chemical
Society Reviews, vol. 46, no. 12. Royal Society of Chemistry, pp. 3510–3528,
2017.
ista: Ortega S, Ibáñez M, Liu Y, Zhang Y, Kovalenko M, Cadavid D, Cabot A. 2017.
Bottom up engineering of thermoelectric nanomaterials and devices from solution
processed nanoparticle building blocks. Chemical Society Reviews. 46(12), 3510–3528.
mla: Ortega, Silvia, et al. “Bottom up Engineering of Thermoelectric Nanomaterials
and Devices from Solution Processed Nanoparticle Building Blocks.” Chemical
Society Reviews, vol. 46, no. 12, Royal Society of Chemistry, 2017, pp. 3510–28,
doi:10.1039/c6cs00567e.
short: S. Ortega, M. Ibáñez, Y. Liu, Y. Zhang, M. Kovalenko, D. Cadavid, A. Cabot,
Chemical Society Reviews 46 (2017) 3510–3528.
corr_author: '1'
date_created: 2018-12-11T11:46:06Z
date_published: 2017-06-21T00:00:00Z
date_updated: 2024-10-09T20:58:15Z
day: '21'
doi: 10.1039/c6cs00567e
extern: '1'
external_id:
pmid:
- '28470243'
fulldoi: https://doi.org/10.1039/c6cs00567e
intvolume: ' 46'
issue: '12'
language:
- iso: eng
month: '06'
oa_version: None
page: 3510 - 3528
pmid: 1
publication: Chemical Society Reviews
publication_identifier:
eissn:
- 1460-4744
issn:
- 0306-0012
publication_status: published
publisher: Royal Society of Chemistry
publist_id: '7454'
quality_controlled: '1'
status: public
title: Bottom up engineering of thermoelectric nanomaterials and devices from solution
processed nanoparticle building blocks
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 46
year: '2017'
...
---
_id: '375'
abstract:
- lang: eng
text: "Branched nanocrystals (NCs) enable high atomic surface exposure within a
crystalline network that provides avenues for charge transport. This combination
of properties makes branched NCs particularly suitable for a range of applications
where both interaction with the media and charge transport are involved. Herein
we report on the colloidal synthesis of branched ceria NCs by means of a ligand-mediated
overgrowth mechanism. In particular, the differential coverage of oleic acid as
an X-type ligand at ceria facets with different atomic density, atomic coordination
deficiency, and oxygen vacancy density resulted in a preferential growth in the
[111] direction and thus in the formation of ceria octapods. Alcohols, through
an esterification alcoholysis reaction, promoted faster growth rates that translated
into nanostructures with higher geometrical complexity, increasing the branch
aspect ratio and triggering the formation of side branches. On the other hand,
the presence of water resulted in a significant reduction of the growth rate,
decreasing the reaction yield and eliminating side branching, which we associate
to a blocking of the surface reaction sites or a displacement of the alcoholysis
reaction. Overall, adjusting the amounts of each chemical, well-defined branched
ceria NCs with tuned number, thickness, and length of branches and with overall
size ranging from 5 to 45 nm could be produced. We further demonstrate that such
branched ceria NCs are able to provide higher surface areas and related oxygen
storage capacities (OSC) than quasi-spherical NCs.\r\n\r\n"
acknowledgement: This work was supported by the European Regional Development Funds
and the Spanish MINECO project BOOSTER. T.B. is grateful for the FI-AGAUR Research
Fellowship Program, Generalitat de Catalunya (2015 FI_B 00744). P.G. acknowledges
the People Programme (Marie Curie Actions) of the FP7/2007-2013 European Union Program
(TECNIOspring Grant Agreement No. 600388) and the Agency for Business Competitiveness
of the Government of Catalonia, ACCIÓ. M.I. thanks AGAUR for Beatriu de Pinós postdoctoral
grant (2013 BP-A00344). Z.L. thanks the China Scholarship Council for scholarship
support.
article_processing_charge: No
article_type: original
author:
- first_name: Taisiia
full_name: Berestok, Taisiia
last_name: Berestok
- first_name: Pablo
full_name: Guardia, Pablo
last_name: Guardia
- first_name: Javier
full_name: Blanco, Javier
last_name: Blanco
- first_name: Raquel
full_name: Nafria, Raquel
last_name: Nafria
- first_name: Pau
full_name: Torruella, Pau
last_name: Torruella
- first_name: Luis
full_name: López Conesa, Luis
last_name: López Conesa
- first_name: Sònia
full_name: Estradé, Sònia
last_name: Estradé
- first_name: Maria
full_name: Ibanez Sabate, Maria
id: 43C61214-F248-11E8-B48F-1D18A9856A87
last_name: Ibanez Sabate
orcid: 0000-0001-5013-2843
- first_name: Jonathan
full_name: De Roo, Jonathan
last_name: De Roo
- first_name: Zhishan
full_name: Luo, Zhishan
last_name: Luo
- first_name: Doris
full_name: Cadavid, Doris
last_name: Cadavid
- first_name: José
full_name: Martins, José
last_name: Martins
- first_name: Maksym
full_name: Kovalenko, Maksym
last_name: Kovalenko
- first_name: Francesca
full_name: Peiró, Francesca
last_name: Peiró
- first_name: Andreu
full_name: Cabot, Andreu
last_name: Cabot
citation:
ama: Berestok T, Guardia P, Blanco J, et al. Tuning branching in ceria nanocrystals.
Chemistry of Materials. 2017;29(10):4418-4424. doi:10.1021/acs.chemmater.7b00896
apa: Berestok, T., Guardia, P., Blanco, J., Nafria, R., Torruella, P., López Conesa,
L., … Cabot, A. (2017). Tuning branching in ceria nanocrystals. Chemistry of
Materials. American Chemical Society. https://doi.org/10.1021/acs.chemmater.7b00896
chicago: Berestok, Taisiia, Pablo Guardia, Javier Blanco, Raquel Nafria, Pau Torruella,
Luis López Conesa, Sònia Estradé, et al. “Tuning Branching in Ceria Nanocrystals.”
Chemistry of Materials. American Chemical Society, 2017. https://doi.org/10.1021/acs.chemmater.7b00896.
ieee: T. Berestok et al., “Tuning branching in ceria nanocrystals,” Chemistry
of Materials, vol. 29, no. 10. American Chemical Society, pp. 4418–4424, 2017.
ista: Berestok T, Guardia P, Blanco J, Nafria R, Torruella P, López Conesa L, Estradé
S, Ibáñez M, De Roo J, Luo Z, Cadavid D, Martins J, Kovalenko M, Peiró F, Cabot
A. 2017. Tuning branching in ceria nanocrystals. Chemistry of Materials. 29(10),
4418–4424.
mla: Berestok, Taisiia, et al. “Tuning Branching in Ceria Nanocrystals.” Chemistry
of Materials, vol. 29, no. 10, American Chemical Society, 2017, pp. 4418–24,
doi:10.1021/acs.chemmater.7b00896.
short: T. Berestok, P. Guardia, J. Blanco, R. Nafria, P. Torruella, L. López Conesa,
S. Estradé, M. Ibáñez, J. De Roo, Z. Luo, D. Cadavid, J. Martins, M. Kovalenko,
F. Peiró, A. Cabot, Chemistry of Materials 29 (2017) 4418–4424.
date_created: 2018-12-11T11:46:07Z
date_published: 2017-04-24T00:00:00Z
date_updated: 2024-03-05T12:19:17Z
day: '24'
doi: 10.1021/acs.chemmater.7b00896
extern: '1'
fulldoi: https://doi.org/10.1021/acs.chemmater.7b00896
intvolume: ' 29'
issue: '10'
language:
- iso: eng
month: '04'
oa_version: None
page: 4418 - 4424
publication: Chemistry of Materials
publication_identifier:
eissn:
- 1520-5002
issn:
- 0897-4756
publication_status: published
publisher: American Chemical Society
publist_id: '7455'
quality_controlled: '1'
status: public
title: Tuning branching in ceria nanocrystals
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 29
year: '2017'
...
---
DOAJ_listed: '1'
OA_place: publisher
OA_type: gold
_id: '391'
abstract:
- lang: eng
text: 'Three-dimensional topological insulators are bulk insulators with Z 2 topological
electronic order that gives rise to conducting light-like surface states. These
surface electrons are exceptionally resistant to localization by non-magnetic
disorder, and have been adopted as the basis for a wide range of proposals to
achieve new quasiparticle species and device functionality. Recent studies have
yielded a surprise by showing that in spite of resisting localization, topological
insulator surface electrons can be reshaped by defects into distinctive resonance
states. Here we use numerical simulations and scanning tunnelling microscopy data
to show that these resonance states have significance well beyond the localized
regime usually associated with impurity bands. At native densities in the model
Bi2X3 (X=Bi, Te) compounds, defect resonance states are predicted to generate
a new quantum basis for an emergent electron gas that supports diffusive electrical
transport. '
article_number: '14081'
article_processing_charge: No
author:
- first_name: Yishuai
full_name: Xu, Yishuai
last_name: Xu
- first_name: Janet
full_name: Chiu, Janet
last_name: Chiu
- first_name: Lin
full_name: Miao, Lin
last_name: Miao
- first_name: Haowei
full_name: He, Haowei
last_name: He
- first_name: Zhanybek
full_name: Alpichshev, Zhanybek
id: 45E67A2A-F248-11E8-B48F-1D18A9856A87
last_name: Alpichshev
orcid: 0000-0002-7183-5203
- first_name: Aharon
full_name: Kapitulnik, Aharon
last_name: Kapitulnik
- first_name: Rudro
full_name: Biswas, Rudro
last_name: Biswas
- first_name: Lewis
full_name: Wray, Lewis
last_name: Wray
citation:
ama: Xu Y, Chiu J, Miao L, et al. Disorder enabled band structure engineering of
a topological insulator surface. Nature Communications. 2017;8. doi:10.1038/ncomms14081
apa: Xu, Y., Chiu, J., Miao, L., He, H., Alpichshev, Z., Kapitulnik, A., … Wray,
L. (2017). Disorder enabled band structure engineering of a topological insulator
surface. Nature Communications. Springer Nature. https://doi.org/10.1038/ncomms14081
chicago: Xu, Yishuai, Janet Chiu, Lin Miao, Haowei He, Zhanybek Alpichshev, Aharon
Kapitulnik, Rudro Biswas, and Lewis Wray. “Disorder Enabled Band Structure Engineering
of a Topological Insulator Surface.” Nature Communications. Springer Nature,
2017. https://doi.org/10.1038/ncomms14081.
ieee: Y. Xu et al., “Disorder enabled band structure engineering of a topological
insulator surface,” Nature Communications, vol. 8. Springer Nature, 2017.
ista: Xu Y, Chiu J, Miao L, He H, Alpichshev Z, Kapitulnik A, Biswas R, Wray L.
2017. Disorder enabled band structure engineering of a topological insulator surface.
Nature Communications. 8, 14081.
mla: Xu, Yishuai, et al. “Disorder Enabled Band Structure Engineering of a Topological
Insulator Surface.” Nature Communications, vol. 8, 14081, Springer Nature,
2017, doi:10.1038/ncomms14081.
short: Y. Xu, J. Chiu, L. Miao, H. He, Z. Alpichshev, A. Kapitulnik, R. Biswas,
L. Wray, Nature Communications 8 (2017).
date_created: 2018-12-11T11:46:12Z
date_published: 2017-02-03T00:00:00Z
date_updated: 2025-07-08T15:09:23Z
day: '03'
doi: 10.1038/ncomms14081
extern: '1'
fulldoi: https://doi.org/10.1038/ncomms14081
intvolume: ' 8'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1038/ncomms14081
month: '02'
oa: 1
oa_version: Published Version
publication: Nature Communications
publication_identifier:
eissn:
- 2041-1723
publication_status: published
publisher: Springer Nature
publist_id: '7438'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Disorder enabled band structure engineering of a topological insulator surface
type: journal_article
user_id: 3E5EF7F0-F248-11E8-B48F-1D18A9856A87
volume: 8
year: '2017'
...
---
OA_place: repository
OA_type: green
_id: '392'
abstract:
- lang: eng
text: We used femtosecond optical pump-probe spectroscopy to study the photoinduced
change in reflectivity of thin films of the electron-doped cuprate La2-xCexCuO4
(LCCO) with dopings of x=0.08 (underdoped) and x=0.11 (optimally doped). Above
Tc, we observe fluence-dependent relaxation rates that begin at a temperature
similar to the one where transport measurements first show signatures of antiferromagnetic
correlations. Upon suppressing superconductivity with a magnetic field, it is
found that the fluence and temperature dependence of relaxation rates are consistent
with bimolecular recombination of electrons and holes across a gap (2ΔAF) originating
from antiferromagnetic correlations which comprise the pseudogap in electron-doped
cuprates. This can be used to learn about coupling between electrons and high-energy
(ω>2ΔAF) excitations in these compounds and set limits on the time scales on
which antiferromagnetic correlations are static.
acknowledgement: Optical pump-probe work was supported by the Gordon and Betty Moore
Foundation's EPiQS initiative through Grant No. GBMF4540. Materials growth and characterization
was supported by AFOSR FA95501410332 and NSF DMR1410665.
article_number: '115125'
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Inna
full_name: Vishik, Inna
last_name: Vishik
- first_name: Fahad
full_name: Mahmood, Fahad
last_name: Mahmood
- first_name: Zhanybek
full_name: Alpichshev, Zhanybek
id: 45E67A2A-F248-11E8-B48F-1D18A9856A87
last_name: Alpichshev
orcid: 0000-0002-7183-5203
- first_name: Nuh
full_name: Gedik, Nuh
last_name: Gedik
- first_name: Joshu
full_name: Higgins, Joshu
last_name: Higgins
- first_name: Richard
full_name: Greene, Richard
last_name: Greene
citation:
ama: Vishik I, Mahmood F, Alpichshev Z, Gedik N, Higgins J, Greene R. Ultrafast
dynamics in the presence of antiferromagnetic correlations in electron doped cuprate
La2 xCexCuO4±δ. Physical Review B. 2017;95(11). doi:10.1103/PhysRevB.95.115125
apa: Vishik, I., Mahmood, F., Alpichshev, Z., Gedik, N., Higgins, J., & Greene,
R. (2017). Ultrafast dynamics in the presence of antiferromagnetic correlations
in electron doped cuprate La2 xCexCuO4±δ. Physical Review B. American Physical
Society. https://doi.org/10.1103/PhysRevB.95.115125
chicago: Vishik, Inna, Fahad Mahmood, Zhanybek Alpichshev, Nuh Gedik, Joshu Higgins,
and Richard Greene. “Ultrafast Dynamics in the Presence of Antiferromagnetic Correlations
in Electron Doped Cuprate La2 XCexCuO4±δ.” Physical Review B. American
Physical Society, 2017. https://doi.org/10.1103/PhysRevB.95.115125.
ieee: I. Vishik, F. Mahmood, Z. Alpichshev, N. Gedik, J. Higgins, and R. Greene,
“Ultrafast dynamics in the presence of antiferromagnetic correlations in electron
doped cuprate La2 xCexCuO4±δ,” Physical Review B, vol. 95, no. 11. American
Physical Society, 2017.
ista: Vishik I, Mahmood F, Alpichshev Z, Gedik N, Higgins J, Greene R. 2017. Ultrafast
dynamics in the presence of antiferromagnetic correlations in electron doped cuprate
La2 xCexCuO4±δ. Physical Review B. 95(11), 115125.
mla: Vishik, Inna, et al. “Ultrafast Dynamics in the Presence of Antiferromagnetic
Correlations in Electron Doped Cuprate La2 XCexCuO4±δ.” Physical Review B,
vol. 95, no. 11, 115125, American Physical Society, 2017, doi:10.1103/PhysRevB.95.115125.
short: I. Vishik, F. Mahmood, Z. Alpichshev, N. Gedik, J. Higgins, R. Greene, Physical
Review B 95 (2017).
date_created: 2018-12-11T11:46:13Z
date_published: 2017-03-13T00:00:00Z
date_updated: 2026-05-06T06:56:15Z
day: '13'
doi: 10.1103/PhysRevB.95.115125
extern: '1'
external_id:
arxiv:
- '1601.06694'
fulldoi: https://doi.org/10.1103/PhysRevB.95.115125
intvolume: ' 95'
issue: '11'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: http://dspace.mit.edu/handle/1721.1/109835
month: '03'
oa: 1
oa_version: Preprint
publication: Physical Review B
publication_identifier:
eissn:
- 2469-9969
issnl:
- 2469-9950
publication_status: published
publisher: American Physical Society
publist_id: '7437'
quality_controlled: '1'
scopus_import: '1'
status: public
title: Ultrafast dynamics in the presence of antiferromagnetic correlations in electron
doped cuprate La2 xCexCuO4±δ
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 95
year: '2017'
...
---
OA_place: repository
OA_type: green
_id: '393'
abstract:
- lang: eng
text: 'We use a three-pulse ultrafast optical spectroscopy to study the relaxation
processes in a frustrated Mott insulator Na2IrO3. By being able to independently
produce the out-of-equilibrium bound states (excitons) of doublons and holons
with the first pulse and suppress the underlying antiferromagnetic order with
the second one, we were able to elucidate the relaxation mechanism of quasiparticles
in this system. By observing the difference in the exciton dynamics in the magnetically
ordered and disordered phases we found that the mass of this quasiparticle is
mostly determined by its interaction with the surrounding spins. '
acknowledgement: Z.A. gratefully acknowledges discussions with P. A. Lee and A. Kemper.
A conversation with J. Zaanen was instrumental in clarifying the physical picture
described in this paper. We would also like to thank A. Kogar for thoroughly reading
the manuscript and making valuable comments. This work was supported by Army Research
Office Grant No. W911NF-15-1-0128 and Gordon and Betty Moore Foundation EPiQS Initiative
through Grant No. GBMF4540 (time resolved optical spectroscopy), Skoltech, as part
of the Skoltech NGP program (theory) and National Science Foundation Grant No. DMR-1265162
(material growth).
article_number: '235141 '
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Zhanybek
full_name: Alpichshev, Zhanybek
id: 45E67A2A-F248-11E8-B48F-1D18A9856A87
last_name: Alpichshev
orcid: 0000-0002-7183-5203
- first_name: Edbert
full_name: Sie, Edbert
last_name: Sie
- first_name: Fahad
full_name: Mahmood, Fahad
last_name: Mahmood
- first_name: Gang
full_name: Cao, Gang
last_name: Cao
- first_name: Nuh
full_name: Gedik, Nuh
last_name: Gedik
citation:
ama: Alpichshev Z, Sie E, Mahmood F, Cao G, Gedik N. Origin of the exciton mass
in the frustrated Mott insulator Na2IrO3. Physical Review B. 2017;96(23).
doi:10.1103/PhysRevB.96.235141
apa: Alpichshev, Z., Sie, E., Mahmood, F., Cao, G., & Gedik, N. (2017). Origin
of the exciton mass in the frustrated Mott insulator Na2IrO3. Physical Review
B. American Physical Society. https://doi.org/10.1103/PhysRevB.96.235141
chicago: Alpichshev, Zhanybek, Edbert Sie, Fahad Mahmood, Gang Cao, and Nuh Gedik.
“Origin of the Exciton Mass in the Frustrated Mott Insulator Na2IrO3.” Physical
Review B. American Physical Society, 2017. https://doi.org/10.1103/PhysRevB.96.235141.
ieee: Z. Alpichshev, E. Sie, F. Mahmood, G. Cao, and N. Gedik, “Origin of the exciton
mass in the frustrated Mott insulator Na2IrO3,” Physical Review B, vol.
96, no. 23. American Physical Society, 2017.
ista: Alpichshev Z, Sie E, Mahmood F, Cao G, Gedik N. 2017. Origin of the exciton
mass in the frustrated Mott insulator Na2IrO3. Physical Review B. 96(23), 235141.
mla: Alpichshev, Zhanybek, et al. “Origin of the Exciton Mass in the Frustrated
Mott Insulator Na2IrO3.” Physical Review B, vol. 96, no. 23, 235141, American
Physical Society, 2017, doi:10.1103/PhysRevB.96.235141.
short: Z. Alpichshev, E. Sie, F. Mahmood, G. Cao, N. Gedik, Physical Review B 96
(2017).
date_created: 2018-12-11T11:46:13Z
date_published: 2017-12-26T00:00:00Z
date_updated: 2026-04-29T06:27:39Z
day: '26'
doi: 10.1103/PhysRevB.96.235141
extern: '1'
external_id:
arxiv:
- '1610.09350'
fulldoi: https://doi.org/10.1103/PhysRevB.96.235141
intvolume: ' 96'
issue: '23'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: http://dspace.mit.edu/handle/1721.1/114259
month: '12'
oa: 1
oa_version: Submitted Version
publication: Physical Review B
publication_status: published
publisher: American Physical Society
publist_id: '7436'
quality_controlled: '1'
status: public
title: Origin of the exciton mass in the frustrated Mott insulator Na2IrO3
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 96
year: '2017'
...
---
_id: '424'
abstract:
- lang: eng
text: 'We show that very weak topological assumptions are enough to ensure the existence
of a Helly-type theorem. More precisely, we show that for any non-negative integers
b and d there exists an integer h(b, d) such that the following holds. If F is
a finite family of subsets of Rd such that βi(∩G)≤b for any G⊊F and every 0 ≤
i ≤ [d/2]-1 then F has Helly number at most h(b, d). Here βi denotes the reduced
Z2-Betti numbers (with singular homology). These topological conditions are sharp:
not controlling any of these [d/2] first Betti numbers allow for families with
unbounded Helly number. Our proofs combine homological non-embeddability results
with a Ramsey-based approach to build, given an arbitrary simplicial complex K,
some well-behaved chain map C*(K)→C*(Rd).'
article_processing_charge: No
arxiv: 1
author:
- first_name: Xavier
full_name: Goaoc, Xavier
last_name: Goaoc
- first_name: Pavel
full_name: Paták, Pavel
last_name: Paták
- first_name: Zuzana
full_name: Patakova, Zuzana
last_name: Patakova
orcid: 0000-0002-3975-1683
- first_name: Martin
full_name: Tancer, Martin
last_name: Tancer
orcid: 0000-0002-1191-6714
- first_name: Uli
full_name: Wagner, Uli
id: 36690CA2-F248-11E8-B48F-1D18A9856A87
last_name: Wagner
orcid: 0000-0002-1494-0568
citation:
ama: 'Goaoc X, Paták P, Patakova Z, Tancer M, Wagner U. Bounding helly numbers via
betti numbers. In: Loebl M, Nešetřil J, Thomas R, eds. A Journey through Discrete
Mathematics: A Tribute to Jiri Matousek. A Journey Through Discrete Mathematics.
Springer; 2017:407-447. doi:10.1007/978-3-319-44479-6_17'
apa: 'Goaoc, X., Paták, P., Patakova, Z., Tancer, M., & Wagner, U. (2017). Bounding
helly numbers via betti numbers. In M. Loebl, J. Nešetřil, & R. Thomas (Eds.),
A Journey through Discrete Mathematics: A Tribute to Jiri Matousek (pp.
407–447). Springer. https://doi.org/10.1007/978-3-319-44479-6_17'
chicago: 'Goaoc, Xavier, Pavel Paták, Zuzana Patakova, Martin Tancer, and Uli Wagner.
“Bounding Helly Numbers via Betti Numbers.” In A Journey through Discrete Mathematics:
A Tribute to Jiri Matousek, edited by Martin Loebl, Jaroslav Nešetřil, and
Robin Thomas, 407–47. A Journey Through Discrete Mathematics. Springer, 2017.
https://doi.org/10.1007/978-3-319-44479-6_17.'
ieee: 'X. Goaoc, P. Paták, Z. Patakova, M. Tancer, and U. Wagner, “Bounding helly
numbers via betti numbers,” in A Journey through Discrete Mathematics: A Tribute
to Jiri Matousek, M. Loebl, J. Nešetřil, and R. Thomas, Eds. Springer, 2017,
pp. 407–447.'
ista: 'Goaoc X, Paták P, Patakova Z, Tancer M, Wagner U. 2017.Bounding helly numbers
via betti numbers. In: A Journey through Discrete Mathematics: A Tribute to Jiri
Matousek. , 407–447.'
mla: 'Goaoc, Xavier, et al. “Bounding Helly Numbers via Betti Numbers.” A Journey
through Discrete Mathematics: A Tribute to Jiri Matousek, edited by Martin
Loebl et al., Springer, 2017, pp. 407–47, doi:10.1007/978-3-319-44479-6_17.'
short: 'X. Goaoc, P. Paták, Z. Patakova, M. Tancer, U. Wagner, in:, M. Loebl, J.
Nešetřil, R. Thomas (Eds.), A Journey through Discrete Mathematics: A Tribute
to Jiri Matousek, Springer, 2017, pp. 407–447.'
date_created: 2018-12-11T11:46:24Z
date_published: 2017-10-06T00:00:00Z
date_updated: 2026-06-18T18:48:49Z
day: '06'
ddc:
- '500'
department:
- _id: UlWa
doi: 10.1007/978-3-319-44479-6_17
editor:
- first_name: Martin
full_name: Loebl, Martin
last_name: Loebl
- first_name: Jaroslav
full_name: Nešetřil, Jaroslav
last_name: Nešetřil
- first_name: Robin
full_name: Thomas, Robin
last_name: Thomas
external_id:
arxiv:
- '1310.4613'
fulldoi: https://doi.org/10.1007/978-3-319-44479-6_17
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1310.4613
month: '10'
oa: 1
oa_version: Published Version
page: 407 - 447
publication: 'A Journey through Discrete Mathematics: A Tribute to Jiri Matousek'
publication_identifier:
isbn:
- 978-331944479-6
publication_status: published
publisher: Springer
publist_id: '7399'
quality_controlled: '1'
related_material:
record:
- id: '1512'
relation: earlier_version
status: public
scopus_import: '1'
series_title: A Journey Through Discrete Mathematics
status: public
title: Bounding helly numbers via betti numbers
type: book_chapter
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2017'
...
---
_id: '431'
abstract:
- lang: eng
text: 'Parallel implementations of stochastic gradient descent (SGD) have received
significant research attention, thanks to its excellent scalability properties.
A fundamental barrier when parallelizing SGD is the high bandwidth cost of communicating
gradient updates between nodes; consequently, several lossy compresion heuristics
have been proposed, by which nodes only communicate quantized gradients. Although
effective in practice, these heuristics do not always converge. In this paper,
we propose Quantized SGD (QSGD), a family of compression schemes with convergence
guarantees and good practical performance. QSGD allows the user to smoothly trade
off communication bandwidth and convergence time: nodes can adjust the number
of bits sent per iteration, at the cost of possibly higher variance. We show that
this trade-off is inherent, in the sense that improving it past some threshold
would violate information-theoretic lower bounds. QSGD guarantees convergence
for convex and non-convex objectives, under asynchrony, and can be extended to
stochastic variance-reduced techniques. When applied to training deep neural networks
for image classification and automated speech recognition, QSGD leads to significant
reductions in end-to-end training time. For instance, on 16GPUs, we can train
the ResNet-152 network to full accuracy on ImageNet 1.8 × faster than the full-precision
variant. '
alternative_title:
- Advances in Neural Information Processing Systems
article_processing_charge: No
arxiv: 1
author:
- first_name: Dan-Adrian
full_name: Alistarh, Dan-Adrian
id: 4A899BFC-F248-11E8-B48F-1D18A9856A87
last_name: Alistarh
orcid: 0000-0003-3650-940X
- first_name: Demjan
full_name: Grubic, Demjan
last_name: Grubic
- first_name: Jerry
full_name: Li, Jerry
last_name: Li
- first_name: Ryota
full_name: Tomioka, Ryota
last_name: Tomioka
- first_name: Milan
full_name: Vojnović, Milan
last_name: Vojnović
citation:
ama: 'Alistarh D-A, Grubic D, Li J, Tomioka R, Vojnović M. QSGD: Communication-efficient
SGD via gradient quantization and encoding. In: Vol 2017. Neural Information Processing
Systems Foundation; 2017:1710-1721.'
apa: 'Alistarh, D.-A., Grubic, D., Li, J., Tomioka, R., & Vojnović, M. (2017).
QSGD: Communication-efficient SGD via gradient quantization and encoding (Vol.
2017, pp. 1710–1721). Presented at the NIPS: Neural Information Processing System,
Long Beach, CA, United States: Neural Information Processing Systems Foundation.'
chicago: 'Alistarh, Dan-Adrian, Demjan Grubic, Jerry Li, Ryota Tomioka, and Milan
Vojnović. “QSGD: Communication-Efficient SGD via Gradient Quantization and Encoding,”
2017:1710–21. Neural Information Processing Systems Foundation, 2017.'
ieee: 'D.-A. Alistarh, D. Grubic, J. Li, R. Tomioka, and M. Vojnović, “QSGD: Communication-efficient
SGD via gradient quantization and encoding,” presented at the NIPS: Neural Information
Processing System, Long Beach, CA, United States, 2017, vol. 2017, pp. 1710–1721.'
ista: 'Alistarh D-A, Grubic D, Li J, Tomioka R, Vojnović M. 2017. QSGD: Communication-efficient
SGD via gradient quantization and encoding. NIPS: Neural Information Processing
System, Advances in Neural Information Processing Systems, vol. 2017, 1710–1721.'
mla: 'Alistarh, Dan-Adrian, et al. QSGD: Communication-Efficient SGD via Gradient
Quantization and Encoding. Vol. 2017, Neural Information Processing Systems
Foundation, 2017, pp. 1710–21.'
short: D.-A. Alistarh, D. Grubic, J. Li, R. Tomioka, M. Vojnović, in:, Neural Information
Processing Systems Foundation, 2017, pp. 1710–1721.
conference:
end_date: 2017-12-09
location: Long Beach, CA, United States
name: 'NIPS: Neural Information Processing System'
start_date: 2017-12-04
corr_author: '1'
date_created: 2018-12-11T11:46:26Z
date_published: 2017-01-01T00:00:00Z
date_updated: 2025-09-18T10:07:20Z
day: '01'
department:
- _id: DaAl
external_id:
arxiv:
- '1610.02132'
isi:
- '000452649401072'
intvolume: ' 2017'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1610.02132
month: '01'
oa: 1
oa_version: Submitted Version
page: 1710-1721
publication_identifier:
issn:
- 1049-5258
publication_status: published
publisher: Neural Information Processing Systems Foundation
publist_id: '7392'
quality_controlled: '1'
status: public
title: 'QSGD: Communication-efficient SGD via gradient quantization and encoding'
type: conference
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 2017
year: '2017'
...
---
_id: '432'
abstract:
- lang: eng
text: 'Recently there has been significant interest in training machine-learning
models at low precision: by reducing precision, one can reduce computation and
communication by one order of magnitude. We examine training at reduced precision,
both from a theoretical and practical perspective, and ask: is it possible to
train models at end-to-end low precision with provable guarantees? Can this lead
to consistent order-of-magnitude speedups? We mainly focus on linear models, and
the answer is yes for linear models. We develop a simple framework called ZipML
based on one simple but novel strategy called double sampling. Our ZipML framework
is able to execute training at low precision with no bias, guaranteeing convergence,
whereas naive quanti- zation would introduce significant bias. We val- idate our
framework across a range of applica- tions, and show that it enables an FPGA proto-
type that is up to 6.5 × faster than an implemen- tation using full 32-bit precision.
We further de- velop a variance-optimal stochastic quantization strategy and show
that it can make a significant difference in a variety of settings. When applied
to linear models together with double sampling, we save up to another 1.7 × in
data movement compared with uniform quantization. When training deep networks
with quantized models, we achieve higher accuracy than the state-of-the- art XNOR-Net. '
alternative_title:
- PMLR Press
article_processing_charge: No
author:
- first_name: Hantian
full_name: Zhang, Hantian
last_name: Zhang
- first_name: Jerry
full_name: Li, Jerry
last_name: Li
- first_name: Kaan
full_name: Kara, Kaan
last_name: Kara
- first_name: Dan-Adrian
full_name: Alistarh, Dan-Adrian
id: 4A899BFC-F248-11E8-B48F-1D18A9856A87
last_name: Alistarh
orcid: 0000-0003-3650-940X
- first_name: Ji
full_name: Liu, Ji
last_name: Liu
- first_name: Ce
full_name: Zhang, Ce
last_name: Zhang
citation:
ama: 'Zhang H, Li J, Kara K, Alistarh D-A, Liu J, Zhang C. ZipML: Training linear
models with end-to-end low precision, and a little bit of deep learning. In: Proceedings
of Machine Learning Research. Vol 70. ML Research Press; 2017:4035-4043.'
apa: 'Zhang, H., Li, J., Kara, K., Alistarh, D.-A., Liu, J., & Zhang, C. (2017).
ZipML: Training linear models with end-to-end low precision, and a little bit
of deep learning. In Proceedings of Machine Learning Research (Vol. 70,
pp. 4035–4043). Sydney, Australia: ML Research Press.'
chicago: 'Zhang, Hantian, Jerry Li, Kaan Kara, Dan-Adrian Alistarh, Ji Liu, and
Ce Zhang. “ZipML: Training Linear Models with End-to-End Low Precision, and a
Little Bit of Deep Learning.” In Proceedings of Machine Learning Research,
70:4035–43. ML Research Press, 2017.'
ieee: 'H. Zhang, J. Li, K. Kara, D.-A. Alistarh, J. Liu, and C. Zhang, “ZipML: Training
linear models with end-to-end low precision, and a little bit of deep learning,”
in Proceedings of Machine Learning Research, Sydney, Australia, 2017, vol.
70, pp. 4035–4043.'
ista: 'Zhang H, Li J, Kara K, Alistarh D-A, Liu J, Zhang C. 2017. ZipML: Training
linear models with end-to-end low precision, and a little bit of deep learning.
Proceedings of Machine Learning Research. ICML: International Conference on Machine
Learning, PMLR Press, vol. 70, 4035–4043.'
mla: 'Zhang, Hantian, et al. “ZipML: Training Linear Models with End-to-End Low
Precision, and a Little Bit of Deep Learning.” Proceedings of Machine Learning
Research, vol. 70, ML Research Press, 2017, pp. 4035–43.'
short: H. Zhang, J. Li, K. Kara, D.-A. Alistarh, J. Liu, C. Zhang, in:, Proceedings
of Machine Learning Research, ML Research Press, 2017, pp. 4035–4043.
conference:
end_date: 2017-08-11
location: Sydney, Australia
name: 'ICML: International Conference on Machine Learning'
start_date: 2017-08-06
corr_author: '1'
date_created: 2018-12-11T11:46:26Z
date_published: 2017-01-01T00:00:00Z
date_updated: 2025-09-18T10:06:02Z
day: '01'
ddc:
- '000'
department:
- _id: DaAl
external_id:
isi:
- '000683309504015'
file:
- access_level: open_access
checksum: 86156ba7f4318e47cef3eb9092593c10
content_type: application/pdf
creator: dernst
date_created: 2019-01-22T08:23:58Z
date_updated: 2020-07-14T12:46:26Z
file_id: '5869'
file_name: 2017_ICML_Zhang.pdf
file_size: 849345
relation: main_file
file_date_updated: 2020-07-14T12:46:26Z
has_accepted_license: '1'
isi: 1
language:
- iso: eng
month: '01'
oa: 1
oa_version: Submitted Version
page: 4035 - 4043
publication: Proceedings of Machine Learning Research
publication_identifier:
isbn:
- 978-151085514-4
publication_status: published
publisher: ML Research Press
publist_id: '7391'
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'ZipML: Training linear models with end-to-end low precision, and a little
bit of deep learning'
type: conference
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: ' 70'
year: '2017'
...
---
_id: '17616'
abstract:
- lang: eng
text: The optical and UV emission from sub-parsec massive black hole binaries (MBHBs)
in active galactic nuclei (AGNs) is believed to vary periodically, on time-scales
comparable to the binary's orbital time. If driven by accretion rate fluctuations,
the variability could be isotropic. If dominated by relativistic Doppler modulation,
the variability should instead be anisotropic, resembling a rotating forward-beamed
lighthouse. We consider the infrared (IR) reverberation of either type of periodic
emission by pc-scale circumbinary dust tori. We predict the phase and amplitude
of IR variability as a function of the ratio of dust light crossing time to the
source variability period, and of the torus inclination and opening angle. We
enumerate several differences between the isotropic and anisotropic cases. Interestingly,
for a nearly face-on binary with an inclined dust torus, the Doppler boost can
produce IR variability without any observable optical/UV variability. Such orphan-IR
variability would have been missed in optical searches for periodic AGNs. We apply
our models to time-domain WISE IR data from the MBHB candidate PG 1302−102 and
find consistency with dust reverberation by both isotropically emitting and Doppler-boosted
sources in the shorter wavelength W1–W2 (2.8 → 5.3 μm) bands. We constrain the
dust torus to be thin (aspect ratio ∼ 0.1), with an inner radius at 1–5 pc. More
generally, our dust-echo models will aid in identifying new MBHB candidates, determining
their nature and constraining the physical properties of MBHBs and their dust
tori.
article_processing_charge: No
article_type: original
author:
- first_name: Daniel J.
full_name: D'Orazio, Daniel J.
last_name: D'Orazio
- first_name: Zoltán
full_name: Haiman, Zoltán
id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
last_name: Haiman
citation:
ama: 'D’Orazio DJ, Haiman Z. Lighthouse in the dust: infrared echoes of periodic
emission from massive black hole binaries★. Monthly Notices of the Royal Astronomical
Society. 2017;470(1):1198-1217. doi:10.1093/mnras/stx1269'
apa: 'D’Orazio, D. J., & Haiman, Z. (2017). Lighthouse in the dust: infrared
echoes of periodic emission from massive black hole binaries★. Monthly Notices
of the Royal Astronomical Society. Oxford University Press. https://doi.org/10.1093/mnras/stx1269'
chicago: 'D’Orazio, Daniel J., and Zoltán Haiman. “Lighthouse in the Dust: Infrared
Echoes of Periodic Emission from Massive Black Hole Binaries★.” Monthly Notices
of the Royal Astronomical Society. Oxford University Press, 2017. https://doi.org/10.1093/mnras/stx1269.'
ieee: 'D. J. D’Orazio and Z. Haiman, “Lighthouse in the dust: infrared echoes of
periodic emission from massive black hole binaries★,” Monthly Notices of the
Royal Astronomical Society, vol. 470, no. 1. Oxford University Press, pp.
1198–1217, 2017.'
ista: 'D’Orazio DJ, Haiman Z. 2017. Lighthouse in the dust: infrared echoes of periodic
emission from massive black hole binaries★. Monthly Notices of the Royal Astronomical
Society. 470(1), 1198–1217.'
mla: 'D’Orazio, Daniel J., and Zoltán Haiman. “Lighthouse in the Dust: Infrared
Echoes of Periodic Emission from Massive Black Hole Binaries★.” Monthly Notices
of the Royal Astronomical Society, vol. 470, no. 1, Oxford University Press,
2017, pp. 1198–217, doi:10.1093/mnras/stx1269.'
short: D.J. D’Orazio, Z. Haiman, Monthly Notices of the Royal Astronomical Society
470 (2017) 1198–1217.
date_created: 2024-09-05T13:32:36Z
date_published: 2017-05-23T00:00:00Z
date_updated: 2024-09-24T08:01:52Z
day: '23'
doi: 10.1093/mnras/stx1269
extern: '1'
fulldoi: https://doi.org/10.1093/mnras/stx1269
intvolume: ' 470'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1093/mnras/stx1269
month: '05'
oa: 1
oa_version: Published Version
page: 1198-1217
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
issn:
- 0035-8711
- 1365-2966
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Lighthouse in the dust: infrared echoes of periodic emission from massive
black hole binaries★'
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 470
year: '2017'
...
---
_id: '17629'
abstract:
- lang: eng
text: We propose an observational test for gravitationally recoiling supermassive
black holes in active galactic nuclei, based on a positive correlation between
the velocities of black holes relative to their host galaxies, |Δv|, and their
obscuring dust column densities, Σdust, both measured along the line of sight.
Our findings using a set of toy models implemented to a Monte Carlo simulation
imply that models of the galactic centre and of recoil dynamics can be tested
by future observations of the potential Σdust–|Δv| correlation. We have also found
that the fraction of obscured quasars decreases with |Δv|, for which the predicted
trend can be compared to the observed fraction of type II quasars, and can further
test combinations of models we may implement.
article_processing_charge: No
article_type: original
author:
- first_name: P.
full_name: Raffai, P.
last_name: Raffai
- first_name: B.
full_name: Bécsy, B.
last_name: Bécsy
- first_name: Zoltán
full_name: Haiman, Zoltán
id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
last_name: Haiman
- first_name: Z.
full_name: Frei, Z.
last_name: Frei
citation:
ama: Raffai P, Bécsy B, Haiman Z, Frei Z. A statistical method for detecting gravitational
recoils of supermassive black holes in active galactic nuclei. Proceedings
of the International Astronomical Union. 2017;12(S324):227-230. doi:10.1017/s1743921317000734
apa: Raffai, P., Bécsy, B., Haiman, Z., & Frei, Z. (2017). A statistical method
for detecting gravitational recoils of supermassive black holes in active galactic
nuclei. Proceedings of the International Astronomical Union. Cambridge
University Press. https://doi.org/10.1017/s1743921317000734
chicago: Raffai, P., B. Bécsy, Zoltán Haiman, and Z. Frei. “A Statistical Method
for Detecting Gravitational Recoils of Supermassive Black Holes in Active Galactic
Nuclei.” Proceedings of the International Astronomical Union. Cambridge
University Press, 2017. https://doi.org/10.1017/s1743921317000734.
ieee: P. Raffai, B. Bécsy, Z. Haiman, and Z. Frei, “A statistical method for detecting
gravitational recoils of supermassive black holes in active galactic nuclei,”
Proceedings of the International Astronomical Union, vol. 12, no. S324.
Cambridge University Press, pp. 227–230, 2017.
ista: Raffai P, Bécsy B, Haiman Z, Frei Z. 2017. A statistical method for detecting
gravitational recoils of supermassive black holes in active galactic nuclei. Proceedings
of the International Astronomical Union. 12(S324), 227–230.
mla: Raffai, P., et al. “A Statistical Method for Detecting Gravitational Recoils
of Supermassive Black Holes in Active Galactic Nuclei.” Proceedings of the
International Astronomical Union, vol. 12, no. S324, Cambridge University
Press, 2017, pp. 227–30, doi:10.1017/s1743921317000734.
short: P. Raffai, B. Bécsy, Z. Haiman, Z. Frei, Proceedings of the International
Astronomical Union 12 (2017) 227–230.
date_created: 2024-09-05T13:58:38Z
date_published: 2017-06-23T00:00:00Z
date_updated: 2024-09-24T09:30:29Z
day: '23'
doi: 10.1017/s1743921317000734
extern: '1'
fulldoi: https://doi.org/10.1017/s1743921317000734
intvolume: ' 12'
issue: S324
language:
- iso: eng
main_file_link:
- url: https://doi.org/10.1017/s1743921317000734
month: '06'
oa_version: None
page: 227-230
publication: Proceedings of the International Astronomical Union
publication_identifier:
issn:
- 1743-9213
- 1743-9221
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: A statistical method for detecting gravitational recoils of supermassive black
holes in active galactic nuclei
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 12
year: '2017'
...
---
_id: '17630'
abstract:
- lang: eng
text: In symmetric gravitating systems experiencing rapid mass-loss, particle orbits
change almost instantaneously, which can lead to the development of a sharply
contoured density profile, including singular caustics for collisionless systems.
This framework can be used to model a variety of dynamical systems, such as accretion
discs following a massive black hole merger and dwarf galaxies following violent
early star formation feedback. Particle interactions in the high-density peaks
seem a promising source of observable signatures of these mass-loss events (i.e.
a possible EM counterpart for black hole mergers or strong gamma-ray emission
from dark matter annihilation around young galaxies), because the interaction
rate depends on the square of the density. We study post-mass-loss density profiles,
both analytic and numerical, in idealized cases and present arguments and methods
to extend to any general system. An analytic derivation is presented for particles
on Keplerian orbits responding to a drop in the central mass. We argue that this
case, with initially circular orbits, gives the most sharply contoured profile
possible. We find that despite the presence of a set of singular caustics, the
total particle interaction rate is reduced compared to the unperturbed system;
this is a result of the overall expansion of the system dominating over the steep
caustics. Finally, we argue that this result holds more generally, and the loss
of central mass decreases the particle interaction rate in any physical system.
article_processing_charge: No
article_type: original
arxiv: 1
author:
- first_name: Zephyr
full_name: Penoyre, Zephyr
last_name: Penoyre
- first_name: Zoltán
full_name: Haiman, Zoltán
id: 7c006e8c-cc0d-11ee-8322-cb904ef76f36
last_name: Haiman
citation:
ama: 'Penoyre Z, Haiman Z. A drop in the pond: The effect of rapid mass-loss on
the dynamics and interaction rate of collisionless particles. Monthly Notices
of the Royal Astronomical Society. 2017;473(1):498-512. doi:10.1093/mnras/stx2469'
apa: 'Penoyre, Z., & Haiman, Z. (2017). A drop in the pond: The effect of rapid
mass-loss on the dynamics and interaction rate of collisionless particles. Monthly
Notices of the Royal Astronomical Society. Oxford University Press. https://doi.org/10.1093/mnras/stx2469'
chicago: 'Penoyre, Zephyr, and Zoltán Haiman. “A Drop in the Pond: The Effect of
Rapid Mass-Loss on the Dynamics and Interaction Rate of Collisionless Particles.”
Monthly Notices of the Royal Astronomical Society. Oxford University Press,
2017. https://doi.org/10.1093/mnras/stx2469.'
ieee: 'Z. Penoyre and Z. Haiman, “A drop in the pond: The effect of rapid mass-loss
on the dynamics and interaction rate of collisionless particles,” Monthly Notices
of the Royal Astronomical Society, vol. 473, no. 1. Oxford University Press,
pp. 498–512, 2017.'
ista: 'Penoyre Z, Haiman Z. 2017. A drop in the pond: The effect of rapid mass-loss
on the dynamics and interaction rate of collisionless particles. Monthly Notices
of the Royal Astronomical Society. 473(1), 498–512.'
mla: 'Penoyre, Zephyr, and Zoltán Haiman. “A Drop in the Pond: The Effect of Rapid
Mass-Loss on the Dynamics and Interaction Rate of Collisionless Particles.” Monthly
Notices of the Royal Astronomical Society, vol. 473, no. 1, Oxford University
Press, 2017, pp. 498–512, doi:10.1093/mnras/stx2469.'
short: Z. Penoyre, Z. Haiman, Monthly Notices of the Royal Astronomical Society
473 (2017) 498–512.
date_created: 2024-09-05T13:59:48Z
date_published: 2017-09-25T00:00:00Z
date_updated: 2024-09-24T09:48:08Z
day: '25'
doi: 10.1093/mnras/stx2469
extern: '1'
external_id:
arxiv:
- '1709.08640'
fulldoi: https://doi.org/10.1093/mnras/stx2469
intvolume: ' 473'
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: ' https://doi.org/10.48550/arXiv.1709.08640'
month: '09'
oa: 1
oa_version: Preprint
page: 498-512
publication: Monthly Notices of the Royal Astronomical Society
publication_identifier:
issn:
- 0035-8711
- 1365-2966
publication_status: published
publisher: Oxford University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'A drop in the pond: The effect of rapid mass-loss on the dynamics and interaction
rate of collisionless particles'
type: journal_article
user_id: 317138e5-6ab7-11ef-aa6d-ffef3953e345
volume: 473
year: '2017'
...