bluuebunny/crossref_metadata_2025 huggingface dataset:
The development of the reproductive system of the Common Ringtail Possum, Pseudocheirus peregrinus (Marsupialia: Petauridae).
Authors: Armati-Gulson P. , Lowe J.
Published: December 2022

Research into the female reproductive system of marsupials has been confined to certain species and has concentrated upon the reproductive system of adults. The reproductive system of Pseudocheirus peregrinus and its development has received little attention. The development of the female reproductive system of P. peregrinus was studied from specimens ranging from six weeks old to fully mature adults. The study, based on anatomical and histological information, showed that the differentiation of the reproductive tract precedes the histological differentiation of the gonads. The tract increased in both length and diameter with the growth of the animal. The blood vessels supplying the reproductive system were also traced and identified and found to be similar to those described in other marsupials. The study confirms the idea that P. peregrinus is more closely related to the Greater Glider, Petauroides volans, than to the Common Brush-tailed Possum, Trichosurus vulpecula.
Australasian mammal specimens in the collections of Merseyside County Museums.
Authors: Fisher C. T.
Published: December 2022

Many of the Australasian mammals once housed in the Liverpool Free Public Museum were originally obtained from John Gould, John Gilbert, John Macgillivray and Frederick Strange by the thirteenth Earl of Derby, who bequeathed them to the city in 1851. Those specimens which survive in the present Merseyside County Museums comprise 20 monotremes; 128 marsupials, including the types of Sminthopsis macroura (Gould, 1845) and Perameles arenaria Gould, 1944; 4 bats and 33 rodents, including the types of Notomys longicaudatus (Gould, 1844), Pseudomys australis lineolatus (Gould, 1845), Pseudomys nanus (Gould, 1858), Pseudomys australis oralis Thomas, 1921 and Rattus sordidus (Gould, 1858).
Form and function: the phylogenesis of predatory behavior.
Authors: Eisenberg J. F .
Published: December 2022

The act of predation is defined here to include the behavior of insectivores. By examining the behavior of a set of morphologically conservative mammals, a common pattern of prey capture can be identified. Mammals with a conservative morphology and that are active predators may have similar bite efficiencies. Acts of predation in nature are only rarely documented and researchers are often constrained by dependence on indirect evidence and captive studies. Remarkable instances of convergence in the form and function of predators are discernible even when different phylogenetic lines are compared. Some marsupials demonstrate patterns of predatory behavior that are comparable to placentals.
Two new localities for Pseudomys oralis Thomas (Rodentia: Muridae) in New South Wales.
Authors: King G. C. , Mackowski C. M.
Published: December 2022

NA
Introductory notes to the First National Flying-fox Symposium.
Authors: Hall L. S.
Published: December 2022

NA
Open forum on movements and feeding patterns in flying-foxes (Chiroptera: Pteropodidae).
Authors: Parry-Jones K. , Martin L.
Published: December 2022

NA
Flying-foxes (Chiroptera: Pteropodidae) as orchard pests.
Authors: Loebel M. R. , Sanewski G.
Published: December 2022

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Flying-fox (Chiroptera: Pteropodidae) research: future needs and priorities.
Authors: Martin L.
Published: December 2022

NA
The eastern pygmy possum, Cercartetus nanus (Marsupialia: Burramyidae), in the Australian Capital Territory.
Authors: Dickman C. R. , Happold D. C. D.
Published: December 2022

NA
Seasonality, density dependence, and spatial population synchrony
Authors: Nicolau Pedro G. , Ims Rolf A. , Sørbye Sigrunn H. , Yoccoz Nigel G.
Published: December 2022

Studies of spatial population synchrony constitute a central approach for understanding the drivers of ecological dynamics. Recently, identifying the ecological impacts of climate change has emerged as a new important focus in population synchrony studies. However, while it is well known that climatic seasonality and sequential density dependence influences local population dynamics, the role of season-specific density dependence in shaping large-scale population synchrony has not received attention. Here, we present a widely applicable analytical protocol that allows us to account for both season and geographic context-specific density dependence to better elucidate the relative roles of deterministic and stochastic sources of population synchrony, including the renowned Moran effect. We exemplify our protocol by analyzing time series of seasonal (spring and fall) abundance estimates of cyclic rodent populations, revealing that season-specific density dependence is a major component of population synchrony. By accounting for deterministic sources of synchrony (in particular season-specific density dependence), we are able to identify stochastic components. These stochastic components include mild winter weather events, which are expected to increase in frequency under climate warming in boreal and Arctic ecosystems. Interestingly, these weather effects act both directly and delayed on the vole populations, thus enhancing the Moran effect. Our study demonstrates how different drivers of population synchrony, presently altered by climate warming, can be disentangled based on seasonally sampled population time-series data and adequate population models.
A model construction and measurement method for tooth surface deviation of spiral bevel gear based on a one-dimensional probe
Authors: Dai Zhen , Li Tianxing , Zhang Yang , Zhou Jingyuan , Zhang Ruiyao
Published: December 2022

The accurate measurement of tooth surface deviation is an important prerequisite for the quality monitoring of high-precision spiral bevel gears. A measurement method for tooth surface deviation of spiral bevel gears is proposed based on a one-dimensional probe, which can accurately measure and evaluate tooth flank. According to the forming principle of the spiral bevel gear tooth surface, the theoretical surface is constructed as the measurement reference flank. A series of measures and methods are adopted to ensure the accuracy and correctness of one-dimensional probe measurement. These effective methods include the construction of a precise positioning model of the gear blank and its surface, the measurement planning of reduction dimension which the gear needs to rotate once the normal angle after each point is measured, and the compensation for the increasing dimension of the one-dimensional probe. In addition, minimization of the normal deviation of the tooth flank is achieved by using the optimum matching technique of the theoretical and the actual surfaces. The deviation degree of the actual surface relative to the theoretical surface can be accurately calculated and evaluated by establishing a deviation model, which ensures the correctness of the evaluation result of the deviation. Finally, the test of tooth surface deviation is carried out on a JD45+ gear measuring center (GMC) using a one-dimensional probe and a Gleason 650GMS GMC using a three-dimensional probe. The measurement results show that the evaluation results of the one-dimensional probe are in good agreement with those of the three-dimensional probe. The proposed theory and method not only expand the measurement range of the GMC using a one-dimensional probe, but also have certain reference significance for the precision measurement of other complex surfaces.
Unbalanced fault diagnosis of rolling bearings using transfer adaptive boosting with squeeze-and-excitation attention convolutional neural network
Authors: Zhao Ke , Jia Feng , Shao Haidong
Published: December 2022

For practical fault diagnosis issues, normal data are always much more numerous than fault data, so this paper focuses on how to accurately classify the unbalanced datasets. Compared to individual models, the ensemble model can combine multiple models together to achieve higher identification accuracy. In this paper, a transfer adaptive boosting method (AdaBoost) with a squeeze-and-excitation attention convolutional neural network (SEACNN) is proposed to tackle the unbalanced fault diagnosis issues of rolling bearings. Firstly, an SEACNN is designed to extract representative fault features and improve identification performance. Secondly, a new AdaBoost is designed for the SEACNN to efficiently handle unbalanced fault datasets. Thirdly, transfer learning is adopted to sequentially transfer the learned knowledge of one SEACNN estimator to the next estimator, and update the weights in the process. Substantial experiments are conducted to sufficiently evaluate the effectiveness of the proposed method.
Local-in-time existence of a free-surface 3D Euler flow with H
2+δ
initial vorticity in a neighborhood of the free boundary
Authors: Kukavica I , Ożański W S
Published: December 2022

We consider the three-dimensional Euler equations in a domain with a free boundary with no surface tension. We assume that

u
0

∈

H

2.5
+
δ

is such that

c
u
r
l

u
0

∈

H

2
+
δ

in an arbitrarily small neighborhood of the free boundary, and we use the Lagrangian approach to derive an a priori estimate that can be used to prove local-in-time existence and uniqueness of solutions under the Rayleigh–Taylor stability condition.
Degenerate lake equations: classical solutions and vanishing viscosity limit
Authors: Al Taki Bilal , Lacave Christophe
Published: December 2022

The objective of this paper is twofold. First, we show the existence of global classical solutions to the degenerate inviscid lake equations. This result is achieved after revising the elliptic regularity for a degenerate equation on the associated stream-function, and adapting the method used for construction of classical solutions to the incompressible Euler equations. Second, we show that the weak solutions of the viscous lake equations converge to classical solutions of the inviscid lake equations when the viscosity coefficient goes to zero, which constitutes an important physical validation of these models. The later result is achieved by the use of energy method as in the proofs of Kato-type theorems. This method also allows us to expose a convergence rate.
Fluid-Structure Interactions Analysis of a Drag-Type Horizontal Axis Hydraulic Turbine
Authors: Song Ke , Kang Yuchi
Published: December 2022

The Fluid-structure interaction characteristics on the two drag-type horizontal axis hydraulic turbinesare investigated. The results show that the two drag-type horizontal axis hydraulic turbines are suitable for operation under low flow rate and low TSR conditions. The Tuebine 2 has a higher CP
value from TSR=0.5 to TSR=2.0, and has a lower CT
value in the whole TSR rangethan the Turbine 1. The maximum stresses are at the blade root area, and the maximum deformations are at the blade tip for both turbines. The Turbine 1 has a higher stress level and total deformation than the Turbine 2. The frequency on 1st, 2nd, 3rd, 4th and 5th order vibration modes of the Turbine 1 is higher than the Turbine 2, and the 6th one is not. The results provide a reference for the drag-type horizontal-axis hydraulic turbines.
Chemical Defects and Impurities Introduce Charge Traps to Silicone Rubber: a Quantum Chemistry Study
Authors: Duan Wei , Guo Guangzhi , Zhu Guozhu , Zhao Xuefeng , Pu Lu , Ju Zeli , Sun Haofei , Gao Jian
Published: December 2022

The distributions of charge trap energy levels in polymer insulation material have an important influence on the charge transport characteristics and breakdown field strength of the polymer insulation, which thus has attracted considerable attention. Based on the quantum chemistry calculations, the characteristics of charge traps induced by different chemical defects and additives in silicone rubber materials are investigated. The projected density of states, and frontier molecular orbital distribution of defective silicone rubber and additive molecules are analyzed. The carbonyl defect, carboxyl defect and diethyl maleate additive all introduce deep electron traps (more than 1eV) in PDMS materials. The carbonyl defect and KH550 additive introduce shallow hole traps (less than 1eV) in PDMS materials. If chemical defects have a dominant contribution to the frontier molecular orbital of polymer is the key factor of whether they can introduce charge traps.
An Improved Adaptive Load Shedding Control Strategy for Primary Frequency Regulation of Wind Power Generation System
Authors: Li Xudong , Li Hua , Ma Chunzhe , Meng Yongqing , Hu Yahan , Duan Ziyue
Published: December 2022

With the continuous improvement of the proportion of wind power generation, the volatility and uncertainty of wind power pose a serious threat to the stable operation of the power system. However, the traditional primary frequency regulation strategy does not fully consider the influence of wind turbine inertia. In addition, it may cause the secondary frequency drop if the instantaneous power of the wind turbine drops too much during the speed recovery. To solve this problem, this paper proposes an adaptive primary frequency regulation strategy for the mobile load shedding power tracking curve. Under this strategy, by controlling the output active power reference value, the kinetic energy stored in the rotor is fully released to support the grid frequency for a short time. Then, in the process of rotor speed recovery, the frequency secondary drop can be alleviated by moving the load-shedding power tracking curve. Finally, the simulation results in MATLAB/Simulink verify the rationality of the proposed adaptive load-shedding control strategy.
The Application of Posterior Error Criterion to Dynamic Equivalence Evaluation
Authors: Sun Zhiyuan , Liu Mosi , Zheng Kun
Published: December 2022

The scale and complexity of the power system are increasing, which carry out a lot of difficulty and effort to detailed simulation of the whole system, so effective dynamic equivalence is the premise of the modeling of electromagnetic transient simulation of large power systems. This paper targeting at the present situation of lack quantization standard in the dynamic equivalence, this paper took the posterior error criterion of grey forecasting model into the Dynamic Equivalence Evaluation, then proposed more detailed and exactly quantization standard appraisal index system, further perfect the error evaluation system of dynamic equivalence efficiency.
A Chance-constrained Optimization Combined with Soft Open Points and Volt/Var Control under Uncertainties in Distribution Networks
Authors: Wang Jing , Pan Zhiyuan , Liu Jing , Li Tianhang , Li Guanghong , Zheng Xin
Published: December 2022

With more and more photovoltaics (PVs) integrated into distribution networks, their drastically fluctuating nature may lead to voltage limits violation. However, the existing studies only focus on capacitor bank dispatching, which cannot address the drastic fluctuation of PV outputs. To adapt to the fast and continuous variation of PVs outputs in the distribution networks, this paper proposes a joint optimization of capacitor banks (CBs) and soft open points (SOPs). A chance-constrained model is established including the nonlinear equations of SOPs. Then, the second-order conic is applied to SOPs equations for efficient and accurate solving of the model. Finally, a cluster satisfying the given confidence level is formed by a proposed heuristic method to improve calculation efficiency. The numerical simulations on distribution networks show the efficiency and accuracy of the proposed algorithm over the existing methods.
An approach to planning the extension of distributed power supplies to the distribution network, taking into account uncertainty
Authors: Lin Huaide
Published: December 2022

At present, there is a problem of high active line network loss in the distribution network expansion planning method for distributed power supply access, and a distributed power supply access distribution network expansion planning method that accounts for uncertainty is designed to improve this phenomenon. According to the coverage of the electricity consumers’ sites, the available supply capacity of the distributed power sources is evaluated, the wind speed is discounted by the hub height of the wind turbines, the uncertainty is taken into account to build a correlation model, the number of nodes in the grid is fully considered, the grid operation characteristics are extracted, the voltage of the nodes along the line is simplified and the distribution network expansion planning model is optimized. Test results: The method designed here has the lowest average active line network loss of 112.58 kW, which is 10.83 kW, 10.3 kW and 12.85 kW less than the other three methods respectively, indicating that the method designed here performs better with full consideration of the uncertainties.
A novel AC-DC hybrid microgrid architecture and control strategy for electric vehicle swap station
Authors: Zheng Zhilong , Liu Rui , Qi Yanlong , Lin Haisheng , Hong Weizhuo , Zhu Yuquan , Xu Chaoyao
Published: December 2022

The characteristics of small volume, modularity, and easy expansion in solid-state transformers (SST), which makes SST widely applied in electric vehicle swapping stations. However, due to various loads and pulsed loads, voltage instability and fluctuation problems inevitably occur in electric vehicle swapping stations. Aiming at these problems, a topology structure based on a Modular Multilevel Solid State Transformer (MMC-SST) is proposed. It is the first choice for realizing the flexible power allocation of AC/DC hybrid system and the interconnection of medium and low voltage. The performance of the DC bus voltage of the charging station has been improved. Based on this topology, an energy management strategy with virtual synchronous generator (VSG) control is proposed to smoothly transition the on-grid and off-grid processes of the distributed power source. In addition, due to the frequency regulation is applied in the control system, the energy storage system has damping and inertia when the output of the new energy power generation equipment changes or load fluctuation, reducing the impact on the load energy storage equipment and improving the stability and safety of the electric vehicle charging station system. Finally, the effectiveness of the proposed topology and its control strategy in different working scenarios are verified by simulation. Simulation analysis shows that the proposed topology has good advantages in DC bus voltage stability, optimization of electric vehicle charging characteristics and load management.
A Transformer Based Complex-YOLOv4-Trans for 3D Point Cloud Object Detection on Embedded Device
Authors: Zhang Jingfeng , Song Qingzeng , Yu Jing
Published: December 2022

3D object detection is widely used in the field of autonomous driving. The embedded devices have few resources and low power consumption, so the existing 3D object detection algorithms are difficult to complete the detection task in the required time under some conditions. In this paper, the Complex-YOLOv4-Trans model is proposed to use point cloud data for 3D object detection. Firstly, a transformer encoder block is introduced to improve the structure of Backbone, which makes full use of its context information to improve detection accuracy. Secondly, the general convolution in Backbone is replaced with a depth-wise separable convolution, which effectively reduces the computational load of the model. Finally, Complete-IoU (CIoU) is used as the loss function, and then 8-bit model quantization is performed to speed up the inference. We select the KITTI dataset and deploy the model on NVIDIA Jetson Xavier NX by using TensorRT acceleration tools to test the methods. The mAP of Bird’s Eye View for Car is 71.79%, the mAP for 3D Detection is 15.82%, and the FPS on the NX device is 42 frames. Experimental results show that our Complex-YOLOv4-Trans can perform real-time 3D object detection tasks on low-energy embedded devices.
Multi-channel High-speed Data Acquisition System Based on Improved SPI Communication
Authors: Yang Changqing , Zhou Dawei , Lu Li
Published: December 2022

A multichannel high-speed data acquisition system based on improved SPI communication is designed to meet the requirements of synchronous acquisition of current and voltage parameters by master and slave control boards. The main architecture of this system is a master-slave FPGA board and AD acquisition card, and the program is developed based on the Vivado platform. Based on traditional SPI communication, this paper puts forward an improved SPI communication. By increasing the number of MISO data lines, the data transmission rate between master and slave control boards is greatly increased, and the FPGA expansion port resources are fully utilized. In addition, a data conversion module is added to the system, which can observe the acquisition results more intuitively. At the same time as high-speed data acquisition, the measurement accuracy within the specified voltage input range is high. The experimental results show that the system can realize multichannel high-speed data acquisition.
Design of Grid Communication Data Gateway Filtering System Based on Microservice Architecture
Authors: Chen Yuxu , Liu Mingwei , Ao Zhiqi , Fan Zhongkai , Liu Zhuqing
Published: December 2022

The grid communication data gateway filtering system has the problem of excessive memory overhead, so a grid communication data gateway filtering system based on micro-service architecture is designed. For the hardware part, the system can support mounting a U disk with a capacity of 16 G and above and use NAND FLASH to realize the expansion of solidified code and storage space. For the software part, the system can get the gateway communication parameters, calculate the bit rate of grid communication data transmission, and match a specific duty cycle. Besides, it can set the existing network port authentication mode according to the instructions, start the gateway filtering program, design the power grid communication data reliability judgment rule base, and optimize the filtering mode based on the micro-service architecture. The test results are that under the conditions of a different number of sensitive words, the average memory overhead of the designed system is 75.93 MB, indicating that the system has better overhead performance under the influence of the microservice architecture.
Fine-grained Vehicle Classification Based on Feature Augmentation
Authors: Chen Junwen , Chen Zhiyi , Tao Simiao , Xia Jing
Published: December 2022

Fine-grained vehicle classification is a hot research topic in the field of computer vision, which aims to recognize different models of vehicles belonging to the same brand. Limited by the large appearance differences of the same vehicle (due to different attitudes and perspectives) and small appearance differences between different vehicles, the vehicle’s reorganization performance is not high and can’t meet the real application requirements. In this paper, a Fine-grained Vehicle Classification is proposed based on Feature Augmentation (FAFCC), which focuses on mining the key discriminative parts of the object. Specifically, the FAFCC first improves the weakly supervised data augmentation network (WSDAN) by using multi-layer feature extraction and fusion instead of single-layer features. Further, the FAFCC assigns local feature weights to select key features, which can solve the problem that the discriminant features in the channel are not prominent enough and realize the high-quality compact fine-grained vehicle recognition task. The performance of the FAFCC on the fine-grained image classification tasks for vehicles has been evaluated through algorithm comparison experiments and ablation experiments. Through visual analysis, it can be seen that the introduction of each new module has optimized the loss function value and convergence speed of the model. In general, our FAFCC algorithm has a certain improvement effect compared with the original algorithm.
Performance Detection of Transformer Oil Based on Wavelet Neural Network Optimized by Sparrow Search Algorithm
Authors: Zhang Xin , Wang Zonglin , Shen Wenqiang , Guo Yongji , Chen Baoqi
Published: December 2022

Transformer oil is an indispensable part of the transformer. The performance of transformer oil largely determines the working condition of the transformer. Therefore, it is necessary to realize accurate and rapid detection of the physical and chemical properties of transformer oil. To realize the detection of transformer oil, firstly, the ultrasonic wave with multiple frequencies is transmitted through the transformer oil, and the physical data such as penetration velocity and attenuation coefficient in the transformer oil are detected. The parameters of the wavelet neural network were optimized using the sparrow search algorithm, and the feasibility of the model was detected using the transformer oil experimental data.
Optical, structural, morphological and chemical properties of doped TiO2 nanoparticles with FeCl3
Authors: Afonso Cátia , Segundo Iran Rocha , Lima Orlando , Landi Salmon , Homem Natália , Costa Manuel F. M. , Freitas Elisabete , Carneiro Joaquim
Published: December 2022

To achieve high photocatalytic activity, TiO2 nanoparticles nanoparticles require an excitation source in ultraviolet radiation. Incorporating chemical elements into the TiO2 lattice can tune its band gap, resulting in an edge-shifted red absorption to reduce energies, improving photocatalytic performance in the visible region of the electromagnetic spectrum. In this research, TiO2 semiconductor nanoparticles were subjected to a doping process using iron chloride (FeCl3) powder to activate photocatalysis under visible light and consequently improve pollutant capture. To study the effectiveness of the doping process, the main ratios (1:1), (1:1.622) and (1:3) of TiO2:FeCl3 were evaluated using Diffuse Reflectance Spectroscopy (DRS), X-ray diffraction (XRD), Fourier-Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The main results of this research show that doping TiO2 with FeCl3 shifted the absorption edge to longer wavelength values, changing the optical properties of the material and decreasing the band gap (Eg) of TiO2 compared to the undoped TiO2 (reference). There are no relevant differences between the XRD pattern of the samples with TiO2-FeCl3 and TiO2 nanoparticles (reference). The fraction of the anatase phase in doped TiO2 nanoparticles has the same magnitude as the reference TiO2. Regarding FTIR, the Fe-doping process alters the TiO2 reference spectrum, increasing the intensity of hydroxyl bonds and peaks particularly, indicating the Ti-O-Fe bond vibration.
Silicon Nitride Interferometers for Optical Sensing with Multi-micron Dimensions
Authors: Costa João , Almeida Daniel , Fantoni Alessandro , Lourenço Paulo , Vieira Manuela
Published: December 2022

Increasing the size of the smallest features of Photonic Integrated Circuits (PICs) to multi-micron dimensions can be advantageous to avoid expensive and complex lithographic steps in the fabrication process. In applications where extremely reduced chip size is not a requirement, the design of devices with multi-micron dimensions is potential interesting to avoid the need for e-beam lithography. Another benefit is that making the dimensions larger reduces the effect of lithographic imperfections such as waveguide surface roughness. However, the benefits do not come without limitations. Coupling the light in and out of the circuit is more challenging since diffraction gratings are not available when designing for such large dimensions. Circuit bends must have a larger radius of curvature and the existence of multimode propagation conditions can have detrimental impact in the performance of several devices, such as interferometers. In this study we perform simulations of the coupling between a lensed multimode optical fiber and a multi-micron a-SiN:H rib waveguide. Light coupling efficiency is analyzed as a function of distance variations using the FDTD method and compared with coupling to a strip waveguide. Moreover, we use numerical simulations to study the performance of a Mach-Zehnder interferometer sensitive to refractive index variations. Both the interferometer, splitters and combiners are designed with multi-micron dimensions.
Assessment of central and peripheral accommodative lag by aberrometry
Authors: Sapkota Kishor , Gomes Jessica , Franco Sandra
Published: December 2022

Accommodation lag is important factor for normal vision. Higher lag of accommodation may cause various ocular symptoms particularly during near tasks. In this study, the lag of accommodation was assessed in the peripheral retina and it was compared with the central accommodative lag with aberrometer. In this cross-sectional study, fifty-three young subjects with normal visual acuity and without any active ocular disease or past ocular surgery were included. Aberrations in the central and peripheral field of view up to 30° off axis from the centre in horizontal and vertical meridian in 10° steps were measured with Hartmann-Shack aberrometer with stimulation of accommodation by -2.50D lens. Accommodative stimulus and accommodative response were calculated with defocus and hence accommodative lag was obtained. Accommodative lag in the centre and periphery was compared. Repeated measure of ANOVA showed that there were significant differences in lag of accommodation in various eccentricities (F(8.912, 454.514) = 2.372, p = 0.013). Pairwise test showed that lag in the centre was similar with lag on other peripheral field of view (p > 0.05). However, accommodative lag at 10° nasal field was significantly lower than the lag at 20° temporal, 20° nasal, 30° temporaland 30° nasal (p < 0.05). Similarly, lag at 10° superior fixation was lower than lag at 20° temporal, 20° nasal, 30° temporal and 30° nasal fixations (p < 0.05). We found higher lag of accommodation in horizontal off-axis fixations in comparison to that of vertical off-axis fixations (p < 0.05). Lag of accommodation was positive correlated with vertical coma and primary spherical aberrations but negative correlated with secondary spherical aberrations (p < 0.05). Thus, Hartmann-Shack aberrometer was successfully used to assess accommodative lag in the peripheral field of view up to 60° visual field. Peripheral lag of accommodation depends up on eccentricity. Lag was found higher in horizontal off-axis fixation than at vertical fixations. Coma and spherical aberration had association with lag.
Imaging sensors for PoET: a spatially resolved solar spectroscopy instrument
Authors: Leite I , Cabral A , Abreu M , Santos N
Published: December 2022

The study of the Sun is an area still open in several topics of astrophysics, in a field that has seen an expansion in recent years - therefore, it is critical that collected data is thoroughly traceable and accurate to be used in new study cases or predictive models. A ground based, portable, optimized system, consisting of a Schmidt-Cassegrain telescope coupled to a refractor telescope acting as a pointing telescope, is being designed to provide high resolution imaging of smaller areas on the Sun’s surface, being able to obtain disk-resolved, high spectral resolution data, at a relative low cost (compared to large consortium developed instruments). The light collected by the telescope will be fibre-fed to a spectrograph - the injection of light in the fibre is critical and requires an imaging sensor to aid the light guiding process. The goal of the present work was to explore the best candidates for the image sensors, their architectures, requirements, and constraints, as well as their expected performance range and signal noise. The trade-off analysis between CMOS and CCD based sensors was made and it was concluded, that for the intended application, either type of architecture is admissible, provided the sensor is within desired parameters.
Innovative hybrid optical sensing design to simultaneously discriminate pressure and temperature
Authors: Freitas Fábio , Matuck Lucca , Bierlich Jörg , Ferreira Marta , Marques Carlos , Nascimento Micael
Published: December 2022

In this work, hybrid optical fiber sensors based on Fabry-Perot (FP) interferometer and Fiber Bragg Grating (FBG) sensors were developed to simultaneously measure two external parameters, pressure, and temperature. The proposed sensor consists of a photosensitive Single-Mode Fiber (SMF), where the FBG is recorded, and spliced to a small section of a Hollow-Core Fiber (HCF). After that, the HCF tip is submerged in a UV-photosensitive polymer (RI = 1.46), creating three cavities, which will create two observable light interferences, allowing the observation of two FP responses in the spectral response. Two sensors with different HCF lengths were created to compare their sensitivities. After curing, the sensors were calibrated to both parameters in the ranges of 0.0 to 4.0 bar (steps of 1.0 bar) and 22.0 to 30.0 °C (steps of 2.0 °C), respectively. By tracking the peak shifts of the FP, it achieved higher sensitivities for the sensor with the shorter HCF tip (182.30 µm of HCF and 28.56 µm of UV-polymer lengths) of around 31.65 nm/bar and 1.53 nm/°C. On the other side, the sensor with the longer HCF tip (318.56 µm of HCF and with 52.17 µm of UV-polymer lengths) achieved 15.65 nm/bar and 1.02 nm/°C. Regarding the FBGs, they achieved 9.65 and 7.86 pm/°C for the longer and shorter sensor, respectively, while presenting insensitivity to pressure. Therefore, the shorter FP cavity produces the more sensitive sensor because, since its length is shorter and possesses a concave shape, it is more susceptible to external changes. Thus, variations of pressure and temperature could be discriminated by using the matrixial method with the FP and FBG sensitivities, given that the determinant of the coefficient matrix results is -0.31, a non-zero value. The developed sensor has the potential to integrate specific applications, such as LiBs to measure and decouple both parameters.
Rubber vulcanization method for FBG pressure sensors
Authors: Avellar Leandro , Frizera Anselmo , Diaz Camilo , Leal-Junior Arnaldo
Published: December 2022

This paper presents the experimental analysis of the vulcanization process of nitrile rubbers for the diaphragms fabrication used in FBG-based pressure sensors. Tests using diaphragms with different rubber thicknesses (0.5mm, 1.0mm, and 1.5mm), vulcanization temperatures (125°C, 150°C, and 200°C), and vulcanization times (2.5min and 5.0min) were performed to analyse the chemical degradation of diaphragms. Degradation analysis was performed using digital macrography of the diaphragm surfaces and the diaphragms stiffness was analysed by tensile tests. An FBG was embedded in the diaphragm which was vulcanized using the temperature and time which resulted in the lowest rubber degradation, and a compression test was performed. Results of the digital macrography show that diaphragms vulcanized at 125°C presented smaller degradation areas, in which diaphragms with 0.5mm rubbers presented an area degradation mean of 17.5%, whereas 1.0mm rubbers presented 14.5%, and 1.5mm rubbers showed 11.0%. Moreover, greater thickness led to smaller degraded area for the same temperature and vulcanization time. Thus, for the same thickness in the rubber, the higher vulcanization temperature results in a higher material stiffness, where stiffness is directly related to the reduction of cross-links due to the degraded area. Results of the sensitivity test using diaphragms vulcanized at 125°C showed a pressure sensitivity of 11.67kPa/mm and wavelength sensitivity of 456.1pm/mm for 0.5mm rubber thicknesses, 18.04kPa/mm pressure sensitivity, and 112.3pm/mm wavelength sensitivity for 1.0mm rubber thickness and 31.55kPa/mm pressure sensitivity and 913.8pm/mm wavelength sensitivity for 1.5mm rubber thickness. It concludes that the 0.5mm rubber vulcanized diaphragm obtained higher sensitivity when comparing pressure and wavelength.
Some recent advances in color science
Authors: Melgosa Manuel
Published: December 2022

We will discuss some of main topics in two recent publications on color from the International Commission on Illumination (CIE): CIE 015:2018 and CIE 248:2022. Regarding CIE 015:2018, it is the 4th edition of the most important CIE general publication on colorimetry, generally known as ‘CIE publication 15’. Among main novelties in CIE 015:2018 with respect to its previous 2004 edition, we can mention the introduction of the next four topics: 1) Cone-fundamental-based colorimetric observers; 2) New CIE illuminants (indoor daylight illuminants, smoothed daylight illuminants, illuminant E, and white LED illuminants); 3) The CIE colour appearance model CIECAM02; 4) The CIE 2017 color fidelity index. As a consequence of the active research on color appearance during the past few years, CIE 248:2022 proposed the CIECAM16 color appearance model for related colors and CIE 1931 standard colorimetric observer. In general, color appearance models provide a viewing-condition-specific method for the transformation of the tristimulus values X, Y, Z, to or from perceptual attribute correlates. CIECAM16 replaces CIECAM02 and may be useful for color management systems and image industries. CIECAM16 is simpler and maintains the predictions of experimental visual data made by CIECAM02. Finally, we will discuss advances in two issues related to color included in the current CIE Research Strategy: 1) A roadmap toward a new CIE colorimetry based on cone fundamentals, currently studied by CIE Technical Committee 1-98; 2) Color differences in tri-dimensional object colors and spatio-chromatic complexity, currently studied by CIE Technical Committees 8-17 and 8-14, respectively. In overall, we can conclude that color science is an active inter- and multi-disciplinary research field where optics continues playing a key role.
Data Augmentation in 3D Object Detection for self-driving vehicles: the role of original and augmented training samples
Authors: Santos X , Georgieva P , Girão P , Drummond M
Published: December 2022

Safe self-driving vehicles require precise 3D Object Identification. LiDAR sensors are key in accomplishing such a task, as LiDARs produce high-definition point clouds. Such point clouds are then processed by 3D Object Detection models to finally detect objects.

Most Object Detection models require massive amounts of data to be trained. Gathering and processing this data is an expensive and time-consuming task, which is why the information taken from each sample must be fully harnessed. Such can be done through Data Augmentation. Data Augmentation contributes significantly for improving performance, being at least as relevant as the advances in the Object Detection models themselves.

A few studies have been reported regarding the effectiveness of Data Augmentation. However, the role played by original and augmented samples has been neglected. This work reports the first-ever detailed quantification of the impact that the inclusion of original and augmented samples in a dataset has in 3D Object Detection in the context of autonomous driving. The obtained results show that although a good augmentation strategy is crucial to the model’s performance, it is only as good as the quality of the original samples allows it to be.
Highly selective, compact and efficient vertical in-coupling for interferometric optical biosensors
Authors: Roggero Ursula F. S. , Rubio-Noriega Ruth E. , Seifert Andreas , Hernández-Figueroa Hugo E.
Published: December 2022

One of the challenges in using integrated optical biosensors is their ability to operate in environments outside laboratories. This occurs, among other reasons, because suitable source coupling components are not considered at the design stage. In this work, a highly selective, compact and efficient in-coupling method is proposed with the aim to develop a genuine Point-of-care (PoC) platform. The proposed configuration consists of a single-mode fiber core placed in parallel and centered above an inverted non-linear taper, which can also be seen as a pigtailed input stage. These components are separated by the cladding of the taper that acts as a gap. In this setup, light is coupled from the fiber to the taper, which then becomes the core of a multimode waveguide. The coupled modes depend on the position of the fiber and the geometry of the taper. For interferometric biosensors, the power distribution between the modes is very important because each one reacts differently to the sample placed on the optical transducer. Therefore, the selectivity of the coupling stage affects the interferometric pattern and, consequently, the detection process. In the model presented in this work, the input is set as the fundamental mode (LP01) of the fiber. Since it is centered, only the even modes are excited in the taper. The width of the taper varies from 2 µm to 3 µm, in order to select only high-order modes, due to their large evanescent tails lead to highly sensitive biosensors. The non-linear format optimizes the design by dividing the entire taper into a cascade of linear sections. Those in which the coupling of the desired modes occurs are prioritized by increasing their lengths, thus making the transition smoother. Instead, the other sections maintain a reduced length. To select other modes or change the power distribution between them, one may just simply change the width of the taper and the length of the prioritized sections. In this work, a fiber-to-taper configuration of 8 mm length is presented, which couples 48% and 17% of the input power to TE8 and TE10 modes, respectively.
Integrating Laser-induced breakdown spectroscopy and photogrammetry towards 3D element mapping
Authors: Rodrigues Pedro , Lopes Tomás , Cavaco Rafael , Capela Diana , Ferreira Miguel F. S. , Jorge Pedro A. S. , Silva Nuno A.
Published: December 2022

The possibility to map the element distribution on a sample surface is one of the interesting applications of laser-induced breakdown spectroscopy that has been extensively explored in recent years. In this manuscript, we explore the combination of photogrammetry and LIBS techniques for the creation of a three-dimensional model of the map of the elements on the surface of the sample. Using a dedicated photogrammetry solution and software, we reconstruct the three-dimensional model of the mineral sample whose mesh is later exploited for the interactive interpretation of the results. Then, making use of Paraview software, which integrates production algorithms and computing performance in a unified solution for scientific purposes, we establish a process pipeline that allows the creation of an interactive three-dimensional model with the spatial distribution of the target elements on top of the sample surface. Our results demonstrate that combining these two techniques can give us a valuable resource for better qualitative analysis and insight, providing an innovative three-dimensional modeling solution that may open the door to a new range of possibilities, from quality control technology involving alloys and mechanical parts to interactive teaching environments for geo and biosciences, just to name a few examples.
The potential development of Porang in North Lombok, Indonesia
Authors: Rohmaya Malina , Sukardi L. , Sjah Taslim
Published: December 2022

Porang has a huge potential to be developed in North Lombok, Indonesia, provided an abundance of land availability and suitability, and this is coupled with a large market porang agribusiness, starting from the subsystem of upstream through to downstream. For better business performance, partnership amongst several parties needs to be developed. This paper aims to identify the model of partnership in porang agribusiness, together with the rights and obligations of each party involved, and finally find the ways to improve the current partnerships in one way or another. This study is carried out in four villages within four districts in North Lombok. Interviews were conducted to collect data from porang farmers and their counterparts in North Lombok. Data were analyzed descriptively to answer the research objectives. The study found that partnership occurred in mutually beneficial for parties, covering advantages and disadvantages in each party, to move together into win-win solutions, in the form of plasma core partnership. The partnership needs to encourage for longer periods and expanded to other regions for its positive impact in helping improve people life and the economics of the regions.
Seasonal and water quality significance of gregarine protozoan parasites occurrence in Wild Bivalve, Anadara cornea (Reeve, 1844) from Terengganu, Malaysia
Authors: Zakariah Mohd Ihwan , Ikhwanuddin Mhd , Hassan Marina , Yusoff Nor Asma Husna Mohamed , Abdullah Farizan , Wahab Wahidah , Draman Ahmad Shuhaimi , Ishak Ahmad Najmi , Alam Jamaluddin Fitrah , Daud Hassan Mohd
Published: December 2022

Malaysia is known as a country that experience two main seasonal patterns, i.e., monsoon and non-monsoon season. Three different categories of seasons based on the quantity of rainfall were divided by previous studies started from January to December 2018, which are dry season, moderate season and rainy season. Wild bivalve, Anadara cornea populations at Setiu Lagoon in Terengganu, Malaysia was examined for gregarine parasites for a year. The objective of this study was to associate the incidence of gregarine in common wild bivalves, A. cornea (Reeve, 1844) concerning seasons and water quality parameters. From the study, the total number of phagocytes found was n = 33,239, with a total of 480 host samples. The total prevalence of the parasites was 97.5%, with a 95% confidence interval value which was CI=96.1% to 98.9%. The prevalence of the parasites was significantly higher during the rainy season as compared to dry and moderate seasons. The findings also proved that the intensity of the parasites decreased at every transition of season. In-depth, the correlation between the prevalence of the parasites vice versa, season, and water quality might be contributed to the intensity of the parasite infestation needs to be clarified.
Application of 17α-methyltestosterone to enhance broodstock maturation of the domesticated black tiger shrimp (Penaeus monodon): A comparative study of injection method and oral method
Authors: Rosmiati R , Lante S , Parenrengi A , Harlina H , Suryati E , Tenriulo A , Nawang A
Published: December 2022

The effects of 17α-methyltestosterone administration on spermatophore quality in captive broodstock of tiger shrimp Penaeus monodon were investigated using injection method and oral method based on the optimized protocol. The experiment was designed to compare the oral administration group and injection group with two replications during a 38-day experimental period. Captive male broodstock of tiger shrimp weighing 57-95 g was collected from ponds and stored in a 10,000 m3 concrete tank (20 shrimp/tank). Male broodstocks were injected and orally administrated with 17α-methyltestosterone at the dose of 300 ng/100 g body weight. Data indicates that the injection of 17α-methyltestosterone showed the percentage of mature broodstock count and the percentage of normal spermatozoa count 1.07 and 1.38% higher and significantly differs from oral administration through mixing in feed at the maturation stage. However, at the time of the maturation and 1st re-maturation of both the methods, the weight of the spermatophores and the number of spermatozoa did not show any difference. Based on the comparison of the two methods used, the results are obtained that the administration of the hormone 17α-methyltestosterone can be done both through mixing in feed and through injection, but the administration of hormones through injection gives better results than the broodstock matures first simultaneously.