bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of Seasonal Effects in Impulse Responses Using Score-Driven Multivariate Location Models
Authors: Blazsek Szabolcs , Escribano Alvaro , Licht Adrian 
Published: November 2020

Abstract
For policy decisions, capturing seasonal effects in impulse responses are important for the correct specification of dynamic models that measure interaction effects for policy-relevant macroeconomic variables. In this paper, a new multivariate method is suggested, which uses the score-driven quasi-vector autoregressive (QVAR) model, to capture seasonal effects in impulse response functions (IRFs). The nonlinear QVAR-based method is compared with the existing linear VAR-based method. The following technical aspects of the new method are presented: (i) mathematical formulation of QVAR; (ii) first-order representation and infinite vector moving average, VMA (∞), representation of QVAR; (iii) IRF of QVAR; (iv) statistical inference of QVAR and conditions of consistency and asymptotic normality of the estimates. Control data are used for the period of 1987:Q1 to 2013:Q2, from the following policy-relevant macroeconomic variables: crude oil real price, United States (US) inflation rate, and US real gross domestic product (GDP). A graphical representation of seasonal effects among variables is provided, by using the IRF. According to the estimation results, annual seasonal effects are almost undetected by using the existing linear VAR tool, but those effects are detected by using the new QVAR tool.
Stability and the inverse gravimetry problem with minimal data
Authors: Isakov Victor , Titi Aseel 
Published: November 2020

Abstract
The inverse problem in gravimetry is to find a domain 𝐷 inside the reference domain Ω from boundary measurements of gravitational force outside Ω.
We found that about five parameters of the unknown 𝐷 can be stably determined given data noise in practical situations.
An ellipse is uniquely determined by five parameters.
We prove uniqueness and stability of recovering an ellipse for the inverse problem from minimal amount of data which are the gravitational force at three boundary points.
In the proofs, we derive and use simple systems of linear and nonlinear algebraic equations for natural parameters of an ellipse.
To illustrate the technique, we use these equations in numerical examples with various location of measurements points on

∂
⁡
Ω

\partial\Omega

.
Similarly, a rectangular 𝐷 is considered.
We consider the problem in the plane as a model for the three-dimensional problem due to simplicity.
Penalty success in professional soccer: a randomised comparison between imagery methodologies
Authors: Rhodes Jonathan , May Jon , Booth Alex 
Published: November 2020

Abstract

Objectives
The PETTLEP model is one of the most cited forms of imagery training to enhance sporting performance, but there is limited evidence for its long-term effectiveness and it is often compared to non-imagery controls rather than other imagery techniques. We compared PETTLEP with an imagery-based behavioural change intervention, Functional Imagery Training (FIT), and assessed long-term effectiveness for enhancing professional soccer player’s penalty kick taking.

Methods
Thirty male professional soccer players conducted a group goal setting task, were introduced to imagery, then randomly assigned to three conditions; individual PETTLEP, group-based FIT, or a control. Baseline penalty kick success was measured, then interventions commenced lasting for a week after which, penalties were conducted again. Penalties were conducted for a third time between 15 and 17 weeks after baseline measurements.

Results
There were no differences in baseline scores between conditions on vividness of imagery and penalty kicking. Whilst the control condition did not improve, both imagery conditions improved penalty performance after one week, as did their vividness of imagery scores. However, after 15 weeks, only the FIT for groups condition maintained improvements on penalty scores and PETTLEP returned to baseline.

Conclusions
Imagery is effective in improving penalty kick taking, but PETTLEP does not support long-term change, whereas the motivational approach of FIT does.
Fast speed switching response and high modulation signal processing bandwidth through LiNbO3 electro-optic modulators
Authors: Eid Mahmoud M. A. , Rashed Ahmed Nabih Zaki , Amiri Iraj S. 
Published: November 2020

Abstract
This work outlined the fast speed response and high modulation bandwidth through LiNbO3 electro-optic modulators. The refractive index is analyzed to estimate the switching voltage and modulation bandwidth for these modulators. The modulation voltage and data transmission data rates are analyzed and discussed clearly through LiNbO3 electro-optic modulators. The modulator’s performance efficiency is upgraded with the optimum modulator length of 10 mm and its thickness of 2 mm. The proposed modulators are compared with GaAs electrooptic modulators under various electro-optic modulators dimensions at 1300 nm near-infrared region and room temperature.
Compact and efficient PC-based directional coupler all-optical switch
Authors: Masilamani Sivasindhu , Samundiswary Punniakodi 
Published: November 2020

Abstract
Recently, the photonic crystal–based optical components and devices have attracted many researchers’ attention because of its nanoscale size which makes it suitable for the photonic integrated applications. Hence, the design of all-optical switch based on photonic crystal structure have been investigated in the past few decades to meet the requirement of ultracompact size with optimized performances such as fast response time, high extinction ratio with low insertion loss. Here, the design of directional coupler–based all-optical switch operating at the wavelength of 1550 nm is proposed with new design values. The resonant operating wavelength of the switch is identified with the help of finite element method. Then, the cross-state switching operation is analysed with the help of finite-difference time-domain method by applying a nonlinear optical Kerr effect switching mechanism. The important performance metrics of the proposed design such as insertion loss, extinction ratio, directivity and the response time are obtained as −0.008 , 26.98, 20.44 dB and 0.13ps, respectively. The total footprint of the proposed optical switch is approximately 128 µm2.
Performance analysis and parameter optimization of all-optical encryption using the FWM effect in semiconductor optical amplifier
Authors: Sasikala Vinayagam , Chitra Krishnan 
Published: November 2020

Abstract
The demand for larger bandwidth to carry high capacity data in optical networks is increasing. Thus, it is expected to replace all digital logic with optical logic soon. Privacy and data security are also of utmost importance in all-optical networks. Generally, all-optical encryption has been carried out using (i) highly nonlinear fiber (HNLF) and (ii) Semiconductor Optical Amplifier (SOA) with interferometric structures. However, the former is limited by the requirement of a lengthy fiber and the latter one with more number of nonlinear components. In this work, an all-optical encryption process using nonlinear effects and four-wave mixing (FWM) in SOA without interferometric structure is presented for different number systems. The basic idea of the proposed system is to use delay operations which are carried out by duo binary modulation units whereas the encryption using single SOA is possible by FWM nonlinear effect. This combination of novel design for different number systems is optimized through SOA structural parameters, pump and probe signal power, and wavelength. Through optimization, the performance improvement is assured by a good extinction ratio of 11.5 dB for the active region length of less than 200 µm. Compared to the existing techniques, the quality factor is 2.28 times and 1.52 times better than HNLF and SOA-MZI, respectively.
Comparative study of all-optical INVERTER and BUFFER gates using MZI structure
Authors: Singh Pallavi , Singh Ashutosh Kumar , Arun Vanya , Tripathi Devendra K 
Published: November 2020

Abstract
In the paper, one input optical gates i.e., INVERTER and BUFFER have been designed using some basic assumption to analyze with the help of Semi-conductor Optical Amplifier based Mach–Zehnder Interferometer structure. The results are optimized by iterative process. The proposed design of optical gates presents low complexity, high scalability and more feasible to evaluate through digital Boolean analyzation. The digital Boolean analyzation is analyzed by some basic Boolean rules and assumptions which makes the design more digital so that it can be compatible for more than one input optical gates also. Optical Gate is designed to get constructive and destructive interference for pump and probe as they are injected into SOA simultaneously. The phase modulation is converted into intensity modulation which gives a Boolean result. The paper is optimized by Eye diagram, Q factor, wavelength spectrum and frequency chirp for both the gates. The comparative results of extinction ratio for both the gates have also been discussed. The design is supported by theoretical analysis, simulation tool (Optsim) and Boolean explanation. The proposed designs are constructed with same pattern which supports the same Boolean analysis.
Dual band radio-over-fibre millimetre–wave system utilizing optical frequency combs
Authors: Kavitha Geethika V. , Sindhu Supriya S. , Zacharias Joseph 
Published: November 2020

Abstract
The urge for high-speed data transmission never ends. The demand for seamless online video streaming services demands a faster data transmission rate. To fulfil the demand optical communication can be used to enhance the overall performance. The union of microwave and optical networks known as Radio-over-Fibre (RoF) technology, may be a reasonable solution for improving capacity and mobility likewise as decreasing costs within the access network. Millimetre-wave (mm-wave) signals can be utilized for multi-Gb/s transmission. But mm-wave generation in the electrical domain is less feasible. Here, the optical domain comes into play. In this paper, two mm-wave frequencies are generated using optical frequency combs (OFCs). This technique is an effective solution for the mm-wave RoF system for 5G and beyond. By simulation, the major restraints of linewidth and relative intensity noise (RIN) are explored. RIN level of −163 dB/Hz is achieved.
Performance enhancement of transceiver system based inter satellite optical wireless channel (IS-OWC) for ultra long distances
Authors: Eid Mahmoud M. A. , Houssien Fatma Mohammed Aref Mahmoud , Rashed Ahmed Nabih Zaki , Mohammed Abd El-Naser A. 
Published: November 2020

Abstract
This work clarified the performance enhancement of transceiver system based (IS-OWC) link by using both vertical cavity surface emitting laser diode (VCSEL) and continuous wave (CW) laser sources. The proposed model has been investigated and discussed. The inter satellite link has been modelled by using optisystem simulator at 10 Gb/s and 40 Gb/s for long distance up to 5000 km by using return to zero (RZ) and non return to zero (NRZ) schemes. The performance of IS-OWC system has been investigated by estimating the evaluation parameters such as Q-factor and bit error rate (BER). The results revealed that the NRZ is superior to RZ due to its reduced bandwidth. The BER obtained at 5000 km distance for NRZ scheme is 10−12 and 10−10 when using VCSEL and CW laser source respectively. The Q-factor records higher values at different distances when using VCSEL.
Novel approach to jointly optimize working and spare capacity of survivable optical networks
Authors: Singh Ashutosh Kumar , Arun Vanya , Singh Pallavi , Upadhayay Kamal Kishore 
Published: November 2020

Abstract
As technology advancing day by day, the data rate of optical network is moving towards Tb/s speed. The minimum capacity utilization and survivability are the crucial requirement in such high speed optical networks. This research work presents a new approach to calculate both working and spare capacity with the help of single mathematical programming model named as joint capacity planning model. The working traffic and restored traffic are routed jointly in proposed joint capacity planning model. Therefore the joint capacity planning model required minimum capacity in as compare to other optimization models. To evaluate our model, three example networks are proposed i.e., network A (6 node), network B (8 node) & National science foundation network (14 node). Results of these networks are analyzed and compared. The capacity utilization is optimized by increasing the backup paths of the optical networks. It has also been proved in this manuscript that capacity requirement is dependent on the backup path. The proposed joint capacity model provides fast restoration speed and guaranteed protection for optical network.
Comparative analysis of the helminth fauna of Dasypus hybridus and Chaetophractus villosus (Xenarthra: Cingulata) in the Pampas region, Argentina
Authors: Ezquiaga María Cecilia , Rios Tatiana Agustina , Abba Agustín Manuel , Navone Graciela Teresa 
Published: November 2020

Abstract

Chaetophractus villosus and Dasypus hybridus are the most widespread and abundant armadillos inhabiting the Pampas grasslands. Studies on the parasitic fauna from an ecological perspective are scarce in both species. We describe and compare the component communities of C. villosus and D. hybridus in the Pampas ecoregion of Argentina and analyse if the composition and structure of the parasitic communities of these host species reveal trophic behaviour and/or habitat use. In the population of C. villosus 10 species of helminths were found, namely Ancylostoma caninum, Aspidodera fasciata, Aspidodera scoleciformis, Mazzia bialata, Moennigia celinae, Orihelia anticlava, Strongyloides sp., Trichohelix tuberculata (Nematoda) and Mathevotaenia sp. (Cestoda), whereas in the population of D. hybridus four species were found, A. fasciata, Delicata abbai, Pterygodermatites chaetophracti and Strongyloides sp. Only A. fasciata and Strongyloides sp. were present in both species. Prevalences and intensities were similar in Strongyloides sp. In A. fasciata, however, there were differences regarding mean intensity. Diversity was higher in C. villosus than in D. hybridus. The differences may be related to the diet, behaviour, evolutionary histories or immune response of the species studied. A combination of several of these factors would possibly influence the composition of their parasitic fauna.
Machine learning–assisted global optimization of photonic devices
Authors: Kudyshev Zhaxylyk A. , Kildishev Alexander V. , Shalaev Vladimir M. , Boltasseva Alexandra 
Published: November 2020

AbstractOver the past decade, artificially engineered optical materials and nanostructured thin films have revolutionized the area of photonics by employing novel concepts of metamaterials and metasurfaces where spatially varying structures yield tailorable “by design” effective electromagnetic properties. The current state-of-the-art approach to designing and optimizing such structures relies heavily on simplistic, intuitive shapes for their unit cells or metaatoms. Such an approach cannot provide the global solution to a complex optimization problem where metaatom shape, in-plane geometry, out-of-plane architecture, and constituent materials have to be properly chosen to yield the maximum performance. In this work, we present a novel machine learning–assisted global optimization framework for photonic metadevice design. We demonstrate that using an adversarial autoencoder (AAE) coupled with a metaheuristic optimization framework significantly enhances the optimization search efficiency of the metadevice configurations with complex topologies. We showcase the concept of physics-driven compressed design space engineering that introduces advanced regularization into the compressed space of an AAE based on the optical responses of the devices. Beyond the significant advancement of the global optimization schemes, our approach can assist in gaining comprehensive design “intuition” by revealing the underlying physics of the optical performance of metadevices with complex topologies and material compositions.
High refractive index and extreme biaxial optical anisotropy of rhenium diselenide for applications in all-dielectric nanophotonics
Authors: Shubnic Anton A. , Polozkov Roman G. , Shelykh Ivan A. , Iorsh Ivan V. 
Published: November 2020

Abstract
We establish a simple quantitative criterium for the search of new dielectric materials with high values of refractive index in the visible range. It is demonstrated, that for light frequencies below the bandgap, the latter is determined by the dimensionless parameter η calculated as the ratio of the sum of the widths of conduction and valence bands and the bandgap. Small values of this parameter, which can be achieved in materials with almost flat bands, lead to dramatic increase of the refractive index. We illustrate this rule with a particular example of rhenium dichalcogenides, for which we perform ab initio calculations of the band structure and optical susceptibility and predict the values of the refractive index

n
>
5

$n{ >}5$

in a wide frequency range around 1 eV together with comparatively low losses. Our findings open new perspectives in search for the new high-index/low-loss materials for all-dielectric nanophotonics.
Temporally modulated energy shuffling in highly interconnected nanosystems
Authors: Mitchell Brandon , Austin Hayley , Timmerman Dolf , Dierolf Volkmar , Fujiwara Yasufumi 
Published: November 2020

Abstract
Advances in lighting and quantum computing will require new degrees of control over the emission of photons, where localized defects and the quantum confinement of carriers can be utilized. In this contribution, recent developments in the controlled redistribution of energy in rare earth (RE)–doped nanosystems, such as quantum dots or within bulk insulating and semiconducting hosts, will be reviewed. In their trivalent form, RE ions are particularly useful dopants because they retain much of their atomic nature regardless of their environment; however, in systems such as GaN and Si, the electronic states of the RE ions couple strongly to those of the host material by forming nanocomplexes. This coupling facilities fast energy transfer (ET) (<100 ps) and a carrier-mediate energy exchange between the host and the various states of the RE ions, which is mediated by the presence of carriers. A model has been developed using a set of rate equations, which takes into consideration the various ET pathways and the lifetimes of each state within the nanocomplex, which can be used to predict the nature of the emitted photons given an excitation condition. This model will be used to elucidate recent experimental observations in Eu-doped GaN.
Polarization-selected nonlinearity transition in gold dolmens coupled to an epsilon-near-zero material
Authors: Niu Xinxiang , Hu Xiaoyong , Sun Quan , Lu Cuicui , Yang Yuanmu , Yang Hong , Gong Qihuang 
Published: November 2020

Abstract
Nonlinear optical materials are cornerstones of modern optics including ultrafast lasers, optical computing, and harmonic generation. The nonlinear coefficients of optical materials suffer from limitations in strength and bandwidth. Also, the nonlinear performance is typically monotonous without polarization selectivity, and to date, no natural material has been found to possess nonlinear coefficients with positive or negative signs simultaneously at a specific wavelength, all of which impede practical applications in the specific scenario. Here, we realize broadband large optical nonlinearity accompanied with ultrafast dynamics in a coupled system composed of gold dolmens and an epsilon-near-zero material for dual orthogonal polarizations simultaneously. The system also shows the polarization-selected nonlinearity transition properties, where the sign of the optical nonlinear refractive indexes can be converted via polarization switching. This guarantees active transitions from self-focusing to self-defocusing by polarization rotation without tuning wavelength in practical utilizations. The measured nonlinear refractive index and susceptibility demonstrate more than three orders of magnitude enhancement over a 400-nm-bandwidth compared with the constituents, while maintaining the sub-1 ps time response. The realized enhanced, ultrafast response, and the polarization tunability ensure the designed system a promising platform for the development of integrated ultrafast laser sources, all-optical circuits and quantum chips.
Crystal structure of (μ2-1,1′-bis(diphenylphosphino)hexane-κ2
P,P′)-bis[(Z)-N-(3-fluorophenyl)-O-methylthiocarbamato-κS]digold(I), C46H46Au2F2N2O2P2S2
Authors: Yeo Chien Ing , Tiekink Edward R.T. 
Published: November 2020

Abstract
C46H46Au2F2N2O2P2S2, triclinic, P1̄ (no. 2), a = 8.2496(3) Å, b = 11.4366(4) Å, c = 12.9504(4) Å, α = 109.171(3)°, β = 92.496(3)°, γ = 100.208(3)°, V = 1128.98(7) Å3, Z = 1, R
gt(F) = 0.0246, wR
ref(F
2) = 0.0560, T = 100(2) K.
The crystal structure of hexakis(2-(pyridin-2-ylamino)pyridin-1-ium) decavanadate(V) dihydrate, C60H64N18O30V10
Authors: Cui Chuansheng , Liu Sen , Zhao Wenli 
Published: November 2020

Abstract
C60H64N18O30V10, orthorhombic, Pbca (no. 61), a = 21.1781(19) Å, b = 14.4198(13) Å, c = 24.543(2) Å, V = 7495.2(12) Å3, Z = 4, R

gt
(F) = 0.0538, wR
ref(F
2) = 0.1482, T = 298 K.
Crystal structure of (E)-2-(4-fluoro-2-(trifluoromethyl)benzylidene)-7-methoxy-3,4-dihydronaphthalen-1(2H)-one, C19H14F4O2
Authors: Luan Ming-Zhu , Wang Hui-Yun , Zhang Mei , Song Jia , Xu Yang-Rong , Zhao Feng-Lan , Meng Qing-Guo 
Published: November 2020

Abstract
C19H14F4O2, monoclinic, C2/c (no. 15), a = 17.1519(13) Å, b = 13.9810(8) Å, c = 15.2299(9) Å, β = 123.031(7)°, V = 3061.9(4) Å3, Z = 8, R

gt
(F) = 0.0410, wR

ref
(F
2) = 0.1010, T = 100(1) K.
The soundscape of the Trevi fountain in Covid-19 silence
Authors: De Lauro Enza , Falanga Mariarosaria , Lalli Laura Tedeschini 
Published: November 2020

Abstract
This paper is devoted to the analyses of sound-scape at fontana di Trevi in Rome (Italy) with the aim to compare its characteristics during the Italian lockdown due to the (Sars-COV2) Covid-19 sanitary emergency and its characteristics before and after such time. The lockdown has represented an exceptional environment due to the silence everywhere, never occurred in centuries, offering the opportunity to recognize the “signature” of the sound emitted by the famous Fontana di Trevi and recognize how it interacts with other features. The signature is important for preservation issues and cultural heritage. The soundscape was documented in a field survey by means of hand held microphones, which acquired simultaneously the acoustic wavefield all around the fountain. We find that the spectral content depends on the microphone location, revealing a very complex wavefield, showing strong amplitudes during the lockdown well below 1kHz and a frequency band extending up to 10kHz. In a time period far from the lockdown, we evidence an additional frequency band around 700-1kHz, which not simply adds to the previous spectrum, but acts as a synchronization mechanism. The important observation is that the Covid-19 silence let emerge sounds that had been there for centuries, and afforded us the possibility to document them in order to study objectively a “soundprint”. Moreover, we studied the spatialization characteristics of the soundfield.