---
_id: '11864'
abstract:
- lang: eng
text: Auctions are widely used on the Web. Applications range from internet advertising
to platforms such as eBay. In most of these applications the auctions in use are
single/multi-item auctions with unit demand. The main drawback of standard mechanisms
for this type of auctions, such as VCG and GSP, is the limited expressiveness
that they offer to the bidders. The General Auction Mechanism (GAM) of [1] is
taking a first step towards addressing the problem of limited expressiveness by
computing a bidder optimal, envy free outcome for linear utility functions with
identical slopes and a single discontinuity per bidder-item pair. We show that
in many practical situations this does not suffice to adequately model the preferences
of the bidders, and we overcome this problem by presenting the first mechanism
for piece-wise linear utility functions with non-identical slopes and multiple
discontinuities. Our mechanism runs in polynomial time. Like GAM it is incentive
compatible for inputs that fulfill a certain non-degeneracy requirement, but our
requirement is more general than the requirement of GAM. For discontinuous utility
functions that are non-degenerate as well as for continuous utility functions
the outcome of our mechanism is a competitive equilibrium. We also show how our
mechanism can be used to compute approximately bidder optimal, envy free outcomes
for a general class of continuous utility functions via piece-wise linear approximation.
Finally, we prove hardness results for even more expressive settings.
article_processing_charge: No
author:
- first_name: Paul
full_name: Dütting, Paul
last_name: Dütting
- first_name: Monika H
full_name: Henzinger, Monika H
id: 540c9bbd-f2de-11ec-812d-d04a5be85630
last_name: Henzinger
orcid: 0000-0002-5008-6530
- first_name: Ingmar
full_name: Weber, Ingmar
last_name: Weber
citation:
ama: 'Dütting P, Henzinger MH, Weber I. An expressive mechanism for auctions on
the web. In: Proceedings of the 20th International Conference on World Wide
Web. Association for Computing Machinery; 2011:127-136. doi:10.1145/1963405.1963427'
apa: 'Dütting, P., Henzinger, M. H., & Weber, I. (2011). An expressive mechanism
for auctions on the web. In Proceedings of the 20th international conference
on World wide web (pp. 127–136). Hyderabad, India: Association for Computing
Machinery. https://doi.org/10.1145/1963405.1963427'
chicago: Dütting, Paul, Monika H Henzinger, and Ingmar Weber. “An Expressive Mechanism
for Auctions on the Web.” In Proceedings of the 20th International Conference
on World Wide Web, 127–36. Association for Computing Machinery, 2011. https://doi.org/10.1145/1963405.1963427.
ieee: P. Dütting, M. H. Henzinger, and I. Weber, “An expressive mechanism for auctions
on the web,” in Proceedings of the 20th international conference on World wide
web, Hyderabad, India, 2011, pp. 127–136.
ista: 'Dütting P, Henzinger MH, Weber I. 2011. An expressive mechanism for auctions
on the web. Proceedings of the 20th international conference on World wide web.
WWW: International Conference on World Wide Web, 127–136.'
mla: Dütting, Paul, et al. “An Expressive Mechanism for Auctions on the Web.” Proceedings
of the 20th International Conference on World Wide Web, Association for Computing
Machinery, 2011, pp. 127–36, doi:10.1145/1963405.1963427.
short: P. Dütting, M.H. Henzinger, I. Weber, in:, Proceedings of the 20th International
Conference on World Wide Web, Association for Computing Machinery, 2011, pp. 127–136.
conference:
end_date: 2011-04-01
location: Hyderabad, India
name: 'WWW: International Conference on World Wide Web'
start_date: 2011-03-28
date_created: 2022-08-16T09:05:34Z
date_published: 2011-04-01T00:00:00Z
date_updated: 2023-02-17T10:21:18Z
day: '01'
doi: 10.1145/1963405.1963427
extern: '1'
language:
- iso: eng
month: '04'
oa_version: None
page: 127 - 136
publication: Proceedings of the 20th international conference on World wide web
publication_identifier:
isbn:
- 978-145030632-4
publication_status: published
publisher: Association for Computing Machinery
quality_controlled: '1'
scopus_import: '1'
status: public
title: An expressive mechanism for auctions on the web
type: conference
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2011'
...
---
_id: '12651'
abstract:
- lang: eng
text: Temperature data from three Automatic Weather Stations and twelve Temperature
Loggers are used to investigate the spatiotemporal variability of temperature
over a glacier, its main atmospheric controls, the suitability of extrapolation
techniques and their effect on melt modeling. We use data collected on Juncal
Norte Glacier, central Chile, during one ablation season. We examine temporal
and spatial variability in lapse rates (LRs), together with alternative statistical
interpolation methods. The main control over the glacier thermal regime is the
development of a katabatic boundary layer (KBL). Katabatic wind occurs at night
and in the morning and is eroded in the afternoon. LRs reveal strong diurnal variability,
with steeper LRs during the day when the katabatic wind weakens and shallower
LRs during the night and morning. We suggest that temporally variable LRs should
be used to account for the observed change. They tend to be steeper than equivalent
constant LRs, and therefore result in a reduction in simulated melt compared to
use of constant LRs when extrapolating from lower to higher elevations. In addition
to the temporal variability, the temperature-elevation relationship varies also
in space. Differences are evident between local LRs and including such variability
in melt modeling affects melt simulations. Extrapolation methods based on the
spatial variability of the observations after removal of the elevation trend,
such as Inverse Distance Weighting or Kriging, do not seem necessary for simulations
of gridded temperature data over a glacier.
article_number: D23109
article_processing_charge: No
article_type: original
author:
- first_name: L.
full_name: Petersen, L.
last_name: Petersen
- first_name: Francesca
full_name: Pellicciotti, Francesca
id: b28f055a-81ea-11ed-b70c-a9fe7f7b0e70
last_name: Pellicciotti
citation:
ama: 'Petersen L, Pellicciotti F. Spatial and temporal variability of air temperature
on a melting glacier: Atmospheric controls, extrapolation methods and their effect
on melt modeling, Juncal Norte Glacier, Chile. Journal of Geophysical Research:
Atmospheres. 2011;116(D23). doi:10.1029/2011jd015842'
apa: 'Petersen, L., & Pellicciotti, F. (2011). Spatial and temporal variability
of air temperature on a melting glacier: Atmospheric controls, extrapolation methods
and their effect on melt modeling, Juncal Norte Glacier, Chile. Journal of
Geophysical Research: Atmospheres. American Geophysical Union. https://doi.org/10.1029/2011jd015842'
chicago: 'Petersen, L., and Francesca Pellicciotti. “Spatial and Temporal Variability
of Air Temperature on a Melting Glacier: Atmospheric Controls, Extrapolation Methods
and Their Effect on Melt Modeling, Juncal Norte Glacier, Chile.” Journal of
Geophysical Research: Atmospheres. American Geophysical Union, 2011. https://doi.org/10.1029/2011jd015842.'
ieee: 'L. Petersen and F. Pellicciotti, “Spatial and temporal variability of air
temperature on a melting glacier: Atmospheric controls, extrapolation methods
and their effect on melt modeling, Juncal Norte Glacier, Chile,” Journal of
Geophysical Research: Atmospheres, vol. 116, no. D23. American Geophysical
Union, 2011.'
ista: 'Petersen L, Pellicciotti F. 2011. Spatial and temporal variability of air
temperature on a melting glacier: Atmospheric controls, extrapolation methods
and their effect on melt modeling, Juncal Norte Glacier, Chile. Journal of Geophysical
Research: Atmospheres. 116(D23), D23109.'
mla: 'Petersen, L., and Francesca Pellicciotti. “Spatial and Temporal Variability
of Air Temperature on a Melting Glacier: Atmospheric Controls, Extrapolation Methods
and Their Effect on Melt Modeling, Juncal Norte Glacier, Chile.” Journal of
Geophysical Research: Atmospheres, vol. 116, no. D23, D23109, American Geophysical
Union, 2011, doi:10.1029/2011jd015842.'
short: 'L. Petersen, F. Pellicciotti, Journal of Geophysical Research: Atmospheres
116 (2011).'
date_created: 2023-02-20T08:18:14Z
date_published: 2011-12-16T00:00:00Z
date_updated: 2023-02-20T10:29:44Z
day: '16'
doi: 10.1029/2011jd015842
extern: '1'
intvolume: ' 116'
issue: D23
keyword:
- Paleontology
- Space and Planetary Science
- Earth and Planetary Sciences (miscellaneous)
- Atmospheric Science
- Earth-Surface Processes
- Geochemistry and Petrology
- Soil Science
- Water Science and Technology
- Ecology
- Aquatic Science
- Forestry
- Oceanography
- Geophysics
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1029/2011JD01584
month: '12'
oa: 1
oa_version: Published Version
publication: 'Journal of Geophysical Research: Atmospheres'
publication_identifier:
issn:
- 0148-0227
publication_status: published
publisher: American Geophysical Union
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Spatial and temporal variability of air temperature on a melting glacier:
Atmospheric controls, extrapolation methods and their effect on melt modeling, Juncal
Norte Glacier, Chile'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 116
year: '2011'
...
---
_id: '12649'
abstract:
- lang: eng
text: Physically based hydrological models describe natural processes more accurately
than conceptual models but require extensive data sets to produce accurate results.
To identify the value of different data sets for improving the performance of
the distributed hydrological model TOPKAPI we combine a multivariable validation
technique with Monte Carlo simulations. The study is carried out in the snow and
ice-dominated Rhonegletscher basin, as these types of mountainous basins are generally
the most critical with respect to data availability and sensitivity to climate
fluctuations. Each observational data set is used individually and in combination
with the other data sets to determine a subset of best parameter combinations
out of 10,000 Monte Carlos runs performed with randomly generated parameter sets.
We validate model results against discharge, glacier mass balance, and satellite
snow cover images for a 14 year time period (1994–2007). While the use of all
data sets combined provides the best overall model performance (defined by the
concurrent best agreement of simulated discharge, snow cover and mass balance
with their respective measurements), the use of one or two variables for constraining
the model results in poorer performance. Using only one data set for constraining
the model glacier mass balance proved to be the most efficient observation leading
to the best overall model performance. Our main result is that a combination of
discharge and satellite snow cover images is best for improving model performance,
since the volumetric information of discharge data and the spatial information
of snow cover images are complementary.
article_number: W07519
article_processing_charge: No
article_type: original
author:
- first_name: David
full_name: Finger, David
last_name: Finger
- first_name: Francesca
full_name: Pellicciotti, Francesca
id: b28f055a-81ea-11ed-b70c-a9fe7f7b0e70
last_name: Pellicciotti
- first_name: Markus
full_name: Konz, Markus
last_name: Konz
- first_name: Stefan
full_name: Rimkus, Stefan
last_name: Rimkus
- first_name: Paolo
full_name: Burlando, Paolo
last_name: Burlando
citation:
ama: Finger D, Pellicciotti F, Konz M, Rimkus S, Burlando P. The value of glacier
mass balance, satellite snow cover images, and hourly discharge for improving
the performance of a physically based distributed hydrological model. Water
Resources Research. 2011;47(7). doi:10.1029/2010wr009824
apa: Finger, D., Pellicciotti, F., Konz, M., Rimkus, S., & Burlando, P. (2011).
The value of glacier mass balance, satellite snow cover images, and hourly discharge
for improving the performance of a physically based distributed hydrological model.
Water Resources Research. American Geophysical Union. https://doi.org/10.1029/2010wr009824
chicago: Finger, David, Francesca Pellicciotti, Markus Konz, Stefan Rimkus, and
Paolo Burlando. “The Value of Glacier Mass Balance, Satellite Snow Cover Images,
and Hourly Discharge for Improving the Performance of a Physically Based Distributed
Hydrological Model.” Water Resources Research. American Geophysical Union,
2011. https://doi.org/10.1029/2010wr009824.
ieee: D. Finger, F. Pellicciotti, M. Konz, S. Rimkus, and P. Burlando, “The value
of glacier mass balance, satellite snow cover images, and hourly discharge for
improving the performance of a physically based distributed hydrological model,”
Water Resources Research, vol. 47, no. 7. American Geophysical Union, 2011.
ista: Finger D, Pellicciotti F, Konz M, Rimkus S, Burlando P. 2011. The value of
glacier mass balance, satellite snow cover images, and hourly discharge for improving
the performance of a physically based distributed hydrological model. Water Resources
Research. 47(7), W07519.
mla: Finger, David, et al. “The Value of Glacier Mass Balance, Satellite Snow Cover
Images, and Hourly Discharge for Improving the Performance of a Physically Based
Distributed Hydrological Model.” Water Resources Research, vol. 47, no.
7, W07519, American Geophysical Union, 2011, doi:10.1029/2010wr009824.
short: D. Finger, F. Pellicciotti, M. Konz, S. Rimkus, P. Burlando, Water Resources
Research 47 (2011).
date_created: 2023-02-20T08:18:03Z
date_published: 2011-07-01T00:00:00Z
date_updated: 2023-02-20T10:39:57Z
day: '01'
doi: 10.1029/2010wr009824
extern: '1'
intvolume: ' 47'
issue: '7'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.1029/2010WR009824
month: '07'
oa: 1
oa_version: Published Version
publication: Water Resources Research
publication_identifier:
issn:
- 0043-1397
publication_status: published
publisher: American Geophysical Union
quality_controlled: '1'
scopus_import: '1'
status: public
title: The value of glacier mass balance, satellite snow cover images, and hourly
discharge for improving the performance of a physically based distributed hydrological
model
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 47
year: '2011'
...
---
_id: '12652'
abstract:
- lang: eng
text: We explore the robustness and transferability of parameterizations of cloud
radiative forcing used in glacier melt models at two sites in the Swiss Alps.
We also look at the rationale behind some of the most commonly used approaches,
and explore the relationship between cloud transmittance and several standard
meteorological variables. The 2 m air-temperature diurnal range is the best predictor
of variations in cloud transmittance. However, linear and exponential parameterizations
can only explain 30–50% of the observed variance in computed cloud transmittance
factors. We examine the impact of modelled cloud transmittance factors on both
solar radiation and ablation rates computed with an enhanced temperature-index
model. The melt model performance decreases when modelled radiation is used, the
reduction being due to an underestimation of incoming solar radiation on clear-sky
days. The model works well under overcast conditions. We also seek alternatives
to the use of in situ ground data. However, outputs from an atmospheric model
(2.2 km horizontal resolution) do not seem to provide an alternative to the parameterizations
of cloud radiative forcing based on observations of air temperature at glacier
automatic weather stations. Conversely, the correct definition of overcast conditions
is important.
article_processing_charge: No
article_type: original
author:
- first_name: Francesca
full_name: Pellicciotti, Francesca
id: b28f055a-81ea-11ed-b70c-a9fe7f7b0e70
last_name: Pellicciotti
- first_name: Thomas
full_name: Raschle, Thomas
last_name: Raschle
- first_name: Thomas
full_name: Huerlimann, Thomas
last_name: Huerlimann
- first_name: Marco
full_name: Carenzo, Marco
last_name: Carenzo
- first_name: Paolo
full_name: Burlando, Paolo
last_name: Burlando
citation:
ama: 'Pellicciotti F, Raschle T, Huerlimann T, Carenzo M, Burlando P. Transmission
of solar radiation through clouds on melting glaciers: A comparison of parameterizations
and their impact on melt modelling. Journal of Glaciology. 2011;57(202):367-381.
doi:10.3189/002214311796406013'
apa: 'Pellicciotti, F., Raschle, T., Huerlimann, T., Carenzo, M., & Burlando,
P. (2011). Transmission of solar radiation through clouds on melting glaciers:
A comparison of parameterizations and their impact on melt modelling. Journal
of Glaciology. Cambridge University Press. https://doi.org/10.3189/002214311796406013'
chicago: 'Pellicciotti, Francesca, Thomas Raschle, Thomas Huerlimann, Marco Carenzo,
and Paolo Burlando. “Transmission of Solar Radiation through Clouds on Melting
Glaciers: A Comparison of Parameterizations and Their Impact on Melt Modelling.”
Journal of Glaciology. Cambridge University Press, 2011. https://doi.org/10.3189/002214311796406013.'
ieee: 'F. Pellicciotti, T. Raschle, T. Huerlimann, M. Carenzo, and P. Burlando,
“Transmission of solar radiation through clouds on melting glaciers: A comparison
of parameterizations and their impact on melt modelling,” Journal of Glaciology,
vol. 57, no. 202. Cambridge University Press, pp. 367–381, 2011.'
ista: 'Pellicciotti F, Raschle T, Huerlimann T, Carenzo M, Burlando P. 2011. Transmission
of solar radiation through clouds on melting glaciers: A comparison of parameterizations
and their impact on melt modelling. Journal of Glaciology. 57(202), 367–381.'
mla: 'Pellicciotti, Francesca, et al. “Transmission of Solar Radiation through Clouds
on Melting Glaciers: A Comparison of Parameterizations and Their Impact on Melt
Modelling.” Journal of Glaciology, vol. 57, no. 202, Cambridge University
Press, 2011, pp. 367–81, doi:10.3189/002214311796406013.'
short: F. Pellicciotti, T. Raschle, T. Huerlimann, M. Carenzo, P. Burlando, Journal
of Glaciology 57 (2011) 367–381.
date_created: 2023-02-20T08:18:21Z
date_published: 2011-03-01T00:00:00Z
date_updated: 2023-02-20T09:47:00Z
day: '01'
doi: 10.3189/002214311796406013
extern: '1'
intvolume: ' 57'
issue: '202'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://doi.org/10.3189/002214311796406013
month: '03'
oa: 1
oa_version: Published Version
page: 367-381
publication: Journal of Glaciology
publication_identifier:
eissn:
- 1727-5652
issn:
- 0022-1430
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: 'Transmission of solar radiation through clouds on melting glaciers: A comparison
of parameterizations and their impact on melt modelling'
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 57
year: '2011'
...
---
_id: '12650'
abstract:
- lang: eng
text: Streamflow is a hydrological variable measured at a defined river cross-section;
it spatially integrates the runoff generating processes in the contributing watershed,
including precipitation and air temperature. Trends in streamflow are progressive
changes in the time series of streamflow that can be detected with statistical
methods and their statistical significance can be assessed. Mountainous regions
are particularly vulnerable to streamflow change because of their high specific
runoff and the sensitivity to the distribution of precipitation and air temperature,
and the processes of snow accumulation and melt.
alternative_title:
- Encyclopedia of Earth Sciences Series
article_processing_charge: No
author:
- first_name: Peter
full_name: Molnar, Peter
last_name: Molnar
- first_name: Paolo
full_name: Burlando, Paolo
last_name: Burlando
- first_name: Francesca
full_name: Pellicciotti, Francesca
id: b28f055a-81ea-11ed-b70c-a9fe7f7b0e70
last_name: Pellicciotti
citation:
ama: 'Molnar P, Burlando P, Pellicciotti F. Streamflow Trends in Mountainous Regions.
In: Singh V, Singh P, Haritashya U, eds. Encyclopedia of Snow, Ice and Glaciers.
1st ed. Dordrecht: Springer Nature; 2011:1084-1089. doi:10.1007/978-90-481-2642-2_543'
apa: 'Molnar, P., Burlando, P., & Pellicciotti, F. (2011). Streamflow Trends
in Mountainous Regions. In V. Singh, P. Singh, & U. Haritashya (Eds.), Encyclopedia
of Snow, Ice and Glaciers (1st ed., pp. 1084–1089). Dordrecht: Springer Nature.
https://doi.org/10.1007/978-90-481-2642-2_543'
chicago: 'Molnar, Peter, Paolo Burlando, and Francesca Pellicciotti. “Streamflow
Trends in Mountainous Regions.” In Encyclopedia of Snow, Ice and Glaciers,
edited by Vijay Singh, Pratap Singh, and Umesh Haritashya, 1st ed., 1084–89. Dordrecht:
Springer Nature, 2011. https://doi.org/10.1007/978-90-481-2642-2_543.'
ieee: 'P. Molnar, P. Burlando, and F. Pellicciotti, “Streamflow Trends in Mountainous
Regions,” in Encyclopedia of Snow, Ice and Glaciers, 1st ed., V. Singh,
P. Singh, and U. Haritashya, Eds. Dordrecht: Springer Nature, 2011, pp. 1084–1089.'
ista: 'Molnar P, Burlando P, Pellicciotti F. 2011.Streamflow Trends in Mountainous
Regions. In: Encyclopedia of Snow, Ice and Glaciers. Encyclopedia of Earth Sciences
Series, , 1084–1089.'
mla: Molnar, Peter, et al. “Streamflow Trends in Mountainous Regions.” Encyclopedia
of Snow, Ice and Glaciers, edited by Vijay Singh et al., 1st ed., Springer
Nature, 2011, pp. 1084–89, doi:10.1007/978-90-481-2642-2_543.
short: P. Molnar, P. Burlando, F. Pellicciotti, in:, V. Singh, P. Singh, U. Haritashya
(Eds.), Encyclopedia of Snow, Ice and Glaciers, 1st ed., Springer Nature, Dordrecht,
2011, pp. 1084–1089.
date_created: 2023-02-20T08:18:07Z
date_published: 2011-07-01T00:00:00Z
date_updated: 2023-02-20T10:35:28Z
day: '01'
doi: 10.1007/978-90-481-2642-2_543
edition: '1'
editor:
- first_name: Vijay
full_name: Singh, Vijay
last_name: Singh
- first_name: Pratap
full_name: Singh, Pratap
last_name: Singh
- first_name: Umesh
full_name: Haritashya, Umesh
last_name: Haritashya
extern: '1'
language:
- iso: eng
month: '07'
oa_version: None
page: 1084-1089
place: Dordrecht
publication: Encyclopedia of Snow, Ice and Glaciers
publication_identifier:
eisbn:
- 978-90-481-2642-2
eissn:
- 1871-756X
isbn:
- 978-90-481-2641-5
issn:
- 1388-4360
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Streamflow Trends in Mountainous Regions
type: book_chapter
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
year: '2011'
...