bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stochastic modelling of wind and wave induced loads on jacket piles
Authors: Seidel Marc , Kelma Sebastian 
Published: September 2012

AbstractSupport structures for offshore wind turbines are loaded by wind and waves. In deeper water so‐called jacket substructures are used, which use driven piles as foundations. In around 40 m water depth and for wind turbines of the 5MW class, these piles are approximately loaded equally by wind and waves.This paper presents investigations into the superposition of the stochastic processes wind and waves. The response statistics due to turbulent wind loading are analysed in detail. For stochastic wave loading a method is given which allows for the consideration of the nonlinearity of large waves in the time domain. A simple approach to determine design loads for combined wind and wave loading is outlined at the end of this paper.Stochastische Modellierung von durch Wind und Wellen induzierte Lasten auf Jacket‐Gründungspfähle. Tragstrukturen von Offshore‐Windenergieanlagen werden durch Wind und Wellen belastet. In größeren Wassertiefen werden fachwerkartige Strukturen, so genannte Jackets, eingesetzt, die mit Rammpfählen im Meeresgrund verankert sind. Die Belastung dieser Pfähle wird bei Wassertiefen um die 40 m und Windenergieanlagen der 5‐MW‐Klasse in etwa gleichermaßen durch Wind und Wellen beansprucht.In diesem Beitrag werden Untersuchungen zur Überlagerung der beiden stochastischen Prozesse Wind und Welle vorgestellt. Es wird auf die Extremwertstatistik der dynamischen Systemantwort infolge der turbulenten Windeinwirkung detailliert eingegangen. Bezüglich des stochastischen Seegangs wird eine Methodik vorgestellt, mit der die nichtlinearen Eigenschaften großer Wellen für eine Überlagerung im Zeitbereich berücksichtigt werden können. Abschließend wird ein einfacher Ansatz präsentiert, der für die Ermittlung der Bemessungslasten infolge von Wind und Wellen verwendet werden kann.
Can Plasma Bile Salt, Triglycerides, and apoA‐V Levels Predict Liver Regeneration?
Authors: Hoekstra Lisette T. , van Lienden Krijn P. , Schaap Frank G. , Chamuleau Rob A. F. M. , Bennink Roel J. , van Gulik Thomas M. 
Published: September 2012

AbstractBackgroundPreoperative portal vein embolization (PVE) is used to increase the future remnant liver (FRL) in patients requiring extensive liver resection. Computed tomography (CT) volumetry, performed not earlier than 3–6 weeks after PVE, is commonly employed to assess hypertrophy of the FRL following PVE. Early parameters to predict effective hypertrophy are therefore desirable. The aim of the present study was to assess plasma bile salt levels, triglycerides (TG), and apoA‐V in the prediction of the hypertrophy response during liver regeneration.MethodsSerum bile salt, TG, and apoA‐V levels were determined in 20 patients with colorectal metastases before PVE, and 5 h, 1, and 21 days after PVE, as well as prior to and after (day 1–7, and day 21) subsequent liver resection. These parameters were correlated with liver volume as measured by CT volumetry (%FRL‐V), and liver function was determined by technetium‐labeled mebrofenin hepatobiliary scintigraphy using single photon emission computed tomography.ResultsTriglyceride levels at baseline correlate with volume increase of the future remnant liver (FRL‐V) post‐PVE. Also, bile salts and TG 5 h after PVE positively correlated with the increase in FRL volume (r = 0.672, p = 0.024; r = 0.620, p = 0.042, resp.) and liver function after 3 weeks (for bile salts r = 0.640, p = 0.046). Following liver surgery, TG levels at 5 h and 1 day after resection were associated with liver remnant volume after 3 months (r = 0.921, p = 0.026 and r = 0.981, p = 0.019, resp). Plasma apoA‐V was increased during liver regeneration.ConclusionsBile salt and TG levels at 5 h after PVE/resection are significant early predictors of liver volume and functional increase. It is suggested that these parameters can be used for early timing of volume assessment and resection after PVE.
The labrum: Structure, function, and injury with femoro-acetabular impingement
Authors: Grant Alfred D. , Sala Debra A. , Davidovitch Roy I. 
Published: September 2012

Background The recognition of the importance of femoro-acetabular impingement (FAI) as a potential cause of hip pain has been stimulated by major efforts to salvage hip joints by reconstruction to prevent or delay the need for replacement. A previous review addressed the nature of FAI, the various types, and how to make the diagnosis. When FAI occurs, the structure between the femur and acetabular rim, the labrum, is initially impinged upon and subsequently injured. Method Injury to the labrum should be recognized when treating the osseous causes of FAI. Preserving or recovering labral function, enhancing hip stability and protecting the articular surface, is critical to restoring the hip to normal or near-normal mechanical and physiologic function. The present review collected the varied essential information about the labrum in a succinct manner, independent of treatment algorithms. Results/conclusion Advanced knowledge of the labrum is presented, including the anatomy, circulation, histology, embryology, and neurology, as well as how the labrum tears, the types of tears, and how to make the diagnosis. The advantages and limitations of diagnostic magnetic resonance techniques are discussed, including magnetic resonance imaging (MRI), indirect magnetic resonance arthrography (i-MRA), and direct magnetic resonance arthrography (d-MRA). The review recognizes the complexity of the labrum and provides a greater understanding of how the labrum is capable of stabilizing the joint and protecting the articular surface of the hip. This information will act as a guide in developing treatment plans when treating FAI.
An Analysis of Equity in Redistribution to the Retired and Children over Recent Decades in the OECD and UK
Authors: BRADSHAW JONATHAN , HOLMES JOHN 
Published: September 2012

AbstractIn The Pinch, David Willetts (2010: xv) attracted attention by asking whether ‘the boomers have been guilty of a monumental failure to protect the interest of future generations’. This was just the latest contribution to a long running concern of social policy analysts about horizontal equity and generational fairness. Using OECD data from 1980–2007, in the first part of this paper we show that there is no evidence that social expenditure has been shifting in favour of the retired at the expense of children, except perhaps recently in some Nordic countries. For the UK, we have created a time-series using the published articles since 1977 and the micro data sets since 1994/5 from the annual Office for National Statistics analyses of the Effect of Taxes and Benefits on Household Incomes and used it to analyse trends in the redistributive impact of cash benefits, direct and indirect taxes and services on the retired and households with children and across the income distribution. The analysis shows how the relative support for the retired versus children has changed over time, which elements have contributed to the changes and for which part of the income distribution. There has been a small shift in final income in favour of the retired but it was not the result of changes in taxes, benefits or services in kind but rather a change in the original income distribution in favour of the retired.
Postcranial morphology of Aristonectes (Plesiosauria, Elasmosauridae) from the Upper Cretaceous of Patagonia and Antarctica
Authors: O'Gorman José P. , Gasparini Zulma , Salgado Leonardo 
Published: September 2012

AbstractA partial, postcranial skeleton of a juvenile individual referred to Aristonectes cf. parvidens from the upper Maastrichtian López de Bertodano Formation, Isla Marambio (Seymour Island), Antarctica, is described. Additionally, two juvenile specimens, also referred to A. cf. parvidens from the Allen Formation (upper Campanian–lower Maastrichtian) and Jagüel Formation (upper Maastrichtian) (Río Negro province, Argentina), are redescribed. The analysis of the systematic value of the cervical centrum proportions of juvenile specimens of Elasmosauridae suggests that these elements can be used to differentiate juvenile specimens of A. cf. parvidens from juveniles of other Elasmosauridae. On this basis, the specimens described are referred to A. cf. parvidens. Based on the proportion of the cervical centra, the first South American plesiosaur described by Gay in 1848 is here referred to A. cf. parvidens. The coracoid of Aristonectes is described for the first time showing a cordiform fenestra, a feature only recorded in the Elasmosauridae among the Plesiosauria, therefore, these new data support the inclusion of Aristonectes within the Elasmosauridae. With the new material described in this paper, Aristonectes is one of the most frecuently recorded genera of Late Cretaceous plesiosaurs in the Southern Hemisphere.
Efficient tabling of structured data with enhanced hash-consing
Authors: ZHOU NENG-FA , HAVE CHRISTIAN THEIL 
Published: September 2012

AbstractCurrent tabling systems suffer from an increase in space complexity, time complexity or both when dealing with sequences due to the use of data structures for tabled subgoals and answers and the need to copy terms into and from the table area. This symptom can be seen in not only B-Prolog, which uses hash tables, but also systems that use tries such as XSB and YAP. In this paper, we apply hash-consing to tabling structured data in B-Prolog. While hash-consing can reduce the space consumption when sharing is effective, it does not change the time complexity. We enhance hash-consing with two techniques, called input sharing and hash code memoization, for reducing the time complexity by avoiding computing hash codes for certain terms. The improved system is able to eliminate the extra linear factor in the old system for processing sequences, thus significantly enhancing the scalability of applications such as language parsing and bio-sequence analysis applications. We confirm this improvement with experimental results.
SMCHR: Satisfiability modulo constraint handling rules
Authors: DUCK GREGORY J. 
Published: September 2012

AbstractConstraint Handling Rules (CHRs) are a high-level rule-based programming language for specification and implementation of constraint solvers. CHR manipulates a global store representing a flat conjunction of constraints. By default, CHR does not support goals with a more complex propositional structure including disjunction, negation, etc., or CHR relies on the host system to provide such features. In this paper we introduce Satisfiability Modulo Constraint Handling Rules (SMCHR): a tight integration of CHR with a modern Boolean Satisfiability (SAT) solver for quantifier-free formulae with an arbitrary propositional structure. SMCHR is essentially a Satisfiability Modulo Theories (SMT) solver where the theory T is implemented in CHR. The execution algorithm of SMCHR is based on lazy clause generation, where a new clause for the SAT solver is generated whenever a rule is applied. We shall also explore the practical aspects of building an SMCHR system, including extending a “built-in” constraint solver supporting equality with unification and justifications.
An Improved Proof-Theoretic Compilation of Logic Programs
Authors: CERVESATO ILIANO 
Published: September 2012

AbstractIn prior work, we showed that logic programming compilation can be given a proof-theoretic justification for generic abstract logic programming languages, and demonstrated this technique in the case of hereditary Harrop formulas and their linear variant. Compiled clauses were themselves logic formulas except for the presence of a second-order abstraction over the atomic goals matching their head. In this paper, we revisit our previous results into a more detailed and fully logical justification that does away with this spurious abstraction. We then refine the resulting technique to support well-moded programs efficiently.
Conflict-driven ASP solving with external sources
Authors: EITER THOMAS , FINK MICHAEL , KRENNWALLNER THOMAS , REDL CHRISTOPH 
Published: September 2012

AbstractAnswer Set Programming (ASP) is a well-known problem solving approach based on nonmonotonic logic programs and efficient solvers. To enable access to external information,hex-programs extend programs withexternal atoms, which allow for a bidirectional communication between the logic program and external sources of computation (e.g., description logic reasoners and Web resources). Current solvers evaluatehex-programs by a translation to ASP itself, in which values of external atoms are guessed and verified after the ordinary answer set computation. This elegant approach does not scale with the number of external accesses in general, in particular in presence of nondeterminism (which is instrumental for ASP). In this paper, we present a novel, native algorithm for evaluatinghex-programs which uses learning techniques. In particular, we extend conflict-driven ASP solving techniques, which prevent the solver from running into the same conflict again, from ordinary tohex-programs. We show how to gain additional knowledge from external source evaluations and how to use it in a conflict-driven algorithm. We first target the uninformed case, i.e., when we have no extra information on external sources, and then extend our approach to the case where additional meta-information is available. Experiments show that learning from external sources can significantly decrease both the runtime and the number of considered candidate compatible sets.
Disjunctive datalog with existential quantifiers: Semantics, decidability, and complexity issues
Authors: ALVIANO MARIO , FABER WOLFGANG , LEONE NICOLA , MANNA MARCO 
Published: September 2012

AbstractDatalogis one of the best-known rule-based languages, and extensions of it are used in a wide context of applications. An importantDatalogextension is DisjunctiveDatalog, which significantly increases the expressivity of the basic language. DisjunctiveDatalogis useful in a wide range of applications, ranging from Databases (e.g., Data Integration) to Artificial Intelligence (e.g., diagnosis and planning under incomplete knowledge). However, in recent years an important shortcoming ofDatalog-based languages became evident, e.g. in the context of data-integration (consistent query-answering, ontology-based data access) and Semantic Web applications: The language does not permit any generation of and reasoning with unnamed individuals in an obvious way. In general, it is weak in supporting many cases of existential quantification. To overcome this problem,Datalog∃has recently been proposed, which extends traditionalDatalogby existential quantification in rule heads. In this work, we propose a natural extension of DisjunctiveDatalogandDatalog∃, calledDatalog∃,˅, which allows both disjunctions and existential quantification in rule heads and is therefore an attractive language for knowledge representation and reasoning, especially in domains where ontology-based reasoning is needed. We formally define syntax and semantics of the languageDatalog∃,˅, and provide a notion of instantiation, which we prove to be adequate forDatalog∃,˅. A main issue ofDatalog∃and hence also ofDatalog∃,˅is that decidability is no longer guaranteed for typical reasoning tasks. In order to address this issue, we identify many decidable fragments of the language, which extend, in a natural way, analog classes defined in the non-disjunctive case. Moreover, we carry out an in-depth complexity analysis, deriving interesting results which range from Logarithmic Space to Exponential Time.
GRB Prompt X-ray Emission
Authors: Sakamoto Takanori 
Published: September 2012

AbstractI present the observational properties of the prompt emission of supernova associated GRBs (SN-GRBs) focusing on temporal and spectral characteristics. I compare the properties of SN-GRBs with typical long GRBs to see whether there is a distinct difference or not. Furthermore, I present our attempt to search for hard X-ray emission prior to the discovery date from optically identified type Ibc supernovae using Swift BAT survey data.
Ultraviolet-Bright Type IIP Supernovae from Massive Red Supergiants
Authors: Moriya Takashi J. , Tominaga Nozomu , Blinnikov Sergei I. , Baklanov Petr V. , Sorokina Elena I. 
Published: September 2012

AbstractRed supergiants (RSGs) are progenitors of Type IIP supernovae (SNe). It is suggested that RSGs can experience a mass loss with a very high mass-loss rate (even as high as 0.01 M⊙ yr−1) due to, e.g., dynamical instabilities of their envelopes (e.g., Yoon & Cantiello (2010)). Because of the extensive mass loss, RSGs can have very dense circumstellar medium (CSM) around them. If a SN explosion occurs soon after the extensive mass loss of a RSG, the SN ejecta will collide with the dense CSM. Due to the collision, the kinetic energy of the ejecta is converted to radiation energy and such SNe with collision can be brighter than usual Type IIP SNe. By performing one-dimensional multi-group radiation hydrodynamical calculations, we investigate the effects of the collision on Type IIP SN LCs. We show that if RSGs explode within a dense CSM, the SN will be very bright, especially in ultraviolet, at early epochs. We also compare our models with the ultraviolet-bright Type IIP SN 2009kf and show that the progenitor of SN 2009kf can be a massive RSG which experienced extensive mass loss just before its explosion. We conclude that this is evidence that massive RSGs experience extensive mass loss and the existence of such mass loss can actually be the cause of the contradiction between theoretical and observational mass ranges of Type IIP SN progenitors.
GRB Progenitors and Observational Criteria
Authors: Zhang Bing 
Published: September 2012

AbstractPhenomenologically, two classes of GRBs (long/soft vs. short/hard) are identified based on their γ-ray properties. The boundary between the two classes is vague. Multi-wavelength observations lead to identification of two types of GRB progenitors: one related to massive stars (Type II), and another related to compact stars (Type I). Evidence suggests that the majority of long GRBs belong to Type II, while at least the majority of nearby short GRBs belong to Type I. Nonetheless, counter examples do exist. Both long-duration Type I and short-duration Type II GRBs have been observed. In this talk, I review the complications in GRB classification and efforts in diagnosing GRB progenitors based on multiple observational criteria. In particular, I raise the caution to readily accept that all short/hard GRBs detected by BATSE are due to compact star mergers. Finally, I propose to introduce “amplitude” as the third dimension (besides “duration” and “hardness”) to quantify burst properties, and point out that the “tip-of-the-iceberg” effect may introduce confusion in defining the physical category of GRBs, especially for low-amplitude, high-redshift GRBs.
3D Core-Collapse Supernova Simulations: Neutron Star Kicks and Nickel Distribution
Authors: Wongwathanarat Annop , Janka Hans-Thomas , Müller Ewald 
Published: September 2012

AbstractWe perform a set of neutrino-driven core-collapse supernova (CCSN) simulations studying the hydrodynamical neutron star kick mechanism in three-dimensions. Our simulations produce neutron star (NS) kick velocities in a range between ~100-600 km/s resulting mainly from the anisotropic gravitational tug by the asymmetric mass distribution behind the supernova shock. This stochastic kick mechanism suggests that a NS kick velocity of more than 1000 km/s may as well be possible. An enhanced production of heavy elements in the direction roughly opposite to the NS recoil direction is also observed as a result of the asymmetric explosion. This large scale asymmetry might be detectable and can be used to constrain the NS kick mechanism.
The soft X-ray landscape of gamma-ray bursts: thermal components
Authors: Starling Rhaana , Page Kim , Sparre Martin 
Published: September 2012

AbstractThe repository of GRB (gamma-ray burst) observations made by the Swift X-ray Telescope, now consisting of over 650 bursts, is a valuable and unique resource for the study of GRB X-ray emission. The observed soft X-ray spectrum typically arises from an underlying power law continuum, absorbed by gas along the line-of-sight. However, particularly at early times in a burst's evolution the continuum emission is not always understood and may comprise multiple components including thermal emission unexpected in the standard model. A thermal X-ray component has been discovered in two very unusual GRBs, perhaps suggesting an association only with this subset of events. However, evidence exists for thermal emission from more typical examples and here we present a new discovery of one such case and describe a systematic search for thermal components among all early GRB X-ray spectra.
The Optically Unbiased GRB Host (TOUGH) Survey
Authors: Jakobsson Páll , Hjorth Jens , Malesani Daniele , Fynbo Johan P. U. , Krühler Thomas , Milvang-Jensen Bo , Tanvir Nial R. 
Published: September 2012

AbstractWe present the results from our Swift/VLT legacy survey, a VLT Large Programme aimed at characterizing the host galaxies of a homogeneously selected sample of Swift gamma-ray bursts (GRBs). The immediate goals are to determine the host luminosity function, study the effects of reddening, determine the fraction of Lyα emitters in the hosts, and obtain redshifts for targets without a reported one. We have carefully selected a sample, obeying strict and well-defined criteria: 69 targets in total. Among the results is a large optical detection rate, the lack of extremely red objects (only one possible case in the sample), and 15 new GRB redshifts with the mean redshift of the host sample assessed to be 〈z〉 ≳ 2.2.
Star Formation and the Metallicity Aversion of Long-Duration Gamma-Ray Bursts
Authors: Graham John F. , Fruchter Andrew S. 
Published: September 2012

AbstractIt has been suggested that the apparent bias of long-duration GRBs (LGRBs) to low metallicity environments might be a result of the fact that star-formation is anti-correlated with metallicity. However, if this were the cause, one would expect other indicators of star formation, such as Type II and Type Ic SNe to demonstrate a similar bias. Here we show that local Type Ic and Type II SNe track the star-formation weighted metallicity distribution of the SDSS galaxies. In contrast LGRBs are typically found at far-lower metallicities than would be expected based on the distribution of star-formation. This is true even when one takes into account so-called “dark bursts”. Indeed, while we will present data that show that some LGRBs form at very high metallicities, these objects enter the sample because of the large effective search volume produced by their bright hosts. The bias of LGRBs to low metallicity is real and must be related to a mechanism which is crucial in their formation.
Detecting the First Supernovae in the Universe with JWST
Authors: Whalen Daniel J. 
Published: September 2012

AbstractMassive Population III stars die as pair-instability supernovae (PI SNe), the most energetic thermonuclear explosions in the universe with energies up to 100 times those of Type Ia or Type II SNe. Their extreme luminosities may allow them to be observed from the earliest epochs, revealing the nature of Pop III stars and the primitive galaxies in which they reside. We present numerical simulations of Pop III PI SNe done with the radiation hydrodynamics code RAGE and calculations of their light curves and spectra performed with the SPECTRUM code. We find that 150 - 250 M⊙ PI SNe will be visible to the James Webb Space Telescope (JWST) out to z ~ 30 and to z ~ 15 - 20 in all-sky NIR surveys by the Wide Field Infrared Survey Telescope (WFIRST).