bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parameter estimation with model order reduction and global measurements
Authors: Lukassen Axel Ariaan , Kiehl Martin 
Published: March 2018

AbstractWe present a new method for parameter estimation for elliptic partial differential equations. Parameter estimation requires the evaluation of the partial differential equation for many different parameter sets. Therefore, model order reduction is reasonable. Model order reduction is composed of an offline phase and an online phase. In the offline phase the reduced model is constructed using snapshots. In this paper we use the given measurement as only snapshot. Hence, the computational costs of the offline phase are reduced. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimality Conditions for Switching Operator Differential Equations
Authors: Rüffler Fabian , Hante Falk M. 
Published: March 2018

AbstractWe consider optimal switching of hybrid abstract evolution equations. The framework includes switching semilinear partial differential equations of parabolic or hyperbolic type, discontinuous state resets, switching costs and allows switching of the principle parts of the equations. We present adjoint‐based formulae for the gradient of the cost functional with respect to position and number of switching time points that lead to first order necessary conditions. Moreover, we discuss an alternate‐direction approach for implementing descent methods. As an application we consider optimal open/close‐switching of valves and on/off‐switching control of compressors in a gas network modelled by a graph with simplified euler equations on edges and suitable coupling conditions at nodes. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Application of Multi‐Parametric Quadratic Programming to Simulation of Deflected Wires in a Wire Saw
Authors: Treyer Daniel , Gaulocher Sebastian , Niederberger Stefan , Rafael Helge , Ams Alfons 
Published: March 2018

AbstractIn the wire sawing process, a silicon brick is fed into a moving wire web, thus deflecting the wires. By considering static deflections only, the wire displacement and the contact forces between wire and brick may be computed by minimizing the potential energy of the wire, which introduces a constrained quadratic optimization problem. In a time‐domain simulation, the continuously changing contour inside the kerf requires the optimization problem to be solved recurringly. This work aims at reducing the optimization‐related computational effort by applying multi‐parametric quadratic programming. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Variational integrators for open‐loop and closed‐loop optimal control of mechanical systems
Authors: Flaßkamp Kathrin , Murphey Todd D. , Büskens Christof 
Published: March 2018

AbstractMechanical systems have structural properties, e.g. symplecticity, symmetry, and a specific energy behavior, which get lost in standard integration methods. Therefore, symplectic integration methods are used in simulation and control of mechanical systems. This paper combines two methods of the class of structure‐preserving control methods, namely a recently developed feedback control method and open loop optimal control based on variational integrator discretization. The combination is applied to the benchmark example of a cart pendulum system. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An operator based notation of the Lagrange equations for systems with non‐material boundary conditions
Authors: Franze Andreas 
Published: March 2018

AbstractProblems with non‐material boundary conditions are very important in many applications of continuum mechanics: for example rolling contact, calenders, breaking disks, band saws and belts. This paper deals with the LAGRANGE‐equation for non‐material boundary conditions. Such boundary conditions can be described by non‐material control volumes that cannot be assigned for one and only one set of particles over time.To define these volumes, a fictitious body is used. Within the scope of this paper several configurations are introduced for the definition of the location of the original and fictitious particles. With the help of the used operator notation it is possible to demonstrate a consistent representation of derivative operators and assign operators as well as entities to their configurations.On this basis, the LAGRANGE‐equation is derived for material and non‐material control volumes in the EULERIAN and LAGRANGIAN representation. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Modeling a heavy rope using redundant coordinates
Authors: Gerbet Daniel , Rudolph Joachim 
Published: March 2018

AbstractA generalized Lagrange formalism using redundant coordinates can be applied to systems with distributed parameters. This is illustrated through an example of a heavy rope. The resulting mathematical model for the rope in three‐dimensional space is singularity‐free, at the expense of redundant coordinates constrained by nonlinear equations. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dynamics of a running gear with IRWs on curved tracks for a robust control development
Authors: Grether Gustav 
Published: March 2018

AbstractAs a major task of the DLR‐internal project “Next Generation Train”, robust state feedback control with gain scheduling was sucessfully applied to guide the experimental running gear with independently rotating wheels (IRWs) at a 1:5 scaled roller rig, see [1]. However, the adaptation of the control structure to the 1:1 multibody model requires to additionally consider the properties of curved tracks. For that reason, an analytical model of a running gear with IRWs is deduced using Euler‐Lagrange‐equations and taking superelevation and track curvature into account. Furthermore, the complexity of the system is reduced to allow for a robust feedback control synthesis and feed‐forward control including model inversion. Finally, the model is discussed and a first approach for a feed‐forward control in transition curves is shown. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Energy‐optimal swing‐up of an electromechanically actuated pendulum
Authors: Kern Dominik , Groß Michael 
Published: March 2018

AbstractA control strategy for swinging up a planar pendulum, from its hanging to its upright position, is presented. Its hinge is actuated by a DC‐motor. In contrast to frequently used models of torque control, the DC‐motor is included as RLC circuits of stator and armature in this paper. The armature voltage is used as input signal, while the stator current is fixed. By passing the horizontal position there is a local loss of controllability, as the motor torque vanishes there. Hamilton's principle is applied and discretized by a variational integrator (VI) in order to compute the optimal feed‐forward control. Thus, the resulting optimal control problem is transferred into a finite‐dimensional optimization problem, and solved by sequential quadratic programming (SQP) methods. The cost function to be minimized is the consumed electrical energy needed to swing up the pendulum in fixed time. In addition to the feed‐forward control (offline), feed‐back control (online) is added in order to stabilize the swing‐up and the upright position. This feedback‐controller is designed as linear‐quadratic regulator (LQR) for the linearization around the nominal trajectory. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nonlinear Pressure Control of a Switched Hydraulic System
Authors: Schröders Simon , Fidlin Alexander 
Published: March 2018

AbstractHydraulic power transmission is often used in a variety of technical applications. Due to the nonlinear and often non smooth behaviour of some hydraulic components concerning their volume flow characteristics, the development of control strategies for hydraulic systems is challenging. Most developed control strategies base on linearized models, allowing only local operation in the environment of certain operating points. In this contribution, a nonlinear control strategy, based on the feedback linearization technique, allowing a global compensation of the nonlinearities [2], is developed for a minimal hydraulic circuit consisting of a pressure regulation valve, a vane pump and an ideal consumer. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Impact of Quantisation on Consistency of DMPC in Street Traffic with Dynamic Priority Rules
Authors: Sprodowski Tobias , Pannek Jürgen 
Published: March 2018

AbstractDistributed systems typically require communication to steer the overall system to a reference or target state and keep it there. We consider an intersection scenario as a spacial set with vehicles as multi‐agents with individual initial and target conditions. Utilising a Distributed Model Predictive Control scheme (DMPC), in every time step each vehicle solves an finite horizon optimal control problem. The resulting optimal state trajectory is projected onto a quantisation of the spatial set and the quantised trajectories are broadcasted to the other vehicles to ensure collision avoidance. The quantisation is mainly motivated to reduce the necessary communication effort among the agents. Here, we introduce prediction coherence as difference of two predictions in two successive time steps. We numerically explore the idea to utilise prediction coherence to derive a lower bound for the communication requirements among the vehicles. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Image Compression with the Region Based Easy Path Wavelet Transform
Authors: Budinich Renato 
Published: March 2018

AbstractWe review the Region Based Easy Path Wavelet Transform method in the context of image compression and how it can be used to encode a Region of Interest in the image with higher quality than the complementary region. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fast Low‐Rank Empirical Cross Gramians
Authors: Himpe Christian , Leibner Tobias , Rave Stephan , Saak Jens 
Published: March 2018

AbstractThe cross Gramian matrix encodes the input‐output coherence of linear control systems and is used in projection‐based model reduction. The empirical cross Gramian is a data‐driven variant of the cross Gramian which also extends to nonlinear systems. A drawback of the empirical cross Gramian for large‐scale systems is its full order and dense structure; yet, it may be computed column‐wise. Using the hierarchical approximate proper orthogonal decomposition (HAPOD), this partial computability can be exploited to obtain a truncated projection for model order reduction without assembling a full cross Gramian. (© 2017 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exome sequencing reveals the genetic landscape and frequent inactivation of PCDHB3 in Chinese rectal cancers
Authors: Ye Wen , Ling Shaoping , Liu Ran‐Yi , Pan Zhi‐Zhong , Wang Gaoyuan , Gao Shijuan , Wu Jiangxue , Cao Lihua , Dong Lili , Li Yingchang , Zhou Yi , Du Wuying , Meng Xiangqi , Chen Jinna , Guan Xinyuan , He Yulong , Pan Changchuan , Zheng XF Steven , Lu Xuemei , Chen Shuai , Huang Wenlin 
Published: March 2018

AbstractColorectal cancer (CRC) is the third most common cancer worldwide, with more than 1.3 million new cases and 690 000 deaths each year. In China, the incidence of CRC has increased dramatically due to dietary and lifestyle changes, to become the fifth leading cause of cancer‐related death. Here, we performed whole‐exome sequencing in 50 rectal cancer cases among the Chinese population as part of the International Cancer Genome Consortium research project. Frequently mutated genes and enriched pathways were identified. Moreover, a previously unreported gene, PCDHB3, was found frequently mutated in 5.19% cases. Additionally, PCDHB3 expression was found decreased in 81.6% of CRC tissues and all eight CRC cell lines tested. Low expression and cytoplasmic localization of PCDHB3 predict poor prognosis in advanced CRC. Copy number decrease and/or CpG island hypermethylation contributes to the pervasive decreased expression of PCDHB3. PCDHB3 inhibits CRC cell proliferation, migration, and epithelial–mesenchymal transition. The tumor‐suppressive effects of PCDHB3 are partially due to inhibition of NF‐κB transcriptional activity through K63 deubiquitination of p50 at lysine 244/252, which increases the binding affinity of inactive p50 homodimer to κB DNA, resulting in competitive inhibition of the transcription of NF‐κB target genes by p65 dimers. Our study identified PCDHB3 as a novel tumor suppressor in CRC via inhibition of the NF‐κB pathway, and its expression and localization may serve as prognostic markers for advanced CRC. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Interaction of cationic antimicrobial peptides from Australian frogs with lipid membranes
Authors: Zhu Shiying , Sani Marc‐Antoine , Separovic Frances 
Published: March 2018

AbstractCationic antimicrobial peptides (AMPs) from Australian frogs have been extensively studied as alternatives to traditional antibiotics. Solid‐state NMR is used to characterize their effect on lipid bilayers, which are the primary target, but correlation with in vivo situations is tentative in view of the complex effects of changes in sample conditions (such as pH, temperature, lipid composition or peptide concentration). We have used 31P and 2H solid‐state NMR and a range of biophysical techniques to study the impact of the AMPs, maculatin 1.1, caerin 1.1, aurein 1.2, kalata B1, and Chex‐Arg20, on membranes that mimic those of E. coli and S. aureus bacteria and red blood cell membranes. Overall, the length of AMPs affects peptide‐membrane interaction but also their conformations are important. While lipid composition plays a critical role in modulating AMP structure and function, electrostatic interactions are not sufficient to explain their specific activity and interactions with other membrane components need to be considered. Although in an early stage of development, in‐cell NMR of labelled peptides in live bacteria, rather than model membrane studies, may provide new insights into bactericidal mechanisms of AMPs.
Herbicide resistance evolution can be tamed by diversity in irrigated Australian cotton: a multi‐species, multi‐herbicide modelling approach
Authors: Thornby David , Werth Jeff , Hereward James , Keenan Michelle , Chauhan Bhagirath S 
Published: March 2018

AbstractBACKGROUNDBecause herbicide resistance evolves in very large populations over periods of many years, modelling is an important tool for investigating the dynamics of the problem. The Diversity model tracks the simultaneous evolution of resistance to multiple herbicides, using multiple genetic pathways, in several weed species at once. Tracking multiple species and simultaneous resistances is an important development in resistance modelling. We used the Diversity model to test weed management strategies for new cropping cotton varieties with multiple herbicide tolerances (‘triple‐stacked’ varieties), in an Australian context.RESULTSThe diversity required for long‐term control of three key weeds in Australian cotton goes beyond using three herbicides, especially where there is already a substantial background of existing resistance to one or more of these herbicides. Assuming some glyphosate resistance is already present, simulations showed that glyphosate‐resistant summer grass populations reach 20 000 seeds m−2 within 12 years using the triple‐stack herbicides (glyphosate, glufosinate and dicamba) and a minimum of other tactics. Adding three pre‐emergent modes of action plus cultivation to the system effectively controls glyphosate‐resistant grasses for over 30 years. In conditions where resistance genes are as frequent as 1 in 100, however, highly fecund weeds such as Conyza bonariensis are hard to control beyond 15 years even with very highly diverse management.CONCLUSIONSStacked herbicide tolerances in new crop varieties offers potential for increased herbicide diversity, but existing glyphosate‐resistant weed populations need substantial extra management beyond what a glyphosate/glufosinate/dicamba resistance stack provides. More diverse systems can provide robust management over 30 years in the absence of very high levels of background resistance to other herbicides. © 2018 Society of Chemical Industry
Design and performance evaluation of LTP enhancements for lossy space channels
Authors: Alessi N. , Burleigh S. , Caini C. , de Cola T. 
Published: March 2018

SummaryThis paper deals with the performance of Licklider Transmission Protocol (LTP) in space environment, focusing on the impact of segment losses and the design of possible improvements. The in‐depth analysis of retransmission mechanisms carried out in the paper shows that, while LTP already achieves delivery time performance very close to the theoretical optimum in ideal conditions (no losses) and when losses affect data segments, a substantial improvement is still possible concerning signaling segments, whose loss can result in a significant increase of the LTP block delivery time. To this end, 2 simple enhancements, the Closing State and the proactive retransmission of signaling segments, are proposed and evaluated in the paper. Both enhancements have been added as optional features to the original Interplanetary Overlay Network LTP implementation (ION 3.5.0), in order to evaluate their effectiveness on a GNU/Linux testbed running the full protocol stack. Results presented in the paper confirm the validity of the proposed enhancements, as they significantly reduce the average delivery time in the presence of high losses and provide the additional advantage, even when losses are relatively low, of largely reducing the difference between average and worst cases.
Measuring long‐term sustainability with shared socioeconomic pathways using an inclusive wealth framework
Authors: Kurniawan Robi , Managi Shunsuke 
Published: March 2018

AbstractTo understand the trajectory of sustainability, it is important to measure historical and future projections of productive capital that contribute to wellbeing. This study considers a productive base that includes the human, natural and produced capital of 140 countries. We then develop projections for 2014–2100 using the newly developed shared socioeconomic pathways (SSPs) that strive to explain the implications of key socioeconomic variables on long‐term global sustainability. Those SSPs with high investments in broad societal development are associated with the highest growth in inclusive wealth. Poverty alleviation, demographic changes and human capital investments are effective instruments to attain greater wealth as shown in East and Southeast Asia. Furthermore, the SSP that describes a sustainability pathway, which poses the least climate change challenges and substantially reduced reliance on natural resources, is more conducive to increasing wellbeing than the fragmented pathways that result in inequality.
Is the Sustainable Development Goals (SDG) index an adequate framework to measure the progress of the 2030 Agenda?
Authors: Diaz‐Sarachaga Jose Manuel , Jato‐Espino Daniel , Castro‐Fresno Daniel 
Published: March 2018

AbstractUnder the consideration of different measures adopted by most United Nations (UN) members, the Sustainable Development Goals (SDGs) included in the 2030 Agenda for Sustainable Development aim to address the main challenges related to social, economic and environmental issues. Numerous single indicators have been established to monitor progress toward sustainable development; however, the need for benchmarking the degree of sustainability of countries triggered the creation of the SDG Index, which originally compiled 77 indicators and has evolved to 99 at present. This research analyzes the suitability of applying this composite index for assessing the fulfillment of the 2030 Agenda. The lack of information resulted in 60% of the SDG indicators being disregarded in the SDG Index. The scores obtained through the application of this index clustered UN countries according to specific geographic areas, highlighting the need for developing regional SDG Indices to emphasize the achievement of lower‐performing goals.
Hidden Nature of the Conversion Reaction from Rare Earth Chloride to Oxychloride and the Application to Novel Separation
Authors: Yamamoto Hiroki , Miyata Motoyuki , Murakami Hajime , Furusawa Katsuyoshi , Uda Tetsuya 
Published: March 2018

AbstractA mutual separation process that uses rare‐earth oxychloride in a proactive way was developed. In particular, the heat‐treatment conditions under which DyCl3 is converted into DyOCl (without causing such conversion of NdCl3) in dry oxygen with 6.5 ppm of H2O (dew point: 209 K) at a relatively low temperature (around 573 K) were determined. A difference between conversion reactions of the two kinds of rare‐earth chlorides into rare‐earth oxychlorides appeared in the case of an oxygen atmosphere with ultra‐low H2O content, although this difference is usually hidden in the presence of atmospheric humidity. Under these conditions, high separability of a NdCl3 and DyCl3 mixture was demonstrated.
Nitrogen and Sulfur Co–Doped Hollow Carbon Nanospheres Derived from Surface‐Attached Polyelectrolyte Monolayers
Authors: Wang Junbo , Li Xiaofeng , Fan Meiling , Zhang Haining , Tu Wenmao 
Published: March 2018

AbstractNitrogen, sulfur co‐doped hollow carbon nanospheres are synthesized by simple pyrolysis of surface‐attached 2‐thiophene acetic acid neutralized poly(4‐vinylpyridine) monolayers on silica nanoparticles, followed by removal of silica templates. The covalently grafted polymer chains prevent the aggregation of silica templates during pyrolysis process, resulting in well‐distributed mesopores. The formed materials exhibit an improved electrocatalytic performance for oxygen reduction reactions under basic conditions compared to nitrogen doped hollow carbon nanospheres in terms of the positive shift of half‐wave potential. The best catalytic activity is observed for the material with surface area of 489 m2g−1 derived from 15 nm silica templated modified with polymers, which is comparable to commercial 20 wt.% Pt/C catalysts (half‐wave potential negatively shifts by 10 mV with similar limiting current density compared with Pt/C catalysts). Although the dual doping can improve the catalytic activity, the increase in sulfur concentration of the formed materials has little effect on the electrocatalytic performance for oxygen reduction reactions. This development offers a new synthetic strategy to synthesize heteroatoms co‐doped or multi‐doped spherical hollow carbon materials not only for application in electrochemical devices, but also as model materials for fundamental understanding of properties of carbon‐based materials.
Transparent and Hydrophobic MTMS/GPTMS Hybrid Aerogel Monoliths and Coatings by Sol‐Gel Method: A Viable Remedy for Oil‐Spill Cleanup
Authors: Smitha Venu Sreekala , Azeez Peer Mohamed Abdul , Warrier Krishna Gopakumar , Nair Balagopal N. , Hareesh Unnikrishnan Nair Saraswathy 
Published: March 2018

AbstractSol‐gel derived hybrid aerogel monoliths and coatings of methyltrimethoxysilane (MTMS) and glycidoxypropyltrimethoxysilane (GPTMS) are prepared sucessfully. MTMS/GPTMS is hydrolyzed under acidic conditions and further condensed under basic conditions to generate a gel network followed by a sequential solvent exchange process and ambient drying to obtain aerogel monoliths. The as‐synthesized alcogel is homogenized in methanol and coatings are fabricated on glass substrates by dip coating method followed by controlled thermal treatment at 400 °C to get organically modified silica (ORMOSIL) based aerogel coatings. The transparent ORMOSIL aerogel coating made from the composition of MTMS/GPTMS ratio 1: 0.5 is found to be highly porous with an average pore size of ∼100 nm and hydrophobic coatings with water contact angle of ∼100 ° are obtained. The hybrid aerogel has ∼334 m2g−1 surface area (BET) with an average pore diameter of ∼2.7 nm, and the coating retains its hydrophobicity even after thermal treatment at 400 °C. Hybrid aerogel coatings were also made on cotton canvas fabrics which demonstrate oil adsorption‐desorption properties and is a viable remedy for oil‐spill cleanup.