bluuebunny/crossref_metadata_2025_split huggingface dataset:
LEAP-ASIA-2019 Centrifuge Test at NCU
Authors: Huang Jun-Xue , Hung Wen-Yi 
Published: February 2024

AbstractTwo centrifuge tests are performed at NCU under centrifugal acceleration field of 26g and 13g to validate the generalized scaling law for LEAP-ASIA-2019. The model arrangement and test process follow the specification of LEAP-UCD-2017. Both models are subjected one destructive motion which is 0.18g, 1 Hz, 16 cycles, tapered sine wave. Test results indicate the model adopted generalized scaling law with virtual 1g modeling factor of 2 can generally simulated the same prototype of the model only adopted centrifuge scaling law. The acceleration response, pore water pressure behavior, and cone tip resistance of both models are in good agreement with each other.
Centrifuge Model Tests at Zhejiang University for LEAP-ASIA-2019
Authors: Ma Qiang , Zhou Yan-Guo , Liu Kai , Chen Yun-Min 
Published: February 2024

AbstractTwo centrifuge models with the same target relative density (Dr = 65%) were conducted in different centrifugal acceleration (30 g for Model-A and 15 g for Model-B) at Zhejiang University (ZJU) to validate generalized scaling law in the program of LEAP-ASIA-2019. The same model used in LEAP-UCD-2017 was repeated, representing a 5-degree slope consisting of saturated Ottawa F-65 sand. This chapter describes test facilities, instrumentations layout, and test procedures. Uncertainty analysis is also carried out in input parameters (e.g., achieved peak ground acceleration, achieved density and the degree of saturation). The test results of acceleration, excess pore water pressures, and displacement etc. were compared at prototype scale to check the validity of the generalized scaling law (GSL). The preliminary experiment results of Zhejiang University show that the Type II generalized scaling law is applicable to the acceleration response while has a weak applicability to the displacement response.
Type-C Simulations of Centrifuge Tests from LEAP-ASIA-2019 Using SANISAND-Sf
Authors: Reyes Andrés , Barrero Andrés R. , Taiebat Mahdi 
Published: February 2024

AbstractThis chapter presents Type-C numerical simulations of prototype-scale centrifuge tests on gently sloped liquefiable deposits of Ottawa F65 sand for the LEAP-ASIA-2019 project. The simulations aim to assess the performance of the numerical modeling approach and a SANISAND-type constitutive model for large post-liquefaction shear deformation of sands. The constitutive model is calibrated against cyclic torsional shear tests conducted at different relative density levels and cyclic shear stress amplitudes. The laboratory-determined hydraulic conductivity of sand is doubled and kept constant during the dynamic stage of the analyses to account for the increase in permeability experienced during liquefaction. The simulations successfully capture the acceleration response and excess pore water pressure generation and dissipation of the slope deposit when soil liquefaction is observed. However, accurately modeling lateral displacements remains challenging in most cases. The results provide insights into the capabilities and limitations of the adopted Type-C numerical simulations, numerical modeling approach, and constitutive model.
LEAP-ASIA-2019 Numerical Simulations Using a Strain Space Multiple Mechanism Model for a Liquefiable Sloping Ground
Authors: Tanaka Yoshikazu , Sahare Anurag , Ueda Kyohei , Yuyama Waka , Iai Susumu 
Published: February 2024

AbstractThis chapter presents the numerical simulations using a strain space multiple mechanism model on a liquefiable sloping ground during earthquake excitation which are compared with the results obtained from the centrifuge tests conducted at different centrifuge facilities as a part of LEAP-ASIA-2019 with an effort to validate the generalized scaling laws. The constitutive model parameters were determined based on the results of cyclic torsional shear tests. One of the key objectives of this chapter is to assess the differences arising in the soil system responses depending on the three different predictors when using the same constitutive model. For this purpose, the soil constitutive model parameters were calibrated differently, and all the predictors were able to capture the important features of saturated sand during undrained cyclic shearing. This was followed by the numerical simulations of the centrifuge data, which showed no predominant differences in the simulated results due to the different soil constitutive model parameters. However, the amount of shear-induced dilatancy experienced by the sand during cyclic shearing was found out to be different among predictors. It is also highlighted that predictors may achieve the ideal measured results either by performing numerical simulations in model scale or in prototype scale.
LEAP-ASIA-2019 Centrifuge Test Simulation at UNINA
Authors: Fasano Gianluca , Chiaradonna Anna , Bilotta Emilio 
Published: February 2024

AbstractThis chapter describes the numerical simulations carried out at the University of Napoli Federico II in the framework of the LEAP-ASIA-2019 Simulation Exercise. An advanced critical state compatible, bounding surface plasticity model for sand has been adopted and calibrated on the available cyclic laboratory test data. The calibration has been finalized to catch the cyclic strength of the investigated sand. Centrifuge test simulations have been performed by means of the finite element code PLAXIS, which is a commercial code well widespread in the community of geotechnical practitioners. Type-C simulations highlighted the capability of the numerical model to reasonably predict the time histories of acceleration and excess pore water pressure measured during the experimental tests.
LEAP-ASIA-2019 Centrifuge Test Simulations of Liquefiable Sloping Ground
Authors: Qiu Zhijian , Elgamal Ahmed 
Published: February 2024

AbstractNumerical simulations of a liquefiable sloping ground for LEAP-ASIA-2019 centrifuge tests are presented. The simulations are performed using a pressure-dependent constitutive model implemented with the characteristics of dilatancy, cyclic mobility, and associated shear deformation. The soil model parameters are determined based on a series of stress-controlled cyclic torsional shear tests of Ottawa F-65 sand with relative density Dr = 60% during calibration phase. Computational framework for the seismic response analysis is discussed and the computed results are presented for all selected centrifuge experiments during Type-C phase. Measured time histories of these experiments are reasonably captured. It is demonstrated that the pressure-dependent constitutive model as well as the overall employed computational framework has the potential to predict the response of the liquefiable sloping ground, and subsequently realistically evaluates the performance of an equivalent soil system subjected to seismically induced liquefaction.
LEAP-ASIA-2019 Simulations at Tsinghua University
Authors: Wang Rui , Zhu Tong , Zhou Chuang , Zhang Jian-Min 
Published: February 2024

AbstractThis chapter presents the constitutive model calibration and numerical simulations of centrifuge shaking table tests for LEAP-ASIA-2019, at Tsinghua University. A plasticity model that can provide unified description for the behavior sand at different states under both monotonic and cyclic loading, with focus on the large post-liquefaction shear deformation, is calibrated and used in this study. New undrained cyclic torsional shear test results for Ottawa F65 sand provided in the most recent phase of the LEAP project are used in the calibration process. Typical results for acceleration, excess pore pressure, and displacement for one of the tests are presented in detail, showing that the numerical simulation is able to capture the liquefaction related behavior in the tests well. Comparisons between the simulation and test residual displacement results for the five different tests show conflicting results. The simulations for the two RPI tests under different centrifuge acceleration levels with different stress states and input motion frequencies generally show adequate agreement with test results, exhibiting the constitutive model and numerical simulation method’s wide applicability range. However, the simulation results for the KyU tests are significantly different to the test results.
Dynamic Torsional Shear Tests of Ottawa F-65 Sand for LEAP-ASIA-2019
Authors: Vargas Ruben R. , Ueda Kyohei , Uemura Kazuaki 
Published: February 2024

AbstractThe Liquefaction Experiments and Analysis Projects (LEAP) is an international collaborative project that aims to verify, validate, and quantify the uncertainty of numerical liquefaction models. Within this project, a series of hollow cylinder cyclic torsional shear tests were performed at the Disaster Prevention Research Institute facility at Kyoto University. These tests focused on examining how the relative density affects the cyclic response of Ottawa F-65 sand. The obtained results will contribute to a dependable database for the ongoing and future verification and validation processes of liquefaction models. This paper presents the details of the model preparation and test results, as well as a brief discussion on the influence of the relative density and the tests’ repeatability.
LEAP-ASIA-2019 Centrifuge Test at KAIST
Authors: Manandhar Satish , Kim Seong-Nam , Kim Dong-Soo 
Published: February 2024

AbstractSince Niigata and Alaska earthquakes in 1964, the dangers of liquefaction are well established, and research into liquefaction has been actively performed. In this context, Liquefaction Experiments and Analysis Projects (LEAP) was launched to provide high-quality experimental data on soil liquefaction using laboratory testing and centrifuge modeling and then validating numerical models to improve predictions. The purpose of LEAP-ASIA-2019, which is one of the LEAP programs, was to fill the gaps and further extend/establish/confirm the trends obtained in the previous LEAP-UCD-2017 program. Further, the validity of the generalized scaling law was also tested for liquefaction simulation using different 1-g and centrifuge scaling factors. During LEAP-ASIA-2019, KAIST performed two model tests (Model A and Model B) with the same target relative density (Dr = 85%) and input motion intensity of 0.3g. Models A and B were identical in construction but were tested under different centrifugal accelerations to verify the generalized scaling factors. This paper describes the experimental procedure in detail and the responses of dense model grounds to strong base shaking in terms of ground accelerations, excess pore pressure, surface displacements, stress-strain behavior, and CPT profiles. Further, discussion on the generalized scaling law and the effect of shaking history on the model behavior are also presented.
Global conformal blocks via shadow formalism
Authors: Belavin Vladimir , Cabezas J. Ramos 
Published: February 2024

Abstract
We study 𝔰𝔩2 and 𝔰𝔩3 global conformal blocks on a sphere and a torus, using the shadow formalism. These blocks arise in the context of Virasoro and 𝒲3 conformal field theories in the large central charge limit. In the 𝔰𝔩2 case, we demonstrate that the shadow formalism yields the known expressions in terms of conformal partial waves. Then, we extend this approach to the 𝔰𝔩3 case and show that it allows to build simple integral representations for 𝔰𝔩3 global blocks. We demonstrate this construction on two examples: the four-point block on the sphere and the one-point torus block.
Endonasal-endoskopische anteriore Schädelbasischirurgie
Authors: Schmitz Lisa , Betz Christian S. , Stölzel Katharina 
Published: February 2024

Zusammenfassung
Hintergrund
Die erweiterte endonasal-endoskopische Chirurgie („extended endoscopic endonasal surgery“, EEES) ist ein wesentlicher Bestandteil der Behandlung diverser pathologischer Veränderungen der vorderen Schädelbasis. Neben einer deutlichen Steigerung der Lebensqualität der betroffenen Patiente:innen und einem geringeren Komplikationsprofil als bei der offenen Schädelbasischirurgie sind die therapeutischen Ergebnisse bei richtiger Indikationsstellung vergleichbar.

Material und Methoden
Es erfolgte eine retrospektive Datenerhebung aller endonasal-endoskopischen Schädelbasiseingriffe, die im Zeitraum von Juni 2018 bis November 2022 am universitären Schädelbasiszentrum Hamburg unter Führung der Klinik für Hals‑, Nasen- und Ohrenheilkunde durchgeführt wurden.

Ergebnisse
Insgesamt 50 Fälle wurden identifiziert. Dabei handelte es sich in 56 % (28/50) um maligne Tumoren, in 24 % (12/50) um benigne pathologische Veränderungen mit direkter Schädelbasisbeteiligung sowie in 20 % (10/50) um anteriore Schädelbasisdefekte mit Rhinoliquorrhö. In 94 % (47/50) der Fälle konnte das präoperativ gesteckte Ziel des Eingriffs (repräsentative Biopsie, vollständige Resektion, Verschluss des Schädelbasisdefekts) erreicht werden. Komplikationen vom Grad III oder höher nach Clavien-Dindo traten in 4/50 Fällen auf. Im Beobachtungszeitraum wurden n = 5 Olfaktoriusneuroblastome diagnostiziert, von denen alle ausschließlich und erfolgreich endoskopisch operiert wurden.

Schlussfolgerung
In den vergangenen Jahren hat sich das Spektrum der endoskopisch resezierbaren pathologischen Veränderungen der anterioren Schädelbasis stetig erweitert. Insbesondere mittellinienbezogene Tumoren wie das Olfaktoriusneuroblastom oder iatrogene/idiopathische Schädelbasisdefekte mit Liquorrhö werden mit sehr guten Ergebnissen vollständig endoskopisch therapiert. Nichtsdestotrotz ergeben sich auch Limitationen für diese Technik. Aufgrund der hohen Varianz des Umfangs frontobasaler Eingriffe, der Ausdehnung und der komplexen Anatomie sowie der sich überschneidenden Zuständigkeiten der Fachdisziplinen ist die Etablierung von zertifizierten Schädelbasiszentren und die Bündelung der frontobasalen Chirurgie an diesen Zentren von hoher Relevanz für die Qualitätssicherung.
A novel step-by-step procedure for the kinematic calibration of robots using a single draw-wire encoder
Authors: Boschetti Giovanni , Sinico Teresa 
Published: February 2024

AbstractRobot positioning accuracy is a key factory when performing high-precision manufacturing tasks. To effectively improve the accuracy of a manipulator, often up to a value close to its repeatability, calibration plays a crucial role. In the literature, various approaches to robot calibration have been proposed, and they range considerably in the type of measurement system and identification algorithm used. Our aim was to develop a novel step-by-step kinematic calibration procedure — where the parameters are subsequently estimated one at a time — that only uses 1D distance measurement data obtained through a draw-wire encoder. To pursue this objective, we derived an analytical approach to find, for each unknown parameter, a set of calibration points where the discrepancy between the measured and predicted distances only depends on that unknown parameter. This reduces the computational burden of the identification process while potentially improving its accuracy. Simulations and experimental tests were carried out on a 6 degrees-of-freedom robot arm: the results confirmed the validity of the proposed strategy. As a result, the proposed step-by-step calibration approach represents a practical, cost-effective and computationally less demanding alternative to standard calibration approaches, making robot calibration more accessible and easier to perform.
Supercritical melt flow in high-speed laser welding and its interdependence with the geometry of the keyhole and the melt pool
Authors: Reinheimer Eveline N. , Berger Peter , Hagenlocher Christian , Weber Rudolf , Graf Thomas 
Published: February 2024

AbstractThe advent of undercuts and humping limits the applicable speed of deep-penetration laser welding. Recent findings additionally show that a significant change of the keyhole’s shape is associated with the occurrence of undercuts. Considering that undercuts and humping are melt flow–induced defects, this leads to the question of how the geometry of the keyhole and the melt pool influence the melt flow and vice versa. In this work, the Froude number was used to characterize the melt flow around a keyhole. X-ray images of the keyhole and cross-sections of the weld were therefore used to determine the geometrical boundaries of the melt flow, to estimate the average melt velocity around the keyhole, and finally determine its Froude number. The flow around a cylindrically shaped keyhole was found to always be subcritical, whereas supercritical melt flow was observed around the elongated keyholes that are formed at higher welding speed. The findings may be interpreted in the sense that the elongation of the keyhole is a consequence of a supercritical stream of the melt flowing underneath and around the keyhole. This perception is consistent with the long-known experience that humping may be avoided by reducing the flow speed of the melt by widening the melt pool surrounding the keyhole (e.g., by means of beam shaping) and suggest a new explanation for the elongation of the keyhole at increased welding speed.
Nash implementation of supermajority rules
Authors: Amorós Pablo 
Published: February 2024

AbstractA committee of n experts from a university department must choose whom to hire from a set of m candidates. Their honest judgments about the best candidate must be aggregated to determine the socially optimal candidates. However, experts’ judgments are not verifiable. Furthermore, the judgment of each expert does not necessarily determine his preferences over candidates. To solve this problem, a mechanism that implements the socially optimal aggregation rule must be designed. We show that the smallest quota q compatible with the existence of a q-supermajoritarian and Nash implementable aggregation rule is $$q=n-\left\lfloor \frac{n-1}{m}\right\rfloor$$

q
=
n
-

n
-
1

m

. Moreover, for such a rule to exist, there must be at least $$m\left\lfloor \frac{n-1}{m}\right\rfloor +1$$

m

n
-
1

m

+
1

impartial experts with respect to each pair of candidates.
Impact of Mannitol Bladder Distension in the Intraoperative Detection of Ureteral Kinking During Pelvic Floor Surgery
Authors: Barba Marta , Cola Alice , Costa Clarissa , Frigerio Matteo 
Published: February 2024

Abstract
Introduction and Hypothesis
Ureteral injuries are the most feared complications of gynecological surgery and therefore intraoperative recognition is of the utmost importance. Intraoperative cystoscopy represents the diagnostics of choice to investigate ureteral patency thanks to the direct visualization of ureteral flows after administration of infusion mediums. In this study, we aimed to compare the diagnostic performance of saline versus mannitol intraoperative cystoscopy in terms of false negatives in a large cohort of patients.

Methods
We retrospectively analyzed data of patients who underwent vaginal hysterectomy and high uterosacral ligament suspension for POP. Patients were divided in two groups based on the use of saline or mannitol medium for intraoperative cystoscopy. Postoperative daily control of serum creatinine was performed until discharge, as well as urinary tract imaging, in symptomatic patients.

Results
A total of 925 patients underwent vaginal hysterectomy followed by high USL suspension for POP. Saline and mannitol medium were used in 545 patients and 380 patients respectively. Postoperative ureteral injuries were identified in 12 patients, specifically in 2% of the saline group and in 0.3% of the mannitol group.

Conclusions
The use of mannitol instead of saline as a bladder distension medium was able to significantly reduce the occurrence of postoperative ureteral sequelae.
Complexity of the (Connected) Cluster Vertex Deletion Problem on H-free Graphs
Authors: Le Hoang-Oanh , Le Van Bang 
Published: February 2024

AbstractThe well-known Cluster Vertex Deletion problem (cluster-vd) asks for a given graph G and an integer k whether it is possible to delete a set S of at most k vertices of G such that the resulting graph $$G-S$$

G
-
S

is a cluster graph (a disjoint union of cliques). We give a complete characterization of graphs H for which cluster-vd on H-free graphs is polynomially solvable and for which it is $$\textsf{NP}$$
NP
-complete. Moreover, in the $$\textsf{NP}$$
NP
-completeness cases, cluster-vd cannot be solved in sub-exponential time in the vertex number of the H-free input graphs unless the Exponential-Time Hypothesis fails. We also consider the connected variant of cluster-vd, the Connected Cluster Vertex Deletion problem (connected cluster-vd), in which the set S has to induce a connected subgraph of G. It turns out that connected cluster-vd admits the same complexity dichotomy for H-free graphs. Our results enlarge a list of rare dichotomy theorems for well-studied problems on H-free graphs.
The foraging ecology of green turtles (Chelonia mydas) in New Caledonia
Authors: Read Tyffen C. , Wantiez Laurent , Keller Florent , Werry Jonathan M. , van de Merwe Jason P. , Meager Justin J. , Chateau Olivier , Farman Richard , Limpus Colin J. 
Published: February 2024

AbstractGreen sea turtles (Chelonia mydas) face many threats from anthropogenic activity and are listed as Endangered on the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species. They spend the majority of their lives in coastal foraging areas, and show strong fidelity to narrow foraging ranges. Understanding the foraging ecology of green turtles is therefore important for their management and conservation. Using stable isotopes analysis (n = 200) and identification of stomach contents (n = 21), this study investigated the foraging ecology of four distinct green turtle foraging aggregations (Goro, Isle of Pines, Ouen Island and Uo/Mato Islands) within the Grand Lagon Sud. This World Heritage Area located in New Caledonia supports regionally important nesting and foraging green turtle populations. The δ13C and δ15N values of skin samples ranged from − 19.3 to  − 7.3‰ and 2.8–15.9‰, respectively. Metrics of isotopic niche and regression analyses were used to assess the degree of omnivory, trophic diversity and potential ontogenetic diet shifts in the different aggregations of foraging green turtles in this location. Each of the four sites and four age-classes had distinct isotopic niches, with evidence of omnivory and ontogenetic shifts, particular in new recruits and juveniles, and at Goro and Uo/Mato Islands. This was generally supported by the stomach contents analyses of a small number of green turtles opportunistically sampled from traditional ceremonies. This study provides important information on the foraging ecology of green turtles in New Caledonia, supporting management outcomes in this region. This collaboration with the tribes of the Grand Lagon Sud is also the first step towards the integrated management of the resource.