bluuebunny/crossref_metadata_2025_split huggingface dataset:
Architectural
contesting
Authors: Najaf-abadi Hashem H. , Rotenberg Eric 
Published: October 2007

Previous studies have proposed techniques to dynamically change the architecture of a processor to better suit the characteristics of the workload at hand. However, all such approaches are prone to a fundamental trade-off between the architectural diversity they can provide and the latency of architectural change, their fixed-configuration performance and the complexity of finding the best architectural configuration for the workload at hand. In this study we argue that the full potential of dynamic architectural customization can only be achieved by diminishing the effect of the degree of available architectural diversity on the aforementioned performance factors.
The performance of a statically designed processing core in a heterogeneous multi-core system is independent of the architectural diversity available. In addition, it is apparent that concurrent execution of code on differently architected cores automatically reveals which architecture is more suitable for the characteristics of a particular workload.
We therefore propose architectural contesting; the redundant execution of code on a number of differently architected processors (each customized for a different set of workload characteristics) in a leader follower arrangement, such that the leader and follower cores continuously shift roles as one core or the other becomes more favorable for new code phases. In this manner effective execution is naturally transferred from one static architecture to the other with little latency.
In this study, we show that the contesting of only processor width can yield an average speedup of 7.5% and up to 12.5% in integer SPEC benchmarks.
Internet nuggets
Authors: Thorson Mark 
Published: October 2007

This column consists of selected traffic from the
comp.arch
newsgroup, a forum for discussion of computer architecture on the Internet---an international computer network.

As always, the opinions expressed in this column are the personal views of the authors, and do not necessarily represent the institutions to which they are affiliated.
Text which sets the context of a message appears underlined or in italics; this is usually text the author has quoted from earlier messages. The code-like expressions below the authors' names are their addresses on Internet.
Development of Low Melting Ionic Liquids using Eutectic Mixtures of Imidazolium and Pyrazolium Ionic Liquids
Authors: Dunstan T Don J. , Caja Josip 
Published: October 2007

Phase diagram of the binary ionic liquid 1-ethyl-3- methylimidazolium hexafluorophosphate ([emim][PF6]) -	1- ethyl-2-methylpyrazolium hexafluorophosphate ([empz][PF6]), was determined. The binary system shows a eutectic at 23oC, (which is 38oC below the melting point of the lower melting salt [emim][PF6]), and at the molar composition [emim][PF6]: [empz][PF6] ≈ 47:53. Therefore using the eutectic method a low melting ionic liquid was formed with single salts that contain only small alkyl groups on the cations. At ambient temperature the ionic conductivity of the eutectic mixture is comparable to that of a low melting single salt such as, 1-n-butyl-3- methylimidazolium hexafluorophosphate ([bmim][PF6]), but at higher temperature (e.g. 90oC) the conductivity of the eutectic mixture is 20% higher. This method allows the preparation of purer ionic liquids since the two single salts can be purified by recrystallization, before they are mixed to form the binary system which is a liquid at ambient temperature. Hence the ionic liquids produced by the eutectic method have the potential for finding wider range of applications compared with low melting ionic liquids (single salts) containing longer alkyl groups prepared by the conventional method.
Fulleride Based Ionic Liquids
Authors: Del Sesto Rico E. , Corley Cynthia A. , Dudis Douglas S. , Yeates Alan T. , Wilkes John S. 
Published: October 2007

A room temperature fulleride-based ionic liquid has been developed and characterized. Utilizing the trihexyl (tetradecyl) phosphonium cation, the ionic liquid [PC6C6C6C14]3 [C60]Cl was synthesized, and distinctly shows spectroscopic characteristics of the [C60]2- anion.	The glass transition of the ionic liquid occurs well below room temperature at -56 {degree sign} C, but it still retains an extremely high viscosity at room temperature. Attempts were made to obtain the pure fulleride salt [PR4]3[C60], but nearly always results in the binary fulleride-chloride salt.
Behaviour of Rare Earth Elements in Molten Salts in Relation to Pyrochemical Reprocessing of Spent Nuclear Fuels
Authors: Volkovich Vladimir A. , Vasin Boris D. D. , Griffiths Trevor R. R. , Polovov Ilya B. , Medvedev Evgenii O. O. , Yakimov Sergei M. M. 
Published: October 2007

The kinetics of chlorination of lanthanide oxides (by Cl2 and HCl) and precipitation of lanthanide phosphates was studied by in situ electronic absorption spectroscopy in 3LiCl-2KCl and NaCl-KCl melts at 400-750 oC. Products of the chlorination are the corresponding hexachlorospecies, LnCl63-, and the rate of chlorination increases with increasing temperature. Composition of the precipitated phosphates depends on the melt composition and 1.5-5 fold excess of phosphate, depending on the nature of lanthanide, is needed for the complete removal of the lanthanides from the melt.	Over three hours are required for completing the reaction of phosphate precipitation.
The 1997–98 Summer Rainfall Season in Southern Africa. Part I: Observations
Authors: Lyon Bradfield , Mason Simon J. 
Published: October 2007

Abstract
Following the onset of the strong El Niño of 1997–98 historical rainfall teleconnection patterns and dynamical model predictions both suggested an enhanced likelihood of drought for southern Africa, but widespread dry conditions failed to materialize. Results from a diagnostic study of NCEP–NCAR reanalysis data are reported here demonstrating how the large- and regional-scale atmospheric circulations during the 1997–98 El Niño differed from previous events. Emphasis is placed on the January–March 1998 season and comparisons with the strong 1982–83 El Niño, although composites of eight events occurring between 1950 and 2000 are also considered. In a companion paper, simulation runs from three atmospheric general circulation models (AGCMs), and forecasts from three fully coupled models are employed to investigate the extent to which the anomalous atmospheric circulation patterns during the 1997–98 El Niño may have been anticipated.
Observational results indicate that the 1997–98 El Niño displayed significant differences from both the 1982–83 episode and the composite event. An unusually strong Angola low, exceptionally high sea surface temperatures (SSTs) in the western Indian and eastern tropical South Atlantic Oceans, and an enhanced northerly moisture flux from the continental interior and the western tropical Indian Ocean all appear to have contributed to more seasonal rainfall in 1997–98 over much of the southern Africa subcontinent than in past El Niño events.
Changes of the Boreal Winter Hadley Circulation in the NCEP–NCAR and ECMWF Reanalyses: A Comparative Study
Authors: Song Hua , Zhang Minghua 
Published: October 2007

Abstract
Both the ECMWF and the NCEP–NCAR reanalyses show a strengthening of the atmospheric Hadley circulation in boreal winter over the last 50 years, but the intensification is much stronger in the ECMWF than in the NCEP–NCAR reanalysis. This study focuses on the difference of these trends in the two reanalyses. It is shown that trends in the Hadley circulation in the two reanalyses differ mainly over the tropical western Pacific. This difference is found to be consistent with respective trends of the atmospheric transport of moist static energy, longwave cloud radiative forcing, and upper-level clouds in the two reanalyses. Two independent datasets of upper-level cloud cover and sea level pressure from ship-based measurements are then used to evaluate the reanalyses over the tropical western Pacific. They are found to be more consistent with the trends in the NCEP–NCAR reanalysis than those in the ECMWF reanalysis. The results suggest a weakening of the vertical motion associated with the Hadley circulation in the tropical western Pacific.
Rapid Holocene Deglaciation of the Labrador Sector of the Laurentide Ice Sheet
Authors: Carlson Anders E. , Clark Peter U. , Raisbeck Grant M. , Brook Edward J. 
Published: October 2007

Abstract
Retreat of the Laurentide Ice Sheet (LIS) following the Last Glacial Maximum 21 000 yr BP affected regional to global climate and accounted for the largest proportion of sea level rise. Although the late Pleistocene LIS retreat chronology is relatively well constrained, its Holocene chronology remains poorly dated, limiting our understanding of its role in Holocene climate change and sea level rise. Here new 10Be cosmogenic exposure ages on glacially deposited boulders are used to date the final disappearance of the Labrador sector of the LIS (LS-LIS). These data suggest that following the deglaciation of the southeastern Hudson Bay coastline at 8.0 ± 0.2 cal ka BP, the southwestern margin of the LS-LIS rapidly retreated ∼600 km in 140 yr and most likely in ∼600 yr at a rate of ∼900 m yr−1, with final deglaciation by 6.8 ± 0.2 10Be ka. The disappearance of the LS-LIS ∼6.8 10Be ka and attendant reduction in freshwater runoff may have induced the formation of Labrador Deep Seawater, while the loss of the high albedo surface may have initiated the Holocene Thermal Maximum in eastern Canada and southern Greenland. Moreover, the rapid melting just prior to ∼6.8 10Be ka indicates that the remnant LIS may be the primary source of a postulated rapid rise in global sea level of ∼5 m that occurred sometime between 7.6 and 6.5 cal ka BP.
Zonal Jet Structure and the Leading Mode of Variability
Authors: Eichelberger Scott J. , Hartmann Dennis L. 
Published: October 2007

Abstract
An observational analysis of the Northern Hemisphere circulation during winter reveals that the leading mode of variability depends on longitude. In particular, the first EOF of the zonal-mean circulation differs over the Atlantic and Pacific sectors. These results provide motivation for a series of model runs where a simple GCM is used to investigate the effects of the zonal jet structure on the leading mode of variability in the Northern Hemisphere. Model results indicate that the leading mode of variability depends on the distance between the eddy-driven and subtropical jets. When the jets are well separated, the leading mode of variability describes latitudinal shifting of the eddy-driven jet. However, when the two jets are nearly collocated, pulsing of the combined jet dominates the variability. This change coincides with a weakening of the positive feedback between the eddies and zonal flow anomalies. These results provide a possible explanation for the reduced amplitude of the Northern Annular Mode in the Pacific sector relative to that in the Atlantic sector during Northern Hemisphere winter.
The ENSO–Asian Monsoon Interaction in a Coupled Ocean–Atmosphere GCM
Authors: Li Ying , Lu Riyu , Dong Buwen 
Published: October 2007

Abstract
In this study, the authors evaluate the (El Niño–Southern Oscillation) ENSO–Asian monsoon interaction in a version of the Hadley Centre coupled ocean–atmosphere general circulation model (CGCM) known as HadCM3. The main focus is on two evolving anomalous anticyclones: one located over the south Indian Ocean (SIO) and the other over the western North Pacific (WNP). These two anomalous anticyclones are closely related to the developing and decaying phases of the ENSO and play a crucial role in linking the Asian monsoon to ENSO. It is found that the HadCM3 can well simulate the main features of the evolution of both anomalous anticyclones and the related SST dipoles, in association with the different phases of the ENSO cycle.
By using the simulated results, the authors examine the relationship between the WNP/SIO anomalous anticyclones and the ENSO cycle, in particular the biennial component of the relationship. It is found that a strong El Niño event tends to be followed by a more rapid decay and is much more likely to become a La Niña event in the subsequent winter. The twin anomalous anticyclones in the western Pacific in the summer of a decaying El Niño are crucial for the transition from an El Niño into a La Niña. The El Niño (La Niña) events, especially the strong ones, strengthen significantly the correspondence between the SIO anticyclonic (cyclonic) anomaly in the preceding autumn and WNP anticyclonic (cyclonic) anomaly in the subsequent spring, and favor the persistence of the WNP anomaly from spring to summer. The present results suggest that both El Niño (La Niña) and the SIO/WNP anticyclonic (cyclonic) anomalies are closely tied with the tropospheric biennial oscillation (TBO). In addition, variability in the East Asian summer monsoon, which is dominated by the internal atmospheric variability, seems to be responsible for the appearance of the WNP anticyclonic anomaly through an upper-tropospheric meridional teleconnection pattern over the western and central Pacific.
Deep Convective System Evolution over Africa and the Tropical Atlantic
Authors: Futyan Joanna M. , Del Genio Anthony D. 
Published: October 2007

AbstractIn the tropical African and neighboring Atlantic region there is a strong contrast in the properties of deep convection between land and ocean. Here, satellite radar observations are used to produce a composite picture of the life cycle of convection in these two regions. Estimates of the broadband thermal flux from the geostationary Meteosat-8 satellite are used to identify and track organized convective systems over their life cycle. The evolution of the system size and vertical extent are used to define five life cycle stages (warm and cold developing, mature, cold and warm dissipating), providing the basis for the composite analysis of the system evolution. The tracked systems are matched to overpasses of the Tropical Rainfall Measuring Mission satellite, and a composite picture of the evolution of various radar and lightning characteristics is built up.The results suggest a fundamental difference in the convective life cycle between land and ocean. African storms evolve from convectively active systems with frequent lightning in their developing stages to more stratiform conditions as they dissipate. Over the Atlantic, the convective fraction remains essentially constant into the dissipating stages, and lightning occurrence peaks late in the life cycle. This behavior is consistent with differences in convective sustainability in land and ocean regions as proposed in previous studies.The area expansion rate during the developing stages of convection is used to provide an estimate of the intensity of convection. Reasonable correlations are found between this index and the convective system lifetime, size, and depth.
Impact of the Atlantic Warm Pool on the Summer Climate of the Western Hemisphere
Authors: Wang Chunzai , Lee Sang-ki , Enfield David B. 
Published: October 2007

Abstract
The Atlantic warm pool (AWP) is a large body of warm water that comprises the Gulf of Mexico, the Caribbean Sea, and the western tropical North Atlantic. Located to its northeastern side is the North Atlantic subtropical high (NASH), which produces the tropical easterly trade winds. The easterly trade winds carry moisture from the tropical North Atlantic into the Caribbean Sea, where the flow intensifies, forming the Caribbean low-level jet (CLLJ). The CLLJ then splits into two branches: one turning northward and connecting with the Great Plains low-level jet (GPLLJ), and the other continuing westward across Central America into the eastern North Pacific. The easterly CLLJ and its westward moisture transport are maximized in the summer and winter, whereas they are minimized in the fall and spring. This semiannual feature results from the semiannual variation of sea level pressure in the Caribbean region owing to the westward extension and eastward retreat of the NASH.
The NCAR Community Atmospheric Model and observational data are used to investigate the impact of the climatological annual mean AWP on the summer climate of the Western Hemisphere. Two groups of the model ensemble runs with and without the AWP are performed and compared. The model results show that the effect of the AWP is to weaken the summertime NASH, especially at its southwestern edge. The AWP also strengthens the summertime continental low over the North American monsoon region. In response to these pressure changes, the CLLJ and its moisture transport are weakened, but its semiannual feature does not disappear. The weakening of the easterly CLLJ increases (decreases) moisture convergence to its upstream (downstream) and thus enhances (suppresses) rainfall in the Caribbean Sea (in the far eastern Pacific west of Central America). Model runs show that the AWP’s effect is to always weaken the southerly GPLLJ. However, the AWP strengthens the GPLLJ’s northward moisture transport in the summer because the AWP-induced increase of specific humidity overcomes the weakening of southerly wind, and vice versa in the fall. Finally, the AWP reduces the tropospheric vertical wind shear in the main development region that favors hurricane formation and development during August–October.
The Plane-Parallel Albedo Bias of Liquid Clouds from MODIS Observations
Authors: Oreopoulos Lazaros , Cahalan Robert F. , Platnick Steven 
Published: October 2007

Abstract
The authors present the global plane-parallel shortwave albedo bias of liquid clouds for two months, July 2003 and January 2004. The cloud optical properties necessary to perform the bias calculations come from the operational Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and MODIS Aqua level-3 datasets. These data, along with ancillary surface albedo and atmospheric information consistent with the MODIS retrievals, are inserted into a broadband shortwave radiative transfer model to calculate the fluxes at the atmospheric column boundaries. The plane-parallel homogeneous (PPH) calculations are based on the mean cloud properties, while independent column approximation (ICA) calculations are based either on 1D histograms of optical thickness or joint 2D histograms of optical thickness and effective radius. The (positive) PPH albedo bias is simply the difference between PPH and ICA albedo calculations. Two types of biases are therefore examined: 1) the bias due to the horizontal inhomogeneity of optical thickness alone (the effective radius is set to the grid mean value) and 2) the bias due to simultaneous variations of optical thickness and effective radius as derived from their joint histograms. The authors find that the global bias of albedo (liquid cloud portion of the grid boxes only) is ∼+0.03, which corresponds to roughly 8% of the global liquid cloud albedo and is only modestly sensitive to the inclusion of horizontal effective radius variability and time of day, but depends strongly on season and latitude. This albedo bias translates to ∼3–3.5 W m−2 of bias (stronger negative values) in the diurnally averaged global shortwave cloud radiative forcing, assuming homogeneous conditions for the fraction of the grid box not covered by liquid clouds; zonal values can be as high as 8 W m−2. Finally, the (positive) broadband atmospheric absorptance bias is about an order of magnitude smaller than the albedo bias. The substantial magnitude of the PPH bias underlines the importance of predicting subgrid variability in GCMs and accounting for its effects on cloud–radiation interactions.
Regional Climate Model Simulation of U.S.–Mexico Summer Precipitation Using the Optimal Ensemble of Two Cumulus Parameterizations
Authors: Liang Xin-Zhong , Xu Min , Kunkel Kenneth E. , Grell Georg A. , Kain John S. 
Published: October 2007

Abstract
The fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5)-based regional climate model (CMM5) simulations of U.S.–Mexico summer precipitation are quite sensitive to the choice of Grell or Kain–Fritsch convective parameterization. An ensemble based on these two parameterizations provides superior performance because distinct regions exist where each scheme complementarily captures certain observed signals. For the interannual anomaly, the ensemble provides the most significant improvement over the Rockies, Great Plains, and North American monsoon region. For the climate mean, the ensemble has the greatest impact on skill over the southeast United States and North American monsoon region, where CMM5 biases associated with the individual schemes are of opposite sign. Results are very sensitive to the specific methods used to generate the ensemble. While equal weighting of individual solutions provides a more skillful result overall, considerable further improvement is achieved when the weighting of individual solutions is optimized as a function of location.
Clinical Comparison of Fixation Methods for Patellar Bone Quadriceps Tendon Autografts in Anterior Cruciate Ligament Reconstruction
Authors: Gorschewsky Ottmar , Stapf Robert , Geiser Laurent , Geitner Ulrich , Neumann Wolfram 
Published: October 2007

Background Recently, the use of the quadriceps tendon transplant with bone block (patellar bone quadriceps tendon autografts) for anterior cruciate ligament reconstruction has increasingly been reported. Hypothesis Clinical results after the implantation of a patellar bone quadriceps tendon autograft fixed with cross-pins or screws will show no significant difference between the 2 techniques with regard to stability, function, and subjective satisfaction. Study Design: Cohort study; Level of evidence, 2. Methods Between 1998 and 2004, 193 patients with anterior cruciate ligament ruptures were implanted with a patellar bone quadriceps tendon autograft. For 100 of these patients, fixation was carried out using absorbable cross-pins, and for the remaining 93, fixation was carried out using absorbable screws. The results were evaluated by means of International Knee Documentation Committee, Noyes, and Lysholm scores, as well as KT-1000 arthrometer measurement and subjective satisfaction. Results The mean follow-up postoperative control period was 29 months. In the International Knee Documentation Committee overall evaluation, the pin group showed a significantly better result (P = .03). The values of the Noyes score produced no significant differences. The mean value of the Lysholm score was 94 points in the screw group and 89 points in the pin group (P < .001). Overall, 90% of the patients subjectively judged their conditions as good or very good. Conclusion With both operating processes examined, 80% to 90% of the cases achieved good to very good results. The use of cross-pins can be recommended for fixing patellar bone quadriceps tendon autografts.