bluuebunny/crossref_metadata_2025 huggingface dataset:
Price jumping mechanism and parameter estimation based on filtered poisson process
Authors: Song Shijia , Li Handong
Published: June 2022

By observing the actual movement of asset prices, we find that there is a persistent shock impact of jumps on prices rather than a transient effect. To address this phenomenon, we propose a new jump-diffusion model that restores the process of price by assuming that its continuous changes are determined by the diffusion process, while individual jumps are inscribed by a filtered Poisson process. We also come up with estimation methods for the parameters involved in the jump process, as well as methods for identifying jumps and determining the duration of the transit impact of jumps based on the actual price series. In terms of simulations, the consistency of the estimation results is verified in detail. Finally, we select two representative indexes in the China’s stock market as empirical objects. We build the price models, perform jump tests and parameter estimation for them, and compare the results with that of the traditional multi-sample BN-s to demonstrate the validity and robustness of the proposed models and estimation methods.
The evolution of international grain trade pattern based on complex network and entropy
Authors: Ma Jinlong , Li Meng , Li Xiaotian
Published: June 2022

Grain is the most basic material condition for human survival and development, and the structure of grain import and export trade has seriously affected national grain security. In this paper, we quantitatively analyze the evolution of international grain (maize, wheat, rice) trade patterns from 1987 to 2019 based on a complex network and entropy methods, and provide some suggestions and references for relevant countries. We measure the ranking of countries by applying various indicators from complex networks to quantify the importance of nodes in international trade networks. Then, we analyze the evolution of trade scale and community structure in different regions. Finally, we analyze the weight structure of the whole network through entropy, revealing the evolution characteristics and mechanism of the system more comprehensively. The results first show that the international grains trade network (IGTN) satisfies the scale-free properties and that global trade volumes are increasing year by year. The distribution of trade volumes in the IGTN follows the 80/20 rule, with less than 20[Formula: see text] of countries accounting for more than 80[Formula: see text] of global trade volumes. Second, countries in the Asian region have gradually increased their position in the grain trade network, while the position of countries in North and South America has declined. Third, the heterogeneity of the topology and weight structure of the international grain trade network is weakened, and the status of hub countries in the IGTN is reduced. The importance gap of nodal connections is narrowing, showing the trend of multilateralization of global trade. Fourth, the world grain export market is highly concentrated. The USA, Canada, Brazil, Argentina and Russia are the major exporters of grain.
Electromagnetic wave propagation in general Kasner-like metrics
Authors: Bochner Brett
Published: June 2022

The curved spacetime Maxwell equations are applied to the anisotropically expanding Kasner metrics. Using the application of vector identities we derive second-order differential wave equations for the electromagnetic field components; through this explicit derivation, we find that the second-order wave equations are not uncoupled for the various components (as previously assumed), but that gravitationally induced coupling between the electric and magnetic field components is generated directly by the anisotropy of the expansion. The lack of such coupling terms in the wave equations from several prior studies may indicate a generally incomplete understanding of the evolution of electromagnetic energy in anisotropic cosmologies. Uncoupling the field components requires the derivation of a fourth-order wave equation, which we obtain for Kasner-like metrics with generalized expansion/contraction rate indices. For the axisymmetric Kasner case, [Formula: see text], we obtain exact field solutions (for general propagation wave vectors), half of which appear not to have been found before in previous studies. For the other axisymmetric Kasner case, [Formula: see text], we use numerical methods to demonstrate the explicit violation of the geometric optics approximation at early times, showing the physical phase velocity of the wave to be inhibited towards the initial singularity, with [Formula: see text] as [Formula: see text].
PORTFOLIO VOLATILITY SPILLOVER
Authors: KONSTANTINOV GUEORGUI S. , FABOZZI FRANK J.
Published: June 2022

In this paper, the authors estimate portfolio volatilities and use variance−decomposition techniques and Cholesky factorization to construct a portfolio volatility spillover index. Furthermore, the authors show that spillover risks are persistent and much more common than well-known indicators like the turbulence index and the CBOE VIX index might suggest. Moreover, portfolio volatilities show contributions to and from other portfolio volatilities, which indicate elevated financial market interconnectedness and heightened risk. Foreign exchange contributes strong volatility shocks to other portfolios. More importantly, its contribution has a different magnitude and direction after the Global Financial Crisis (GFC) than before depending on the base currency. To show the causality effects of portfolio volatility spillover the authors apply both econometric models and graph theory, demonstrating that the importance is time varying. This requires monitoring and analysis in decision making regarding portfolio management, portfolio construction, and risk management.
New jump operators on equivalence relations
Authors: Clemens John D. , Coskey Samuel
Published: June 2022

We introduce a new family of jump operators on Borel equivalence relations; specifically, for each countable group [Formula: see text] we introduce the [Formula: see text]-jump. We study the elementary properties of the [Formula: see text]-jumps and compare them with other previously studied jump operators. One of our main results is to establish that for many groups [Formula: see text], the [Formula: see text]-jump is proper in the sense that for any Borel equivalence relation [Formula: see text] the [Formula: see text]-jump of [Formula: see text] is strictly higher than [Formula: see text] in the Borel reducibility hierarchy. On the other hand, there are examples of groups [Formula: see text] for which the [Formula: see text]-jump is not proper. To establish properness, we produce an analysis of Borel equivalence relations induced by continuous actions of the automorphism group of what we denote the full [Formula: see text]-tree, and relate these to iterates of the [Formula: see text]-jump. We also produce several new examples of equivalence relations that arise from applying the [Formula: see text]-jump to classically studied equivalence relations and derive generic ergodicity results related to these. We apply our results to show that the complexity of the isomorphism problem for countable scattered linear orders properly increases with the rank.
Decomposing Aronszajn lines
Authors: Barbosa Keegan Dasilva
Published: June 2022

We show that under the proper forcing axiom the class of all Aronszajn lines behave like [Formula: see text]-scattered orders under the embeddability relation. In particular, we are able to show that the class of better-quasi-order labeled fragmented Aronszajn lines is itself a better-quasi-order. Moreover, we show that every better-quasi-order labeled Aronszajn line can be expressed as a finite sum of labeled types which are algebraically indecomposable. By encoding lines with finite labeled trees, we are also able to deduce a decomposition result, that for every Aronszajn line [Formula: see text] there is an integer [Formula: see text] such that for any finite coloring of [Formula: see text] there is subset [Formula: see text] of [Formula: see text] isomorphic to [Formula: see text] which uses no more than [Formula: see text] colors.
Compactness and guessing principles in the Radin extensions
Authors: Ben-Neria Omer , Zhang Jing
Published: June 2022

We investigate the interaction between compactness principles and guessing principles in the Radin forcing extensions. In particular, we show that in any Radin forcing extension with respect to a measure sequence on [Formula: see text], if [Formula: see text] is weakly compact, then [Formula: see text] holds. This provides contrast with a well-known theorem of Woodin, who showed that in a certain Radin extension over a suitably prepared ground model relative to the existence of large cardinals, the diamond principle fails at a strongly inaccessible Mahlo cardinal. Refining the analysis of the Radin extensions, we consistently demonstrate a scenario where a compactness principle, stronger than the diagonal stationary reflection principle, holds yet the diamond principle fails at a strongly inaccessible cardinal, improving a result from [O. B. -Neria, Diamonds, compactness, and measure sequences, J. Math. Log. 19(1) (2019) 1950002].
A Novel Microwave-Assisted Green Synthesis of Copper Nanoparticles Using Citrus limon and Its Application for Antibacterial and Antifungal Activity
Authors: Ansari Niha , Lodha Anand , Patel Tallika L.
Published: June 2022

Synthesis of metal nanoparticles using efficient, eco-friendly green chemistry methods is widely applied nowadays. Use of plant extract is one of the most considered methods as it is more stable and the rate of synthesis is faster. In this study, for the first time, we synthesized biocompatible, eco-friendly and cost-effective copper nanoparticles (CuNPs) using a well-characterized plant Citrus limon, a natural product, which acts as a reducing agent. The synthesized CuNPs were characterized by UV–Vis spectroscopy and dynamic light scattering and were applied to investigate the antibacterial and antifungal activities along with their fluorescent properties. The microwave-assisted green CuNPs-treated cotton fabric exhibited high efficiency against both Gram-positive and Gram-negative bacteria and fungi. The particles showed highest activity against Gram-negative bacteria Escherichia coli. In future, the in vivo toxicity studies of these nanomaterials will allow the formulation of new types of antimicrobial materials for pharmaceutical and biomedical applications, such as antimicrobial next-to-skin fabrics.
Exploring the Ranking, Classifications and Evolution Mechanisms of Research Fronts: A Method Based on Multiattribute Decision Making and Clustering
Authors: Xiong Kai , Dong Yucheng , Guo Zhaoxia , Chiclana Francisco , Herrera-Viedma Enrique
Published: June 2022

This study aims to present a multiattribute decision-making (MADM) and clustering method to explore the ranking, classifications and evolution mechanisms of the research fronts in the Web of Science Essential Science Indicators (ESI) database. First, bibliometrics are used to reveal the characteristics of the 57 ESI research fronts with more than 40 ESI highly cited papers (ESI-HCPs) for each research front. Second, the eight representative indicators are discovered to get answers to the following two questions: (i) Who publishes the ESI-HCPs that form a research front? and (ii) Where citations to these ESI-HCPs come from on a research front? Next, we investigate the ranking and clusters among the 57 ESI research fronts using the MADM and [Formula: see text]-means clustering method and uncover the evolution process of the research fronts in different clusters based on the representative indicators. We also compare the performances of different countries in these research fronts and find that the USA and China are the leading countries in most research fronts. However, the two countries behave differently with regard to the rankings, the classifications and the evolution.
A Group Decision-Making Approach for Global Consistency of Heterogeneous Models
Authors: Bennani Saloua , Ebersold Sophie , El Hamlaoui Mahmoud , Coulette Bernard , Nassar Mahmoud
Published: June 2022

The design of complex systems goes through a multi-view paradigm in which separate teams, from different viewpoints, build partial source models describing the system. These source models are called heterogeneous models since they are expressed in different languages. The main objective of this paper is to provide an approach — called CAHM for Collaborative Alignment of Heterogeneous Models — that leverages collaborative engineering and especially group decision-making principles to ensure the overall consistency of heterogeneous source models. This approach defines two sub-processes: a first one to collaboratively match heterogeneous models to develop the inter-model correspondences and a second one ensuring the consistency of the produced model of correspondences in case of model evolution. In this paper, we restate the basis of the CAHM approach, then, we detail the second sub-process that aims at maintaining the coherence of the overall system. This sub-process handles the evolution of source models by managing the impact of these evolutions on the established model of correspondences. It incorporates mechanisms to calculate the impact of changes, as well as mechanisms to formalize the group decision-making, while addressing the inconsistencies that may occur due to changes. CAHM is illustrated and validated on a real example of a hospital emergency department case study.
Sufficient dimension reduction via distance covariance for survival data
Authors: Cui Wenquan , He Xu , Cheng Haoyang , Xu Jianjun
Published: June 2022

Sufficient dimension reduction (SDR) plays an essential role in high-dimensional regression analysis, and most existing SDR methods suffer when data are subject to censoring. This paper tries to extend distance covariance (dCov) to SDR for survival data. Unlike most methods requiring strict constraints on predictors and survival time, the method based on dCov only relies on very mild conditions and works well when many predictors are categorical or discrete. The difficulty of SDR for survival data is that we cannot completely observe the real survival time, which may introduce a substantial bias. When the censoring time is independent of survival time, we show that the dCov-SDR method can estimate the SDR directions with a surrogate response. Furthermore, under other censoring assumptions, we extend the dCov-SDR method by proposing a new consistent empirical version of dCov for survival data. We discuss the inherent properties of our method, and under regularity conditions, statistical consistency is established for our estimators. Both simulations and real data analysis demonstrate the promising performance of the proposed method.
PROXIMITY DIMENSIONS AND DYNAMICS WITHIN AN ORGANISATION: EXPERIENCES FROM A CHANGE PROCESS
Authors: JØRGENSEN EVA JENNY B. , OLAFSEN ANJA HAGEN , NILSEN ETTY RAGNHILD
Published: June 2022

Proximity between actors within an organisation can be relevant for interactive learning and innovation because it promotes collaboration and knowledge exchange. However, proximity has mainly been studied as a characteristic of the relationships between actors belonging to different organisations. In this paper, a case study of a faculty at a university is used to investigate proximity within this organisation and related to a change process. Based on 23 interviews and a self-ethnographic approach, we offer a detailed micro-perspective on how the geographic, cognitive, and social dimensions of proximity influence interactive learning and innovation between employees within the organisation. We also identify two distinct proximity configurations that have emerged during the change process. Finally, we analyse how the proximity dimensions are balanced within these configurations and offer two propositions explaining their influence on interactive learning and innovation. We thereby contribute to the existing theory on proximity by extending the insight into proximity from an inter-organisational to an intra-organisational level and by adding new knowledge to the understanding of proximity dynamics.
Dynamic Crushing Behaviors of Second-Order Hexagonal Honeycombs
Authors: Wu Hexiang , Sun Fanyue , Sun Quansheng , Zhang Xinchun , Yang Shuai
Published: June 2022

Hexagonal honeycombs form the common core of composite sandwich structures. In this study, on the basis of the hexagonal honeycomb model, a second-order hexagonal honeycomb is established by cutting pores on the cell wall to realize secondary lightweight design. Furthermore, the in-plane and out-of-plane dynamic crushing behaviors of the second-order hexagonal honeycombs are investigated by combining theoretical analysis with numerical simulation. The effect of the variation in the pore sizes on the cell wall on the in-plane and out-of-plane deformation modes, the mechanical properties, and the energy absorption capacities of second-order hexagonal honeycombs under different impact velocities is discussed. Semi-empirical theoretical formulas for the in-plane and out-of-plane bearing strength of second-order hexagonal honeycombs are proposed. The results show that cutting pores on the cell wall reduces the weights of hexagonal honeycombs and improves their energy absorption capacities. This also provides a new method to realize hexagonal honeycombs that display pore characteristics along both in-plane and out-of-plane directions.
Ductile Failure Under Combined Tension and Shear: Simulation Using A Gurson-Type Porous Plasticity Model
Authors: Siad Larbi , Fekih Ahmed Walid
Published: June 2022

A modification of the Gurson–Tvergaard’s yield function based on the micromechanics analysis of the plastic deformation of the porous materials containing spherical empty voids arranged in cubic arrays was proposed by Sean McElwain et al. [2006a, Yield criterion for porous materials subjected to complex stress states, Acta Materialia, 54, 1995–2002; 2006b, Yield functions for porous materials with cubic symmetry using different definitions of yield, Advanced Engineering Materials, 8, 870–876]. The derived yield function possesses in particular the distinctiveness to explicitly depend upon the third stress invariant. On another note, a phenomenological modification of the well-known Gurson–Tvergaard–Needleman (GTN) isotropic hardening model that incorporates damage accumulation under shearing was proposed by Nahshon and Hutchinson, [2008, Modification of the Gurson model for shear failure, European Journal of Mechanics A/Solids, 27, 1–17]. This model incorporates only one extra parameter to account for damage under shear-dominated loadings. In this work, the quasi-static ductile damage and failure behavior of a butterfly specimen is numerically studied using a further extension of this model based on both of the above modifications. To this end, a stress integration algorithm based on the general backwards-Euler return algorithm has been implemented into a finite element code. The simulations show that the proposed extended damage evolution model can capture both the tension and shear failure mechanisms. As long as the softening initiation of the considered specimen is not reached, the computational fracture results highlight the similarities and almost have perfect agreement with those provided by the use of the GTN model. This observation holds for tension-dominated deformation and shear-dominated deformation as well. However, for the later loading, discrepancy shows up at the onset of softening and especially as soon as the failure of material is triggered.
A Hybrid Method for Predicting Fatigue Life of Lead-Free Solder Joints Under Coupled Electrical–Thermal–Mechanical Fields
Authors: Yi J. L. , Chen J. H. , Qu C. , Zhang Y. X. , Cui Y. H.
Published: June 2022

A hybrid method was developed in this study for fatigue life prediction (FLP) of lead-free solder (LFS) joints in ball grid array package under the coupled electrical–thermal–mechanical (ETM) fields. A modified constitutive model for lead-free solder joints under coupled ETM fields was proposed to describe the mechanical and fatigue behavior of solder joints under coupled ETM fields. A modified damage model under coupled ETM fields was then developed to obtain the fatigue life of LFS joints under coupled ETM fields. Uniaxial tension tests of an Sn–3.0Ag–0.5Cu (SAC305) solders and coupled multifields fatigue experiments were performed to verify the accuracy, applicability and validity by the modified constitutive model and fatigue damage model under coupled ETM fields. Based on the modified constitutive model and fatigue damage model, a hybrid method, including current, temperature and mechanics parameters, was proposed for the FLP of the LFS joints, which was demonstrated to be able to predict the results well. A hybrid method provides an idea for investigating the fatigue life of lead-free solder joints in coupled fields.
Research on the effect of thickness difference of weld seam on strip breaking during rolling in PL-TCM
Authors: Wu Zedong , Wang Xiaochen , Yang Quan , Xu Dong , Zhou Yun , Zhao Jianwei , Chen Dan , Li Jingdong
Published: June 2022

At the entry of the pickling and tandem cold strip mill (PL-TCM), the unreasonable cut length of the head and tail of the strip often causes a thickness difference between the weld surfaces of the front and back strip, resulting in a weld seam with thickness difference after welding. This can easily lead to strip breaking at the weld seam in the cold rolling process. In this paper, a finite element model of roll and strip with weld seam is established to investigate the mechanism of strip breaking at weld seam due to thickness difference. By simulating the working conditions in the rolling process for weld seam with different thickness differences, the evolution of the stress state of the weld seam in the rolling process under each working condition is analyzed. The influence of thickness difference in the rolling process of the weld seam is revealed, and the effect of thickness difference on the risk of strip breaking at weld seam during the rolling process is further discussed. According to the research results, the optimization method of strip head and tail shear length was designed and applied to the industrial site. After application, the accident rate of strip breaking is reduced and the effect is as expected.
Viscoelastic behavior in discrete element method realized by interparticle Maxwell–Zener model
Authors: Wahn A. , Gan Y. , Kamlah M.
Published: June 2022

The discrete element method describes the motion of granular structures numerically. Each particle is considered as a discrete element. Combining springs and dashpot for the normal contact forces, viscoelastic behavior represented by rheological models is realized via a nonlinear Maxwell–Zener model in a dynamic routine. For individual contacts and large particle structures, this model is compared to the Hertzian contact model for elastic behavior and studied with respect to rate dependence and the effect of model parameters.
The Candidate Molecules, RBD-ACE2 Binding Inhibitors to Prevent Sars-CoV-2 Infection
Authors: Güven M. Haluk , Garip Ali Kemal
Published: June 2022

Angiotension-converting enzyme 2 (ACE2) is the host receptor of the serious-acute respiratory syndrome coronavirus 2 (Sars-CoV-2) spike protein. In this article, the interaction of ACE2 with the receptor binding domains (RBD) of Wuhan-Hu-1 and United Kingdom (UK) and South African (SA) variants is examined in silico. Their Gibbs free energies were computed using a protein binding energies prediction model. The interaction characteristics of RBDs with possible inhibitory compounds as well as a standard drug, Paxlovid, were also investigated, and Gibbs free energies were computed. Molecular modeling, molecular dynamics and molecular docking methods were employed and the results are compared and discussed.
Multi-UAV Synchronous Approaching Using Homotopy-Based Trajectory Planning
Authors: Yao Weiran , Chen Yang , Tian Haoyu , Wu Chengwei , Wu Ligang
Published: June 2022

Synchronous approaching is an important capability for autonomous cooperation of multiple unmanned aerial vehicles (UAVs). In this paper, a homotopy-based trajectory planning method is presented for the multi-UAV synchronous approaching problem. A homotopic trajectory description is employed to construct the trajectory solution space of the UAVs. A novel onion-like homotopy structure is proposed to decouple the performance indexes of the trajectory planning problem. Local trajectory homotopy structures are designed based on the detouring model and the hovering model of UAV. The optimal trajectories for synchronous approaching are searched within the homotopy structures. Simulation results show how synchronous the UAVs are, by using the proposed homotopy-based trajectory planning method.
A Parallel Mapping and Planning Strategy for Micro Aerial Vehicle
Authors: Wang Zhuo , Zong Qun , Shen Hongming , Tian Bailing , Lu Hanchen
Published: June 2022

Autonomous flight is a fundamental problem for various applications of micro aerial vehicles (MAVs). Thanks to the development of Guidance, Navigation and Control (GNC) technologies, the research on this problem is also becoming mature. However, safe flight in unknown, cluttered environments remains an open question, especially with real-time requirement on onboard computer. This paper proposes a framework including parallelly mapping and planning and implements it on Graphics Processing Unit (GPU). First, a spherical coordinate projection is used in the occupancy grid map to avoid memory conflicts. After that, in the planning phase, a method based on lattice state space sampling is applied to obtain multiple trajectories parallelly. Then, we design a series of soft constraints to ensure that the MAV is in a safe known space with optimal dynamics. By solving the cost for each trajectory and comparison, the optimal trajectory can be generated. The effectiveness of the proposed strategy is demonstrated through simulation tests.
Recent Advances in Ocular Therapy by Hydrogel Biomaterials
Authors: Zheng Lan , Han Yi , Ye Enyi , Zhu Qiang , Loh Xian Jun , Li Zibiao , Li Cheng
Published: June 2022

Current clinical practice in ocular disease treatment dosage forms primarily relies on eye drops or eye ointments, which face significant challenges in terms of low bioavailability profiles, rapid removal from the administration site, and thus ineffective therapeutic efficiency. Hydrogel has several distinct properties in semi-solid thermodynamics and viscoelasticity, as well as diverse functions and performance in biocompatibility and degradation, making it extremely promising for overcoming the challenges in current ocular treatment. In this review, the most recent developments in the use of hydrogel biomaterials in ocular therapy are presented. These sophisticated hydrogel biomaterials with diverse functions, aimed at therapeutic administration for ocular treatment, are further classified into several active domains, including drug delivery system, surface repair patch, tissue-engineered cornea, intraocular lens, and vitreous substitute. Finally, the possible strategies for future design of multifunctional hydrogels by combining materials science with biological interface are proposed.
EdgeXAR: A 6-DoF Camera Multi-target Interaction Framework for MAR with User-friendly Latency Compensation
Authors: Zhang Wenxiao , Lin Sikun , Bijarbooneh Farshid Hassani , Cheng Hao-Fei , Braud Tristan , Zhou Pengyuan , Lee Lik-Hang , Hui Pan
Published: June 2022

The computational capabilities of recent mobile devices enable the processing of natural features for Augmented Reality (AR), but the scalability is still limited by the devices' computation power and available resources. In this paper, we propose EdgeXAR, a mobile AR framework that utilizes the advantages of edge computing through task offloading to support flexible camera-based AR interaction. We propose a hybrid tracking system for mobile devices that provides lightweight tracking with 6 Degrees of Freedom and hides the offloading latency from users' perception. A practical, reliable and unreliable communication mechanism is used to achieve fast response and consistency of crucial information. We also propose a multi-object image retrieval pipeline that executes fast and accurate image recognition tasks on the cloud and edge servers. Extensive experiments are carried out to evaluate the performance of EdgeXAR by building mobile AR apps upon it. Regarding the Quality of Experience (QoE), the mobile AR apps powered by EdgeXAR framework run on average at the speed of 30 frames per second with precise tracking of only 1-2 pixel errors and accurate image recognition of at least 97% accuracy. As compared to Vuforia, one of the leading commercial AR frameworks, EdgeXAR transmits 87% less data while providing a stable 30FPS performance and reducing the offloading latency by 50 to 70% depending on the transmission medium. Our work facilitates the large-scale deployment of AR as the next generation of ubiquitous interfaces.
Software Engineering for Augmented Reality - A Research Agenda
Authors: Börsting Ingo , Heikamp Markus , Hesenius Marc , Koop Wilhelm , Gruhn Volker
Published: June 2022

Augmented reality changes the way we perceive reality and how we interact with computers. However, we argue that to create augmented reality solutions, we need to rethink the way we develop software. In this paper, we review the state of the art in software engineering for augmented reality applications, derive open questions, and define a research agenda. For this purpose, we consider different engineering phases and evaluate conventional techniques regarding their applicability for AR development. In requirements engineering, we found the integration of AR experts and the associated collaboration between actors to be of key aspect in the development process. Additionally, requirements about the physical world must be considered, which in turn has a huge impact on UI design. The relevance of the physical environment is not yet sufficiently addressed in applicable techniques, which also applies to current implementation frameworks and tools, complicating the AR development process. When evaluating AR software iterations, we found interaction testing and test automation to have great potential, although they have not yet been sufficiently researched. Our paper contributes to AR research by revealing current core challenges within the AR development process and formulating explicit research questions that should be considered by future research.
QuantumLeap, a Framework for Engineering Gestural User Interfaces based on the Leap Motion Controller
Authors: Sluÿters Arthur , Ousmer Mehdi , Roselli Paolo , Vanderdonckt Jean
Published: June 2022

Despite the tremendous progress made for recognizing gestures acquired by various devices, such as the Leap Motion Controller, developing a gestural user interface based on such devices still induces a significant programming and software engineering effort before obtaining a running interactive application. To facilitate this development, we present QuantumLeap, a framework for engineering gestural user interfaces based on the Leap Motion Controller. Its pipeline software architecture can be parameterized to define a workflow among modules for acquiring gestures from the Leap Motion Controller, for segmenting them, recognizing them, and managing their mapping to functions of the application. To demonstrate its practical usage, we implement two gesture-based applications: an image viewer that allows healthcare workers to browse DICOM medical images of their patients without any hygiene issues commonly associated with touch user interfaces and a large-scale application for managing multimedia contents on wall screens. To evaluate the usability of QuantumLeap, seven participants took part in an experiment in which they used QuantumLeap to add a gestural interface to an existing application.
Kart-ON: An Extensible Paper Programming Strategy for Affordable Early Programming Education
Authors: Sabuncuoglu Alpay , Sezgin T. Metin
Published: June 2022

Programming has become a core subject in primary and middle school curricula. Yet, conventional solutions for in-class programming activities require each student to have expensive equipment, which creates an opportunity gap for low-income students. Paper programming can provide an affordable, engaging, and collaborative in-class programming experience by allowing groups of students to use inexpensive materials and share smartphones. However, current paper-programming examples are limited in terms of language expressivity and generalizability. Addressing these limitations, we developed a paper-programming flow and its variants in different abstraction levels and input/output styles. The programming environments consist of pre-defined tangible programming cards and a mobile application that runs computer vision models to recognize them. This paper describes our educational and technical development process, presents a qualitative analysis of the early user study results and shares our design considerations to help develop wide-reaching paper programming environments.
Mod2Dash: A Framework for Model-Driven Dashboards Generation
Authors: Jiang Liuyue , Tran Nguyen Khoi , Ali Babar Muhammad
Published: June 2022

The construction of an interactive dashboard involves deciding on what information to present and how to display it and implementing those design decisions to create an operational dashboard. Traditionally, a dashboard's design is implied in the deployed dashboard rather captured explicitly as a digital artifact, preventing it from being backed up, version-controlled, and shared. Moreover, practitioners have to implement this implicit design manually by coding or configuring it on a dashboard platform. This paper proposes Mod2Dash, a software framework that enables practitioners to capture their dashboard designs as models and generate operational dashboards automatically from these models. The framework also provides a GUI-driven customization approach for practitioners to fine-tune the auto-generated dashboards and update their models. With these abilities, Mod2Dash enables practitioners to rapidly prototype and deploy dashboards for both operational and research purposes. We evaluated the framework's effectiveness in a case study on cyber security visualization for decision support. A proof-of-concept of Mod2Dash was employed to model and reconstruct 31 diverse real-world cyber security dashboards. A human-assisted comparison between the Mod2Dash-generated dashboards and the baseline dashboards shows a close matching, indicating the framework's effectiveness for real-world scenarios.
A Survey on Data Augmentation for Text Classification
Authors: Bayer Markus , Kaufhold Marc-André , Reuter Christian
Published: June 2022

Data augmentation, the artificial creation of training data for machine learning by transformations, is a widely studied research field across machine learning disciplines. While it is useful for increasing a model's generalization capabilities, it can also address many other challenges and problems, from overcoming a limited amount of training data to regularizing the objective, to limiting the amount of data used to protect privacy. Based on a precise description of the goals and applications of data augmentation and a taxonomy for existing works, this survey is concerned with data augmentation methods for textual classification and aims at providing a concise and comprehensive overview for researchers and practitioners. Derived from the taxonomy, we divide more than 100 methods into 12 different groupings and give state-of-the-art references expounding which methods are highly promising by relating them to each other. Finally, research perspectives that may constitute a building block for future work are provided.
Improved Cycling Performance and Safety Characteristics of NMC811/G-Si Battery Cells with an Optimised Electrolyte Formulation
Authors: Barghamadi Marzi , Rüther Thomas , Lechtenfeld Christian , Best Adam S.
Published: June 2022

An increase in the practical energy density of anodes can be achieved when using 10%–25% silicon in graphite composite anodes. This is sufficient as the practical capacity of lithium-ion batteries (LIBs) is limited by the cathode capacity and applicable current densities (<4 mA cm−2). Using an NMC811 cathode and a graphite–15% silicon (G-Si15%) composite anode, the performance of more than 20 electrolyte formulations have been evaluated. Of these formulations, EC/EMC+1.2 M LiPF6 containing FEC/VC or LiFSI/VC combinations were shown to have superior performance over the parent electrolyte. Safer to operate ionic liquid-based electrolytes (ILELs) were found to be compatible with these electrodes at moderate cycling rates, with discharge capacities 15% lower compared to the conventional electrolytes. DSC data for both electrodes, cycled and uncycled, in contact with three different electrolytes were recorded. For the cathode in contact with the ILEL, temperatures of exothermic events were higher compared to those of carbonate-based electrolyte counterparts, whereas they were significantly lower for the G-Si15% anodes. In both cases when in contact with ILEL, the heat generated is considerably higher not only compared to samples containing carbonate-based electrolytes but also with respect to data reported for common graphite electrodes with the same ILEL.
Effect of Carbon Nanotube Content in ZnO/Carbon Nanotube Based Photoanode for Dye Sensitized Solar Cells
Authors: S. Aseena , Abraham Nelsa , Babu V. Suresh , S. Beena
Published: June 2022

ZnO/Carbon Nanotube (CNT) nanocomposite is explored as a ZnO based photoanode which helps in the performance enhancement of DSSC. The ultra-sonication followed by magnetic stirring of ZnO nanopowders with 0.01, 0.05, 0.1, 0.2, to 0.3 wt% of microwave irradiated functionalized CNTs are experimentally done to obtain ZnO/CNT nanocomposite. The effect of CNT loading on ZnO are analysed by the morphological and optical characterization studies. DSSCs are fabricated with ZnO/CNT nanocomposite with different weight ratios of CNT as photoanode material. It has been observed that the performance of DSSC is greatly influenced by the varying amount of CNTs in ZnO/CNT. An optimum content of 0.1 wt% of CNT exhibits maximum power conversion efficiency of 2.9%. The improvement in efficiency is mainly due to the increased dye adsorption and enhanced visible light absorption provided by the ZnO/CNT nanocomposite. The optimization studies on photoanode thickness are also conducted to analyse its effect on output performance. An optimum two layer coating of 0.1 wt% ZnO/CNT could improve the efficiency to about 3%. The increased number of layer coatings of ZnO/CNT hinders the light absorption due to the blocking effect of thicker CNT layers.
Enhanced Ga2O3-Based RRAM via Stacked Bilayer ZnO/Ga2O3
Authors: Wang Chih-Yung , Chang Sheng-Po , Huang Wei-Lun
Published: June 2022

The stability and endurance of resistive random-access memory (RRAM) devices over long-term use has been widely acknowledged as a concern. Therefore, different top electrodes and oxygen concentration flows were used with stacked ZnO/Ga2O3 as the switching layer to enhance the performance of Ga2O3-based RRAM. All switching layers were deposited by radio frequency sputtering in this study, and the oxygen vacancies were well controlled by controlling the oxygen concentration flow. When a stacked structure was formed, the gradients in the concentration of oxygen vacancies and mobility influenced the set and reset processes. With the stacked structure, the average set voltage was 1.5 V, and the average reset voltage was −0.7 V. In addition, under DC sweeps, the stacked RRAM demonstrated a high operating life of more than 300 cycles. In conclusion, the performance and stability of RRAM can be enhanced by adjusting the concentration of oxygen vacancies using different compositions of elements.
Sex-specific phenotypes in the aging mouse heart and consequences for chronic fibrosis
Authors: Angelini Aude , Ortiz-Urbina Jesus , Trial JoAnn , Reddy Anilkumar K. , Malovannaya Anna , Jain Antrix , Entman Mark L. , Taffet George E. , Cieslik Katarzyna A.
Published: June 2022

The aging heart develops diastolic dysfunction because of increased collagen deposition. We attempted to reduce collagen expression in the old heart by activating AMPK using AICAR. An improvement of diastolic function and reduction of cardiac fibrosis was found only in the female heart and correlated with decreased procollagen expression and increased degradation of the transcription factor Gli1. Male hearts display blunted AICAR-dependent AMPK activation and therefore this treatment had no benefits for the male mice.
Low-dose morphine reduces pain perception and blood pressure, but not muscle sympathetic outflow, responses during the cold pressor test
Authors: Watso Joseph C. , Belval Luke N. , Cimino Frank A. , Orth Bonnie D. , Hendrix Joseph M. , Huang Mu , Johnson Elias , Foster Josh , Hinojosa-Laborde Carmen , Crandall Craig G.
Published: June 2022

In this randomized, crossover, placebo-controlled trial, we found that low-dose morphine administration reduced pain perception and blood pressure responses during the cold pressor test via attenuated increases in heart rate and cardiac output. We also determined that muscle sympathetic outflow responses during the cold pressor test seem to be unaffected by low-dose morphine administration. Finally, our exploratory analysis suggests that biological sex does not influence morphine-induced antinociception in healthy adults.
Th17 cell-linked mechanisms mediate vascular dysfunction induced by testosterone in a mouse model of gender-affirming hormone therapy
Authors: Santos Jeimison D. , Oliveira-Neto José T. , Barros Paula R. , Damasceno Luis E. A. , Lautherbach Natalia , Assis Ana P. , Silva Carlos A. A. , Sorgi Carlos A. , Faccioli Lucia H. , Kettelhut Isis C. , Salgado Hélio C. , Carneiro Fernando S. , Alves-Filho José C. , Tostes Rita C.
Published: June 2022

Sex hormone-induced cardiovascular events are important undesirable effects in transgender people under GAHT. Studies addressing the cardiovascular impact of GAHT will certainly contribute to improve healthcare services offered to this population. Our study showing that vascular dysfunction, via Th17 cell-related mechanisms, precedes increased blood pressure induced by testosterone in a GAHT mouse model, reveals potential mechanisms involved in GAHT-related cardiovascular events and may provide new markers/targets for clinical practices in transmasculine people.
Application of Low-Intensity Laser in the Treatment of Skeletal Muscle Injury in Runners
Authors: Chen Youdong , Li Qiang
Published: June 2022

With the continuous improvement of people’s economic level, running, as the most common sports, is not limited by sports venues and sports levels and deeply loved by people. However, during running, soft tissue resonates with the impact force, increasing the load on joints and tendons and potentially leading to sports injuries. The purpose of this article is to study the application of low-intensity laser in the treatment of muscle strain. This article analyzes running, muscle adjustment, and lower limb stiffness. On the basis of theory, 20 healthy male college students were selected as research objects in the experimental part. The subjects were allowed to run at three speeds: slow, medium, and fast. The kinematics, dynamics, and surface EMG signals of the subjects during running were collected to analyze the effect of low-intensity laser therapy on exercise muscle strain. The experimental results showed that a low-intensity laser can effectively alleviate muscle inflammation, reduce the number of cell damage, bring the mean and integral optical density of protein to the normal level significantly, and reduce the strain degree of exercise muscle. In this article, a statistical method was used to obtain the gait cycle time (P & LT; 0.01) and support cycle time (slow

P
<
0.01

).
Neural Peptide α‐CGRP Coregulated Angiogenesis and Osteogenesis via Promoting the Cross‐Talk between Mesenchymal Stem Cells and Endothelial Cells
Authors: Shi Zongxin , Wang Shikun , Deng Jiechao , Gong Zishun
Published: June 2022

Background. The coupled vascularization and bone remodeling are key steps during bone healing, during which the cross‐talk between mesenchymal stem cells (MSCs) and endothelial cells plays vital roles. Evidence indicates the well‐characterized neuropeptide Calcitonin Gene‐Related Peptide‐α (CGRP) is proven to play an important role during bone regeneration. However, the regulatory effects of αCGRP on angiogenesis and osteogenesis, as well as underlying cellular and molecular mechanisms, remain unclear. Aim. The present study was performed to verify the availability of the CGRP for osteogenic capacity in MSCs and explore its potential underlying molecular mechanism. After that, the promoted angiogenic effect of CGRP as well as its underlying mechanisms was studied. Methods and Results. The results showed that CGRP could significantly increase the cyclic adenosine monophosphate (cAMP) level and promote the osteogenesis ability of MSCs via cAMP/PKA signaling pathway. Direct exposure to CGRP increased nitric oxide synthase expression, the release of NO, tube formation, and wound healing of human umbilical vein endothelial cells (HUVEC). The CGRP‐treated MSCs were observed with high expression levels of angiogenic factors, such as bFGF and VEGF‐α; the conditioned medium derived from CGRP‐treated MSCs was also able to promote tube formation and transmembrane migration of HUVECs. Conclusion. These findings demonstrate the coregulated angiogenesis and osteogenesis effects of CGRP, especially for its regulation effects on the cross‐talk between mesenchymal stem cells and endothelial cells.
Wushu Routine Movement and Diagnosis Based on Deep Learning and Symmetric Difference Algorithm
Authors: Yan Shifang , Chen Jun , Huang Hai
Published: June 2022

Wushu is one of the traditional cultural symbols of the Chinese nation. It is also one of the most popular sports activities among the people. With the attention and love of contemporary people to sports activities, Wushu is also constantly developing and innovating. The requirements for professional martial arts routines of martial arts athletes are higher than ever. The development of martial arts has also made martial arts competitions more intense, and often a small detail of martial arts movements can determine the success or failure of the competition. Therefore, various Wushu teams pay more and more attention to the analysis and diagnosis of Wushu routines. It ensures that coaches and athletes can obtain more quantitative indicators of technical movement training. The analysis and diagnosis of martial arts routines are inseparable from the support of reliable science and technology and related algorithms. This article aims to study the analysis and diagnosis of martial arts routines based on deep learning and symmetric difference algorithm. It combines deep learning and symmetric difference algorithm to analyze and diagnose martial arts routines. The article concludes that the level of martial arts routines of martial arts athletes has the greatest influence on their martial arts competition performance, and its comprehensive influence index is as high as 4.3.