bluuebunny/crossref_metadata_2025_split huggingface dataset:
Time-optimal construction of overlay networks
Authors: Götte Thorsten , Hinnenthal Kristian , Scheideler Christian , Werthmann Julian 
Published: February 2023

AbstractThis article shows how to construct an overlay network of constant degree and diameter$$O(\log n)$$O(logn)in$$O(\log n)$$O(logn)time starting from an arbitrary weakly connected graph. We assume a synchronous communication network in which nodes can send messages to nodes they know the identifier of, and new connections can be established by sending node identifiers. Suppose the initial network’s graph is weakly connected and has constant degree. In that case, our algorithm constructs the desired topology with each node sending and receiving only$$O(\log n)$$O(logn)messages in each round in$$O(\log n)$$O(logn)time w.h.p., which beats the currently best$$O(\log ^{3/2} n)$$O(log3/2n)time algorithm of Götte et al. (International colloquium on structural information and communication complexity (SIROCCO), Springer, 2019). Since the problem cannot be solved faster than by using pointer jumping for$$O(\log n)$$O(logn)rounds (which would even require each node to communicate$$\Omega (n)$$Ω(n)bits), our algorithm is asymptotically optimal. We achieve this speedup by using short random walks to repeatedly establish random connections between the nodes that quickly reduce the conductance of the graph using an observation of Kwok and Lau (Approximation, randomization, and combinatorial optimization. Algorithms and techniques (APPROX/RANDOM 2014), Schloss Dagstuhl-Leibniz-Zentrum fuer Informatik, 2014). Additionally, we show how our algorithm can be used to efficiently solve graph problems inhybrid networks(Augustine et al. in Proceedings of the fourteenth annual ACM-SIAM symposium on discrete algorithms, SIAM, 2020). Motivated by the idea that nodes possess two different modes of communication, we assume that communication of theinitialedges is unrestricted, whereas only polylogarithmically many messages can be sent over edges that have been established throughout an algorithm’s execution. For an (undirected) graphGwith arbitrary degree, we show how to compute connected components, a spanning tree, and biconnected components in$$O(\log n)$$O(logn)time w.h.p. Furthermore, we show how to compute an MIS in$$O(\log d + \log \log n)$$O(logd+loglogn)time w.h.p., wheredis the initial degree ofG.
Combinatorics and Real Lifts of Bitangents to Tropical Quartic Curves
Authors: Cueto Maria Angelica , Markwig Hannah 
Published: February 2023

AbstractSmooth algebraic plane quartics over algebraically closed fields of characteristic different than two have 28 bitangent lines. Their tropical counterparts often have infinitely many bitangents. They are grouped into seven equivalence classes, one for each linear system associated to an effective tropical theta characteristic on the tropical quartic. We show such classes determine tropically convex sets and provide a complete combinatorial classification of such objects into 41 types (up to symmetry). The occurrence of a given class is determined by both the combinatorial type and the metric structure of the input tropical plane quartic. We use this result to provide explicit sign-rules to obtain real lifts for each tropical bitangent class, and confirm that each one has either zero or exactly four real lifts, as previously conjectured by Len and the second author. Furthermore, such real lifts are always totally-real.
Efficient probabilistic prediction of tsunami inundation considering random tsunami sources and the failure probability of seawalls
Authors: Fukutani Yo , Yasuda Tomohiro , Yamanaka Ryoichi 
Published: February 2023

AbstractProbabilistic tsunami inundation assessment ordinarily requires many inundation simulations that consider various uncertainties; thus, the computational cost is very high. In recent years, active research has been conducted to reduce the computational cost. In this study, the number of random tsunami sources was reduced to 20% of the original number by applying proper orthogonal decomposition (POD) to tsunami inundation depth distributions obtained from random tsunami sources. Additionally, the failure degree of seawalls was stochastically assessed, and its impact was incorporated into the evaluation model for tsunami inundation hazards because this factor has a significant impact on the tsunami inundation depth assessment for land areas. Although the randomness of the slip distribution in tsunami sources has been studied extensively in the past, the idea of simultaneously modelling the failure degree of seawalls is a novel feature of this study. Finally, tsunami inundation distribution maps were developed to represent the probability of occurrence of different inundation depths for the next 50 years and 10 years by using a number of tsunami inundation distributions that consider the randomness of the tsunami sources and the failure probability of the seawalls.
Statistical arbitrage in the stock markets by the means of multiple time horizons clustering
Authors: Gatta Federico , Iorio Carmela , Chiaro Diletta , Giampaolo Fabio , Cuomo Salvatore 
Published: February 2023

AbstractNowadays, statistical arbitrage is one of the most attractive fields of study for researchers, and its applications are widely used also in the financial industry. In this work, we propose a new approach for statistical arbitrage based on clustering stocks according to their exposition on common risk factors. A linear multifactor model is exploited as theoretical background. The risk factors of such a model are extracted via Principal Component Analysis by looking at different time granularity. Furthermore, they are standardized to be handled by a feature selection technique, namely the Adaptive Lasso, whose aim is to find the factors that strongly drive each stock’s return. The assets are then clustered by using the information provided by the feature selection, and their exposition on each factor is deleted to obtain the statistical arbitrage. Finally, the Sequential Least SQuares Programming is used to determine the optimal weights to construct the portfolio. The proposed methodology is tested on the Italian, German, American, Japanese, Brazilian, and Indian Stock Markets. Its performances, evaluated through a Cross-Validation approach, are compared with three benchmarks to assess the robustness of our strategy.
Thermochronological constraints on the post-Variscan exhumation history of the southeastern Bohemian Massif (Waldviertel and Weinsberg Forest, Austria): palaeogeographic and geomorphologic implications
Authors: Hejl Ewald , Heberer Bianca , Salcher Bernhard , Sekyra Gert , Van den haute Peter , Leichmann Jaromír 
Published: February 2023

AbstractResolving the Mesozoic and Cenozoic palaeogeography and geomorphologic development of outcropping Variscan basement is a pre-condition for the understanding of central European geodynamics. For our study, we have applied apatite fission-track (AFT) and apatite (U–Th)/He (AHe) thermochronology to surface rocks of the southeastern Bohemian Massif. 46 samples were examined by the AFT method. Additional AHe dating was applied to 8 of them. The AFT ages range from 251 ± 46 to 60.2 ± 4.8 Ma. AHe ages range from 25 to 525 Ma with rather high intra-sample scatter. On a regional scale, the AFT ages generally decrease from mainly late Variscan in the NE to Late Cretaceous and Paleocene in the SW. This regional age asymmetry relative to the NW–SE trending watershed of the Weinsberg Forest is neither compatible with regional uplift of a single block nor with large-scale lithospheric updoming. The lack of age breaks along late Variscan faults demonstrates that strong vertical offset cannot have occurred in Cretaceous and Cenozoic times. Inverse modeling of thermochronological data indicates regional Early Cretaceous cooling and subsequent reheating during the Late Cretaceous. Rocks of the present-day surface were heated up to a temperature of ca. 80 °C without full reset of the AFT system. This thermal history is compatible with the existence of a large mainland in Early Cretaceous times and a subsequent sedimentary reburial until the Campanian on the order of up to 1 km overburden. Parts of the exhumed weathering basal relief to the N and NE of the Weinsberg Forest are inherited as ‘sealed relief’ from Middle Cretaceous time. The observed regional asymmetry of AFT data is best explained by the development of a continental escarpment adjacent to the North Penninic Ocean in latest Cretaceous to Paleogene times. A final episode of accelerated cooling after ca. 20 Ma, as indicated by thermochronological modeling, is tentatively ascribed to either collisional coupling of the Alpine-Carpathian nappe pile with its northern foreland or to East-Alpine slab detachment.
A Limit Equilibrium Model to Simulate Time-Dependent Pillar Scaling in Hard Rock Bord and Pillar Mines
Authors: Wessels D. G. , Malan D. F. 
Published: February 2023

AbstractThis study investigated the use of a limit equilibrium model to simulate the time-dependent scaling of hard rock pillars. In the manganese bord and pillar mines in South Africa, extensive scaling is observed for pillars characterised by a high joint density. It appears that the scaling occurs in a time-dependent fashion. Evidence for this is the ongoing deterioration of pillars in old areas, even after the pillars are reinforced with thin spray-on liners. Monitoring of selected pillars were conducted in an attempt to quantify the rate of time-dependent scaling. Contrary to expectations, almost no additional scaling was recorded for the pillars during a 3-month monitoring period. The scaling distance for pillars of different ages could be measured and it seems as if most of the scaling occurred soon after the pillars are formed. Only a limited amount of additional time-dependent scaling seems to occur after this. Numerical simulations of the time-dependent scaling were conducted using a displacement discontinuity code and a limit equilibrium constitutive model. The postulated exponential decay of the failed rock mass strength at the edges of the pillars resulted in simulated behaviour that is qualitatively similar to the underground observations. The results from this study are encouraging and the method can be used to investigate the long-term stability of bord and pillar excavations. Further work is required to improve on the calibration of the model and to better quantify the rate of scaling of the underground pillars.
Removal or retention of minimally invasive screws in thoracolumbar fractures? Systematic review and case–control study
Authors: Visagan Ravindran , Kearney Siobhan , Trifoi Sebastian , Kalyal Nida , Hogg Florence , Quercetti Beatrice , Abdalla Mohamed , Danciut Mihai , Papadopoulos Marios C. 
Published: February 2023

Abstract
Background

There is uncertainty regarding delayed removal versus retention of minimally invasive screws following percutaneous fixation for thoracolumbar fractures. We conducted a systematic review and case–control study to test the hypothesis that delayed metalwork removal following percutaneous fixation for thoracolumbar fractures improves outcome.

Methods
A systematic review was performed in accordance with the PRISMA guidelines. Our case–control study retrospectively evaluated 55 consecutive patients with thoracolumbar fractures who underwent percutaneous fixation in a single unit: 19 with metalwork retained (controls) and 36 with metalwork removed. Outcomes were the Oswestry Disability Index (ODI), a supplemental questionnaire, and complications.

Results
The systematic review evaluated nine articles. Back pain was reduced in most patients after metalwork removal. One study found no difference in the ODI after versus before metalwork removal, whereas three studies reported significant improvement. Six studies noted no significant alterations in radiological markers of stability after metalwork removal. Mean complication rate was 1.7% (0–6.7). Complications were superficial wound infection, screw breakage at the time of removal, pull-out screw, and a broken rod. In the case–control study, both groups were well matched. For metalwork removal, mean operative time was 69.5 min (range 30–120) and length of stay was 1.3 days (0–4). After metalwork removal, 24 (68.6%) patients felt better, 10 (28.6%) the same and one felt worse. Two patients had superficial hematomas, one had a superficial wound infection, and none required re-operation. Metalwork removal was a significant predictor of return to work or baseline household duties (odds ratio 5.0 [1.4–18.9]). The ODI was not different between groups.

Conclusions
The findings of both the systematic review and our case–control study suggest that removal of metalwork following percutaneous fixation of thoracolumbar fractures is safe and is associated with improved outcome in most patients.
Review and perspectives in applied mechanics of axially moving flexible structures
Authors: Scheidl Jakob , Vetyukov Yury 
Published: February 2023

AbstractThis comprehensive review primarily concerns axially moving flexible structures in problems involving distributed structure-to-solid contact. The distinguishing features of axially moving structures are presented in terms of prevalent studies regarding models with simplified support conditions. Subsequent sections focus on the particular difficulties of treating contact problems with classical structural theories, on the appropriate non-material kinematic description for travelling structures, on the proper formulation of established mechanical principles for open systems and on the category of Arbitrary Lagrangian–Eulerian (ALE) approaches, which are frequently applied for the development of application-oriented finite element schemes. Novel analytical and numerical transient solutions for the benchmark problem of an axially moving beam, which is travelling across a rough surface between two misaligned joints, are presented to illustrate particular challenges as well as to highlight perspectives for future research activities. There are 177 references cited in this paper.
Eigenschaften und Einsatz von verschiedenen Drähten in der Gefäßmedizin
Authors: Oberhuber Alexander , Hofmann Marcel , Wendorff Heiko , Reichert Viktor , Oikonomou Kyriakos , Weidenhagen Rolf , Straeten Georg ,   Sektion Endovaskuläre Techniken der Privaten Akademie der DGG
Published: February 2023

ZusammenfassungErst das Zusammenspiel von Drähten und Kathetern hat die moderne endovaskuläre Therapie möglich gemacht. Nur der richtige Draht mit seinen speziellen Eigenschaften, abhängig vom Gefäßgebiet, kann zum Erfolg führen. Deswegen ist es wichtig, die Eigenschaften der eingesetzten Drähte zu kennen und zu verstehen. Drähte werden prinzipiell in 3 Gruppen (Zugangs‑, Sondierungs- und Haltedrähte) eingeteilt. Elementare Eigenschaften eines Drahtes sind Drahtlänge, Durchmesser, Steifigkeit, Beschichtung, Spitzenkonfiguration, Torsionsstabilität und Tip Load. Es gibt keinen Draht, der für alle Bereiche eingesetzt werden kann. Aortale Therapien im thorakalen Beriech brauchen ultrasteife 0,035″ Drähte, welche mindestens 260 cm lang sind. Tip Load, Spitzenkonfiguration und Torsionsstabilität sind von untergeordneter Bedeutung, während bei Rekanalisationsdrähten für den Unterschenkel gerade diese wichtig für den Erfolg sind.
Butterfly counting and bitruss decomposition on uncertain bipartite graphs
Authors: Zhou Alexander , Wang Yue , Chen Lei 
Published: February 2023

AbstractUncertain butterflies are one of, if not the, most important graphlet structures on uncertain bipartite networks. In this paper, we examine the uncertain butterfly structure (in which the existential probability of the graphlet is greater than or equal to a threshold parameter), as well as the global Uncertain Butterfly Counting Problem (to count the total number of these instances over an entire network). To solve this task, we propose a non-trivial exact baseline (UBFC), as well as an improved algorithm (IUBFC) which we show to be faster both theoretically and practically. We also design two sampling frameworks (UBS and PES) which can sample either a vertex, edge or wedge from the network uniformly and estimate the global count quickly. Furthermore, a notable butterfly-based community structure which has been examined in the past is the k-bitruss. We adapt this community structure onto the uncertain bipartite graph setting and introduce the Uncertain Bitruss Decomposition Problem (which can be used to directly answer any k-bitruss search query for any k). We then propose an exact algorithm (UBitD) to solve our problem with three variations in deriving the initial uncertain support. Using a range of networks with different edge existential probability distributions, we validate the efficiency and effectiveness of our solutions.
Leisure time activities in adolescents predict problematic technology use
Authors: Ibabe Izaskun , Albertos Aranzazu , Lopez-del Burgo Cristina 
Published: February 2023

Abstract
The problematic use of technology of children and adolescents is becoming a growing problem. Research has shown that excessive technology use predicts a variety of psychological and physical health problems. The aim of this study was to analyze the role of leisure time activities (structured and unstructured) in adolescents as a predictor of problematic technology use. Participants were 7723 adolescents, of which 55% were girls, from four Spanish-speaking countries (Chile, Spain, Mexico, and Peru) between the ages of 13 and 18 years. The evaluation instrument applied was the YOURLIFE project self-report questionnaire. Two executive functions were measured: goal setting and inhibitory control. Using structural equation modeling, findings indicated that structured leisure time activities predicted less PTU, whereas unstructured activities predicted more PTU, MLχ2 (69, N = 7723) = 806.60; CFI = 0.929, RMSEA = 0.042, and the model had good predictive capacity for PTU (R2 = 0.46). Structured and unstructured activities also showed indirect effects on PTU through executive functions. As adolescents spent more time in unstructured leisure activities, poorer goal setting, inhibitory control skills, and more PTU were found. The opposite was true for structured leisure time activities. Implications of structured leisure activities to develop executive functioning and to prevent PTU for adolescents are discussed.
Robust two-degrees of freedom linear quadratic gaussian position control for the front axle actuator of a steer-by-wire system
Authors: Gonschorek Robert , Bertram Torsten 
Published: February 2023

AbstractThe Steer-by-Wire (SbW) system is a key technology for highly automated driving. For automated lateral vehicle guidance, the precise position control of the SbW Front Axle Actuator is an essential prerequisite. This contribution presents the modeling, control design, nominal performance, and stability analysis as well as the robustness analysis of the position control for the SbW Front Axle Actuator. Based on a nonlinear model of the plant a simplified linear system model is derived. This model yields the basis for the design of a Two-Degrees of Freedom Linear Quadratic Gaussian Control (2DOF LQG control), which allows an independent design of the command and the disturbance response. Besides an evaluation of the nominal control behavior, μ-analysis is applied to assess the robustness of performance and stability. Finally, real vehicle tests for different driving maneuvers are presented to verify simulation results.
From virtual to physical environments when judging action opportunities: are diagnostics and trainings transferable?
Authors: Gölz Milena S. , Finkel Lisa , Kehlbeck Rebecca , Herschbach Anne , Bauer Isabel , Scheib Jean P. P. , Deussen Oliver , Randerath Jennifer 
Published: February 2023

AbstractThe proper evaluation of whether our given bodily capabilities and environmental properties allow particular actions is indispensable for pertinent decisions, so-called affordance judgments. These can be impacted by older age or brain damage. Virtual Environments (VEs) may provide an efficient opportunity to offer trainings. But do people make affordance judgments in VEs in the same way that they do in Physical Environments (PEs)? And are these decisions trainable by use of VEs? We investigated 24 healthy young adults’ judgment performance of whether or not they could fit their hand into a given aperture. They were presented with a set of opening-increments and indicated their judgments by pressing a yes- or no-button. The stimuli were presented in PE using an aperture apparatus and in VE displayed by use of Oculus Rift goggles. Our results demonstrated the level of equivalence to be specific to the variable: While we found equivalence between VE and PE for the accuracy parameter, results were uncertain or non-equivalent for perceptual sensitivity and for judgment tendency, respectively. When applying training in VE, judgment accuracy improved significantly when tested subsequently within VE. Improvement appeared detectable in PE only on a descriptive level. Furthermore, equivalence testing post-training revealed that perceptual sensitivity performance in VE approached a PE-level. Promisingly, the VE training approach appeared applicable and efficacious within the VE. Future studies need to specify factors that enhance equivalence for detection theory variables and that facilitate transfer from VEs to PEs when judging action opportunities.
Secure cloud-based mobile apps: attack taxonomy, requirements, mechanisms, tests and automation
Authors: Chimuco Francisco T. , Sequeiros João B. F. , Lopes Carolina Galvão , Simões Tiago M. C. , Freire Mário M. , Inácio Pedro R. M. 
Published: February 2023

AbstractThe adoption and popularization of mobile devices, such as smartphones and tablets, accentuated after the second decade of this century, has been motivated by the growing number of mobile applications, which can solve problems in different areas of contemporary societies. Conversely, the software development industry is motivated by the increasing number and quality of resources that mobile devices possess nowadays (e.g., memory, sensors, processing power or battery). While powerful mobile devices do exist, one of the main driving factors behind the increase of resources is the usage of Cloud technology, which strongly complement mobile computing. As expected, the adoption of measures to mitigate security issues has not accompanied the growth and speed of development for Cloud and Mobile software, to ensure that these are resilient to attacks by design. Aiming to contribute to decrease the gap between software and security engineering, this paper presents a deep approach to attack taxonomy, security mechanisms, and security test specification for the Cloud and Mobile ecosystem of applications. This is also the first time an encompassing and conjoined approach is provided for attack taxonomy and specification of security tests automation tools for this ecosystem.