bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstructure of quasi-one-dimensional superconductor KCr3As3 prepared by K-ion deintercalation
Authors: Zhang Lu , Li Jun , Mu Qingge , Liu Tong , Yang Dong , Zhu Chunhui , Ren Zhi-an , Tian Huanfang , Li Zi-an , Li Jianqi , Yang Huaixin 
Published: February 2021

Abstract
The microstructure of quasi-one-dimensional KCr3As3 (133) superconductors, which were prepared by chemical cation deintercalation from their counterpart K2Cr3As3 (233) compounds, are investigated using scanning transmission electron microscopy. The nominal KCr3As3 crystals generally exhibit irregular nanoscale 133-phase domains accompanied by an amorphous As-deficient phase and cracks as a result of alkali cation deintercalation processes. Analysis of local defective structures reveals the existence of an intermediate state in the transformation from 233 to 133 phase and a possible K-deficient 233-type structure as a nanoscale cluster. Our microscopic investigations offer insight into the microstructure of KCr3As3 and the alkali metal cation deintercalation processes.
Characterization of mechanical deformation in aluminum by optical second harmonic generation
Authors: Rellaford Kaylee N , Averett Shawn C , Farnsworth Alexander J , Adams Derrik D , Smith Scott D , Fullwood David T , Patterson James E 
Published: February 2021

Abstract
Second harmonic generation (SHG), a laser-based surface technique, was used to characterize near-surface defect evolution associated with mechanical deformation in 2024-T3 aluminum due to tensile loads. Electron backscatter diffraction (EBSD) measurements were also performed to determine the geometrically necessary dislocation density before and after tensile deformation. Comparison of the EBSD and SHG results found that dislocation density and SHG signal are inversely proportional; tensile deformation in the plastic regime led to an increase in dislocation density and a decrease in SHG response. A similar trend was seen in the SHG results on as-received (unpolished) Al samples; SHG response decreases with extent of plastic deformation. This study suggests that SHG has potential as a nondestructive evaluation technique.
Verification of KURBUC-based ion track structure mode for proton and carbon ions in the PHITS code
Authors: Matsuya Yusuke , Kai Takeshi , Sato Tatsuhiko , Liamsuwan Thiansin , Sasaki Kohei , Nikjoo Hooshang 
Published: February 2021

Abstract
The particle and heavy ion transport code system (PHITS) is a general-purpose Monte Carlo radiation transport simulation code. It has the ability to handle diverse particle types over a wide range of energy. The latest PHITS development enables the generation of track structure for proton and carbon ions (1H+, 12C6+) based on the algorithms in the KURBUC code, which is considered as one of the most verified track-structure codes worldwide. This ion track-structure mode is referred to as the PHITS-KURBUC mode. In this study, the range, radial dose distributions, and microdosimetric distributions were calculated using the PHITS-KURBUC mode. Subsequently, they were compared with the corresponding data obtained from the original KURBUC and from other studies. These comparative studies confirm the successful inclusion of the KURBUC code in the PHITS code. As results of the synergistic effect between the macroscopic and microscopic radiation transport codes, this implementation enabled the detailed calculation of the microdosimetric and nanodosimetric quantities under complex radiation fields, such as proton beam therapy with the spread-out Bragg peak.
Background impurities in a delta-doped QW. Part II: Edge doping
Authors: Akimov V , Tulupenko V , Duque C A , Morales A L , Demediuk R , Tiutiunnyk A , Laroze D , Kovalov V , Sushchenko D 
Published: February 2021

Abstract
This is the second part of our study of the background impurity influence on the intersubband energy structure of a single SiGe/Si/SiGe quantum well with the impurity delta layer within the well. By the background impurity we mean sparse shallow donor doping throughout the infinitely wide barriers. In this part we consider a situation where the delta layer is positioned near the edge of the well and the structure symmetry is broken. We explain in detail the necessary modifications of our self-consistent method that includes calculation of impurity binding energy. The results particularly show that the mentioned asymmetry combined with the background impurity in the barriers provides new features to the effect of tuning the intersubband optical transitions by the ionization grade of the impurity in delta-layer that provides new technological possibilities.
Experimental investigation on the performance degradations of the GaN class-F power amplifier under humidity conditions
Authors: Zhou Shaohua 
Published: February 2021

Abstract
To investigate the humidity dependency of the specifications for a GaN class-F power amplifier (PA), humidity experiments are conducted in the Vötsch Industrietechnik SC3 1000 MHG environmental test chamber. The experimental results show that the key specifications of the PA, such as the output power and power-added efficiency, the large-signal gain, and the drain current show degradation as humidity increases. The reason for this degradation may be the reduction of the 2DEG mobility density due to surface degradation at AlGaN recess regions caused by diffusion phenomena of Ga, and Al. The results concluded here would be helpful for the PA designers to understand the humidity effects on the key specifications for the GaN class-F PA comprehensively, so that the designers could consider the effects on the design cycle of the compensation circuits in advance.
A cubic B-spline collocation method with new approximation for the numerical treatment of the heat equation with classical and non-classical boundary conditions
Authors: Tassaddiq Asifa , Yaseen Muhammad , Yousaf Aatika , Srivastava Rekha 
Published: February 2021

Abstract
In this paper, a cubic B-spline collocation method equipped with new approximations for second-order derivatives is used to approximate the solution of the heat equation. This technique depends on the typical finite difference scheme to discretize the time derivative while cubic B-splines are utilized as interpolation functions in the space dimension. The key advantage of using this approach is that the solution is obtained as a piecewise continuous function empowering one to find approximation at any desired location of the domain. The stability and convergence analysis of the presented method are studied rigorously. The capability of the scheme is checked by some test problems. The effectiveness and exactness of the proposed method are confirmed by computing the error norms. Numerical results are contrasted with some existing numerical schemes to exhibit the predominance of our scheme.
Modulation instability of ion-acoustic waves and exchange interaction in magnetized quantum plasma with relative density effects of spin-up and spin-down electrons
Authors: Gul Nabi , Ahmad Rashid 
Published: February 2021

Abstract
The separate-spin evolution quantum hydrodynamic (SSE-QHD) model is used to study Ion-Acoustic Waves (IAWs) in a magnetized quantum plasma having electrons with different spin populations in the presence of the spin particle exchange interactions (Coulomb type) in spin-down electrons only. The plasma consists of inertia-less separated spin-up and spin-down electrons states, while ions are inertial and classical. Besides, a uniform magnetic field is assumed to be directed in the Z-direction i.e.

B

⃗

=

B

0

z

ˆ

. An interesting interplay between exchange interaction and density polarization ratio κ has been observed on dispersive properties, effective Debye screening length and effective ion-acoustic speed. The non-linear Schrödinger equation is derived through a reductive perturbation approach. Moreover, the modulation instability condition and resulting envelope waves are analyzed. The parametric effects of density polarization ratio κ and Coulomb exchange interaction on dispersion, effective screening length, effective ion-acoustic speed, instability growth rate, and on the solitons profile have been discussed in detail. This model can be helpful to study properties of the dilute magnetic semiconductors and degenerate 2D & 3D Fermi electron gas, where exchange interactions are significant.
Neuroprotective effect of hypoxic preconditioning and neuronal activation in a in vitro human model of the ischemic penumbra
Authors: Pires Monteiro Sara , Voogd Eva , Muzzi Lorenzo , De Vecchis Gianmarco , Mossink Britt , Levers Marloes , Hassink Gerco , Van Putten Michel , Le Feber Joost , Hofmeijer Jeannette , Frega Monica 
Published: February 2021

Abstract

Objective. In ischemic stroke, treatments to protect neurons from irreversible damage are urgently needed. Studies in animal models have shown that neuroprotective treatments targeting neuronal silencing improve brain recovery, but in clinical trials none of these were effective in patients. This failure of translation poses doubts on the real efficacy of treatments tested and on the validity of animal models for human stroke. Here, we established a human neuronal model of the ischemic penumbra by using human induced pluripotent stem cells and we provided an in-depth characterization of neuronal responses to hypoxia and treatment strategies at the network level.
Approach. We generated neurons from induced pluripotent stem cells derived from healthy donor and we cultured them on micro-electrode arrays. We measured the electrophysiological activity of human neuronal networks under controlled hypoxic conditions. We tested the effect of different treatment strategies on neuronal network functionality.
Main results. Human neuronal networks are vulnerable to hypoxia reflected by a decrease in activity and synchronicity under low oxygen conditions. We observe that full, partial or absent recovery depend on the timing of re-oxygenation and we provide a critical time threshold that, if crossed, is associated with irreversible impairments. We found that hypoxic preconditioning improves resistance to a second hypoxic insult. Finally, in contrast to previously tested, ineffective treatments, we show that stimulatory treatments counteracting neuronal silencing during hypoxia, such as optogenetic stimulation, are neuroprotective.
Significance. We presented a human neuronal model of the ischemic penumbra and we provided insights that may offer the basis for novel therapeutic approaches for patients after stroke. The use of human neurons might improve drug discovery and translation of findings to patients and might open new perspectives for personalized investigations.
The impact of ELM mitigation on tungsten source in the EAST divertor
Authors: Chen X.H. , Ding F. , Wang L. , Sun Y.W. , Ding R. , Brezinsek S. , Zang Q. , Wang Y.M. , Duan Y.M. , Zhang L. , Hu Z.H. , Zhang Q. , Ye D.W. , Luo Y. , Meng L.Y. , Liu J.B. , Yang Z.S. , Xu G.S. , Liang Y.F. , Luo G.-N. , Ding H.B. , Hu J.S. 
Published: February 2021

Abstract
Divertor tungsten (W) erosion source during edge localized mode (ELM) bursts in EAST is investigated based on optical emission spectroscopy on atomic neutral tungsten line emission at 400.9 nm. Both temporal evolution and total source strength are analyzed and compared in three different ELM mitigation schemes including natural ELMs, resonant magnetic perturbations (RMP) and 2.45 GHz lower hybrid wave (LHW). The mitigation of W source caused by single ELM impact at the divertor target is mainly attributed to the reduction of the W source production in the ELM decay phase. However, with the increase of ELM frequency, the time-averaged intra-ELM W source during an ELM cycle rises and dominates the evolution of the total W source with increasing fraction, which exhibits strong correlation with the core W level in the RMP scheme. In the natural ELM scheme, the pedestal electron temperature is found not only to control the effective W sputtering yield at target during ELMs, thus influencing the intra-ELM W source, but also to be related to the delay time between the divertor ELM WI emission and the core extreme ultraviolet bolometer (XUV) signal which can scale with the parallel ion transit time. Furthermore, the delay time is found to have more consistent dependence on the pedestal plasma collisionality. The rise time of intra-ELM WI emission increases when RMP or LHW is applied, revealing a different ELM mitigation mechanism in comparison with the natural ELM scheme. The temporal profiles of the intra-ELM WI emission in different ELM mitigation schemes are compared and the potential mechanism is discussed. Besides, the ELM mitigation effects with RMP are found to be asymmetric at the outer and inner divertor targets, which is characterized by the different variations of the intra-ELM W source strength and the rise time of WI emission with the ramp-up of RMP coil current. Divertor partial detachment is achieved simultaneously with strong ELM mitigation under a suitable RMP phase difference without additional gas puff.
A mathematical modelling and numerical simulation of the SIRS political fanaticism figure voters model with presence of media in Indonesian presidential election
Authors: Yong B 
Published: February 2021

Abstract
In presidential election, the presidential candidates who will be standing in it should try to get as much support among the voters. Understanding the dynamics of voters spread help presidential candidates or parties which supporting the candidates in designing appropriate strategies to win presidential election. In this paper, the dynamics of voters is described by using a mathematical model of the SIRS deterministic model. The model is constructed as a three-dimensional form of the non-linear differential equation. The spread of voters can move from neutral voters to supportive voters, neutral voters to apathetic voters, supportive voters to apathetic voters, or apathetic voters to neutral voters. Since presidential candidates need media to get the exposure they need to win the elections, we also consider its dynamics with the presence of media to estimate the number of votes in Indonesian presidential election. From the mathematical analysis of the model, we find the political fanaticism figure voters free equilibrium state explicitly and the political fanaticism figure voters endemic equilibrium state implicitly. Sufficient conditions for their existence and local stability of both equilibrium states are derived. Numerical simulation using R based on data from The General Election Commission are carried out to verify the analytical results.
Cyber Insurance Rate Making Based on Markov Model for Regular Networks Topology
Authors: Antonio Y , Indratno S W 
Published: February 2021

Abstract
Computers and Internet play a key role in the processes of data transaction, data exchange and data storage in a business. Malicious software or computer viruses is one of the biggest threats that can attack computer networks and cause huge losses due to loss of data and information. As a way to transfer risk, cyber insurance requires precise and appropriate calculations even though many challenges are faced including the effects of differences in network structure. Standards of cyber insurance that have not been established as in the mortality table for life insurance open the possibility to set a standard calculation based on network structure by determining cyber insurance rates. This study uses a general susceptible-infectious-susceptible model with Markovian property to simulate the process of spreading computer virus and calculate the total loss for each computer. Rate making will consider the number of infected neighbours on a node as an exposure to set insurance rates on regular network topology. The simulation process shows that the rates at each node are affected by the probability of initial infection, the degree of each node on the network, and the parameters of infection or recovery.
SEIR Model and Simulation for Typus Disease
Authors: Side S , Badwi N , Abdy M , Sanusi W 
Published: February 2021

Abstract
The objectives of this research are to obtain a mathematical model for the spread of typhoid by including the factor of flies and food as variables in the model; analyze and simulation models that will provide predictions and status of typhoid. The data used are secondary data on the number of Typhus cases in Makassar City, analysis of the model is done using the lyapunov function method, while the simulation uses the MatLab model. The results of this study are the SEIR model for typhoid spread, then the simulation results of the model using secondary data on the number of typhoid cases in the city of Makassar provide the number of typhus sufferers and the status of typhoid in Makassar city that is disease free or endemic. Prediction of the number of typhoid cases which can be a reference in the early steps of typhoid cases in Makassar.
Mathematical Modelling for Event Occurrence Rainbow Secondary
Authors: Rifandy M , Rahmawati  , Side S 
Published: February 2021

Abstract
Secondary rainbow is a rainbow that formed because light is reflected twice when entering the rain drops and looks right out over the primary rainbow. Rules to formation of the secondary rainbow is same as the primary rainbow when it rains coincide with the sun shining from the other side and the observer is between them. The aims of research are: determine the mathematical model of the secondary rainbow, determine the angle, and the angle secondary rainbow colors using differential calculus. This observation method using literature study which is based on the theoretical framework underlying the ways of solving the problems that include, derivatives, maximum/minimum value, and the properties of light. The results of this research is deviation angle of the mathematical models secondary rainbow;

D
S

=

2

θ
1

−
6

(

sin

−
1

(

n
u

sin

θ
1

n
a

)

)

+
2
π

. This model found the optimum angle of the I V
na )) secondary rainbow is 51 °. Large corner secondary rainbow of colors Red, Orange, Yellow, Green, Blue, Indigo and Violet are respectively 50.57, 51.12, 51.72, 52.42, 52.78, 53.45 and 53.60 (in degrees). It is shown that large rainbow angle for each colors of secondary rainbow are different, it is explains that the secondary rainbow is composed of seven colors.
A Regression-Based Approach for Mediation Analysis with Censored Data
Authors: Salehah N A , Suhartono  
Published: February 2021

Abstract
The regression method is one of the most applied approaches to estimate the direct and indirect effect of the causal variable (X) to an outcome (Y) with any mediating variable (M) in their mechanism. Censored or limited data on any one of the inputs, mediators, and output often observed in a randomized trial with a specific follow-up time or with certain conditions and limitations caused by a particular setting. In this study, several regression strategies were employed to estimate each different path parameter, i.e., the effect of X on M(a), the effect of M on Y (b), and the effect of X on Y (c’) for a single mediator model. A simulation study was conducted under various conditions to assess the performance of the proposed strategy while dealing with a censored mediator. A continuous mediator and outcome are observed in this study so that the product method can be applied to understand the estimation of the indirect effect. Based on the results, it is clearly shown that a higher censoring percentage in the mediating variable yields higher bias estimate. By applying Tobit model in M-regression can minimize the bias of estimate effect with higher censoring percentage. Furthermore, it can conclude that the proposed strategy can effectively perform the estimation of indirect effect with a censored mediator.
A Hybrid Generalized Space-Time Autoregressive-Elman Recurrent Neural Network Model for Forecasting Space-Time Data with Exogenous Variables
Authors: Setyowati E , Suhartono  , Prastyo D D 
Published: February 2021

Abstract
This research proposes a hybrid method by combining Generalized Space-Time Autoregressive with exogenous variables and Elman Recurrent Neural Network (GSTARX-Elman RNN) to forecast space-time data. GSTAR method is used for modeling and forecasting multivariate data which including time and location factors. The modeling GSTAR with exogenous variables is to capture time series factors, i.e., trend, seasonal, and calendar variation. This method combines with Elman RNN as a nonlinear forecasting method for the data that have a nonlinear pattern. Hybrid GSTARX-Elman RNN compares with time series regression and GSTARX methods based on RMSE criteria. This research focused on simulation data that consist of a trend, seasonal, and calendar variation patterns, and using two scenarios of noise, i.e., linear and nonlinear noise. The result of these simulations showed that time series regression and GSTARX method could capture well the exogenous variables, but hybrid GSTARX-Elman RNN is a more accurate method than others. Hybrid GSTARX-Elman RNN could capture nonlinearity data pattern from these simulations. In general, the hybrid models tend to provide more accurate forecast performance than individual forecast models that it is in line with the results of the M4 forecasting competition.
Bivariate Poisson Inverse Gaussian Regression Model with Exposure Variable: Infant and Maternal Death Case Study
Authors: Mardalena S , Purhadi  , Purnomo J T D , Prastyo D D 
Published: February 2021

AbstractOne of appropriate methods that could be used to model positive integers response and its corresponding predictors is Poisson regression. This method has a strict assumption to be achieved, that is the mean and variance of response variable must be equal (equidispersion). In many practical issues, sometimes, the variance is larger than the mean (overdispersion). Bivariate Poisson Inverse Gaussian Regression (BPIGR) is proposed to overcome the overdispersion issue. In this study, the BPIGR model is developed by adding the exposure variable as the weight of each sample unit. This study applies the proposed method to model the infant and maternal death data (as the responses) and the factors that influence them. The data of East Java 2017 are used for the application. Maximum Likelihood Estimation (MLE) method is used to estimate the parameters, while the hypothesis testing of the BPIGR model is derived using Maximum Likelihood Ratio Test (MLRT) approach. The results showed that the BPIGR model is a proper model for modeling the number of infant and maternal deaths. Furthermore, all predictor variables significantly influence those two responses.
Modeling of Human Development Index in Papua Province Using Spline Smoothing Estimator in Nonparametric Regression
Authors: Rahmawati D P , Budiantara I N , Prastyo D D , Octavanny M A D 
Published: February 2021

Abstract
The development goal of a country must be focused on the quality of human life to achieve prosperity. One important indicator for measuring the success of a country’s development is the Human Development Index (HDI). In 2018, Papua was the province with the lowest HDI in Indonesia. Special attention is needed to improve HDI in Papua Province, one of them is by paying attention to the variables that affect HDI such as population growth rate, percentage of poor population, and economic growth. The relationships between HDI and the predictor variables do not have a clear pattern and tend to change at certain subintervals. This case can be approached using Spline Smoothing in multivariable nonparametric regression. Spline Smoothing is a type of estimator in nonparametric regression that has an excellent ability to handle data that tend to change at certain subintervals. Therefore, the purposes of this study are to obtain the form of Spline Smoothing estimator function in multivariable nonparametric regression, estimate the function and apply it to the HDI in Papua Province. The empirical results of modeling HDI in Papua Province show that it can be adequately applied which gives GCV = 58.108, R2 = 99.77% and RMSE = 0.0505.