bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-Interactive Detection of Malicious Vehicular Network Data
Authors: Di Crescenzo Giovanni , Ling Yibei , Zhang Tao , Pietrowicz Stan
Published: July 2021

Vehicular networks might be deployed in the near future, and as a consequence a potentially large number of exciting applications are expected to enhance the human driving experience. Unless the security of such applications is guaranteed, however, such enhancements may be accompanied by similarly powerful and yet undesired consequences in malicious behaviour. While current research in the vehicular networks security area has recognized conventional security and cryptographic threats, detailed modeling and analysis of threats that are specific to vehicle traffic are rarely considered in the literature. In this paper we lay ground for a comprehensive investigation of “traffic-related” threats to vehicular networks. We study the problem of modeling traffic-related attacks in these networks and present automatic and efficient (i.e., no human intervention and no expensive cryptographic protocols) yet general solutions to prevent or tolerate a number of these attacks. Specifically, we propose techniques based on the capability of implementing simple and non-interactive voting algorithms that use the mere participations of vehicles to the network and, while doing that, attempt to maximize use of already exchanged and relevant network data. We validate our techniques by providing analysis results based on both simulated and real-life mobility data in typical urban environments. Previous work required interactive protocols to implement voting or consensus techniques, and implicitly left open the question we solve in this paper.
The Number continuity service, Part I GSM <-> Satellite phone
Authors: Henry-Labord`ere Arnaud
Published: July 2021

Mobile Number Portability is now a widely used service allowing users to keep their number if they change their subscribed operator. It was first deployed in Hong-Kong (1999). « Number Continuity » corresponds to the same service but with the switch to another technology, because the subscribed main terminal does not have coverage. The new terminal may be a PC, a smartphone / WiFi, a “satphone”, a GSM phone if the main one is CDMA, with (almost) the same service transparently. Making calls or SMS with its normal CLI shown, receiving calls, SMS, MMS to his normal GSM number (unlike « Skype »). This article explains the GSM <-> satphone number continuity implementation. The Geostationnary and Low Earth Orbit characteristics are presented as well the consequences of orbit drifts for which the exact computation is given based on the formal integration of Kepler's area law. The handover implementation and cases for the satellite service are explained. The constellation and services of the main satellite operators are compared. The telecom core network implementation of the service is detailed in the cases of a GSM type core network and an IS-41 (CDMA) core network.
Model-based Approach to Multi-domain Monitoring Data Aggregation
Authors: Pastor Antonio , López Diego R. , Ordonez-Lucena Jose , Fernández Sonia , Folgueira Jesús
Published: July 2021

The essential propellant for any closed-loop management mechanism is data related to the managed entity. While this is a general evidence, it becomes even more true when dealing with advanced closed-loop systems like the ones supported by Artificial Intelligence (AI), as they require a trustworthy, up-to-date and steady flow of state data to be applicable. Modern network infrastructures provide a vast amount of disparate data sources, especially in the multi-domain scenarios considered by the ETSI Industry Specification Group (ISG) Zero Touch Network and Service Management (ZSM) framework, and proper mechanisms for data aggregation, pre-processing and normalization are required to make possible AI-enabled closed-loop management. So far, solutions proposed for these data aggregation tasks have been specific to concrete data sources and consumers, following ad-hoc approaches unsuitable to address the vast heterogeneity of data sources and potential data consumers. This paper presents a model-based approach to a data aggregator framework, relying on standardized data models and telemetry protocols, and integrated with an open-source network orchestration stack to support their incorporation within network service lifecycles.
NR Sidelink Enhancement in 3GPP Release 17
Authors: Ganesan Karthikeyan , Mallick Prateek Basu , Löhr Joachim
Published: July 2021

3GPP is currently studying enhancements to Sidelink (SL) operations for 5G New Radio (NR) in a Release 17 Work Item which is planned to be finished by end of 2021. The NR Sidelink (SL) Work Item in Release 17 includes several key features targeting reliability enhancements, power saving and coverage enhancements by expanding the scope of NR sidelink to target V2X, commercial D2D use-case and Public safety. This paper provides an insight on the current 3GPP Release 17 NR SL design describing necessary enhancements in the physical, protocol layer to support inter-UE coordination message for reliability enhancement for autonomous resource selection procedure by providing feedback on the half-duplex, persistent collision and hidden nodes. In addition, the power saving feature is addressed by introducing a SL DRX mechanism for the PC5 interface which defines active reception and transmission periods between a TX and the peer Rx UE(s) and also between Tx UE and gNB. Furthermore, this paper outlines details on the Sidelink Relay feature for coverage enhancement by describing possible solutions for UE to Network relay and UE to UE relay.
Inter-PLMN Mobility Management Challenges for Supporting Cross-Border Connected and Automated Mobility (CAM) Over 5G
Authors: Trichias Konstantinos , Demestichas Panagiotis , Mitrou Nikolaos
Published: July 2021

As the first 5G networks are being deployed across the world, new services enabled by the superior performance of 5G in terms of throughput, latency and reliability are emerging. Connected and Automated Mobility (CAM) services are perhaps among the most demanding applications that 5G networks will have to support and their deployment, performance and potential for improvement has been well investigated over the past few years. However, CAM operation in multi-operator environments and the inevitable inter-PLMN handover caused by the inherent mobility of CAM services have not been studied in length. Moreover, the multiple domains, multi-vendor components and inherent high mobility of the cross-border vehicular environment, introduce multiple challenges in terms of network management and dynamic slicing, making Zero-touch network and Service Management (ZSM) solutions an attractive alternative for these environments. The work presented in this study attempts to analyse the requirements for cross-border CAM operation for the five main CAM use cases selected by 3GPP, based on input from key European stakeholders (Network Operators, vendors, Automotive Manufacturers etc.). A detailed analysis and categorization into four categories of the main challenges for cross-border CAM service provisioning is performed, namely Telecommunication, Application, Security/Privacy and Regulatory issues, while potential solutions based on existing and upcoming technological enablers are discussed for each of them. The role of standardization and relevant regulatory and administrative bodies is analysed, leading to insights regarding the most promising future research directions in the field of cross-border CAM services.
Optimizing MultiStack Parallel (MSP) Sorting Algorithm
Authors: Rattanatranurak Apisit , Kittitornkun Surin
Published: July 2021

Mobile smartphones/laptops are becoming much more powerful in terms of core count and memory capacity. Demanding games and parallel applications/algorithms can hopefully take advantages of the hardware. Our parallel MSPSort algorithm is one of those examples. However, MSPSort can be optimized and fine tuned even further to achieve its highest capabilities. To evaluate the effectiveness of MSPSort, two Linux systems are quad core ARM Cortex-A72 and 24-core AMD ThreadRipper R9-2920. It has been demonstrated that MSPSort is comparable to the well-known parallel standard template library sorting functions, i.e. Balanced QuickSort and Multiway MergeSort in various aspects such as run time and memory requirements.
Enhanced Road Lane Detection Facing Sun Glare
Authors: Moumene Mohammed El Amine , Benkedadra Mohamed
Published: July 2021

There are several studies on road lane detection but very few address adverse conditions for acquisition such as sun glare. Loss of details in underexposed images captured facing a low sun leads to misleading road lane detection. High Dynamic Range Imaging methods are used to acquire most details in such scenes. Unfortunately, these techniques are heavy on computations and therefore unsuitable for real time road lane detection. In this paper, we propose a machine learning solution that avoids High Dynamic Range Imaging computations that are the radiance map estimation, tone-mapping algorithms and quality measures calculation. We train a neural network on a High Dynamic Range Imaging dataset. The resulting model produces suitable images for road lane detection facing sun glare, in real time. Subjective and objective comparisons with the most popular High Dynamic Range Imaging method, Mertens Algorithm, are conducted to prove the effectiveness of the proposed Neural Network. The delivered images demonstrated an improvement in road lane detection.
Adjusted JPEG Quantization Tables in Support of GPS Maps
Authors: Wiseman Yair
Published: July 2021

Image quality manipulating in JPEG is done by quantization tables. JPEG has two quantization tables – one table for the luminance information and one table for the chrominance information. These quantization tables have been designed in support of images with few sharp changes; however, typically most GPS image maps have many sharp changes and as a result, the images are not optimally compressed. The designers of the quantization tables have presumed that sharp changes in the colors will rarely occur. Therefore, they divide the values that represent sharp changes in the frequency space by large numbers and divide other values by smaller numbers. As a result, when there are sharp changes in an image, the proportional allocation for each kind of data in the compressed image is inappropriate and results in an inefficient compression. In this paper the standard quantization tables have been modified as to handle the different kinds of GPS image map data appropriately. Consequently, the experimental results show that images with sharp changes are compressed more efficiently when making use of the new quantization tables.
An Algorithm with Efficiently Collecting and Aggregating Data for Wireless Sensor Networks
Authors: Xiong Peng , Su Qinggang
Published: July 2021

Due to the resource constraint, in wireless sensor network, the node processing ability, wireless bandwidth and battery capacity and other resources are scarcer. For improving the energy efficient and extend the lifetime of the network, this paper proposes a novel algorithm with the distributed and energy-efficient for collecting and aggregating data of wireless sensor network. In the proposed protocol, nodes can autonomously compete for the cluster head based on its own residual energy and the signal strength of its neighbouring nodes. To reduce the energy overhead of cluster head nodes, with a multi-hop way among cluster heads, the collected data from cluster heads is sent to a designated cluster head so as to further send these data to a base station. For improving the performance of the proposed protocol, a new cluster coverage method is proposed to fit the proposed protocol so that when the node density increases, network lifetime can be increased linearly as the number of nodes is increased. Simulations experiments show that network lifetime adopting the proposed protocol is sharply increased. And, the proposed protocol makes all the nodes die (network lifetime is defined as the death of last one node) in the last 40 rounds so that networks adopting the proposed protocol have higher reliability than networks adopting compared protocols.
Multi-Rhythm Capsule Network Recognition Structure for Motor Imagery Classification
Authors: Xu Meiyan , Yao Junfeng , Zheng Yifeng , Lin Yaojin
Published: July 2021

Existing machine learning methods for classification and recognition of EEG motor imagery usually suffer from reduced accuracy for limited training data. To address this problem, this paper proposes a multi-rhythm capsule network (FBCapsNet) that uses as little EEG information as possible with key features to classify motor imagery and further improves the classification efficiency. The network conforms to a small recognition model with only 3 acquisition channels but it can effectively use the limited data for feature learning. Based on the BCI Competition IV 2b data set, experimental results show that the proposed network can achieve 2.41% better performance than existing cutting-edge methods.
A Probability Distribution and Location-aware ResNet Approach for QoS Prediction
Authors: Zhang Wenyan , Xu Ling , Yan Meng , Wang Ziliang , Fu Chunlei
Published: July 2021

In recent years, the number of online services has grown rapidly, invoking the required services through the cloud platform has become the primary trend. How to help users choose and recommend high-quality services among huge amounts of unused services has become a hot issue in research. Among the existing QoS prediction methods, the collaborative filtering (CF) method can only learn low-dimensional linear characteristics, and its effect is limited by sparse data. Although existing deep learning methods could capture high-dimensional nonlinear features better, most of them only use the single feature of identity, and the problem of network deepening gradient disappearance is serious, so the effect of QoS prediction is unsatisfactory. To address these problems, we propose an advanced probability distribution and location-aware ResNet approach for QoS Prediction (PLRes). This approach considers the historical invocations probability distribution and location characteristics of users and services, and first uses the ResNet in QoS prediction to reuses the features, which alleviates the problems of gradient disappearance and model degradation. A series of experiments are conducted on a real-world web service dataset WS-DREAM. At the density of 5%–30%, the experimental results on both QoS attribute response time and throughput indicate that PLRes performs better than the existing five state-of-the-art QoS prediction approaches.
A New Semantic Approach to Improve Webpage Segmentation
Authors: Ghaemmaghami Saeedeh Sadat Sajjadi , Miller James
Published: July 2021

Webpage analysis is carried out for various purposes such as webpage segmentation. The goal of webpage segmentation is to divide a page into blocks that have similar elements. A fusion approach that combines different analyses is required in order to obtain high segmentation accuracy. In this paper, we propose a new fusion model for webpage segmentation, where we (1) merge webpage content into basic-blocks by simulating human perception; and, (2) identify similar blocks using semantic text similarity and regroup these similar blocks as fusion blocks. This approach is applied to three public datasets and evaluated by comparing with state-of-the-art algorithms. The results characterize that our proposed approach outperforms other existing webpage segmentation methods, in terms of accuracy.
Numerical methods for solid particles in particulate flow simulations
Authors: Laure Patrice , Beaume Gregory , Basset Olivier , Silva Luisa , Coupez Thierry
Published: July 2021

The flow motion of solid particle suspensions is a fundamental issue in many problems of practical interest. The velocity field of a such system is computed by a finite element method with a multi-domain approach of two phases (namely a viscous fluid and rigid bodies), whereas the particle displacement is made by a particulate method. We focus our paper on a simple shear flow of Newtonian fluid.
Strong coupling for fluid structure interaction problems
Authors: Capron Nicolas , Mompean Gilmar , Naji Hassan
Published: July 2021

The computation of fluid forces acting on a rigid or deformable structure constitutes a major problem in fluid structure interaction. However, the majority of numerical tests consists in using two different codes to separately solve pressure of the fluid and structural displacements. In this paper, a monolithic with an ALE formulation approach is used to implicitly calculate the pressure of an incompressible fluid applied to the structure. The projection method proposed by Gresho is used to decouple the velocity and pressure.
Numerical investigation of structural behavior during fluid excited vibrations
Authors: Yigit Saim , Schäfer Michael , Heck Marcus
Published: July 2021

In the present paper different occurring phenomena during the interaction between certain structural configurations and laminar incompressible flows are investigated. Preliminary investigations concerning the grid movement technique provide the basis for the adequate treatment of the fluid structure interaction problems. Several mechanisms according to real experiments are presented. Systematical numerical studies of material parameters are performed on the basis of a moderately complex fluid structure interaction test configuration. The solution procedure involves the finite-volume flow solver FASTEST, the finite-element structural solver FEAP, and the coupling interface MpCCI.
Elément de poutre multicouche avec glissement d’interface
Authors: Rebora Blaise , Frey François
Published: July 2021

This paper presents a multilayered two node planar beam element, straight or shallow, of Bernoulli type, with an arbitrary number of layers with interlayer slip. Material and geometric nonlinearities are included. Small strains and slips are assumed. Large displacements are dealt with von Karman strain coupled with corotational formulation. No locking appears. Various tests show the capabilities of this element.
Modèle numérique pour l’étude des structures fissurées soumises à des contraintes résiduelles
Authors: Gaiech Zohra , Kebir Hocine , Chambon Laurent , Roelandt Jean-Marc
Published: July 2021

During their operational use the aeronautic structures can be submitted to relatively moderate cyclic loads and more rarely to stern loads. These last can generate residual stress field, which will influence the in-service behaviour. Otherwise, residual stress field can be created in a voluntary way by a specific treatment (compressive stresses). They permit to improve fatigue tolerance behaviour. This illustrates the importance of the study of the structure behavior under residual stresses, and the need to consider them in numerical simulations. The objective of this work is to develop a numerical method, based on the boundary element method and the principle of superposition, to assess the influence of residual stresses on fracture mechanics parameters.
Analyse numérique du régime THD dans un patin échelon
Authors: Dobrica Mihai B. , Fillon Michel
Published: July 2021

A lack of thermohydrodynamic (THD) models adapted to discontinuous fluid film geometries can be noted in the lubrication-related literature. The finite differences method, largely used in THD analysis, cannot be easily applied to discontinuous flow domains. This article proposes two finite volumes based models, suitable for discontinuous domains. The first model, based on Reynolds generalized equation, lacks in accuracy near the discontinuity line, but gains in computing speed. The second model, based on Navier-Stokes equations, is more accurate but also significantly more demanding in terms of computing requirements. The two models are applied and compared on the simple geometry of a bi-dimensional Rayleigh step bearing. Different configurations are analyzed, allowing the validation of the Reynolds model for most of the cases encountered in fluid film lubrication.
Résolution des équations de Saint-Venant par la méthode des volumes finis non structurés
Authors: Shi Yu-e , Nguyen Kim Dan , Nguyen The Hung
Published: July 2021

This paper presents a resolution of the Saint-Venant equations by a projection method. Using unstructured finite-volumes methods, a 2-D horizontal shallow water numerical model is developed. Two applications with complex bathymetries are reported in this article. The model can be applied to the calculation of river, estuarine and coastal flows.
Solveurs multigrilles et méthode asymptotique numérique
Authors: Mtalaa Anas , Cadou Jean-Marc , Potier-Ferry Michel
Published: July 2021

The aim of this work is to build up new numerical techniques to solve non-linear large scale problems. We propose to couple multigrid techniques with the asymptotic numerical method (ANM) which associates a perturbation technique with the finite element method.
A comparative evaluation of genetic and gradient-based algorithms applied to aerodynamic optimization
Authors: Zingg David W. , Nemec Marian , Pulliam Thomas H.
Published: July 2021

A genetic algorithm is compared with a gradient-based (adjoint) algorithm in the context of several aerodynamic shape optimization problems. The examples include singlepoint and multipoint optimization problems, as well as the computation of a Pareto front. The results demonstrate that both algorithms converge reliably to the same optimum. Depending on the nature of the problem, the number of design variables, and the degree of convergence, the genetic algorithm requires from 5 to 200 times as many function evaluations as the gradientbased algorithm.
Modélisation numérique du comportement thermique d’un disque de frein
Authors: Kchaou Hédi , Kaffel Mohamed , Chehadi Fadi , Baccar Mounir
Published: July 2021

Temperature is an important parameter in the design and interpretation of the thermomechanical behaviour of braking systems. The frictional heat generated on the diskpad interface induces high temperature which can cause disk brake fade phenomena, local scoring, thermal cracking and thermo elastic instabilities. In this study we present a thermomechanical modelling of an automotive braking system. For this purpose, a three dimensional simulation thermal model for a ventilated brake-disk of an Anti lock-Braking System (ABS) is conducted in instationary state in different operating conditions. Sliding boundary conditions techniques were developed to consider the effects of the thermomechanical load source (the pad) motion with a decelerated speed. The numerical results were presented in the form of cartographies showing the temperature fields versus time in the r-θ and r-z planes for different braking scenarios.
Geometry modelling and industrial parameterisation issues
Authors: Selmin Vittorio
Published: July 2021

The paper addresses issues related to the development of a geometrical modelling system and its connection with shape parameterisation and computational grid update. In particular, it is thought that the use of parameterisations based on the modification of an existing shape instead to exploit the direct representation of the geometry results in an increase of flexibility and accuracy. Selected examples related to aircraft design illustrate the capability of the system.
Contrôle des défauts d’emboutissage par optimisation des efforts serre-flan
Authors: Ayed Lanouar Ben , Delamézière Arnaud , Batoz Jean-Louis , Knopf-Lenoir Catherine
Published: July 2021

That paper deals with the optimization of the blankholder forces in deep drawing, the blankholder is made of several zones. The optimal forces applied on those zones are computed to avoid defects during the process (necking and wrinkling of the blank). A necking criterion has been formulated. The optimization procedure uses a response surface computed by a moving lest square technique. The methodology is applied to a front door panel, benchmark at the Numisheet’99 conference.
Formulation et évaluation d’un modèle d’élément fini discret au sens de Mindlin pour l’analyse des structures isotropes
Authors: Sakami Siham , Sabhi Hamid , Ayad Rezak , Talbi Nabil
Published: July 2021

This work deals with a displacement formulation using local discrete hypothesises, to lead to a simple and accurate shell finite element. A first kinematic hypothesis allows introducing the transverse displacement in the 4 corner nodes. The other 4 mid-side nodes are eliminated using a 2nd mechanical hypothesis. The new element DMQS (Discrete Mindlin Quadrilateral for Shells) has 4 nodes and 6 dofs/node. Its numerical performances are analysed using some known standard tests. It can be considered as an alternative to thin structure finite elements without transverse shear, called Discrete Kirchooff Elements.
Effect of surface defects on structure failure
Authors: Brancherie Delphine , Dambrine Marc , Vial Grégory , Villon Pierre
Published: July 2021

This work aims to take into account the influence of boundary defects on the behaviour till rupture of structures without any fine geometrical description of the domain. This is achieved by appealing to two approaches: an asymptotic analysis of Navier equations and strong discontinuity models. We present in this work a strategy to couple the two approaches in order to provide the analysis till rupture of the structure behavior. The approach is validated on an academic example.
A hybrid method for vibroacoustic coupling
Authors: Sadoulet-Reboul Emeline , Le Bot Alain , Perret-Liaudet Joël
Published: July 2021

hybrid method is proposed to study the noise radiated in the high frequency range by a gearbox inside an engine compartment. Due to its elastodynamic characteristics, the vibratory behaviour of the transmission lies in the low frequency range. However, the noise radiated is rather in the high frequency range facing the size of the acoustical cavity. Thus the proposed hybrid method allows to couple a low-frequency vibratory approach to the radiative transfer method used for the high frequency acoustical calculation. The coupling is realized through equivalent energy sources introduced on the surface of the vibrating structure.
A method for updating joint parameters in medium-frequency vibrations
Authors: Dorival Olivier , Rouch Philippe , Allix Olivier
Published: July 2021

Joints between substructures play a significant role in the vibrational behavior of complex structures because they govern energy flow and most of the dissipative phenomena. In order to identify joint models, this paper proposes a robust updating method which was initially based on studies of the error in constitutive relation in relation to finite element model updating. Here, it is redesigned in order to focus on joint models in medium-frequency problems. In order to do that, we use an alternative numerical approach called the Variational Theory of Complex Rays (VTCR). After introducing the new formulation, the paper analyzes the effectiveness of the approach in identifying a joint’s stiffness and damping.
Explicit dynamics “SPH – Finite Element” coupling using the Arlequin method
Authors: Chuzel-Marmot Yann , Combescure Alain , Ortiz Roland
Published: July 2021

The Arlequin method gives a simple and effective framework to glue models using various formulations. It is extended here in explicit dynamics and used in order to link a zone showing ruptures by fragmentation meshed with Smoothed Particles Hydrodynamics (SPH) and a larger second undamaged one meshed with finite elements (FEM). This paper gives some details on the method implemented in the EUROPLEXUS code, its validation on simple benchmarks and a confrontation between numerical simulations and results of an experimental study of concrete slab resistance to projectile impacts.
Anisotropic 3D delay-damage model to simulate concrete structures
Authors: Gatuingt Fabrice , Desmorat Rodrigue , Chambart Marion , Combescure Didier , Guilbaud Daniel
Published: July 2021

Dynamic loadings lead to material degradation and structural failure. This is even more the case for concrete structures where the parts initially in compression break in tension due to waves propagation and reflection. The dissymmetry (mainly due to damage induced anisotropy) of the material behavior plays a major role in such cases. Loading induced damage is often anisotropic and one proposes here to take advantage of such a feature to build a damage model for concrete, dissymmetric in tension and in compression, 3D, suitable for dynamic computations. A single 2nd order tensorial damage variable D is considered with a damage law ensuring a damage rate proportional to the square of the positive part of the strain tensor. One focus in the present work on viscous regularizations for the anisotropic damage model proposed. Numerical examples illustrate the efficiency of the model to deal with 3D structures.
Structural analysis by interval approach
Authors: Massa Franck , Mourier-Ruffin Karine , Lallemand Bertrand , Tison Thierry
Published: July 2021

Finite element simulations are well established in industry and are an essential part of the design phase for mechanical structures. Although numerical models have become more and more complex and realistic, the results can still be relatively far from observed reality. Nowadays, use of deterministic analysis is limited due to the existence of several kinds of imperfections in the different steps of the structural design process. This paper presents a general non-probabilistic methodology that uses interval sets to propagate the imperfections. This methodology incorporates sensitivity analysis and reanalysis techniques. Numerical interval results for a test case were compared to experimental interval results to demonstrate the capabilities of the proposed methodology.
Extension of fixed point PDE solvers for optimal design by one-shot method
Authors: Gauger Nicolas R. , Griewank Andreas , Riehme Jan
Published: July 2021

This paper concerns mathematical methods, algorithmic techniques and software tools for the transition from simulation to optimization. We focus in particular on applications in aerodynamics. The methodology is applicable to all areas of scientific computing, where large scale governing equations involving discretized PDEs are treated by custom made fixed point solvers. To exploit the domain specific experience and expertise invested in these simulation tools we propose to extend them in a semi-automated fashion. First they are augmented with an adjoint solvers to obtain (reduced) derivatives and then this sensitivity information is immediately used to determine optimization corrections.
Non uniform warping for beams
Authors: El Fatmi Rached
Published: July 2021

A non-uniform warping beam theory including the effects of torsion and shear forces is presented. Based on a displacement model using three warping parameters associated to the three St Venant warping functions corresponding to torsion and shear forces, this theory is free from the classical assumptions on the warpings or on the shears, and valid for any kind of homogeneous elastic and isotropic cross-section. This general theory is applied to analyze, for a representative set of cross-sections, the elastic behavior of cantilever beams subjected to torsion or shear-bending. Numerical results are given for the one-dimensional structural behavior and the three-dimensional stresses distributions; for the stresses in the critical region of the built-in section, comparisons with three-dimensional finite elements computations are presented. The study clearly shows when the effect of the restrained warping is localized or not.
The lasting imprint of childhood disadvantage: cumulative histories of exposure to childhood adversity and trajectories of psychological distress in adulthood
Authors: Heidinger Loanna S. , Willson Andrea E.
Published: July 2021

This study contributes to the literature on the long-term effects of childhood disadvantage on mental health by estimating the association between patterns of cumulative childhood adversity on trajectories of psychological distress in adulthood. There is little research that investigates how compositional variations in the accumulation of childhood adversity may initiate distinct processes of disadvantage and differentially shape trajectories of psychological distress across the adult life course. Using the Panel Study of Income Dynamics’ Childhood Retrospective Circumstance Study and latent class analysis, we first identify distinct classes representing varied histories of exposure to childhood adversities using 25 indicators of adversity across multiple childhood domains. Next, the latent classes are included as predictors of trajectories of psychological distress in adulthood. The results demonstrate that patterns of experiences of childhood adversity are associated with higher levels of adult psychological distress that persists, and in some cases worsens, in adulthood, contributing to disparities in mental health across the life course.
High-dynamic-range blood flow rate measurement in a large-diameter vessel
Authors: Yuan Yuan , Bi Yong , Gao Xiao Cao , Sun Min Yuan , Gao Wei Nan
Published: July 2021

We propose a new, to the best of our knowledge, compound technique to measure high-dynamic-range blood flow rate in a large-diameter vessel, which combines the dynamic scattering light (DLS) and the laser speckle contrast imaging (LSCI) methods, possessing the advantages of the high temporal resolution of DLS and the robust property of LSCI. By controlling the second-order spatial correlations of the laser speckle through two imaging systems, the speckle temporal intensity autocorrelation function

g
2

(
t
)

and the decorrelation time

τ
c

are directly measured using a high-speed camera. It turns out the enhanced spatial second-order correlation helps to measure the blood flow with higher dynamic range and that the measured parameter

β

and the blood flow dynamics

n

were accurately determined. For further improvement the dynamic range, the modified LSCI method was adopted, and the decorrelation time as a function of blood flow rate was constructed. It reveals the feasibility of measuring the high flow rate in large-diameter vessels and provides significant guidance for the future biomedical study of the myocardial perfusion in coronary artery bypass grafting, ghost imaging, and ghost cytometry.
Rapid pseudo-H&E imaging using a fluorescence-inbuilt optical coherence microscopic imaging system
Authors: Lin Sey-En , Jheng Dong-Yo , Hsu Kuang-Yu , Liu Yun-Ru , Huang Wei-Hsiang , Lee Hsiang-Chieh , Tsai Chien-Chung
Published: July 2021

A technique using Linnik-based optical coherence microscopy (OCM), with built-in fluorescence microscopy (FM), is demonstrated here to describe cellular-level morphology for fresh porcine and biobank tissue specimens. The proposed method utilizes color-coding to generate digital pseudo-H&E (p-H&E) images. Using the same camera, colocalized FM images are merged with corresponding morphological OCM images using a 24-bit RGB composition process to generate position-matched p-H&E images. From receipt of dissected fresh tissue piece to generation of stitched images, the total processing time is <15 min for a 1-cm2 specimen, which is on average two times faster than frozen-section H&E process for fatty or water-rich fresh tissue specimens. This technique was successfully used to scan human and animal fresh tissue pieces, demonstrating its applicability for both biobank and veterinary purposes. We provide an in-depth comparison between p-H&E and human frozen-section H&E images acquired from the same metastatic sentinel lymph node slice (∼10 µm thick), and show the differences, like elastic fibers of a tiny blood vessel and cytoplasm of tumor cells. This optical sectioning technique provides histopathologists with a convenient assessment method that outputs large-field H&E-like images of fresh tissue pieces without requiring any physical embedment.
Secure fiber-optic communication system based on Internet-accessible multipath transmission of ciphertext fragments
Authors: Jin Ya , Qi Yichao , Chen Yinfang , Chen Wei , Li Wei , Zhu Ninghua
Published: July 2021

A secure fiber-optic communication system based on Internet-accessible multipath transmission of ciphertext fragment (MTCF) technology is proposed and demonstrated in this paper. By performing algorithm encryption on the transmitted data before randomly assigning them to multiple channels corresponding to different wavelengths or Internet protocols (IPs), the secure and long-distance transmission can be realized. A field trial experiment over 125 km between Beijing and Xiongan has been successfully undertaken, and the results show that the maximum throughput can reach 60 Mb/s, which demonstrates the feasibility of the scheme. We also established a theoretical model to analyze the security performance of the proposed system. As far as we know, this is the first time that MTCF, an optical physical layer and application layer integrated security technology, has been enjoyed the capacity to access the public network, which provides an exciting opportunity to advance our knowledge of long-distance secure communication.
Nanometric displacement sensor with a switchable measuring range using a cylindrical vector beam excited silicon nanoantenna
Authors: Zhang Hanmou , Gao Kun , Han Lei , Liu Sheng , Mei Ting , Xiao Fajun , Zhao Jianlin
Published: July 2021

We demonstrate a nanometric displacement sensor with a switchable measuring range by using a single silicon nanoantenna. It is revealed that the interference between the longitudinal and transverse dipolar scattering can be well tuned by moving the nanoantenna in the focal field of the cylindrical vector beam. As a result, a position related scattering directivity is found and is used as a displacement sensor with a 4.5 nm lateral resolution. Interestingly, the measuring range of this displacement sensor can be extended by twice through simply changing the excitation from the azimuthally polarized beam to the radially polarized beam. Our results provide a facile way to tune the measuring range of the nanometric displacement sensor and may open up an avenue to super-resolution microscopy and optical nanometrology.
Absolute frequency readout derived from ULE cavity for next generation geodesy missions
Authors: Rees Emily Rose , Wade Andrew R. , Sutton Andrew J. , Spero Robert E. , Shaddock Daniel A. , Mckenzie Kirk
Published: July 2021

The next generation of Gravity Recovery and Climate Experiment (GRACE)-like dual-satellite geodesy missions proposals will rely on inter-spacecraft laser interferometry as the primary instrument to recover geodesy signals. Laser frequency stability is one of the main limits of this measurement and is important at two distinct timescales: short timescales over 10-1000 seconds to measure the local gravity below the satellites, and at the month to year timescales, where the subsequent gravity measurements are compared to indicate loss or gain of mass (or water and ice) over that period. This paper demonstrates a simple phase modulation scheme to directly measure laser frequency change over long timescales by comparing an on-board Ultra-Stable Oscillator (USO) clocked frequency reference to the Free Spectral Range (FSR) of the on-board optical cavity. By recording the fractional frequency variations the scale correction factor may be computed for a laser locked to a known longitudinal mode of the optical cavity. The experimental results demonstrate a fractional absolute laser frequency stability at the 10 ppb level (10−8) at time scales greater than 10 000 seconds, likely sufficient for next generation mission requirements.
Reconfigurable millimeter-range optical binding of dielectric microparticles in hollow-core photonic crystal fiber
Authors: Sharma Abhinav , Xie Shangran , Russell Philip St.J.
Published: July 2021

Optical binding of microparticles offers a versatile playground for investigating the optomechanics of levitated multi-particle systems. We report millimeter-range optical binding of polystyrene microparticles in hollow-core photonic crystal fiber. The first particle scatters the incident

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mode into several

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modes, creating a beat pattern that exerts a position-dependent force on the second particle. Particle binding results from the interplay of the forces created by counterpropagating beams. A femtosecond trapping laser is used so that group velocity walk-off eliminates disturbance caused by higher order modes accidentally excited at the fiber input. The inter-particle distance can be optically switched over 2 orders of magnitude (from 42 µm to 3 mm), and the bound particle pairs can be translated along the fiber by unbalancing the powers in the counterpropagating trapping beams. The frequency response of a bound particle pair is investigated at low gas pressure by driving with an intensity-modulated control beam. The system offers new degrees of freedom for manipulating the dynamics and configurations of optically levitated microparticle arrays.
Event-based laser speckle correlation for micro motion estimation
Authors: Ge Zhou , Gao Yizhao , So Hayden K.-H. , Lam Edmund Y.
Published: July 2021

Micro motion estimation has important applications in various fields such as microfluidic particle detection and biomedical cell imaging. Conventional methods analyze the motion from intensity images captured using frame-based imaging sensors such as the complementary metal–oxide semiconductor (CMOS) and the charge-coupled device (CCD). Recently, event-based sensors have evolved with the special capability to record asynchronous light changes with high dynamic range, high temporal resolution, low latency, and no motion blur. In this Letter, we explore the potential of using the event sensor to estimate the micro motion based on the laser speckle correlation technique.
An experimental-mathematical approach to predict tumor cell growth as a function of glucose availability in breast cancer cell lines
Authors: Yang Jianchen , Virostko Jack , Hormuth David A. , Liu Junyan , Brock Amy , Kowalski Jeanne , Yankeelov Thomas E.
Published: July 2021

We present the development and validation of a mathematical model that predicts how glucose dynamics influence metabolism and therefore tumor cell growth. Glucose, the starting material for glycolysis, has a fundamental influence on tumor cell growth. We employed time-resolved microscopy to track the temporal change of the number of live and dead tumor cells under different initial glucose concentrations and seeding densities. We then constructed a family of mathematical models (where cell death was accounted for differently in each member of the family) to describe overall tumor cell growth in response to the initial glucose and confluence conditions. The Akaikie Information Criteria was then employed to identify the most parsimonious model. The selected model was then trained on 75% of the data to calibrate the system and identify trends in model parameters as a function of initial glucose concentration and confluence. The calibrated parameters were applied to the remaining 25% of the data to predict the temporal dynamics given the known initial glucose concentration and confluence, and tested against the corresponding experimental measurements. With the selected model, we achieved an accuracy (defined as the fraction of measured data that fell within the 95% confidence intervals of the predicted growth curves) of 77.2 ± 6.3% and 87.2 ± 5.1% for live BT-474 and MDA-MB-231 cells, respectively.
The impact of sonication cultures when the diagnosis of prosthetic joint infection is inconclusive
Authors: Ribeiro Taiana Cunha , Honda Emerson Kiyoshi , Daniachi Daniel , Cury Ricardo de Paula Leite , da Silva Cely Barreto , Klautau Giselle Burlamaqui , Salles Mauro Jose
Published: July 2021

Background

In the absence of a gold standard criterion for diagnosing prosthetic joint infections (PJI), sonication of the removed implant may provide superior microbiological identification to synovial fluid and peri-implant tissue cultures. The aim of this retrospective study was to assess the role of sonication culture compared to tissue cultures for diagnosing PJI, using different consensus and international guidelines for PJI definition.

Methods

Data of 146 patients undergoing removal of hip or knee arthroplasties between 2010 and 2018 were retrospectively reviewed. The International Consensus Meeting (ICM-2018), Musculoskeletal Infection Society (MSIS), Infectious Diseases Society of America (IDSA), the European Bone and Joint Infection Society (EBJIS), and a modified clinical criterion, were used to compare the performance of microbiological tests. McNemar´s test and proportion comparison were employed to calculate p-value.

Results

Overall, 56% (82/146) were diagnosed with PJI using the clinical criteria. Out of these cases, 57% (47/82) tested positive on tissue culture and 93% (76/82) on sonication culture. Applying this clinical criterion, the sensitivity of sonication fluid and tissue cultures was 92.7% (95% CI: 87.1%- 98.3%) and 57.3% (95% CI: 46.6%-68.0%) (p<0.001), respectively. When both methods were combined for diagnosis (sonication and tissue cultures) sensitivity reached 96.3% (95% CI: 91.5%-100%). Sonication culture and the combination of sonication with tissue cultures, showed higher sensitivity rates than tissue cultures alone for all diagnostic criteria (ICM-18, MSIS, IDSA and EBJIS) applied. Conversely, tissue culture provided greater specificity than sonication culture for all the criteria assessed, except for the EBJIS criteria, in which sonication and tissue cultures specificity was 100% and 95.3% (95% CI: 87.8–100%), respectively (p = 0.024).

Conclusions

In a context where diagnostic criteria available have shortcomings and tissue cultures remain the gold standard, sonication cultures can aid PJI diagnosis, especially when diagnostic criteria are inconclusive due to some important missing data (joint puncture, histology).