bluuebunny/crossref_metadata_2025_split huggingface dataset:
Open source robot localization for nonplanar environments
Authors: Rico Francisco Martín , Hernández José Miguel Guerrero , Pérez‐Rodríguez Rodrigo , Peña‐Narvaez Juan Diego , Gómez‐Jacinto Alberto García 
Published: May 2024

AbstractThe operational environments in which a mobile robot executes its missions often exhibit nonflat terrain characteristics, encompassing outdoor and indoor settings featuring ramps and slopes. In such scenarios, the conventional methodologies employed for localization encounter novel challenges and limitations. This study delineates a localization framework incorporating ground elevation and incline considerations, deviating from traditional two‐dimensional localization paradigms that may falter in such contexts. In our proposed approach, the map encompasses elevation and spatial occupancy information, employing Gridmaps and Octomaps. At the same time, the perception model is designed to accommodate the robot's inclined orientation and the potential presence of ground as an obstacle, besides usual structural and dynamic obstacles. We provide an implementation of our approach fully working with Nav2, ready to replace the baseline Adaptative Monte Carlo Localization (AMCL) approach when the robot is in nonplanar environments. Our methodology was rigorously tested in both simulated environments and through practical application on actual robots, including the Tiago and Summit XL models, across various settings ranging from indoor and outdoor to flat and uneven terrains. Demonstrating exceptional precision, our approach yielded error margins below 10 cm and 0.05 radians in indoor settings and less than 1.0 m in extensive outdoor routes. While our results exhibit a slight improvement over AMCL in indoor environments, the enhancement in performance is significantly more pronounced when compared to three‐dimensional simultaneous localization and mapping algorithms. This underscores the considerable robustness and efficiency of our approach, positioning it as an effective strategy for mobile robots tasked with navigating expansive and intricate indoor/outdoor environments.
Controlled Synthesis of Bead‐like Pt as an Efficient Electrocatalyst for Electrocatalytic Ammonia Oxidation
Authors: Tang Han , Gu Yufeng , Luo Jiabing , Zhang Wei , Zhang Jun , Zhou Yan 
Published: May 2024

AbstractPromoting electrocatalytic ammonia oxidation reaction (AOR) holds the key to develop efficient direct ammonia fuel cells (DAFCs) and ammonia‐mediated hydrogen production (AMHP). Recent investigations indicated that Pt with the exposure of (100) facet has a moderate *N intermediate bonding strength, resulting in the highest AOR electrocatalytic activity among others. Therefore, maximizing the exposure of (100) planes with high active surface area is highly desired for efficient electrocatalysts. In this paper, Pt catalyst composed of directional alignment of nanoparticles around 50 nm (Pt‐100/C) were synthesized by hydrothermal method in the presence of KOH. The KOH concentration was found to modulate the one‐dimensional alignment of nanoparticles. The electrocatalyst showed the largest electrochemically active areas and the highest peak current density (3.14 mA cm−2), and the catalyst exhibited high stability after 500 cycles. A series of electrochemical tests and structural characterizations show that unique bead‐structured Pt combines the excellent activity of nanoparticles with the structural stability of nanowires. A scheme for “exchanging electrodes” has been proposed to solve the problem of catalyst poisoning caused by AOR in AMHP.
Bright Bifacial White‐Light Illumination by Highly Deformable Electroluminescent Devices Based on Transparent Ionic‐Hydrogel Electrodes and Quantum‐Dot Color Conversion
Authors: Zhu Yijie , Hong Ahyoung , Yoon SukYoung , Park Jeongbin , Yang Heesun , Kwak Jeonghun , Yoon Jinhwan 
Published: May 2024

AbstractDeformable alternating‐current electroluminescent (ACEL) devices are of increasing interest because of their potential to drive innovation in soft optoelectronics. Despite the research focus on efficient white ACEL devices, achieving deformable devices with high luminance remains difficult. In this study, this challenge is addressed by fabricating white ACEL devices using color‐conversion materials, transparent and durable hydrogel electrodes, and high‐k nanoparticles. The incorporation of quantum dots enables the highly efficient generation of red and green light through the color conversion of blue electroluminescence. Although the ionic‐hydrogel electrode provides high toughness, excellent light transmittance, and superior conductivity, the luminance of the device is remarkably enhanced by the incorporation of a high‐k dielectric, BaTiO3. The fabricated ACEL device uniformly emits very bright white light (489 cd m−2) with a high color‐rendering index (91) from both the top and bottom. The soft and tough characteristics of the device allow seamless operation in various deformed states, including bending, twisting, and stretching up to 400%, providing a promising platform for applications in a wide array of soft optoelectronics.
Integrating Sulfur Doping with a Multi‐Heterointerface Fe7S8/NiS@C Composite for Wideband Microwave Absorption
Authors: Chen Yikun , Wang Yan , Li Chenchen , Wang Wei , Xue Xu , Pan Hongge , Che Renchao 
Published: May 2024

AbstractHeterointerface engineering is presently considered a valuable strategy for enhancing the microwave absorption (MA) properties of materials via compositional modification and structural design. In this study, a sulfur‐doped multi‐interfacial composite (Fe7S8/NiS@C) coated with NiFe‐layered double hydroxides (LDHs) is successfully prepared using a hydrothermal method and post‐high‐temperature vulcanization. When assembled into twisted surfaces, the NiFe‐LDH nanosheets exhibit porous morphologies, improving impedance matching, and microwave scattering. Sulfur doping in composites generates heterointerfaces, numerous sulfur vacancies, and lattice defects, which facilitate the polarization process to enhance MA. Owing to the controllable heterointerface design, the unique porous structure induced multiple heterointerfaces, numerous vacancies, and defects, endowing the Fe7S8/NiS@C composite with an enhanced MA capability. In particular, the minimum reflection loss (RLmin) value reached −58.1 dB at 15.8 GHz at a thickness of 2.1 mm, and a broad effective absorption bandwidth (EAB) value of 7.3 GHz is achieved at 2.5 mm. Therefore, the Fe7S8/NiS@C composite exhibits remarkable potential as a high‐efficiency MA material owing to the synergistic effects of the polarization processes, multiple scatterings, porous structures, and impedance matching.
On quantifying heterogeneous treatment effects with regression‐based individualized treatment rules: Loss function families and bounds on estimation error
Authors: Gorczyca Michael T. , Kang Chaeryon 
Published: May 2024

SummaryHeterogeneity in response to treatment is a pervasive problem in medicine. Many researchers have proposed individualized treatment rule methods for this problem, which personalize treatment recommendations based on an individual's recorded covariates. A challenge with using these methods in practice is that they determine a treatment rule, rather than quantify treatment benefit. This can be problematic, as a recommended treatment could be burdensome and have negligible improvements in outcome for some individuals. With the aim of helping practitioners make informed modelling choices, we identify two families of loss functions to use with individualized treatment rule methods. Under the assumption of correct model specification, estimation with a loss function from one family ensures that the model's treatment recommendations can be interpreted in terms of the risk difference, while the other family of loss functions ensures that the model's treatment recommendations can be interpreted in terms of the risk ratio. We also derive two upper bounds for a model's error in risk difference and risk ratio estimation. Each upper bound can be calculated using observed data and can provide insight to practitioners regarding model error in estimating treatment effects. We illustrate our contributions with simulation studies as well as with data from the ACTG‐175 AIDS study.
Wirklich nur ein Würfel? Fassade des Ronald O. Perelman Centers of Performing Arts in New York
Authors: Engelmann Michael , Wolf Gerold , Ott Stefan 
Published: May 2024

AbstractEin neues New Yorker Wahrzeichen – das Ronald O. Perelman Center of Performing Arts – erhebt sich in steinerner Eleganz neben dem World Trade Center. Eine einzigartige Fassade von 7200 m2 Fläche umhüllt das asketisch würfelförmige Bauwerk, getragen von zweifach gestoßenen, insgesamt 36 m langen Stahlpfosten, welche mit versenkten Schraubverbindungen gesichert und am Dach montiert sind, um der architektonischen Absicht gerecht zu werden. Alle Laschenstöße zeigen sich an der Grenze machbarer Randabstände und ohne erhabene Konturen, um dem dramatischen Toleranzsprung zwischen gewaltigem Haupttragwerk und filigraner Fassade gerecht zu werden. Doch welche Fragen stellen sich beim Planen und Fertigen einer solchen exponierten Gebäudehülle? Das Team musste zur Stahlfertigung nicht nur bürokratische Hürden zwischen DIN und ASTM/AWS überwinden, sondern auch höchste Anforderungen an die Montagequalität einhalten, da alle Flächen im Sichtbereich erbarmungslos exponiert sind. Zur realitätsnahen Einschätzung half ein erster Probeaufbau in Deutschland. Das dabei erkannte Lochspiel konnte in der Konstruktion mit bemerkenswerter Präzision und Liebe zum Detail eliminiert werden. Dank diesem Aufwand erreichten fast 5000 Einzelscheiben auf Mega‐Panels ihre individuellen und vorab geplanten Endpositionen auf der Gebäudeoberfläche – eine Logistikkette vom Steinbruch bis auf die Baustelle. Wo der Teufel im Detail eines so architektonisch anspruchsvollen Projekts liegt, zeigt der nun folgende Aufsatz.
Development of functional architectures for cyber‐physical systems using interconnectable models
Authors: Eichmann Oliver C. , Lamm Jesko G. , Melzer Sylvia , Weilkiens Tim , God Ralf 
Published: May 2024

AbstractCyber‐physical Systems (CPSs) are characterized by entities in both the physical and the virtual space, thus enabling an immersion of the physical world into the cyberspace. Connectivity via the cyberspace allows CPS cooperation for new services in product service systems (PSS). In consequence, cooperating CPSs act as actors with interest in the CPS in focus. Considering the needs of human actors and cooperating CPSs is a challenging task in CPS development because of many actors, interdepending CPS functions, and multiple CPS interfaces. For systems, the known Functional Architectures for Systems (FAS) method offers a solution approach for deriving functional system architectures from system use cases originating from human actors. For CPS development, this publication presents an expansion of the FAS method for developing functional architectures based on use cases originating from human actors as well as from cooperating CPSs and offers a model‐based approach based on the method description. In the authors’ opinion, interconnectable CPSs and models of cooperating CPSs can be integrated and interconnected with each other into a unifying aggregated model to represent the joint behavior of CPSs in an aggregated system. The paper explains this novel approach through a CPS functional architecture development example related to the prediction of remaining boarding time in an aircraft. The result is an approach that allows the consideration of initial CPS functions and new aggregated system functions, that pays special attention to the interconnectivity of CPSs and the required interfaces, and enables the systematic analysis of functions for the identification of redundancies.
Female black bear home range and resource selection in relation to West Virginia mine lands
Authors: Price Lucas E. , Skelly Brett P. , Morrison Erin E. , Carpenter Colin P. , Ryan Christopher W. , Rota Christopher T. 
Published: May 2024

AbstractWildlife space use is a key component to consider when determining effective conservation and management practices. Home range size and resource selection can vary temporally and spatially depending on mortality risks in the area and access to food resources. Lands used for coal mining can contain unique mortality risks and food resources for American black bears (Ursus americanus) relative to surrounding landscapes due to hunting restrictions, vegetation planted as part of the reclamation process, and other anthropogenic food resources. We examined the influence of mining sites on resource selection of female black bears in southern West Virginia, USA, during 2007 and 2008. We estimated home range size with Brownian Bridge movement models and evaluated variation in home range size with mixed‐effects linear regression. We evaluated resource selection with mixed‐effects Poisson point process models. On mine sites, the mean 95% home range for female black bears was 1,996 ha (SD = 2,633) in the autumn and 544 ha (SD = 238) in the spring, and on non‐mine sites the mean 95% home range was 1,926 ha (SD = 1,292) in the autumn and 771 ha (SD = 480) in the spring. Our resource selection model indicated black bears used nonhunting zones associated with mine lands much greater than their availability, and that black bears in mine areas disproportionately used areas in close proximity to anthropogenic structures. Interannual variation in home range size was likely associated with mast conditions, because smaller home ranges were associated with high mast production. Our data suggest black bears may be using non‐hunting zones within mine lands as refugia from hunting and are using anthropogenic food sources available at refuse sites on mine lands, which may increase regional black bear populations in areas with high mining activity.
Transboundary water resources management and food security: An Indonesian perspective
Authors: Asdak Chay , Yulizar Yulizar 
Published: May 2024

AbstractTransboundary water resource management is one of the key components of ensuring that water is managed appropriately for a number of objectives, including assisting in food production. Inadequate water management may aggravate social conflict in the near future as precipitation patterns change. This study evaluates long‐term government policies, plans, and initiatives based on their responsibility. Strategic environmental assessment is used as an approach to address problems relating to the transboundary flow of water resources. It takes into account the requirements for integrating environmental constraints into government planning and development programs. To make sure that water resources are functioning correctly from upstream to downstream locations, various levels of government are urged to employ spatial planning based on water resource information. This study uses the Cimanuk watershed area in Indonesia to demonstrate this perspective.
Integration of Remote and Social Sensing Data Reveals Uneven Quality of Broadband Connectivity Across World Cities
Authors: Melchiorri Michele , Sulis Patrizia , Proietti Paola , Schiavina Marcello , Siragusa Alice 
Published: May 2024

AbstractUrbanisation and digitalisation are two of the megatrends characterising contemporary human society. Digital broadband access is an essential enabler, and despite its large growth potential, it can differ across territories. Taking a comparative approach from a global perspective, this chapter studies the relationship between urbanisation and digitalisation by looking at the quality of broadband access in urban centres using geospatial data processing. It is based on a combination of open and free data sourced from earth observation (Copernicus and Landsat programmes) to map and classify human settlements, with social sensing data to assess broadband quality with open data released by Ookla® at the grid level. We analyse the database in a stratified way to identify whether urban centres in high-income countries are better in terms of broadband connectivity compared to those in developing economies; whether urban centre population size is an advantage in the regions of the world where connectivity is low; and whether urban centres that have experienced stronger population growth in recent years display an advantage in terms of digitalisation. This work sheds light on the nature and type of deprivation related to uneven access to infrastructure, especially digital ones. The results indicate significant geographical and income disparities in terms of internet download speeds across the world. The performance of mobile and fixed broadband connectivity is different, and mobile connectivity offers a higher performance alternative to fixed networks in less affluent countries.
Wigner 6j symbols with gluon lines: completing the set of 6j symbols required for color decomposition
Authors: Keppeler Stefan , Plätzer Simon , Sjodahl Malin 
Published: May 2024

Abstract
We construct a set of Wigner 6𝑗 symbols with gluon lines (adjoint representations) in closed form, expressed in terms of similar 6𝑗 symbols with quark lines (fundamental representations). Together with these Wigner 6𝑗 symbols with quark lines, this gives a set of 6𝑗 symbols sufficient for treating QCD color structure for any number of external particles, in or beyond perturbation theory. This facilitates a complete treatment of QCD color structure in terms of orthogonal multiplet bases, without the need of ever explicitly constructing the corresponding bases. We thereby open up for a completely representation theory based treatment of SU(N) color structure, with the potential of significantly speeding up the color structure treatment.
Dually Weighted Multi-matrix Models as a Path to Causal Gravity-Matter Systems
Authors: Abranches Juan L. A. , Pereira Antonio D. , Toriumi Reiko 
Published: May 2024

AbstractWe introduce a dually-weighted multi-matrix model that for a suitable choice of weights reproduce two-dimensional Causal Dynamical Triangulations (CDT) coupled to the Ising model. When Ising degrees of freedom are removed, this model corresponds to the CDT-matrix model introduced by Benedetti and Henson (Phys Lett B 678:222, 2009). We present exact as well as approximate results for the Gaussian averages of characters of a Hermitian matrixAand$$A^2$$A2for a given representation and establish the present limitations that prevent us to solve the model analytically. This sets the stage for the formulation of more sophisticated matter models coupled to two-dimensional CDT as dually weighted multi-matrix models providing a complementary view to the standard simplicial formulation of CDT-matter models.
The Power Word Problem in Graph Products
Authors: Lohrey Markus , Stober Florian , Weiß Armin 
Published: May 2024

AbstractThe power word problem for a group $$\varvec{G}$$

G

asks whether an expression $$\varvec{u_1^{x_1} \cdots u_n^{x_n}}$$

u
1

x
1

⋯

u
n

x
n

, where the $$\varvec{u_i}$$

u
i

are words over a finite set of generators of $$\varvec{G}$$

G

and the $$\varvec{x_i}$$

x
i

binary encoded integers, is equal to the identity of $$\varvec{G}$$

G

. It is a restriction of the compressed word problem, where the input word is represented by a straight-line program (i.e., an algebraic circuit over $$\varvec{G}$$

G

). We start by showing some easy results concerning the power word problem. In particular, the power word problem for a group $$\varvec{G}$$

G

is $$\varvec{\textsf{uNC}^{1}}$$

uNC
1

-many-one reducible to the power word problem for a finite-index subgroup of $$\varvec{G}$$

G

. For our main result, we consider graph products of groups that do not have elements of order two. We show that the power word problem in a fixed such graph product is $$\varvec{\textsf{AC} ^0}$$

AC
0

-Turing-reducible to the word problem for the free group $$\varvec{F_2}$$

F
2

and the power word problems of the base groups. Furthermore, we look into the uniform power word problem in a graph product, where the dependence graph and the base groups are part of the input. Given a class of finitely generated groups $$\varvec{\mathcal {C}}$$

C

without order two elements, the uniform power word problem in a graph product can be solved in $$\varvec{\textsf{AC} ^0[\textsf{C}_=\textsf{L} ^{{{\,\textrm{UPowWP}\,}}(\mathcal {C})}]}$$

AC
0

[

C
=

L

UPowWP

(
C
)

]

, where $$\varvec{{{\,\textrm{UPowWP}\,}}(\mathcal {C})}$$

UPowWP

(
C
)

denotes the uniform power word problem for groups from the class $$\varvec{\mathcal {C}}$$

C

. As a consequence of our results, the uniform knapsack problem in right-angled Artin groups is $$\varvec{\textsf{NP}}$$

NP

-complete. The present paper is a combination of the two conference papers (Lohrey and Weiß 2019b, Stober and Weiß 2022a). In Stober and Weiß (2022a) our results on graph products were wrongly stated without the additional assumption that the base groups do not have elements of order two. In the present work we correct this mistake. While we strongly conjecture that the result as stated in Stober and Weiß (2022a) is true, our proof relies on this additional assumption.
An unexpected role of EasDaf: catalyzing the conversion of chanoclavine aldehyde to chanoclavine acid
Authors: Yu Zhi-Pu , An Chunyan , Yao Yongpeng , Yan Ju-Zhang , Gao Shu-Shan , Gu Yu-Cheng , Wang Chang-Yun , Cui Chengsen 
Published: May 2024

Abstract
Ergot alkaloids (EAs) are a diverse group of indole alkaloids known for their complex structures, significant pharmacological effects, and toxicity to plants. The biosynthesis of these compounds begins with chanoclavine-I aldehyde (CC aldehyde, 2), an important intermediate produced by the enzyme EasDaf or its counterpart FgaDH from chanoclavine-I (CC, 1). However, how CC aldehyde 2 is converted to chanoclavine-I acid (CC acid, 3), first isolated from Ipomoea violacea several decades ago, is still unclear. In this study, we provide in vitro biochemical evidence showing that EasDaf not only converts CC 1 to CC aldehyde 2 but also directly transforms CC 1 into CC acid 3 through two sequential oxidations. Molecular docking and site-directed mutagenesis experiments confirmed the crucial role of two amino acids, Y166 and S153, within the active site, which suggests that Y166 acts as a general base for hydride transfer, while S153 facilitates proton transfer, thereby increasing the acidity of the reaction.

Key points
•EAs possess complicated skeletons and are widely used in several clinical diseases
•EasDafbelongs to the short-chain dehydrogenases/reductases (SDRs) and converted CC or CC aldehyde to CC acid
•The catalytic mechanism of EasDaffor dehydrogenation was analyzed by molecular docking and site mutations