bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel 2D B2S3 as a metal-free photocatalyst for water splitting
Authors: Li Xiaoteng , Cui Bin , Zhao Wenkai , Xu Yuqing , Zou Dongqing , Yang Chuanlu
Published: February 2021

Metal-free semiconductors with desirable characteristics have recently gained great attention in the field of hydrogen generation. The non-metal material B2S3 has two phases, hexagonal B2S3 (h-B2S3) and orthorhombic B2S3 (o-B2S3), which compose a novel class of 2D materials. Both h-B2S3 and o-B2S3 monolayers are direct semiconductors with bandgaps of 2.89 and 3.77 eV by the Heyd-Scuserria-Ernzerhof (HSE) function, respectively. Under appropriate uniaxial strain (1%), the bandgap of h-B2S3 can be decreased to 2.8 eV. The carrier mobility can reach 1160 cm2 V−1 s−1, supporting the fast migration of photo-induced carriers. Most importantly, the band edges of both h-B2S3 and o-B2S3 cover the reduction and oxidation levels for water splitting. We explore the process of photocatalytic water splitting on h-B2S3 monolayers by analyzing the feasibility of the decomposition of H2O and the generation of H2. The results indicate that the special mesoporous structure of B2S3 is helpful for photocatalytic hydrogen production. The new nanomaterial, B2S3, offers great promise as a metal-free photocatalyst due to its tunable bandgaps, its useful band edges, and its other excellent electronic properties.
Proposal of graphene band-gap enhancement via heterostructure of graphene with boron nitride in vertical stacking scheme
Authors: Sattar Abdul , Moazzam Uzair , Bashir Azmat Iqbal , Reza Ali , Latif Hamid , Usman Arslan , Amjad Raja Junaid , Mubshrah Ayesha , Nasir Abdullah
Published: February 2021

Since the discovery of graphene and other two-dimensional (2D) materials in recent years, heterostructures composed of multilayered 2D materials have attracted immense research interest. This is mainly due to the potential prospects of the heterostructures for basic and applied applications related to the emerging technology of energy-efficient optoelectronic devices. In particular, heterostructures of graphene with 2D materials of similar structure have been proposed to open up the band gap to tune the transport properties of graphene for a variety of technological applications. In this paper, we propose a heterostructure scheme of band-gap engineering and modification of the electronic band structure of graphene via the heterostructure of graphene–boron nitride (GBN) based on first-principles calculations. For a comparative analysis of the properties of the proposed GBN heterostructure, we employ Kohn–Sham density functional theory (DFT) using local density and generalized gradient approximations within Perdew–Burke–Ernzehof parameterization. To account for weak interlayer van der Waals interactions, we employ the semi-empirical dispersion-corrected DFT scheme of Grimme, called the DFT-D2 approximation. In the vertical stacking arrangement of boron-nitride-doped graphene with hexagonal boron nitride, we predict a band-gap opening of 1.12 eV which, to our knowledge, is the largest value attained for this kind of system. The impact of interlayer spacing on the band-gap opening arising from the interlayer coupling effect is also analyzed. The band-gap enhancement supports the widely proposed promise of GBN heterostructure in design of high-performance optoelectronic devices such as field-effect transistors for potential applications.
Synthetic dual-energy CT for MRI-only based proton therapy treatment planning using label-GAN
Authors: Liu Ruirui , Lei Yang , Wang Tonghe , Zhou Jun , Roper Justin , Lin Liyong , McDonald Mark W , Bradley Jeffrey D , Curran Walter J , Liu Tian , Yang Xiaofeng
Published: February 2021

MRI-only treatment planning is highly desirable in the current proton radiation therapy workflow due to its appealing advantages such as bypassing MR-CT co-registration, avoiding x-ray CT exposure dose and reduced medical cost. However, MRI alone cannot provide stopping power ratio (SPR) information for dose calculations. Given that dual energy CT (DECT) can estimate SPR with higher accuracy than conventional single energy CT, we propose a deep learning-based method in this study to generate synthetic DECT (sDECT) from MRI to calculate SPR. Since the contrast difference between high-energy and low-energy CT (LECT) is important, and in order to accurately model this difference, we propose a novel label generative adversarial network-based model which can not only discriminate the realism of sDECT but also differentiate high-energy CT (HECT) and LECT from DECT. A cohort of 57 head-and-neck cancer patients with DECT and MRI pairs were used to validate the performance of the proposed framework. The results of sDECT and its derived SPR maps were compared with clinical DECT and the corresponding SPR, respectively. The mean absolute error for synthetic LECT and HECT were 79.98 ± 18.11 HU and 80.15 ± 16.27 HU, respectively. The corresponding SPR maps generated from sDECT showed a normalized mean absolute error as 5.22% ± 1.23%. By comparing with the traditional Cycle GANs, our proposed method significantly improves the accuracy of sDECT. The results indicate that on our dataset, the sDECT image form MRI is close to planning DECT, and thus shows promising potential for generating SPR maps for proton therapy.
Auto-calibration of cone beam geometries from arbitrary rotating markers using a vector geometry formulation of projection matrices
Authors: Graetz Jonas
Published: February 2021

An efficient method for the determination of the projection geometry of cone beam micro computed tomography systems based on two or more fiducial markers of unknown position within the field of view is derived. By employing the projection matrix formalism commonly used in computer graphics, a very clear presentation of the resulting self consistent calibration problem can be given relating the sought-for matrix to observable parameters of the markers’ projections. Both an easy to implement solution procedure for both the unknown projection matrix and the marker assembly as well as the mapping from projection matrices to real space positions and orientations of source and detector relative to the rotational axis are provided. The separate treatment of the calibration problem in terms of projection matrices on the one hand and the independent transformation to a more intuitive geometry representation on the other hand proves to be very helpful with respect to the discussion of the ambiguities occurring in reference-free calibration. In particular, a link between methods based on knowledge on the sample and those based on knowledge solely on the detector geometry can be drawn. This further provides another intuitive view on the often reported difficulty in the estimation of the detector tilt towards the rotational axis. A simulation study considering 106 randomly generated cone beam imaging configurations and fiducial marker distributions within a range of typical scenarios is performed in order to assess the stability of the proposed technique. An experimental example supports the simulation results.
A thick semi-monolithic scintillator detector for clinical PET scanners
Authors: Zhang Chunhui , Wang Xiaohui , Sun Mingdao , Kuang Zhonghua , Zhang Xianming , Ren Ning , Wu San , Sang Ziru , Sun Tao , Hu Zhanli , Yang Yongfeng , Liu Zheng
Published: February 2021

Both monolithic and semi-monolithic scintillator positron emission tomography (PET) detectors can measure the depth of interaction with single-ended readout. Usually scintillators with a thickness of 10 mm or less are used since the position resolutions of the detectors degrade as the scintillator thickness increases. In this work, the performance of a 20 mm thick long rectangular semi-monolithic scintillator PET detector was measured by using both single-ended and dual-ended readouts with silicon photomultiplier (SiPM) arrays to provide a high detection efficiency. The semi-monolithic scintillator detector consists of nine lutetium–yttrium oxyorthosilicate slices measuring 1.37 × 51.2 × 20 mm3 with erythrocyte sedimentation rate foils of 0.065 mm thickness in between the slices. The SiPM array at each end of the scintillator detector consists of 16 × 4 SiPMs with a pixel size of 3.0 × 3.0 mm2 and a pitch of 3.2 mm. The 64 signals of each SiPM array are processed by using the TOFPET2 application-specific integrated circuit individually. All but the edge slices can be clearly resolved for the detectors with both single-ended and dual-ended readouts. The single-ended readout detector provides an average full width at half maximum (FWHM) Y (continuous direction) position resolution of 2.43 mm, Z (depth direction) position resolution of 4.77 mm, energy resolution of 25.7% and timing resolution of 779 ps. The dual-ended readout detector significantly improves the Y and Z position resolutions, slightly improves the energy and timing resolution at the cost of two photodetectors required for one detector module and provides an average FWHM Y position resolution of 1.97 mm, Z position resolution of 2.60 mm, energy resolution of 21.7% and timing resolution of 718 ps. The energy and timing resolution of the semi-monolithic scintillator detector in this work are worse than those of the segmented scintillator array detector and need to be further improved. The semi-monolithic scintillator detector described in this work reduces costs as compared to the traditional segmented scintillator array detector and reduces the edge effect as compared to the monolithic scintillator detector.
Simulation based evaluation of a fan beam coded aperture x-ray diffraction imaging system for biospecimen analysis
Authors: Stryker Stefan , Kapadia Anuj J , Greenberg Joel A
Published: February 2021

X-ray diffraction (XRD) imaging yields spatially resolved, material-specific information, which can aid medical diagnosis and inform treatment. In this work we used simulations to analyze the utility of fan beam coded aperture XRD imaging for fast, high-resolution scatter imaging of biospecimens for tissue assessment. To evaluate the proposed system’s utility in a specific task, we employed a deterministic model to produce simulated data from biologically realistic breast tissue phantoms and model-based reconstruction to recover a spatial map of the XRD signatures throughout the phantoms. We found an XRD spatial resolution of ≈1 mm with a mean reconstructed spectral accuracy of 0.98 ± 0.01 for a simulated 1 × 150 mm2 fan beam operating at 160 kVp, 10 mA, and 4.5 s exposures. A classifier for cancer detection was developed utilizing cross-correlation of XRD spectra against a spectral library, with a receiver operating characteristic curve with an area under the curve value of 0.972. Our results indicated a potential diagnostic modality that could aid in tasks ranging from analysis of ex-vivo pathology biospecimens to intraoperative cancer margin assessment, motivating future work to develop an experimental system while enabling the development of improved algorithms for imaging and tissue analysis-based classification performance.
Intrasheath electron dynamics in low pressure capacitively coupled plasmas
Authors: Vass Máté , Derzsi Aranka , Schulze Julian , Donkó Zoltán
Published: February 2021

We present a detailed analysis of electron trajectories within the sheath regions of capacitively coupled plasmas excited by radio-frequency voltage waveforms at low pressures. Complex features inside the sheaths are identified in several physical quantities, which are sculptured by the trajectories of bouncing energetic electrons (predominantly ion induced secondary electrons) under the influence of the spatio-temporally varying electric field. Based on a systematic parameter variation the generation of the various features as a function of surface processes is explained and the trajectories of electrons of different origin are identified.
Foundations and interpretations of the pulsed-Townsend experiment
Authors: Casey M J E , Stokes P W , Cocks D G , Bošnjaković D , Simonović I , Brunger M J , Dujko S , Petrović Z Lj , Robson R E , White R D
Published: February 2021

The pulsed-Townsend (PT) experiment is a well known swarm technique used to measure transport properties from a current in an external circuit, the analysis of which is based on the governing equation of continuity. In this paper, the Brambring representation (1964 Z. Phys.
179 532) of the equation of continuity often used to analyse the PT experiment, is shown to be fundamentally flawed when non-conservative processes are operative. The Brambring representation of the continuity equation is not derivable from Boltzmann’s equation and consequently transport properties defined within the framework are not clearly representable in terms of the phase-space distribution function. We present a re-analysis of the PT experiment in terms of the standard diffusion equation which has firm kinetic theory foundations, furnishing an expression for the current measured by the PT experiment in terms of the universal bulk transport coefficients (net ionisation rate, bulk drift velocity and bulk longitudinal diffusion coefficient). Furthermore, a relationship between the transport properties previously extracted from the PT experiment using the Brambring representation, and the universal bulk transport coefficients is presented. The validity of the relationship is tested for two gases Ar and SF6, highlighting also estimates of the differences.
Cryogenic readout of superconducting nanowire single-photon detectors using high-sensitivity adiabatic quantum-flux-parametron circuits
Authors: China Fumihiro , Takeuchi Naoki , Miki Shigehito , Yabuno Masahiro , Miyajima Shigeyuki , Terai Hirotaka
Published: February 2021

We have been developing readout interfaces for superconducting nanowire single-photon detectors (SSPDs) using adiabatic quantum-flux-parametron (AQFP) logic. AQFP circuits operate with low power consumption, low bias currents, and high sensitivity, and thus are suitable as readout interfaces for large SSPD arrays. In this study, we develop a high-sensitivity AQFP interface, consisting of a current transformer, comparator, and rising-edge detector. We systematically investigated the current sensitivity of the AQFP interface by operating an NbTiN SSPD with the interface in a 0.1 W Gifford–McMahon cryocooler. We compared the outputs from the AQFP interface with the direct outputs from the SSPD, thereby demonstrating a sensitivity of 3.5 μA, which is much smaller than that of the single-flux-quantum interfaces that we developed before.
Superconducting fluctuations above T
c in (Li1−

x
Fe
x
)OHFeSe single crystal
Authors: Wu Yuxian , Wen Zhiwei , Li Yong , Chen Yongliang , Zhao Yong
Published: February 2021

The magnetization and resistivity measurements have been done to investigate the superconducting fluctuations effect above the superconducting transition temperature (T
c) in (Li1−x
Fe
x
)OHFeSe single crystal. These measurements were performed with applying the external magnetic fields in the ab plane of (Li1−x
Fe
x
)OHFeSe single crystal. By analyzing the diamagnetism response and excess conductivity, the behavior of superconducting fluctuations in the normal state is studied. The upper limit temperature of superconducting fluctuation is determined to be around 1.2 times larger than T
c, suggesting that the superconducting fluctuation of (Li1−x
Fe
x
)OHFeSe is a large one. This exceeding value is obviously higher than the conventional superconductors. In addition, the superconductivity of (Li1−x
Fe
x
)OHFeSe coexists with the magnetism rooted in the (Li, Fe)OH layer and induced by magnetic field at low temperature.
Ultrafast spin dynamics in inhomogeneous systems: a density-matrix approach applied to Co/Cu interfaces
Authors: Töpler F , Henk J , Mertig I
Published: February 2021

Ultrafast spin dynamics on femto- to picosecond timescales is simulated within a density-operator approach for a Co/Cu bilayer. The electronic structure is represented in a tight-binding form; during the evolution of the density operator, optical excitation by a femtosecond laser pulse, coupling to a bosonic bath as well as dephasing are taken into account. Our simulations corroborate the importance of interfaces for ultrafast transport phenomena and demagnetisation processes. Moreover, we establish a reflow from Cu d orbitals across the interface into Co d orbitals, which shows up prominently in the mean occupation numbers. On top of this, this refilling manifests itself as a minority-spin current proceeding several layers into the Cu region. The present study suggests that the approach captures essential ultrafast phenomena and provides insight into microscopic processes.
Generation and stability of diversiform nonlinear localized modes in exciton–polariton condensates
Authors: Zhang Kun , Wen Wen , Lin Ji , Li Hui-jun
Published: February 2021

We propose a scheme to generate and stabilize one- and two-dimensional dark, bright, dark-like, bright-like solitons, and vortices with m = 1 and m = 2 in a nonresonantly incoherent pumped exciton–polariton condensate. A spatially modulating pumping is introduced, which can compensate (counteract) the loss (gain) originated from the nonlinear excitation of the stable homogeneous polariton. The numerical simulations show that the balance between the gain and loss in this scheme can support and stabilize various nonlinear modes, not just stable dark solitons which have been found in the previous studies. Our proposal may provide a way to generate, stabilize, and control nonlinear modes in the nonresonantly pumped exciton–polariton system.
Compact silica-based equal nine-channel generated by triple-layer arrays
Authors: Fang Jimin , Wang Bo
Published: February 2021

In order to achieve the demands of multi-beam splitting in the optical communication system, a compact high-efficiency silica-based nine-channel beam splitter grating (BSG) at infrared wavelength is proposed based on a three-layer array structure. The grating profile parameters are investigated by the rigorous coupled-wave analysis (RCWA) and the finite-element method (FEM). The total efficiency of the nine-channel beam splitter reaches 96.98%, and the error of uniformity is reduced to 2.98%. The results show that the theoretical values of the two optimization methods are in good agreement. Moreover, the presented grating has a good performance against fabrication tolerances. The modal method is used for detailed physical explanation of the energy exchange and propagation modes inside the grating. The proposed high-efficiency nine-channel beam separation by three-layer arrays should be helpful for developing the multi-beam splitting of the optical system of the lithography machine and the new ultra-precision optical devices.
MARS-Q modeling of kink-peeling instabilities in DIII-D QH-mode plasma
Authors: Dong G.Q. , Liu Y.Q. , Chen X. , Hao G.Z. , Liu Y. , Wang S. , Zhang N. , Xia G.L.
Published: February 2021

In quiescent H-mode (QH-mode) regime, edge harmonic oscillations (EHOs) are believed to provide necessary radial transport to prevent occurrence of large edge localized modes. A systematic modeling study is performed here on the low-n EHOs in a DIII-D QH-mode plasma (Chen et al 2016 Nucl. Fusion
56 076011), by utilizing the MARS-Q code (Liu et al 2013 Phys. Plasmas
20 042503). Both the n = 1 and n = 2 instabilities are found to be strongly localized near the plasma edge, exhibiting the edge-peeling characteristics. The DIII-D resistive wall is found to have minor effects on these instabilities. The plasma resistivity is found to strongly modify the mode growth rate. Assuming the Spitzer model for the plasma resistivity, the computed mode growth rate scales as S
−1/3 with S being the Lundquist number. Toroidal flow of the plasma slightly stabilizes these edge localized kink-peeling modes. Drift kinetic effects all have a destabilization effect on these modes. Non-perturbative magneto-hydrodynamic-kinetic hybrid computations find that the drift kinetic effects associated with thermal particle species push the peak location of the eigenmode radially inward but still in the pedestal region. The modeled plasma temperature and density fluctuations in the plasma edge region, as well as the poloidal magnetic field perturbations along both the low and high field sides of the plasma surface, are in good agreement with experimental measurements. Finally, the quasi-linear initial value simulations find a strong non-linear interplay between the kink-peeling instability and the toroidal flow near the plasma edge. The combined effect of the damping of the flow amplitude and change of the edge flow shear is found to be the stabilizing factor for the kink-peeling mode, leading to the mode saturation and thus EHOs.
Triangular Norm (δ, γ)-Fuzzy co-sets and Homomorphism
Authors: Jayaraj J , Arul Selvaraj X
Published: February 2021

The concept of fuzzy sets was introduced by Zadeh [2] in 1965. Rosenfield [3] introduced the notion of a fuzzy group as easily as 1971. We expand the notion of triangular norm (t-norm) from Rajesh Kumar [1]. The author have already introduced the notation (δ,γ)-fuzzy in [4] and t – norm (δ,γ)-fuzzy [5]. In this paper, we study the notion of t – norm (δ,γ)-fuzzy co-set of the t – norm (δ,γ)-normal subgroup of the group G.
An Introduction to δ-open sets in a Neutrosophic Topological Spaces
Authors: Vadivel A , Seenivasan M , John Sundar C
Published: February 2021

In this paper, we introduce a new types of δ-open sets and δ-closed sets in neutrosophic topological spaces which are a stronger form. Also, the notion of neutrosophic δ mappings were introduced and also discuss their relationship between near mappings in neutro-sophic topological spaces. Moreover, we investigate some of their basic properties and examples in neutrosophic topological spaces.
Safety Monitoring System in Minimg Environment Using Iot
Authors: Kavitha D. , Chinnasamy A. , Devi A. Sangeerani , Shali A.
Published: February 2021

The average mine worker is exposed to the harsh underground environment which can sometimes cause an injury or loss of life. The older methods of mine condition monitoring involved using a person to go down and report back. This method is however dangerous as the person who is monitoring a specific hazard could be harmed by that hazard. This standard can be reinforced through the implementation of modern technology which is central to the non-invasive mine safety system with wireless sensor networks to obtain the best possible result.
Research on Project Management Computer System Based on BIM
Authors: Ying Danlei , Cheong Chew Boon , Wang Libin
Published: February 2021

In the engineering industry, its development is combined with information technology. The traditional method is to use CAD (Computer Aided Design) technology. With the economic growth and the development of information technology, engineering projects become more and more complex. The traditional technology has gradually been unable to adapt to the development of the project, and its disadvantages have gradually emerged, which cannot meet the requirements of project management. Therefore, BIM Technology should also be applied It can greatly make up for the shortcomings of traditional technology in complex engineering and promote the development of engineering projects. According to the principle of BIM Technology, this paper applies BIM Technology to project management. According to the characteristics of BIM Technology and the difficulties of large-scale project management, the application of BIM Technology in engineering is studied and analyzed. Combined with computer technology, this paper studies the project management computer system based on BIM, which can improve the management level of large-scale engineering projects, improve the management level of large-scale projects, and save costs. It can provide certain reference for the follow-up research and promote the application of BIM Technology in project management.
Design of Remote Control System for Smart Home Based on Unity and the Internet of Thing
Authors: Zhang Yujie , Yin Xiao”na
Published: February 2021

In view of the problems of unintuitive operation and poor user experience in the human-computer interaction of smart homes, the article proposes the application of virtual reality technology on the basis of relevant theoretical analysis, based on unity development platform and smart home control center, a smart home control system based on virtual reality technology is designed and developed. The system is composed of client, cloud and device. The client realizes virtual roaming, real-time display of device status and remote control. The cloud realizes the functions of control command forwarding and data storage. The gateway is used to communicate with each home device and cloud to realize the functions of sending control commands and reporting device status data. The test shows that the system is novel and practical. Using virtual reality technology as a human-computer interaction interface for smart home control can give users an intuitive smart home control experience and improve the user’s experience.
The Status Quo of Aerospace Engine Vibration Fatigue
Authors: Zhang Longfei , Li Jing , Kou Ying
Published: February 2021

In the working environment of aero engine blades, it is necessary to withstand the influence of factors such as aerodynamic stress, vibration stress, centrifugal stress, thermal stress, high temperature oxidation, thermal corrosion, etc. The blades often exhibit vibration fatigue fracture, foreign object damage, corrosion, material defects, and sports damage. This article summarizes the fatigue fracture problems of aero-engine blades, provides a systematic basic theory for the design, innovation and development of aero-engine blades, and has certain reference value.
An Artificial Bee Colony Algorithm for Multi-objective Optimization of Cold Chain Distribution Path
Authors: Zhao Ming , Wang Shoujin , Jiang Hui , Liu Ying
Published: February 2021

Optimization of the distribution path of cold chain distribution path has always been a focus and hot issue in the field of cold chain logistics. In this paper, firstly, a mathematical model with minimum transportation cost and cold cost as the optimization objectives is established, and then an artificial bee colony algorithm to solve the multi-objective model is designed. Finally, an experimental example is generated by combining relevant literature example and random method to verify the effectiveness of the model and algorithm, and the convergence process of the example solution is also given.
Risk Data Analysis of Cross Border E-commerce Transactions Based on Data Mining
Authors: Qing Haohua , Zheng Guokai , Fu Die
Published: February 2021

At present, China’s foreign trade volume of cross-border e-commerce is still relatively small, the targeted legal system has not been established, and the industry access threshold is relatively low. The development of cross-border e-commerce faces many risks. Relying on data mining technology, data docking and risk control. At the data level, the risk of cross-border e-commerce transaction is processed and analyzed, and the potential risk is predicted, and more targeted risk control methods are proposed to reduce the risk of cross-border e-commerce transaction business. Aiming at this problem, this paper establishes the risk data analysis of cross-border e-commerce transactions based on data mining. In order to further verify the data accuracy of data mining technology, this paper analyzes the test values of neural network algorithm, seizure rate and inspection rate. When the misclassification loss parameter value is increased from 1 to 4, the detection rate of the model increases and the detection rate decreases. When the misclassification loss value is higher than 4, the detection rate increases, but the seizure rate decreases significantly. Therefore, the target inspection rate of the model can be changed by adjusting the misclassification loss parameter value of the model. If we set the parameter value of misclassification loss reasonably, we can achieve the goal of preventing and controlling the maximum risk with the lowest data mining cost. Through the analysis, the research in this paper has achieved ideal results, and made a contribution to data mining in cross-border e-commerce transaction risk data analysis.
Discussion on O+P Landscape Architecture Teaching Mode under the Background of Internet
Authors: Wang Xiaobo , Liang Weinan , Wang Hui
Published: February 2021

The landscape architecture teaching model under the Internet background needs to make full use of the O+P model that combines online teaching with on-site offline practice. The curriculum group of landscape architecture is divided into three types: knowledge, operation, and practice. Each type of course uses different online and offline teaching methods. This teaching mode is conducive to the integration of internationally superior teachers, demonstrates the practical value of landscape architecture, and enhances college students’ awareness of serving the society.
Application of Artificial Intelligence Technology in Personalized Online Teaching under the Background of Big Data
Authors: Chen Lujun
Published: February 2021

Big data technology allows you to extract laws from large amounts of data. Through various industry practices, data mining, classification and analysis of large amounts of data can provide effective reference for decision-making. The same is true for the education industry. The introduction of data mining technology online education platform can effectively improve students’ learning efficiency and education management level. In this article, I will mainly introduce the application of artificial intelligence technology in personalized online education in the context of big data. In this article, we apply constructive theory and big data technology to the online education system, and define some general education models for the current status of online education. The model monitors the learning process of students, adjusts educational strategies according to the characteristics of each student, and enables students to receive appropriate training to understand their personal information. Through the analysis of the experiment, it can be concluded that the personalized online education platform under the background of big data has been significantly improved. From a specific point of view, in the context of artificial intelligence, the number of users has increased by 9%.
Research on Driver Fatigue State Detection Method Based on Deep Learning
Authors: Wang Yonghui , Qu Roufei
Published: February 2021

Fatigue driving detection is essential to ensure the safety of society and drivers. At present, most fatigue detection methods are relatively traditional and single, and have complex algorithms, low accuracy, and low fault tolerance. Based on the improved Multi-task Cascaded Convolutional Network (MTCNN) to achieve precise positioning of facial feature points, combined with the Res-SE-net model to achieve eye, mouth area and state classification. The model is trained, and finally the driver fatigue is judged based on the PERCLOS rule combined with the OMR rule of mouth opening and closing frequency. Experimental results show that this method can effectively extract fatigue features, has high detection accuracy, meets real-time requirements, and has high robustness to complex environments.
Effect of Mathematical Concept Understanding and Mathematical Reasoning on Mathematical Literacy Abilities
Authors: Kharis S A A , Salsabila E , Haeruman L D
Published: February 2021

This study aims to obtain information about the effect of mathematical concept understanding and mathematical reasoning on mathematical literacy abilities. The problems in this study include: 1) Is there an effect of mathematical concept understanding to the ability of mathematical literacy 2) Is there an effect of mathematical reasoning on mathematical literacy abilities and 3) Is there an effect of the ability to understand concepts and mathematical reasoning on mathematical literacy abilities. This research uses a quantitative approach with survey methods and correlational techniques. The variables in this study: the dependent variable is the ability of mathematical literacy (Y) and the independent variables are mathematical concept understanding (X1) and mathematical reasoning (X2). The population are all students of the Mathematics Department with sample of 51 students taken using the Simple Random Sampling method. The data obtained were analyzed including descriptive analysis and inferential analysis using SPSS software. Inferential analysis using multiple regression analysis after going through the process of checking the prerequisites/assumptions of the analysis that must be met. From the research, there is an effect of the ability to understand mathematical concepts and mathematical reasoning together on the mathematical literacy of students in the amount of 35.3%.
Cell Sizes Study of Encapsulated Coconut Oil for Heat Exchanger Application
Authors: Jurizat Aldissain , Andoni Heri , Sutjahja Inge Magdalena , Wonorahardjo Surjamanto
Published: February 2021

Study of heat exchanger system using phase change material (PCM) for air conditioning system application in buildings is still very rare. The potential application of natural materials such as coconut oil as heat storage and heat exchangers in buildings in the tropics is quite large because the melting point of this material is in the human comfortable temperature range and a relatively large heat enthalpy corresponds to the stored heat. The heat exchange of such materials is strongly influenced by its thermal conductivity so that the heat flow rate greatly affects the effectiveness of heat exchange. This paper shows the role of cell size on the effectiveness of coconut oil as the heat exchanger. The experiment was conducted by measuring the temperature of coconut oil cell with diameter 4 cm, 5 cm, 6 cm, 8 cm, 12 cm and 16 cm in the natural air environment. The temperature was measured using thermocouples for 2 × 24 hours with a data retrieval interval for 15 minutes. The results showed that cell size provides different responses to changes in environmental temperature, so that its role as a heat exchanger can be designed according to its needs.
An investigation into the phenomenon of macroscopic plastic deformation localization in metals
Authors: Versaillot P D , Wu Y F , Zhao Z L
Published: February 2021

Experimental and theoretical studies are combined to investigate the phenomenon of macroscopic plastic deformation localization in metallic tensile specimens of AL6061, HSLA350 and Q235. The longitudinal strain and cross-section reduction of the specimens at different instant during testing are estimated through the measurement technique of three dimensional digital image correlation (3D-DIC). The Ling weighted-average method referred as WAM is used to compare the true stress-strain relation obtained from the experiment. A new mathematical model is suggested to estimate the localization zone length, which is a crucial parameter that can be used to anticipate the behaviour of metals past the peak load. The effect of material property on the necking zone length is examined. The experimental results show that the axial strain within the necking zone is non-uniform. It is also found that the WAM can precisely derive the true stress of steels Q235 and HSLA350 but not AL6061. The localization zone length of the round specimens Q235, HSLA350, and AL6061 equals six, five, and four times their initial diameter, respectively. Materials with a higher fracture strain ratio to the ultimate strain have a shorter necking zone length. This work provides insights into the physical mechanism of macroscopic plastic deformation localization.
Spatial Variability Model for Water Quality Assessment of the Physicochemical Parameters and the Water Quality Index of Laguna Lake and its Tributaries
Authors: Capili N I F , Marilla J F , Montes K M S , Villaseñor F C
Published: February 2021

Assessment and mapping of quality of surface water are essential because chemical and physical characteristics of the water determine its suitability for domestic, industrial, and agricultural usages. Geographic information system (GIS) is an effective and efficient technique in problem-solving where spatial data are essential. Six Physicochemical parameters; Biological Oxygen Demand, Minimum Dissolved Oxygen, Level of Acidity or pH, Nitrate, Phosphate, and Ammonia from Laguna Lake and its tributary rivers were examined from the year 2016 to 2019. Ordinary Kriging and Universal Kriging were used as the spatial interpolation methods that carried out the estimation of the concentrations of the parameters at the unsampled location. It showed that Ordinary kriging performed better compared to Universal Kriging. This paper attempted to obtain the water quality index (WQI) from the year 2016 to 2019. Results showed that Laguna Lake has a WQI rank of marginal to excellent. The WQI of its tributary rivers is mostly poor. The physicochemical parameters indicated that the life of the lake and its tributaries are in threat. Rehabilitation must be given attention and must be suitably planned and executed. The national government and the responsible authorities must collaborate for the effort in rehabilitating and cleaning.
The erroneous use of the term construction project manager in lieu of construction manager in South Africa
Authors: Taje T , Smallwood J J
Published: February 2021

The aim of the research was to evolve a range of interventions to address the misconception within the construction industry that Construction Managers (CMs) and Construction Project Managers (CPMs) are one and the same. The objectives of the study were to determine: the importance of CMs and CPMs within the construction industry; their contributions to the overall success of a construction project; nomenclatures used; what the practice of each profession entails, and the competencies, roles and responsibilities of a CM and CPM. The study entailed a quantitative survey using a self-administered questionnaire delivered per e-mail to a range of built environment stakeholders including Architects, Civil Engineers, CMs, CPMs, Health and Safety (H&S) practitioners, and Quantity Surveyors. in the Nelson Mandela Bay metropole, South Africa. Findings include: CM and CPM are both very important, but different professions; incorrect nomenclatures are used; they require a degree of common competencies and attributes, and a CPM requires experience as a CM. Conclusions include: the common competencies and attributes contribute to the erroneous use of ‘Project Manager’ for a person in the employ of a contractor, managing projects, and the use thereof is to highlight the ‘status’ of the aforementioned. Recommendations include: contractors should use the correct nomenclatures for their respective personnel; the industry should be enlightened regarding the appropriate nomenclatures, and tertiary built environment institutions should enlighten their students regarding the respective disciplines and nomenclatures.
Mechanical and thermal properties of a novel Spinifex Littoreus fiber reinforced polymer composites as an alternate for synthetic glass fiber composites
Authors: S Milan , Christopher T , Manivannan A , Mayandi K , Jappes J T Winowlin
Published: February 2021

The usage of natural fiber reinforced composite is large in engineering applications due to the presence of high extensive properties and economy. This paper aims at presenting a new fiber, its characteristics, and composite in a polymeric matrix empowering the generation of less weight composites for load conveying applications. Spinifex Littoreus Fiber (SLF) is a genus of perennial coastal plants in the grass family. The comprehensive characterization that includes physical analysis, chemical analysis, thermal analysis, mechanical and microstructural characteristics have been carried out on the fiber. The effect of fiber weight percentage was studied from the point of view of the mechanical properties of the compression moulded Spinifex Littoreus Fiber Composites (SLFC). Mechanical properties attained at 40 wt% of fiber content were better. In addition to more fiber, it tends to cause inadequate bonding among the matrix and fiber, resulting in a decrease in mechanical performance. The specific properties of SLFC polymer composites are comparable to those of the glass fiber composite. This makes SLFC composite as an alternate lightweight material. SEM was performed for a study of the interfacial mechanism.
Chitosan-based nanocomposites: preparation and characterization for food packing industry
Authors: M Ahmed Emad , Saber D , Abd ElAziz Kh , Alghtani Abdulaziz H , Felemban Bassem F , Ali Hafiz T , Megahed M
Published: February 2021

In the present work, Cerium (IV)-Zirconium (IV) oxide nanoparticles (CeO4ZrNPs) was successfully dispersed into Chitosan/15Gelatin nanocomposites with different quantities. The obtained chitosan-based nanocomposites represented remarkable improvements in structural, morphological, mechanical, and thermal properties. Roughness increased from 74 nm to 6.4 nm, Young’s Modulus enhanced from 1.36 GPa to 2.99 GPa. The influence of dispersed CeO4ZrNPs contents on the phase transition temperature (T
g) and the non-isothermal degradation processes of chitosan-based nanocomposites were examined using Differential Scanning Galorimetry (DSC) with different heating rates. Kinetic parameters of the thermal degradation for chitosan-based nanocomposites were evaluated using Kissinger-Akahira-Sunose (KAS) and Kissenger (KIS) procedures. Chitosan-based nanocomposites showed an increase in the thermal degradation temperature with higher activation energies, indicating improved thermal stability. Thermal analysis demonstrated that chitosan-based nanocomposites became more ordered by increasing CeO4ZrNPs as inferred from the negative entropy increase. Moreover, the degradation of chitosan-based nanocomposites has been described as a non-spontaneous process. The resulting information is particularly important in applications in which there is a need to obtain chitosan nanocomposites with improved mechanical and thermal properties such as food packing industry.
High-throughput screening to modulate electronic and optical properties of alloyed Cs2AgBiCl6 for enhanced solar cell efficiency
Authors: Gill Deepika , Bhumla Preeti , Kumar Manish , Bhattacharya Saswata
Published: February 2021

The lead-free double perovskite material (viz. Cs2AgBiCl6) has emerged as an efficient and environmentally friendly alternative to lead halide perovskites. To make Cs2AgBiCl6 optically active in the visible region of solar spectrum, band gap engineering approach has been undertaken. Using Cs2AgBiCl6 as a host, band gap and optical properties of Cs2AgBiCl6 have been modulated by alloying with M(I), M(II), and M(III) cations at Ag-/Bi-sites. Here, we have employed density functional theory (DFT) with suitable exchange-correlation functionals in light of spin–orbit coupling (SOC) to determine the stability, band gap and optical properties of different compositions, that are obtained on Ag–Cl and Bi–Cl sublattices mixing. On analyzing 64 combinations within Cs2AgBiCl6, we have identified 19 promising configurations having band gap sensitive to solar cell applications. The most suitable configurations with Ge(II) and Sn(II) substitutions have spectroscopic limited maximum efficiency (SLME) of 32.08% and 30.91%, respectively, which are apt for solar cell absorber.
Full-color computational ghost imaging using a chromatic LED array and image interpolation
Authors: Li Li-Jing , Huang Hong-Xu , Sun Ming-Jie
Published: February 2021

Computational ghost imaging has been an interesting topic for the imaging research community. However, low resolution and quality of image have been a major problem inhibiting the application of computational ghost imaging technique. In this work, we develop a chromatic 64 × 64 LED array which provides high-speed structured illumination up to 2.5 MHz for computational ghost imaging. Importantly, rather than using regular Cartesian arrangement which is commonly used in a digital camera’s detection array, the LED chips on chromatic LED array we propose are arranged in a special way we refer to as basket-weave sampling. The experimental results demonstrate that our proposed arrangement outperforms Cartesian arrangement for storing high-frequency information of colored pictures, with averaged root mean squared error (RMSE) reduced by 4.6%. Meanwhile, considering the physical structure of the LED array, we propose a targeted interpolation algorithm for resulting images obtained from the experiment, and results show that our algorithm has lower averaged RMSE by 2% when compared to bilinear algorithm and by 6.4% when compared to bicubic algorithm.
Optimization of therapeutic antibodies
Authors: Wang Bo , Gallolu Kankanamalage Sachith , Dong Jianbo , Liu Yue
Published: February 2021

In this review, we have summarized the current landscape of therapeutic antibody optimization for successful development. By engineering antibodies with display technology, computer-aided design and site mutagenesis, various properties of the therapeutic antibody candidates can be improved with the purpose of enhancing their safety, efficacy and developability. These properties include antigen binding affinity and specificity, biological efficacy, pharmacokinetics and pharmacodynamics, immunogenicity and physicochemical developability features. A best-in-class strategy may require the optimization of all these properties to generate a good therapeutic antibody.
The effect of opioids on the cognitive function of older adults: results from the Personality and Total Health through life study
Authors: Neelamegam Malinee , Zgibor Janice , Chen Henian , O’rourke Kathleen , Bakour Chighaf , Rajaram Lakshminarayan , Anstey Kaarin J
Published: February 2021

Background

chronic pain, a common complaint among older adults, affects physical and mental well-being. While opioid use for pain management has increased over the years, pain management in older adults remains challenging, due to potential severe adverse effects of opioids in this population.

Objective

we examined the association between opioid use, and changes in cognitive function of older adults.

Design

prospective study.

Setting

community dwelling older adults.

Subjects

study population consisted of 2,222 individuals aged 65–69 years at baseline from the Personality and Total Health Through Life Study in Australia.

Methods

medication data were obtained from the Pharmaceutical Benefits Scheme. Cognitive measures were obtained from neuropsychological battery assessment. Opioid exposure was quantified as Total Morphine Equivalent Dose (MED). The association between change in cognitive function between Wave 2 and Wave 3, and cumulative opioid use was assessed through generalized linear models.

Results

cumulative opioid exposure exceeding total MED of 2,940 was significantly associated with poorer performance in the Mini Mental State Examination (MMSE). Compared with those not on opioids, individuals exposed to opioids resulting in cumulative total MED of greater than 2,940 had significantly lower scores in the MMSE (Model 1: β = −0.34, Model 2: β = −0.35 and Model 3: β = −0.39, P < 0.01). Performance in other cognitive assessments was not associated with opioid use.

Conclusion

prolonged opioid use in older adults can affect cognitive function, further encouraging the need for alternative pain management strategies in this population. Pain management options should not adversely affect healthy ageing trajectories and cognitive health.