bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design and development of Cu‐Al‐Mn‐Ni shape memory alloy coated optical fibre sensor for condition‐based monitoring of physical systems
Authors: Subramaniam Karthick , Singh Shalini , Raikwar Sumeet , Shukla Ashish Kumar , Anand Palani Iyamperumal 
Published: March 2021

AbstractOnline fault detection, isolation and recovery using smart sensors play an important role in intelligent manufacturing system. Fibre optic sensors are very interesting for condition monitoring applications due to the advantage of this technology. Here, the experimental demonstration of Cu‐based shape memory alloy (SMA) coated optical fibre for temperature‐based sensing applications is reported. The benefit of Cu‐based SMA coated optical fibre over conventional metallic coating has been evaluated in the study. For consistent coating, an in situ fixture with a rotary drive setup has been designed and developed. Thermo optic test bench has been developed to study the actuation characteristics of the SMA coated optical fibre for varying current and voltage. Experiments were performed to investigate the light intensity in the SMA coated optical fibre at different actuation conditions. The displacement that takes place in the optical fibre due to the external temperature stimuli will create proportional intensity and wavelength shifts. The maximum average displacement of 4.9 mm has been achieved for Cu‐Al‐Mn‐Ni coated optical fibre. Results show variation in the optical fibre signal due to heating and cooling of the fibre from the applied electrical stimulus on Cu‐based SMA coating in the form of austenite to martensite transformation.
Cross‐layer multipath congestion control, routing and scheduling design in ad hoc wireless networks
Authors: Aljubayri Mohammed , Yang Zhaohui , Shikh‐Bahaei Mohammad 
Published: March 2021

AbstractDemands for stable and efficient transmission are increasing due to the ongoing expansion of global wireless data traffic. One of the most promising ways to moderate burden of traffic load and decrease the queuing delay is to design cross‐layer protocols. This paper considers a utility maximization problem for multipath ad hoc wireless networks via joint cross‐layer congestion control, routing and scheduling design. In the formulated utility maximization problem, rate, scheduling and queuing delay constraints are involved under the condition of fixed channels and time varying channels. To solve this utility maximization problem, two scheduling methods are proposed, that is, perfect scheduling and distributed scheduling. In perfect scheduling, all nodes in the network contribute to the scheduling process, while distributed method only takes into account adjacent nodes. For both methods, the global convergence is proved. A comprehensive simulation evaluation is performed which shows that this proposed algorithms outperform existing cross layer protocols in terms of increasing source rate and reducing congestion price.
Artificial intelligence enhances the performance of chaotic baseband wireless communication
Authors: Ren Hai‐Peng , Yin Hui‐Ping , Zhao Hong‐Er , Bai Chao , Grebogi Celso 
Published: March 2021

AbstractIt was reported recently that chaos properties could be used to relieve inter‐symbol interference caused by multipath propagation in chaos‐based wireless communication system. Although there exists the optimal decoding threshold to theoretically eliminate the inter‐symbol interference, its practical implementation is still a challenge due to the strong requirement to know the future symbols to be transmitted. To tackle this almost ‘impossible’ task, convolutional neural network with deep learning structure is proposed to predict future symbols based on the received signal, to further reduce inter‐symbol interference and to obtain a better bit error rate performance. Due to the short time predictability of chaotic signal, the proposed method is able to predict short‐term future symbols and get a better threshold suitable for the time‐variant channel. The analytical bit error rate of the proposed method is derived. The contributions of the paper are as follows: firstly, a convolutional neural network with deep learning structure is proposed for the first time to predict the future symbols in the chaos baseband wireless communication system, which does not require much training in this important application; secondly, the future bits predicted by the trained convolutional neural network are used together with the past decoded bits to calculate more accurate decoding threshold compared with the existing methods, yielding a better bit error rate performance. Numerical simulations and experimental results validate the effectiveness of our theory and the superiority of the proposed method.
Joint optimization based satellite handover strategy for low earth orbit satellite networks
Authors: Liu Yifei , Feng Lang , Wu Liang , Zhang Zaichen , Dang Jian , Zhu Bingcheng , Wang Lei 
Published: March 2021

AbstractLow earth orbit constellation satellite communication has the characteristics of low propagation delay, low path loss, low launch cost and wide range of applications. Due to the low orbital altitude and the short orbital period of low earth orbit satellites, the relative position between satellites and gateway stations changes fast. As a result, the links between gateway stations and satellites need to be switched continuously. Based on the minimum handover frequency algorithm, this paper considers the balance of satellite workloads, and proposes a load balanced satellite handover strategy. In the proposed handover strategy, a joint optimization algorithm is employed, and the power allocation of the satellite is optimized to improve the system capacity. In the multi‐satellite connection model, an adaptive power allocation algorithm is proposed to guarantee the service quality of the system. Simulation results demonstrate the efficiency of the proposed satellite handover strategy.
Quantized‐feedback hands‐off control for nonlinear systems
Authors: Sachan Ankit , Xiong Xiaogang , Soni Sandeep Kumar , Kamal Shyam , Ghosh Sandip 
Published: March 2021

AbstractThis paper addresses a quantized feedback hands‐off control for a class of nonlinear systems. Here, sector is constructed with the suitable choice of control‐Lyapunov function. With adjustment policy of quantization parameters, the quantized feedback hands‐off control can force the states of the nonlinear feedback system to the interior of a continuous‐time sector infinite time and the Lyapunov‐candidate function decreases automatically inside the designed sector. Finally, the effectiveness of the proposed method is illustrated by numerical examples.
Fault‐tolerant control strategy of open‐winding brushless doubly fed wind power generator based on direct power control
Authors: Jin Shi , Shi Long , Zhang Yue , Sun Dan , Ji Bing 
Published: March 2021

AbstractThis study presents a study of fault‐tolerant operation for a brushless doubly fed reluctance generator (BDFRG) system under a converter switch fault. The topology of the dual converter fed open‐winding BDFRG is adopted to improve post‐fault operation capacity. For post‐fault operation, the appropriate voltage vectors of control winding are selected to directly adjust the active and reactive power of power winding based on the direct power control theory. Switching tables are formulated under different switch faults. The simulation and experimental results demonstrate the feasibility of the proposed strategy.
Compact single‐varactor diode frequency‐reconfigurable microstrip patch antenna
Authors: Al Ahmad Mahmoud , Kabeer Saifudeen , Sanad Ala Abu , Olule Lillian J. A. 
Published: March 2021

AbstractA single‐varactor frequency‐reconfigurable microstrip patch antenna is presented. The antenna comprises a symmetrical arrangement of four metallised patches coupled and interconnected via slots and metallic bars, respectively. The antenna structure is excited through a single feed probe connected to one of the patches. To achieve a compact size of 22 × 21 × 1.57 mm, a shorting pin is placed close to the feed point to pull down the antenna's resonant frequency. By adding a varactor diode at the centre of the patch, frequency reconfigurability is introduced. Variation in the varactor's DC reverse bias voltage from 0 to 7.5 V results in a corresponding resonant frequency shift from 1000 to 1150 MHz, thus providing a tuning range of 15%. The proposed design is compact and achieves frequency reconfiguration with a single‐varactor diode and a low bias voltage requirement compared with the design characteristics reported in existing works. The antenna can find application in various existing and emerging communication systems.
Improved ionic solid/viologen hybrid electrochromic device using pre‐bleached Prussian‐blue electrode
Authors: Chaudhary Anjali , Pathak Devesh K. , Tanwar Manushree , Kandpal Suchita , Ghosh Tanushree , Rani Chanchal , Kumar Rajesh 
Published: March 2021

AbstractThe authors demonstrate how a simple step of loading an electrochromically active Prussian blue (PB; an ionic solid) electrode with Li+ ions can help in achieving a more efficient viologen based solid state hybrid electrochromic device. To accomplish this, two different devices, with and without Li+ ion loaded PB electrodes, have been fabricated. These devices have been compared in terms of their current‐voltage response, bias dependent optical modulation and corresponding colour switching to establish the role of Li+ ion in charge transport and charge balancing involved during bias induced redox mediated colour switching of the two devices. The Li+ containing PB electrode device exhibits a superior performance with twice (40%) the value of colour contrast (20%), quick response switching (1.3 s), excellent stability (8400 s) and better power efficiency as compared to the device containing as‐synthesised PB electrode. A mechanism has been proposed to explain the role of the Li+ ion which is later substantiated using bias‐dependent in situ Raman spectroscopic evidences.
Bony Union and Flap Resorption in Cranioplasty with Autologous Subcutaneous Pocket Preserved Bone Flap: Early Report on an Ambidirectional CT Scan-Based Study
Authors: Sengupta Sudip Kumar , Kumar Andrews Navin , Maurya Vinay , Bajaj Harish , Yadav Krishan Kumar , G. Ashwath K. , Faujdar Dharamjeet Singh 
Published: March 2021

Abstract
Introduction Absence of sufficient number of prospective randomized controlled studies and comparatively small sample size and short follow-up period of most of the studies, available so far, have left ambiguity and lack of standardization of different aspects of cranioplasty.
Materials and Methods This is an early report of a computed tomography scan image-based ambidirectional study on cranioplasties performed with autologous subcutaneous pocket preserved bone flaps. Retrospective arm compared bony union and factors influencing it between cranioplasties and craniotomies. Patients with poor bony union and aseptic resorption were followed up in the prospective arm.
Results Retrospective arm of the study, followed up for five years (mean 32.2 months), comprised 42 patients as cases (Group 1) and 29 as controls (Group 2). Twenty-seven individuals (64.3%) in Group 1 had good bony union, as compared with 20 (68.9%) good unions in Group 2 out of the 29 patients. Four patients (9.5%) in Group 1 showed evidence of flap resorption, a finding absent in any patient in Group 2. Age, sex, smoking habits, superficial skin infection, and method of fixation did not appear to have any implication on bony union. Craniotomies done using Gigli saws fared better as compared with those done with pneumatic saw with lesser flap size–craniectomy size discrepancy, though it was not statistically significant. Fifteen patients have been included in the Prospective arm at the time of submission of this article.
Conclusion Ours is a study with a small sample size, unable to put its weight on any side, but can surely add some more data to help the Neurosurgeons in choosing the best for their patients.
Environmental problems and Geographic education. A case study: Learning about the climate and landscape in Ontinyent (Spain)
Authors: Campo-Pais Benito , Morales-Hernández Antonio José , Morote-Seguido Álvaro , Souto-González Xosé Manuel 
Published: March 2021

AbstractCultural perceptions of the environment bring us back to elements and factors guided by “natural” cause-effect principles. It seems that academic education has had little effect on the manner and results of learning about changes in the local landscape, especially as regards rational explanations. There is considerable difficulty relating academic concepts about the climate to transformations in the environmental landscape. Teaching tasks are mediatized due to the use of rigorous and precise concepts which facilitate functional and satisfactory learning. This is the objective of the research this article aims to undertake, for which we have chosen the case of Ontinyent (Spain). This research will include two parts: the first aims to identify problems in geographical education of the climate, and the second applies to didactic suggestions for improvement. Methodologically, this study involves qualitative, non-experimental, research-oriented toward change, which purports to understand the educational reality. Our sample included a total of 431 students. Moreover, a semi-structured interview, conducted with teachers in schools and universities in Ontinyent, was organized. Fourteen teachers were interviewed, including two who participated as research professors in the action-research method. The study revealed that students’ conceptual and stereotypical errors, in the different educational stages, vary according to the type (climate, weather, climate change, landscape) and stage (Primary, Secondary, University). They are persistent and continuous, given that they are repeated and appear anchored in the ideas and knowledge development of students regarding the problems and the study of the climate throughout their education.
Primate innate immune responses to bacterial and viral pathogens reveals an evolutionary trade-off between strength and specificity
Authors: Hawash Mohamed B. F. , Sanz-Remón Joaquin , Grenier Jean-Christophe , Kohn Jordan , Yotova Vania , Johnson Zach , Lanford Robert E. , Brinkworth Jessica F. , Barreiro Luis B. 
Published: March 2021

SignificanceHumans and our close evolutionary relatives respond differently to a large number of infections. Such differences are thought to result, at least in part, from interspecies differences in immune function. Here, we report on the whole-genome expression of blood leukocytes from four primate species responding to bacterial and viral stimulation. We show that apes mount a markedly stronger early transcriptional response to both viral and bacterial stimulation when compared to African and Asian monkeys. In addition, our findings suggest that apes activate a broader array of defense molecules that may be beneficial for early pathogen killing at the potential cost of increased energy expenditure and tissue damage. Our results provide insight into the evolution of immune responses in primates.
Iron colloids dominate sedimentary supply to the ocean interior
Authors: Homoky William B. , Conway Tim M. , John Seth G. , König Daniela , Deng FeiFei , Tagliabue Alessandro , Mills Rachel A. 
Published: March 2021

Significance
Phytoplankton assimilate carbon dioxide, produce oxygen, and nourish food webs on a scale that impacts planetary processes but are limited by iron deficiency over much of the global surface ocean. Therefore, we must understand processes that regulate the ocean’s iron inventory to accurately simulate and predict the ocean’s response to change. This study reveals that the widespread production of nanosized iron colloids from the weathering of lithogenic material drives sedimentary iron supply throughout the deep ocean. The discovery accounts for the unexplained occurrence of colloids and patterns of iron isotope variation previously observed in other parts of the deep ocean and suggests how long-standing assumptions we have used to simulate iron supply in ocean models must be revised.
Differential regulation of local mRNA dynamics and translation following long-term potentiation and depression
Authors: Donlin-Asp Paul G. , Polisseni Claudio , Klimek Robin , Heckel Alexander , Schuman Erin M. 
Published: March 2021

Significance
Local protein synthesis is important for neuronal function and synaptic plasticity. Thousands of mRNAs are found in axons and dendrites, and it is believed that regulating their dynamic transport and distribution is a key determinant of where and when proteins are made. In this work we quantitatively assessed the dynamic transport of three synaptically localized mRNAs in live cultured neurons without exogenous stimulation and following induction of two distinct forms of synaptic plasticity. Coupling observations of mRNA dynamics with live imaging of endogenous protein synthesis dynamics, we found that alterations in mRNA movements occur independently of their translational state, indicating a multistep mechanism of capture and decoding of an mRNA to determine when translation occurs.
Short-term forecasts of expected deaths
Authors: Rizzi Silvia , Vaupel James W. 
Published: March 2021

Significance
We introduce a simple but powerful method for analyzing mortality after a major shock. We apply the method to show, more conclusively than up to now, that Denmark, which imposed a lockdown during the first wave of the coronavirus pandemic, suffered considerably lower risks of death than Sweden, which did not impose a lockdown. Our method makes short-term forecasts of the number of deaths that would have occurred if the coronavirus pandemic or other health catastrophe had not occurred. By subtracting the forecast counts from actual death counts, excess mortality can be estimated. This can be done by age, sex, and other characteristics. The method can also be used for other kinds of short-term forecasting.
Exploring the Case: Buciti & Tara Resort: Going Beyond Corporate Social Responsibility
Authors: Dodds Rachel , Graci Sonya 
Published: March 2021

Introduction
The Bucuti & Tara Resort is a world-class resort in Aruba that has focused on reducing its environmental footprint. It was the first certified carbon neutral hotel in the Caribbean. It is also a hotel that is socially conscious and service-oriented. In 2018, it had a 97% occupancy rate and almost 70% were repeat customers. This is due to the leadership and vision of the Bucuti & Tara owner, Ewald Biemans. Despite the many social and environmental initiatives implemented by the Bucuti & Tara Resort, it wishes to increase its sustainability efforts and influence on the community around it.
Optical control of the density and spin spatial profiles of a planar Bose gas
Authors: Zou Y-Q , Le Cerf É , Bakkali-Hassani B , Maury C , Chauveau G , Castilho P C M , Saint-Jalm R , Nascimbene S , Dalibard J , Beugnon J 
Published: March 2021

Abstract
We demonstrate the arbitrary control of the density profile of a two-dimensional Bose gas by shaping the optical potential applied to the atoms. We use a digital micromirror device (DMD) directly imaged onto the atomic cloud through a high resolution imaging system. Our approach relies on averaging the response of many pixels of the DMD over the diffraction spot of the imaging system, which allows us to create an optical potential with an arbitrary intensity profile and with micron-scale resolution. The obtained density distribution is optimized with a feedback loop based on the measured absorption images of the cloud. Using the same device, we also engineer arbitrary spin distributions thanks to a two-photon Raman transfer between internal ground states.
Light-scattering of tracer particles for liquid flow measurements
Authors: Das Prashant , Ghaemi Sina 
Published: March 2021

Abstract
A variety of modern flow measurement techniques use tracer particles that should accurately follow fluid motions and should scatter sufficient light to be detectable by imagining systems. These two requirements are at odds if they are to be full-filled by varying the tracer size. For this reason, other particle properties such as material, structure, and coating are also considered. While the effect of these properties on the particle response time can be estimated, it is challenging to quantify their effect on the scattered light using the Mie scattering theory. To address this issue, we investigated the light scattering properties of several commercially available tracer particles and provided simple guidelines for selecting appropriate particles. The investigations were carried out using particle images recorded in forward, side, and backward-scatter angles that are typically used in 3D-particle tracking velocimetry. The selected particles represent a wide spectrum of particle sizes and included glass, polymer, and fluorescent particles used in liquid flows. Other properties such as hollow structures and metallic coatings were also investigated. The results showed that glass particles had greater light scattering in the forward-scatter direction, while the polystyrene particles scattered more light in the back-scatter direction. The fluorescent particles had a relatively narrow intensity distribution with a strong side-scatter. We found that silver-coated glass particles had two to four times higher image intensity in the side and back-scatter cameras when compared with uncoated glass particles. The hollow glass particles had a higher forward-scatter compared with the solid glass particles. The recorded images were also used to obtain 3D particle tracks. A large intensity variation was observed along the 3D tracks that was mainly associated with the discretization of particle images on the camera sensor.
Compound fault diagnosis of rolling bearings based on improved tunable Q-factor wavelet transform
Authors: Hu Yongtao , Zhou Qiang , Gao Jinfeng , Li Jie , Xu Yonggang 
Published: March 2021

Abstract
In order to solve the difficulty of compound fault diagnosis of rolling bearings, a novel rolling bearings fault diagnosis method based on improved tunable Q-factor wavelet transform (TQWT) is proposed in this paper. Firstly, a new evaluation index of signal decomposition called KR is defined by summing kurtosis and root mean square (RMS) with weight. KR is the compromise between impulse factor and energy factor, which can better represent the fault characteristics of sub-bands obtained by TQWT. Secondly, the KR is used to improve the TQWT. The improved TQWT can adaptively determine the parameters Q-factor and decomposition level. Thirdly, the bearing vibration signal is decomposed by the improved TQWT and the sub-bands are sorted descending according to the KR. Finally, the Hilbert envelope analysis is carried out and the fault types are determined by comparing the fault characteristic frequencies obtained from the Hilbert envelopes to the fault characteristic frequencies calculated by formula. The proposed fault diagnosis method is fully evaluated by simulation and experiments. The results demonstrate that the KR takes advantage of kurtosis and RMS and can be better used to optimize the parameter of TQWT. And the compound fault features of rolling bearings can be accurately separated into different sub-bands by the improved TQWT, which is helpful to improve the accuracy of compound fault diagnosis of rolling bearings.