bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation on Tool Deflection During Tapping
Authors: Geßner Felix , Weigold Matthias , Abele Eberhard 
Published: May 2021

AbstractTapping is a challenging process at the end of the value chain. Hence, tool failure is associated with rejected components or expensive rework. For modelling the tapping process we choose a mechanistic approach. In the present work, we focus on the tool model, which describes the deflection and inclination of the tool as a result of the radial forces during tapping. Since radial forces always occur during tapping due to the uneven load distribution on the individual teeth, the tool model represents an essential part of the entire closed-loop model. Especially in the entry phase of the tap, when the guidance within the already cut thread is not yet given, radial forces can lead to deflection of the tool. Therefore, the effects of geometric uncertainty in the thread geometry are experimentally investigated, using optical surface measurement to evaluate the position of the thread relative to the pre-drilled bore. Based on the findings, the tool deflection during tapping is mapped using a cylindrical cantilever beam model, which is calibrated using experimental data. The model is then validated and the implementation within an existing model framework is described.
How to Predict the Product Reliability Confidently and Fast with a Minimum Number of Samples in the Wöhler Test
Authors: Mischko Jens , Einbock Stefan , Wagener Rainer 
Published: May 2021

AbstractTo accurately estimate and predict the (product) lifetime, a large sample size is mandatory, especially for new and unknown materials. The realization of such a sample size is rarely feasible for reasons of cost and capacity. The prior knowledge must be systematically and consistently used to be able to predict the lifetime accurately. By using the example of Wöhler test, it will be shown that the lifetime prediction with a minimum number of specimen and test time can be successful, when taking the prior knowledge into account.
Forward vs. Bayesian Inference Parameter Calibration: Two Approaches for Non-deterministic Parameter Calibration of a Beam-Column Model
Authors: Schaeffner Maximilian , Gehb Christopher M. , Feldmann Robert , Melz Tobias 
Published: May 2021

AbstractMathematical models are commonly used to predict the dynamic behavior of mechanical structures or to synthesize controllers for active systems. Calibrating the model parameters to experimental data is crucial to achieve reliable and adequate model predictions. However, the experimental dynamic behavior is uncertain due to variations in component properties, assembly and mounting. Therefore, uncertainty in the model parameters can be considered in a non-deterministic calibration. In this paper, we compare two approaches for a non-deterministic parameter calibration, which both consider uncertainty in the parameters of a beam-column model. The goal is to improve the model prediction of the axial load-dependent lateral dynamic behavior. The investigation is based on a beam-column system subjected to compressive axial loads used for active buckling control. A representative sample of 30 nominally identical beam-column systems characterizes the variations in the experimental lateral axial load-dependent dynamic behavior. First, in a forward parameter calibration approach, the parameters of the beam-column model are calibrated separately for all 30 investigated beam-column systems using a least squares optimization. The uncertainty in the parameters is obtained by assuming normal distributions of the separately calibrated parameters. Second, in a Bayesian inference parameter calibration approach, the parameters are calibrated using the complete sample of experimental data. Posterior distributions of the parameters characterize the uncertain dynamic behavior of the beam-column model. For both non-deterministic parameter calibration approaches, the predicted uncertainty ranges of the axial load-dependent lateral dynamic behavior are compared to the uncertain experimental behavior and the most accurate results are identified.
On Uncertainty, Decision Values and Innovation
Authors: Thöns Sebastian , Irman Arifian Agusta , Limongelli Maria Pina 
Published: May 2021

AbstractThis paper contains a description, an alignment and a joint approach for technology readiness development with a three phases support of decision value analyses. The three phases are separated into the decision value forecasting, decision value analysis and the technology value quantification supporting the technological concept formulation and experimental testing, the prototype development and the technology qualification and operation. Decision value forecasting allows technology development guidance by technology performance requirements and the value creation even before the technology development is started. This approach is exemplified with load, damage and resistance information based integrity management of a structure and the ranking of the different strategies. The results can be used to guide a technology screening for matching with performance characteristics in terms of precision, cost and employability. Moreover, the first estimate of value creation of the technology for stakeholders, business models and market evaluation is provided.
Potentials and Challenges of Resilience as a Paradigm for Designing Technical Systems
Authors: Leise Philipp , Niessen Pia , Schulte Fiona , Dietrich Ingo , Kirchner Eckhard , Pelz Peter F. 
Published: May 2021

AbstractThe resilience paradigm constitutes that systems can overcome arbitrary system failures and recover quickly. This paradigm has already been applied successfully in multiple disciplines outside the engineering domain. For the development and design of engineering systems the realization of this resilience concept is more challenging and often leads to confusion, because technical systems are characterized by a lower intrinsic complexity compared to, e.g., socio-technical systems. The transfer of the resilience paradigm to technical systems though also offers high potential for the engineering domain. We present results from four-year research on transferring the resilience paradigm to the engineering domain based on mechanical engineering systems and summarize relevant design approaches to quantify the potentials of this paradigm. Furthermore, we present important challenges we faced while transferring this paradigm and present the lessons learned from this interdisciplinary research.
Validation of an Optimized Resilient Water Supply System
Authors: Müller Tim M. , Schmitt Andreas , Leise Philipp , Meck Tobias , Altherr Lena C. , Pelz Peter F. , Pfetsch Marc E. 
Published: May 2021

AbstractComponent failures within water supply systems can lead to significant performance losses. One way to address these losses is the explicit anticipation of failures within the design process. We consider a water supply system for high-rise buildings, where pump failures are the most likely failure scenarios. We explicitly consider these failures within an early design stage which leads to a more resilient system, i.e., a system which is able to operate under a predefined number of arbitrary pump failures. We use a mathematical optimization approach to compute such a resilient design. This is based on a multi-stage model for topology optimization, which can be described by a system of nonlinear inequalities and integrality constraints. Such a model has to be both computationally tractable and to represent the real-world system accurately. We therefore validate the algorithmic solutions using experiments on a scaled test rig for high-rise buildings. The test rig allows for an arbitrary connection of pumps to reproduce scaled versions of booster station designs for high-rise buildings. We experimentally verify the applicability of the presented optimization model and that the proposed resilience properties are also fulfilled in real systems.
Lowering the scale of Pati-Salam breaking through seesaw mixing
Authors: Dolan Matthew J. , Dutka Tomasz P. , Volkas Raymond R. 
Published: May 2021

Abstract
We analyse the experimental limits on the breaking scale of Pati-Salam extensions of the Standard Model. These arise from the experimental limits on rare-meson decay processes mediated at tree-level by the vector leptoquark in the model. This leptoquark ordinarily couples to both left- and right-handed SM fermions and therefore the meson decays do not experience a helicity suppression. We find that the current limits vary from $$ \mathcal{O} $$
O
(80–2500) TeV depending on the choice of matrix structure appearing in the relevant three-generational charged-current interactions. We extensively analyse scenarios where additional fermionic degrees of freedom are introduced, transforming as complete Pati-Salam multiplets. These can lower the scales of Pati-Salam breaking through mass-mixing within the charged-lepton and down-quark sectors, leading to a helicity suppression of the meson decay widths which constrain Pati-Salam breaking. We find four multiplets with varying degrees of viability for this purpose: an SU(2)L/R bidoublet, a pair of SU(4) decuplets and either an SU(2)L or SU(2)R triplet all of which contain heavy exotic versions of the SM charged leptons. We find that the Pati-Salam limits can be as low as $$ \mathcal{O} $$
O
(5–150) TeV with the addition of these four multiplets. We also identify an interesting possible connection between the smallness of the neutrino masses and a helicity suppression of the Pati-Salam limits for three of the four multiplets.
A note on discrete dynamical systems in theories of class S
Authors: Cirafici Michele 
Published: May 2021

Abstract
In this note we consider the set of line operators in theories of class S. We show that this set carries the action of a natural discrete dynamical system associated with the BPS spectrum. We discuss several applications of this perspective; the relation with global properties of the theory; the set of constraints imposed on the spectrum generator, in particular for the case of SU(2) $$ \mathcal{N} $$
N
= 2*; and the relation between line defects and certain spherical Double Affine Hecke Algebras.
Jet wake from linearized hydrodynamics
Authors: Casalderrey-Solana Jorge , Milhano José Guilherme , Pablos Daniel , Rajagopal Krishna , Yao Xiaojun 
Published: May 2021

AbstractWe explore how to improve the hybrid model description of the particles originating from the wake that a jet produced in a heavy ion collision leaves in the droplet of quark-gluon plasma (QGP) through which it propagates, using linearized hydrodynamics on a background Bjorken flow. Jet energy and momentum loss described by the hybrid model become currents sourcing linearized hydrodynamics. By solving the linearized hydrodynamic equations numerically, we investigate the development of the wake in the dynamically evolving droplet of QGP, study the effect of viscosity, scrutinize energy-momentum conservation, and check the validity of the linear approximation. We find that linearized hydrodynamics works better in the viscous case because diffusive modes damp the energy-momentum perturbation produced by the jet. We calculate the distribution of particles produced from the jet wake by using the Cooper-Frye prescription and find that both the transverse momentum spectrum and the distribution of particles in azimuthal angle are similar in shape in linearized hydrodynamics and in the hybrid model. Their normalizations are different because the momentum-rapidity distribution in the linearized hydrodynamics analysis is more spread out, due to sound modes. Since the Bjorken flow has no transverse expansion, we explore the effect of transverse flow by using local boosts to add it into the Cooper-Frye formula. After including the effects of transverse flow in this way, the transverse momentum spectrum becomes harder: more particles with transverse momenta bigger than 2 GeV are produced than in the hybrid model. Although we defer implementing this analysis in a jet Monte Carlo, as would be needed to make quantitative comparisons to data, we gain a qualitative sense of how the jet wake may modify jet observables by computing proxies for two example observables: the lost energy recovered in a cone of varying open angle, and the fragmentation function. We find that linearized hydrodynamics with transverse flow effects added improves the description of the jet wake in the hybrid model in just the way that comparison to data indicates is needed. Our study illuminates a path to improving the description of the wake in the hybrid model, highlighting the need to take into account the effects of both transverse flow and the broadening of the energy-momentum perturbation in spacetime rapidity on particle production.
A calculation of the Weyl anomaly for 6D conformal higher spins
Authors: Aros R. , Bugini F. , Diaz D. E. 
Published: May 2021

Abstract
In this work we continue the study of the one-loop partition function for higher derivative conformal higher spin (CHS) fields in six dimensions and its holographic counterpart given by massless higher spin Fronsdal fields in seven dimensions.In going beyond the conformal class of the boundary round 6-sphere, we start by considering a Ricci-flat, but not conformally flat, boundary and the corresponding Poincaré-Einstein space-filling metric. Here we are able to match the UV logarithmic divergence of the boundary with the IR logarithmic divergence of the bulk, very much like in the known 4D/5D setting, under the assumptions of factorization of the higher derivative CHS kinetic operator and WKB-exactness of the heat kernel of the dual bulk field. A key technical ingredient in this construction is the determination of the fourth heat kernel coefficient b6 for Lichnerowicz Laplacians on both 6D and 7D Einstein manifolds. These results allow to obtain, in addition to the already known type-A Weyl anomaly, two of the three independent type-B anomaly coefficients in terms of the third, say c3 for instance.In order to gain access to c3, and thus determine the four central charges independently, we further consider a generic non Ricci-flat Einstein boundary. However, in this case we find a mismatch between boundary and bulk computations for spins higher than two. We close by discussing the nature of this discrepancy and perspectives for a possible amendment.
Machine learning steered symbolic execution framework for complex software code
Authors: Bu Lei , Liang Yongjuan , Xie Zhunyi , Qian Hong , Hu Yi-Qi , Yu Yang , Chen Xin , Li Xuandong 
Published: May 2021

AbstractDuring program traversing, symbolic execution collects path conditions and feeds them to a constraint solver to obtain feasible solutions. However, complex path conditions, like nonlinear constraints, which widely appear in programs, are hard to be handled efficiently by the existing solvers. In this paper, we adapt the classical symbolic execution framework with a machine learning approach for constraint satisfaction. The approach samples and learns from different solutions to identify potentially feasible area. This sampling-learning style solving can be applied in different class of complex problems easily. Therefore, incorporating this approach, our framework, MLBSE, supports the symbolic execution of not only simple linear path conditions, but also nonlinear arithmetic operations, and even black-box function calls of library methods. Meanwhile, thanks to the theoretical foundation of the machine learning based approach, when the solver fails to solve a path condition, we can have an estimation of the confidence in the satisfiability (ECS) of the problem to give users insights about how the problem is analyzed and whether they could ultimately find a solution. We implement MLBSE on the basis of Symbolic Path Finder (SPF) into a fully automatic Java symbolic execution engine. Users can feed their code to MLBSE directly, which is very convenient to use. To evaluate its performance, 22 real case programs are used as the benchmarks for MLBSE to generate test cases, which involve a total number of 1042 methods that are full of nonlinear operations, floating-point arithmetic as well as native method calls. Experiment results show that the coverage achieved by MLBSE is much higher than the state-of-the-art tools.
Local Well-Posedness of Strong Solutions to the Three-Dimensional Compressible Primitive Equations
Authors: Liu Xin , Titi Edriss S. 
Published: May 2021

AbstractThis work is devoted to establishing the local-in-time well-posedness of strong solutions to the three-dimensional compressible primitive equations of atmospheric dynamics. It is shown that strong solutions exist, are unique, and depend continuously on the initial data, for a short time in two cases: with gravity but without vacuum, and with vacuum but without gravity.
Engineering of the unfolded protein response pathway in Pichia pastoris: enhancing production of secreted recombinant proteins
Authors: Raschmanová Hana , Weninger Astrid , Knejzlík Zdeněk , Melzoch Karel , Kovar Karin 
Published: May 2021

Abstract
Folding and processing of proteins in the endoplasmic reticulum (ER) are major impediments in the production and secretion of proteins from Pichia pastoris (Komagataella sp.). Overexpression of recombinant genes can overwhelm the innate secretory machinery of the P. pastoris cell, and incorrectly folded proteins may accumulate inside the ER. To restore proper protein folding, the cell naturally triggers an unfolded protein response (UPR) pathway, which upregulates the expression of genes coding for chaperones and other folding-assisting proteins (e.g., Kar2p, Pdi1, Ero1p) via the transcription activator Hac1p. Unfolded/misfolded proteins that cannot be repaired are degraded via the ER-associated degradation (ERAD) pathway, which decreases productivity. Co-expression of selected UPR genes, along with the recombinant gene of interest, is a common approach to enhance the production of properly folded, secreted proteins. Such an approach, however, is not always successful and sometimes, protein productivity decreases because of an unbalanced UPR. This review summarizes successful chaperone co-expression strategies in P. pastoris that are specifically related to overproduction of foreign proteins and the UPR. In addition, it illustrates possible negative effects on the cell’s physiology and productivity resulting from genetic engineering of the UPR pathway. We have focused on Pichia’s potential for commercial production of valuable proteins and we aim to optimize molecular designs so that production strains can be tailored to suit a specific heterologous product.

Key points
• Chaperones co-expressed with recombinant genes affect productivity in P. pastoris.
• Enhanced UPR may impair strain physiology and promote protein degradation.
• Gene copy number of the target gene and the chaperone determine the secretion rate.
Complex challenges of estimating the age and vitality of muscle wounds: a study with matrix metalloproteinases and their inhibitors on animal and human tissue samples
Authors: Niedecker A. , Huhn R. , Ritz-Timme St. , Mayer F. 
Published: May 2021

AbstractThe estimation of wound age and wound vitality is a recurring task in forensic routine work and has been subject of forensic research for a long time. By now, an unrestrictedly reliable marker or set of markers has not been found. In a study on myocardial infarctions, matrix metalloproteinases (MMP) 2 and 9 as well as tissue inhibitor of matrix metalloproteinases 1 (TIMP-1) were detected immunohistochemically in mechanically wounded myocardium (ECG electrodes, vessel ligations). Against this background, the potency of MMP-9, MMP-2, and TIMP-1 as markers for the estimation of wound age and wound vitality was tested in a broad approach with human tissue samples drawn during autopsies and with an animal model, the isolated perfused Langendorff heart. The study comprised samples of injured human skeletal muscle, injured human myocardium, rats’ hearts with vital wounds, and rats’ hearts with postmortem-inflicted wounds that were all stained immunohistochemically. The results showed great scattering, leading to the conclusion that MMP-2, MMP-9, and TIMP-1 are not suitable for wound age estimation. Merely the results for TIMP-1 suggested that this marker might be able to differentiate between vital and postmortem-inflicted wounds. With a view to the promising results of the preceding study, the results underline the necessity to test possible markers of wound age/wound vitality on a large and diverse sample set.
Adhesion prevention after endometriosis surgery — results of a randomized, controlled clinical trial with second-look laparoscopy
Authors: Krämer Bernhard , Andress Jürgen , Neis Felix , Hoffmann Sascha , Brucker Sara , Kommoss Stefan , Höller Alice 
Published: May 2021

Abstract
Purpose
Adhesion formation after endometriosis surgery is a severe problem affecting up to 90% of patients. Possible complications include chronic pain, ileus, and secondary infertility. Therefore, effective adhesion prophylaxis is desirable, for which the adhesion barrier 4DryField® PH is evaluated in the present clinical study. It is a starch-based powder that forms a gel after irrigation with saline solution and thus separates surgical sites as physical barrier for adhesion prevention.

Methods
Fifty patients with extensive and deep infiltrating endometriosis were included in this prospective, randomized, controlled clinical trial with two-staged laparoscopic approach. The patients were randomized into two groups, one receiving 4DryField® PH and the other irrigation with saline solution for adhesion prevention. Adhesion formation was directly scored during second-look interventions considering incidence, extent, and severity. Adhesion prevention treatment in the second surgery was performed corresponding to the first intervention to evaluate the long-term outcome in the later course.

Results
Both groups were comparable with respect to relevant patient parameters. Severity and extent of adhesions were significantly reduced by 85% in the 4DryField® PH group compared to the control group (mean total adhesion score 2.2 vs. 14.2; p = 0.004). Incidence of adhesion formation based on the number of affected sites was significantly reduced by 53% in the intervention vs. control group (mean 1.1 vs. 2.3 sites; p = 0.004). Follow-up of secondary endpoints is not yet completed; results will become available at a later stage.

Conclusion
Adhesion formation could be reduced significantly by 85% by application of the adhesion barrier 4DryField® PH.

Trial registration
Trial registration main ID: DRKS00014720, secondary ID: U1111-1213-4142; date of registration 09th May 2018.