bluuebunny/crossref_metadata_2025 huggingface dataset:
Data-driven modeling of nonlinear traveling waves
Authors: Koch J.
Published: April 2021

Presented is a data-driven machine learning framework for modeling traveling wave spatiotemporal dynamics. The presented framework is based on the steadily propagating traveling wave ansatz, u(x,t)=U(ξ=x−ct+a). For known evolution equations, this coordinate transformation reduces governing partial differential equations to a set of coupled ordinary differential equations (ODEs) in the traveling wave coordinate ξ. Although traveling waves are readily observed in many physical systems, the underlying governing equations may be unknown. For these instances, the traveling wave dynamical system can be modeled empirically with neural ODEs. Presented are these ideas applied to several physical systems that admit traveling waves. Examples include traveling wave fronts, pulses, and wavetrains restricted to one-way wave propagation in a single spatial dimension. Last, applicability to real-world physical systems is presented with an exploration of data-driven modeling of rotating detonation waves.
A method of electron density of positive column diagnosis—Combining machine learning and Langmuir probe
Authors: Ding Zhe , Guan Qiuyu , Yuan Chengxun , Zhou Zhongxiang , Qu Zhenshen
Published: April 2021

In the present study, the machine learning algorithm is utilized for the first time to improve the probe diagnosis. Machine learning methods are utilized to improve the Langmuir probe diagnostic accuracy and the diagnosable plasma parameter range without changing the probe structure based on the Langmuir probe. They provide a new way for experimentally obtaining electron density. A DC glow discharge simulation model and experimental equipment are established. Utilizing the discharge pressure and voltage as independent variables, the simulation and experimental electron densities are collected, the simulation and experimental data are utilized for training, and the plasma electron density outside of the pressure and voltage range of the training data is predicted, thereby achieving the prediction. Simultaneously, when the data amount is large enough, even without experimental measurement, the electron density can be obtained directly through the input parameters, without relying on the plasma physical model.
Application of an energy-dependent instrument response function to analysis of nTOF data from cryogenic DT experiments
Authors: Mohamed Z. L. , Mannion O. M. , Knauer J. P. , Forrest C. J. , Glebov V. Yu. , Stoeckl C. , Romanofsky M. H.
Published: April 2021

Neutron time-of-flight (nTOF) detectors are used to diagnose the conditions present in inertial confinement fusion (ICF) experiments and basic laboratory physics experiments performed on an ICF platform. The instrument response function (IRF) of these detectors is constructed by convolution of two components: an x-ray IRF and a neutron interaction response. The shape of the neutron interaction response varies with incident neutron energy, changing the shape of the total IRF. Analyses of nTOF data that span a broad range of energies must account for this energy-dependence in order to accurately infer plasma parameters and nuclear properties in ICF experiments. This work briefly reviews a matrix multiplication approach to convolution, which allows for an energy-dependent change in the shape of the IRF. This method is applied to synthetic data resembling symmetric cryogenic DT implosions to examine the effect of the energy-dependent IRF on the inferred areal density. The results of forward fits that infer ion temperatures and areal densities from nTOF data collected during cryogenic DT experiments on OMEGA are also discussed.
Broadband all-silicon hybrid plasmonic TM-pass polarizer using bend waveguides
Authors: Saber Md Ghulam , Plant David V. , Abadía Nicolás
Published: April 2021

A complementary–metal–oxide semiconductor (CMOS) compatible all-silicon TM-pass polarizer using plasmonic bends is proposed. To simplify the fabrication and be compatible with the CMOS process, we employ only two materials: silicon and silicon dioxide. Highly doped silicon is used to support the plasmons. We obtain an extinction ratio and an insertion loss of 45.4 and 1.7 dB, respectively, at 1550 nm and a maximum extinction ratio of 58 dB. This is the highest reported extinction ratio for a TM-pass polarizer to the best of our knowledge. Furthermore, we achieved >20 dB of extinction ratio and <2 dB of insertion loss over 72 nm bandwidth for a device footprint <8.8 × 5.4 μm2. To achieve this, we exploit the properties of tight bends in plasmonic waveguides. Another advantage of the device is that it is robust against fabrication variations.
An investigation of the characteristics of dam-break flood in a confluence channel based on the lattice Boltzmann method
Authors: Zhang Juyi , Wang Wei , Tian Zhong , Li Yingjin
Published: April 2021

In this study, we use a lattice Boltzmann method with a multi-relaxation-time model to simulate dam-break flooding in confluence channels with four confluence angles. Compared with physical experiment, the simulation proves reliable. We analyze the influence of the confluence angle on the propagation of dam-break flood. The stage hydrograph at the confluence area can be divided into four stages: before the wavefront reaches—rising rapidly—falling gradually—planarization with periodic fluctuation. The water depth of the measuring points in the confluence area is influenced by two factors: the confluence angle and the distance from the measuring point to the first impact point. The results demonstrate that the backwater effect of the confluence is enhanced at higher confluence angles. As the confluence angle increases, the first impact point moves upstream. Moreover, there is a strong backwater effect close to the first impact point, resulting in superelevation mainly occurring in the confluence area.
Study on broadband low-frequency sound insulation of multi-channel resonator acoustic metamaterials
Authors: Xu Chi , Guo Hui , Chen Yinghang , Dong Xiaori , Ye Hongling , Wang Yansong
Published: April 2021

A novel acoustic metamaterial structure, made up of both resonator and multiple channels, is proposed to insulate low-frequency broadband noises. Three bandgaps with a total width of 658 Hz can be obtained below 900 Hz when the structure appears as a single negative characteristic within specific frequency ranges. These bandgaps are caused by the standing-wave characteristics under the coupling action of the interior and exterior cavities and the multiple channels. By changing structural parameters and materials, the low-frequency broadband sound insulation performance of the structure can be improved. Experimental results further prove the sound insulation characteristics. The results obtained herein can be used as a guide toward achieving low-frequency broadband sound insulation using a lightweight structure.
Evaluation of 3D-printed molds for fabrication of non-planar microchannels
Authors: Parthiban Pravien , Vijayan Sindhu , Doyle Patrick S. , Hashimoto Michinao
Published: April 2021

Replica obtained from micromolds patterned by simple photolithography has features with uniform heights, and attainable microchannels are thus quasi-two-dimensional. Recent progress in three-dimensional (3D) printing has enabled facile desktop fabrication of molds to replicate microchannels with varying heights. We investigated the replica obtained from four common techniques of 3D printing—fused deposition modeling, selective laser sintering, photo-polymer inkjet printing (PJ), and stereolithography (SL)—for the suitability to form microchannels in terms of the surface roughness inherent to the mechanism of 3D printing. There have been limited quantitative studies that focused on the surface roughness of a 3D-printed mold with different methods of 3D printing. We discussed that the surface roughness of the molds affected (1) transparency of the replica and (2) delamination pressure of poly(dimethylsiloxane) replica bonded to flat glass substrates. Thereafter, we quantified the accuracy of replication from 3D-printed molds by comparing the dimensions of the replicated parts to the designed dimensions and tested the ability to fabricate closely spaced microchannels. This study suggested that molds printed by PJ and SL printers were suitable for replica molding to fabricate microchannels with varying heights. The insight from this study shall be useful to fabricate 3D microchannels with controlled 3D patterns of flows guided by the geometry of the microchannels.
Secondary electron emission due to multi-species iodine ion bombardment of different target materials
Authors: Habl L. , Rafalskyi D. , Lafleur T.
Published: April 2021

Ion-induced secondary electron emission (SEE) is a fundamental surface interaction that strongly influences many plasma discharges. Recently, interest in iodine plasmas is growing due to new material processing and space propulsion applications, but data for SEE yields due to iodine ion bombardment remain scarce. Additionally, due to the formation of multiple ion species in typical iodine plasmas and surface chemical reactions leading to iodide layer formation, the effective SEE yield is expected to differ from that for individual ion species on clean surfaces. In this work, we measure the SEE yield of multi-species iodine ion beams bombarding different target materials (Mo, W, Al, Ti, Cu, carbon-carbon, and steel) in the energy range of 0.6–1.4 keV. An ion beam is produced by extracting and accelerating ions from a gridded ion source based on an inductively coupled plasma (ICP). SEE yields of downstream targets are measured using a conventional electrostatic probe technique, and the ion beam composition is determined using time-of-flight spectrometry. The beam is composed predominately of atomic (I+) and molecular (I2+) ions whose ratio changes depending on the ICP power. Yields depend strongly on the target material and beam composition and vary between 0.05 and 0.4 depending on whether potential or kinetic emission processes dominate.
Calculation of pair and triplet correlation functions for a Lennard-Jones fluid at ρ*≤1.41 and T*≤25
Authors: Gottschalk Matthias
Published: April 2021

On the basis of Monte Carlo simulations, configurations and pair and triplet correlation functions for a Lennard-Jones fluid are reported over a large range of densities and temperatures (0.002 ≤ ρ* ≤ 1.41 and 0.45 ≤ T* ≤ 25, dimensionless). In total, data for 27 615 ρ*–T*-state points including 750 configurations for each state point are used for the calculation of the pair and triplet correlation functions. For the pair configuration function, an approximation over the whole set of state points is provided, which reproduces the pair configuration with high accuracy (3σ < 0.0075). The results for the triplet configuration functions are compared to the Kirkwood superposition approximation. With the exception of low ρ* (<0.3), the application of the Kirkwood superposition approximation seems not to be a proper choice, showing errors >20%. The configurations and pair and triplet correlation functions of all simulations are openly accessible and can be used as a reference for future theoretical developments of Lennard-Jones fluids and, especially, the liquid state.
Human retroviral antisense mRNAs are retained in the nuclei of infected cells for viral persistence
Authors: Ma Guangyong , Yasunaga Jun-ichirou , Shimura Kazuya , Takemoto Keiko , Watanabe Miho , Amano Masayuki , Nakata Hirotomo , Liu Benquan , Zuo Xiaorui , Matsuoka Masao
Published: April 2021

Significance

Two deadly human retroviruses, human T cell leukemia virus type 1 (HTLV-1) and HIV type 1 (HIV-1), enter latency in vivo, rendering viral countermeasures ineffective. Recently, novel retroviral genes have been discovered to be expressed from the antisense strand of retroviruses even during latency; they are called antisense genes, including the
HBZ
gene for HTLV-1 and
ASP
gene for HIV-1. We employed RNA-fluorescence in situ hybridization technology and discovered that human retroviral antisense messenger RNAs (mRNAs) are predominantly localized in the nucleus of infected cells, despite their coding function. Moreover, human retroviral antisense mRNAs are constantly expressed in latent retroviruses and retained in nucleus to support retroviral persistence; this may allow them to become novel feasible targets for retrovirus elimination.
Phylogenetically diverse diets favor more complex venoms in North American pitvipers
Authors: Holding Matthew L. , Strickland Jason L. , Rautsaw Rhett M. , Hofmann Erich P. , Mason Andrew J. , Hogan Michael P. , Nystrom Gunnar S. , Ellsworth Schyler A. , Colston Timothy J. , Borja Miguel , Castañeda-Gaytán Gamaliel , Grünwald Christoph I. , Jones Jason M. , Freitas-de-Sousa Luciana A. , Viala Vincent Louis , Margres Mark J. , Hingst-Zaher Erika , Junqueira-de-Azevedo Inácio L. M. , Moura-da-Silva Ana M. , Grazziotin Felipe G. , Gibbs H. Lisle , Rokyta Darin R. , Parkinson Christopher L.
Published: April 2021

Significance

Why biological complexity evolves is a major question in the life sciences, but the specific selection pressures favoring simple or complex traits remain unclear. Using high-resolution measurements of venom complexity in North American pitvipers, we link changes in complexity to natural history via phylogenetic diversity of snake diets. The results indicate that venom complexity evolves in response to phylogenetic diversity in a community of species, likely reflecting divergence in the physiological targets of venom. The nature of a species community, rather than their richness alone, is an important feature in the evolution of complex traits.
Evidence from South Africa for a protracted end-Permian extinction on land
Authors: Viglietti Pia A. , Benson Roger B. J. , Smith Roger M. H. , Botha Jennifer , Kammerer Christian F. , Skosan Zaituna , Butler Elize , Crean Annelise , Eloff Bobby , Kaal Sheena , Mohoi Joël , Molehe William , Mtalana Nolusindiso , Mtungata Sibusiso , Ntheri Nthaopa , Ntsala Thabang , Nyaphuli John , October Paul , Skinner Georgina , Strong Mike , Stummer Hedi , Wolvaardt Frederik P. , Angielczyk Kenneth D.
Published: April 2021

Significance

Mass extinctions permanently altered life’s evolutionary trajectory five times in Earth’s history, and the end-Permian extinction was the greatest of these biotic crises. South Africa’s unparalleled fossil record provides a window into mass extinction dynamics on land. We analyze a unique dataset comprising hundreds of precisely positioned tetrapod fossils, identifying a protracted (∼1 Ma) extinction. This contrasts with the rapid marine extinction, demonstrating that the effects of biotic crises vary prominently among Earth’s surface environments. We also identify the blooming of “disaster taxa” before the main extinction rather than in its aftermath as assumed previously. These changes contributed to breaking the incumbency of previously dominant mammal relatives (synapsids) after the extinction and to the Triassic rise of crocodile- and dinosaur-line archosaurs.
Assessment of battery utilization and energy consumption in the large-scale development of urban electric vehicles
Authors: Zhao Yang , Wang Zhenpo , Shen Zuo-Jun Max , Sun Fengchun
Published: April 2021

Significance

The surging demand for battery resources and energy from EVs signifies a need to reassess the real-world battery utilization and energy consumption of urban EVs. In this work, we incorporate unique and previously unavailable datasets of urban-scale EV operation to better understand the battery utilization and energy consumption of large-scale EV utilization. High-resolution operating data of EVs across multiple regions are collected and integrated with vehicle feature data as the input for modeling. Accordingly, we expose several issues that have nonnegligible impacts on battery resources and the urban power supply, such as low battery utilization and seasonal changes in the energy consumption of EVs. The provided models and data can be extensively utilized for further EV-related resource and energy investigations.
Transcriptional profiling reveals signatures of latent developmental potential in
Arabidopsis
stomatal lineage ground cells
Authors: Ho Chin-Min Kimmy , Bringmann Martin , Oshima Yoshimi , Mitsuda Nobutaka , Bergmann Dominique C.
Published: April 2021

Significance

In organisms that exhibit flexible morphologies, such as plants, the developmental origin of flexibility is an interesting but unsolved mystery. Here, by capturing gene-expression profiles of overlapping cell populations in the
Arabidopsis
stomatal lineage, we define genetic networks underlying the latent division potential of a multipotent cell type—the stomatal lineage ground cell—and identify roles for specific and general transcriptional regulators in modulating outputs of the stomatal lineage.
People have shaped most of terrestrial nature for at least 12,000 years
Authors: Ellis Erle C. , Gauthier Nicolas , Klein Goldewijk Kees , Bliege Bird Rebecca , Boivin Nicole , Díaz Sandra , Fuller Dorian Q. , Gill Jacquelyn L. , Kaplan Jed O. , Kingston Naomi , Locke Harvey , McMichael Crystal N. H. , Ranco Darren , Rick Torben C. , Shaw M. Rebecca , Stephens Lucas , Svenning Jens-Christian , Watson James E. M.
Published: April 2021

Significance

The current biodiversity crisis is often depicted as a struggle to preserve untouched habitats. Here, we combine global maps of human populations and land use over the past 12,000 y with current biodiversity data to show that nearly three quarters of terrestrial nature has long been shaped by diverse histories of human habitation and use by Indigenous and traditional peoples. With rare exceptions, current biodiversity losses are caused not by human conversion or degradation of untouched ecosystems, but rather by the appropriation, colonization, and intensification of use in lands inhabited and used by prior societies. Global land use history confirms that empowering the environmental stewardship of Indigenous peoples and local communities will be critical to conserving biodiversity across the planet.
Temporally and spatially partitioned neuropeptide release from individual clock neurons
Authors: Klose Markus K. , Bruchez Marcel P. , Deitcher David L. , Levitan Edwin S.
Published: April 2021

Significance

It is believed that electrical activity simultaneously stimulates widespread release sites in single neurons to elicit neuropeptide-dependent behaviors. However, optically detecting neuropeptide release in the intact brain shows that clock neurons release neuropeptides from different sites at different times of the day. This is possible because one neuronal compartment, the soma, uses biochemical signaling instead of electrical activity to evoke release. Disrupting somatic release affects specific features of circadian locomotor activity and sleep. Thus, neuropeptide release is elicited by independent triggers from distinct parts of clock neurons to engage different regions of behavior-regulating circuitry. This strategy for expanding the connectome may be used for other neuropeptide-dependent behaviors, such as feeding and pain perception.
1940 nm, 1966 nm and 2066 nm multi-wavelength CW and passively-Q-switched operation of L-shaped Tm3+:Lu2O3 ceramic laser in-band fiber-laser pumped at 1670 nm
Authors: Antipov O L , Getmanovskiy Yu A , Balabanov S S , Larin S V , Sharkov V V
Published: April 2021

A Tm3+:Lu2O3 ceramics laser with the L-shaped cavity in-band pumped by a fiber laser at 1670 nm was studied in CW and passively Q-switched multi-wavelength regimes. The CW laser operated at 2066 nm at the weak pump power and self-tuned to 1966 nm and further to 1940 nm at higher pump power. The maximum power in the CW regime at 1940 nm reached 9.5 W, while the average power of 3.6 W was registered in the Q-switched regime with the pulse repetition rate of 110–170 kHz and the pulse duration of 200–240 ns. The Q-switched operation was obtained using a Cr2+:ZnSe saturable absorber. Pulsed regime started at the shortest wavelength of 1940 nm and self-tuned to the double-wavelength of 1940 nm and 1966 nm at higher pump power.
An ultrasonic multi-wave focusing and imaging method for linear phased arrays*
Authors: Dai Yu-Xiang , Yan Shou-Guo , Zhang Bi-Xing
Published: April 2021

To overcome the inherent limits of traditional single wave imaging for nondestructive testing, the multi-wave focusing and imaging method is thoroughly studied. This method makes the compressional waves and shear waves focused in both emission and reception processes, which strengthens the focusing energy and improves the signal-to-noise ratio of received signals. A numerical model is developed to study the characteristics of a multi-wave focusing field. It is shown that the element width approaching 0.8 wavelengths of shear waves can keep a balance between the radiation energy of two waves, which can achieve a desirable multi-wave focusing performance. And an experiment using different imaging methods for a linear phased array is performed. It can be concluded that due to the combination of the propagation and reflection characteristics of two waves, the multi-wave focusing and imaging method can significantly improve the imaging distinguishability of defects and expand the available sweeping range to a sector of –65° to 65°.
Correlation between cooling power and heat quantity of Er-Ho binary nitride as regenerator of 4K-GM cryocooler
Authors: Arita S , Takahashi K , Shiraishi T , Fujieda S , Nakagawa T , Yamamoto T A , Seino S , Masuyama S
Published: April 2021

Advanced regenerator materials of erbium and holmium binary nitrides, Er
x
Ho1-x
N (x = 0 - 1) were studied. Its specific heat vs. temperature curve, possesses a peak due to the magnetic phase transition at their Curie temperature. The cooling power at 4.2 K of a commercial 4K-GM cryocooler filled with the binary nitride of x = 0.625, 0.75, 0.875 or 1 was evaluated. It was found that the cooling power at 4.2 K has a good linear correlation with the heat quantity, which is calculated by integrating C with respect to T in the region of 4.2 - 7.0 K. Three binary nitrides (x = 0.625, 0.875 and 1) filled in series along the regenerator column gave 26% higher cooling power than that filled with HoCu2.
Dielectric BN nanosheet / PVDF composites with high thermal conductivity
Authors: Zhou Zhengrong , Zhang Chi , Zhao Yalin , Wu Zhixiong , Zhang Hua , Guo Shibin , Huang Rongjin , Li Laifeng
Published: April 2021

With the development of electronic devices, high thermal conductivity polymer will become an ideal electronic packaging material. Therefore, Polyvinylidene fluoride (PVDF) nanocomposite was prepared doped with boron nitride nanosheet (BNNS), which has significantly improved thermal conductivity, excellent electrical insulation and outstanding flexibility. These nanocomposite films were prepared by mixing BNNS/PVDF in organic solution, drying, slicing, and then hot-pressing. Compared with the pristine polymers, the nanocomposite films have excellent thermal conduction, which indicates that new high-performance thermal conductivity materials will play an important role in high-power density electronic devices.
Rotating magnetization method for inspection of local defect in HTS conductor
Authors: Onodera Y , Mito T , Hirano N
Published: April 2021

High temperature superconducting (HTS) magnet used for a accelerator for high energy physics or a large-scale magnetic confinement system for nuclear fusion requires large current capacity HTS conductor in order to dump the stored magnetic energy quickly to protect the coil when quench has been occurred. To realize the HTS conductor, superimposed or stacked HTS tapes conductors are invented. However, local degradation of the critical current has been observed in the production of HTS conductors. Therefore, to confirm the soundness of the HTS conductor, it is necessary to establish the non-destructive detection method for the observation of degraded HTS tapes. In this study, we have investigated to inspect the degradation position in stacked HTS tapes by adopting rotating magnetization measurement method. This measurement method is measuring magnetization signal by rotating and transporting stacked HTS tapes in a static magnetic field. As a result, intentionally introduced buckling defect positions were detected by this measurement method.
Trapped field evaluation of ring-shaped GdBCO bulk magnet excited by pulsed field magnetization
Authors: Yokoyama K , Oka T
Published: April 2021

Recently, physical and mechanical properties of REBCO bulk are improved, and, accordingly, various practical applications are considered. As one of them, a portable bulk NMR system has been developed, and, then, the improvement of the system for practical use are progressing. In that system, 6 stacked bulks were magnetized by a superconducting magnet for NMR, resulting that the magnetic field of 4.74 T and inhomogeneity of 6.9 ppm were achieved. In this paper, we fabricated the bulk magnet with the room-temperature bore specialized in pulsed-field magnetization. The ring-shaped bulk was activated by pulsed-field magnetization, and, magnetic fields on the bulk surface and in the room-temperature bore of bulk magnet were evaluated. In the bore, the trapped field was approximately 0.79 T and homogeneity was over 150000 ppm.
The Impact of Relapse Rate on Deterministic Epidemiological Models with Pseudo-recovery
Authors: Qunia Anisa Fatta , Kusnanto Ali , Sianturi Paian
Published: April 2021

The deterministic epidemiological model with pseudo-recovery called the SEIRI model is a model that describes disease transmission in a population. Pseudo-recovery is a term for individuals who have recovered of infection, but some of them might be re-infected. This research aims to reconstruct the model, to analyse stability of fixed point and sensitivity of parameters. Also, to carry out numerical simulations upon combination of parameter values. The stability itself was determined using the Lyapunov functions. In this work, the sensitivity analysis was focussed on the effects of the effective contact rate and relapse rate on basic reproduction numbers. Both the effective contact rate and relapse rate increase with basic reproduction number. This may suggest that controlling the spread of the diseases can be done by decreasing both the effective contact rate or the relapse rate.
Disease Mapping of Leprosy in Maluku Province, 2019 using Hierarchical Bayes
Authors: Mahdy I F , Fitriani R , Revildy W D
Published: April 2021

Leprosy is a chronic disease caused by Mycobacterium.lepreae that affects the nerves of the extremities, skin, nasal mucosa, and upper respiratory tract. As of today, some countries include Indonesia facing difficulties to fight leprosy. The health ministry of Indonesia noted that the majority of leprosy cases occurred in the eastern region, like Maluku Province. Therefore disease mapping is needed to develop a map of leprosy so that the handling of this disease could operate optimally, especially in Maluku. One of the disease mapping techniques is Hierarchical Bayes (HB), which involves a measure of uncertainty compared to other methods such as Standardized Mortality Ratio (SMR). The results showed that the relative risk of leprosy in Maluku was almost the same in each region. It indicates that the disease is prevalent in Maluku, with the highest value in Ambon City and the lowest value in the Aru Islands.
Literacy Description of Probability for the Senior Secondary School Students in Makassar City
Authors: Tiro Muhammad Arif , Ruliana  , Aswi Aswi
Published: April 2021

This development research has obtained an assessment model of probability literacy in senior secondary school students. Such literacy is crucial because the statistical assessment as part of mathematics today in senior secondary schools tend to emphasize technical procedures with many mathematical formulae. Literacy of probability consists of five basic competencies, namely: (1) understanding the concept of probability, (2) insight into the application of the probability concepts, (3) skills in calculating the value of probability, (4) careful interpretation of the probability value, and (5) skills in visualization and communication of probabilities and conclusion that may be drawn from them. This study maps ability levels in these five competencies across Makassar City, identifying weaknesses in several questions about probability literacy that need to be revised. The emphasis on the concept of literacy is a major strategy to improve learning in secondary schools. These five competencies are mapped according to the type of questions that refer to the guidelines for implementing the skills of the 21st-century Curriculum 2013 in senior secondary school. The level of probability literacy achieved by high school students in Makassar is categorized as medium (47%-72%), highlighting an overall need for improved learning strategies that emphasize the five basic competencies. Additionally, morning classes are seen to correspond to a higher level of achievement than afternoon classes, for all five competencies.
Designing Rainfall Index Insurance for Rubber Plantation in Balikpapan
Authors: Azka Muhammad , Fauziyyah  , Hasanah Primadina , Wira Dinata Syalam Ali
Published: April 2021

Rubber commodity is one of the essential agricultural sectors in the City of Balikpapan. Rubber plantation has become a leading product to boost the economic growth in Balikpapan from the agricultural sector. However, this commodity is vulnerable through the changes of rainfall index since less rainfall can decrease the amount of latex in a rubber tree. This unexpected event will make a financial loss to farmers because of delaying the cultivation time. Therefore, the crop insurance for rubber farmers should be discovered. This study applied the Burn Analysis method to determine some classes of rainfall index and calculating the crop insurance premiums based on Black Scholes methods. The lowest class of rainfall index is 1264.36 mm with the crop insurance premiums at this class is Rp. 521,482.73. Otherwise, the highest rainfall index is 1761,36 mm whereas the premium level is Rp.568,592.93.
Comparison of GLM, GLMM and HGLM in Identifying Factors that Influence the District or City Poverty Level in Aceh Province
Authors: Rusyana A , Kurnia A , Sadik K , Wigena A H , Sumertajaya I M , Sartono B
Published: April 2021

The purpose of research is to evaluate the GLM, GLMM and HGLM models to poverty data in Aceh Province and then identify the best model. The response variable is the percentage of district or city poverty while the fixed effect is population density, sex ratio, the number of populations, the number of industries, area types, percentage of PLN user, poverty line and percentage of productive age group. The random effect for the GLMM and HGLM models is the average monthly expenditure. The data in 2019 were taken from website of the Aceh Central Statistics Agency (BPS) on April 13, 2020. For aggregate, the response variable and the random effect met the normal and gamma distribution. the results showed that the population density has an influence on the percentage of poverty in the GLM and HGLM, while in the GLMM, there are no factors that affect it. The scores of determination coefficient (R2) for GLM, GLMM and HGLM were 75.795%, 68.441% and 75.881%, respectively whereas scores of RMSE of them were 0.121, 1.917 and 0.120, respectively. Because the HGLM model has the largest R2 and the smallest RMSE, the HGLM was said to be the best model for the case.
Numerical Prediction of paddy weight of Crop Cutting Survey using Generalized Geoadditive Linear Mixed Model
Authors: Ardiansyah M , Kurnia A , Sadik K , Djuraidah A , Wijayanto H
Published: April 2021

Rice production data is needed to support the information about achieving the second SDGs. Rice production data requires rice productivity data obtained from Crop Cutting Survey by BPS-Statistics Indonesia. The problem is that the measurement of unhulled rice weight in this survey is not always successful. This problem causes the unhulled rice weight data to be missing values. We proposed Geo-GLMM with covariate interaction to estimate the missing values. The proposed methods was compared by GLM, GLMM, and Geo-GLMM. The results showed that seed varieties, TSP/SP36 fertilizer, NPK / compound fertilizer, urea, organic fertilizer, the number of clumps per plot, pest attack, and climate impacts significantly affected rice productivity. Then, we selected the variables and got the best explanatory variables, namely seed varieties, fertilizer, interaction between urea and KCL fertilizer. Geo-GLMM with fertilizer interaction has better prediction performance than GLM, GLMM, and Geo-GLMM without interaction. Based on the results of the simulations, the Geo-GLMM with covariate interaction produces a smaller bias and RMSE. Therefore, it is recommended that the surveyors of Crop Cutting Survey continue to interview farmers when they fail to take sample plots, so we get covariate data can be used to estimate the unhulled rice weight.
A Bayesian approach for Generalized Linear Model Using Non-local Prior (Case Study: Poverty Status in East Java)
Authors: Dwinata A , Kurnia A , Sadik K
Published: April 2021

Generalized Linear Model (GLM) is an extension of the linear regression model. GLM is useful for determining the effect of predictor variables to the response variable that is a member of the exponential distribution family. This study uses a binary response variable having a Binomial distribution. This modelling uses the logit link function. This study aims to evaluate the performance of the Bayesian GLM modelling using local prior distribution and non-local prior distribution. The non-local prior density in this study was pi-MOM. The results of the research on modelling poverty status in East Java using the local prior distribution produced a predictor variable that had a significant effect on poverty status in East Java. Meanwhile, modelling using non-local prior distribution produced three predictor variables that significantly affected the status of poverty in East Java. The goodness criteria of the model showed that the Bayesian GLM modelling using the prior non-local distribution was the best model with the smallest misclassification and the lowest AIC value.
The Application of Firth Bias Correction in Variance Components Estimation of Clustered Random Intercept Binary Model
Authors: Arisanti R , Sumertajaya I M , Notodiputro K A , Indahwati
Published: April 2021

Firth Bias Correction has been discussed in literatures as an alternative method for reducing the bias of variance components in generalized linear mixed model. This paper discusses the application of Firth’s correction in a clustered random intercept binary model in which the penalized quasi likelihood method is utilized. The clustered random intercept binary model is usually applied in clustered data in which the data can be naturally clustered. In this paper the Firth’s correction has been applied to low birth weight data in Indonesia to investigate factors affecting the incidence of the low birth weight as well as its variation within and between clusters.
Smartphone hedonic price study based on online retail price in Indonesia
Authors: Listianingrum T , Jayanti D , Afendi F M
Published: April 2021

The price of a smartphone is determined by its series of specifications, which makes it suitable to be modelled with a hedonic approach. We collected smartphone prices from various e-commerce along with the specifications using web scraping method. This study demonstrates statistical analysis of smartphone prices in Indonesia by constructing a hedonic model and investigate key variables determining smartphone price. An OLS regression model is employed to total of 1120 handsets data to construct a hedonic model. In addition, random forest regression and XGBoost regression were used to determine the variable importance. The results indicated that only 2 of 5 brands are significantly influence the price of smartphones; Xiaomi and Realme. Meanwhile, the other variables such as RAM, Internal Storage, NFC, Screen Size and Weight have significant positive effect on smartphone prices. In contrast to the use of brand as a weighing basis for calculating CPI, we discovered that RAM is the ultimate key variable determining smartphone prices.
Spatial autoregressive stochastic frontier model with application to Indonesia’s aquaculture
Authors: Zulkarnain R , Djuraidah A , Sumertajaya I M
Published: April 2021

Stochastic frontier analysis (SFA) is one of the popular methods for measuring efficiency and productivity. SFA generally assumes that decision making units are independent. However, this assumption may be inappropriate since decision making units are probable interdependent depending on their spatial proximities. This paper aims to incorporate spatial lag into standard SFA model. The performance of spatial autoregressive stochastic frontier model (SAR-SFA) is compared to standard SFA using simulation and real data. Simulation study is undertaken using various degrees of spatial autocorrelation. Furthermore, SAR-SFA is applied to estimate technical efficiency of aquaculture in Indonesia. Simulation results showed that the SAR-SFA generally produces better performance than the standard SFA. If spatial dependencies are significant, then the estimation of production frontier from standard SFA could be misleading. It affects the distribution of technical efficiency and its ranking. Moran’s I test indicated that Indonesia’s aquaculture has significant positive spatial autocorrelation. If standard SFA is applied to estimate technical efficiency of Indonesia’s aquaculture, then the resulted technical efficiency is implausible. This issue is well handled by the SAR-SFA model. Moreover, SAR-SFA model serves procedure to estimate efficiency spillovers.
Dynamic Spatial Durbin Modeling (Case: Percentage of Poor Population in Indonesia 2010-2019)
Authors: Sunandi E , Sumertajaya I M , Djuraidah A , Wigena A H , Fitrianto A
Published: April 2021

The dynamic panel model assumes that each observation unit is independent of each other. But sometimes this assumption is violated, so there are spatial effects in the model. This study aimed to make percentage modeling of poverty in Indonesia using the Dynamic Spatial Durbin Model (DSDM). The data used in this study were secondary data obtained from the Statistics Indonesia in the period 2010-2019. The parameter estimation method used in this model was the Maximum Likelihood (ML). According to Moral-Benito, Allison and Williams the ML method has the best performance when used on panel data that has small cross-section data dimensions. The results of this study indicated that spatial dependence, time lag, variables of Poverty Gap Index, Poverty Severity Index and Logarithm of Expenditures per Capita affect poverty in Indonesia significantly. Other results showed that DSDM was able to explain the diversity in models at 95.6 %. This seemed higher when it’s compared to the Spatial Durbin Model (SDM). Thus, the result of the study proved that DSDM is the best model for modelling dynamic poverty data panel in Indonesia during 2010-2019.
Mixed Geographically and Temporally Weighted Autoregressive to Modeling the Levels of Poverty Population in Java in 2012-2018
Authors: Djuraidah Anik , Djalihu Hartinah , Soleh Agus Mohamad
Published: April 2021

Geographically and temporally weighted regression (GTWR) is a method applied when there is spatial and temporal diversity in the observation. In the GTWR model not all variables were local or insignificant (global in nature) so the GTWR model was developed into Mixed Geographically and Temporally Weighted Regression (MGTWR). The GTWR model can also add an autoregressive component of response variable, the resulting model is known as a geographically and temporally weighted autoregressive model (GTWAR). This study develops the MGTWR model and the GTWAR model which produces a Geographically and Temporally Weighted Autoregressive model (MGTWAR) which is used to model data on the percentage of poor people in regency/municipality on Java Island in 2012-2018. The results showed that MGTWAR produced Akaike Information Criterion (AIC) smaller than GTWR, and the coefficient of determination (R2) is higher than GTWR.
Development of the Panel ARDL by Adding Space-Time effect to Modeling Monthly Paddy Producer Price in Java
Authors: Ardiansyah M , Djuraidah A , Sumertajaya I M , Wigena A H , Fitrianto A
Published: April 2021

Classic panel data modelling has large cross section data (N) and small time series data (T). The aim of the study was to develop a panel data type T > N by adding space-time effect to a panel ARDL model. The basic idea was to combine between the AR (Autoregressive), DL (Distributed Lag), and ST (space-time) effect. The model was applied to paddy producer price at the farmer level in Java from January 2016 to December 2019 where the explanatory variable was the Farmers’ Terms of Trade. Both variables were stationary in the first-difference I (1). The results showed that the ST-ARDL model was good for T > N panel data types. The ST-ARDL model with reparameterization of explanatory variables was able to overcome the problem of multicollinearity. The ST-ARDL model was able to improve the performance of the classic panel data model which was able to reduce the RMSE and increased R2-adj. The linear combination of this model was cointegrated or had a long-term equilibrium relationship. Another result of the study was the ST-ARDL model provided better estimation performance than the AR (p), ARDL (p, q) and GSTAR (p, λ) models with the smaller MAPE values. For further research, the ST-ARDL model can be developed by adding the effect of space-time interaction.
Study of X-13 ARIMA SEATS Modeling for Rice Price Index Data in Indonesia
Authors: Putri Agnes Maludfi , Sadik Kusman , Afendi Farit Mochamad
Published: April 2021

Outlier on a data can cause several problems, including a model that is formed to produce a large residual, and the variance of data will increase. A robust method for outlier problems is needed in order to produce an unbiased model. X-13 ARIMA SEATS is one of robust method in time series. X-13 ARIMA SEATS is a seasonal adjustment method capable of detecting, resolving the presence of outliers, and overcoming seasonal and calendar effect. The X-13 ARIMA SEATS consists of two stages that is using regARIMA model, and using X-12 seasonal adjustment. In this paper, X-13 ARIMA SEATS method is compared with ARIMA method to prove its ability to overcome outliers based on the smallest error value. In this paper, the X-13 ARIMA SEATS method is applied to model and forecast the rice price index in Indonesia in January 2010-December 2018. The results showed that the X-13 ARIMA SEATS method produces a model with smaller MAPE and RMSE values than the ARIMA model.
Classification modeling of support vector machine (SVM) and random forest in predicting pharmacodynamics interactions
Authors: Farhana N A , Afendi F M , Fitrianto A , Wijaya S H
Published: April 2021

Drug-drug interaction (DDI) is a drug’s effectiveness that can affect the body’s response to the treatment process. DDI occurs when food, drinks, chemicals, and other drugs change the effectiveness of a drug that is given simultaneously. One type of DDI is pharmacodynamics interactions. This interaction is difficult to detect and is very dangerous to humans. Therefore it is necessary to do classification modeling to identify pharmacodynamics interactions based on the value of Side Effect Similarity (SES), Chemical Similarity (CS), and Target Protein Connectedness (TPC). The Support Vector Machine (SVM) and random forest classification method that can be used to predict pharmacodynamics interactions. This study aims to find the best classifications technique by first applying the scaling process, variables interaction, resampling technique, and binarization technique. Best on the analysis result obtained by the random forest is the best model with the highest accuracy and AUC value to other models. The accuracy and AUC values for the best models are 89.93% and 79.96%.
Affecting mechanical on some growth properties for corn, MAHA cultivar
Authors: Alwan Alsharifi Salih K. , Shtewy Naim , Imran Alaamer Shathar A.
Published: April 2021

The effect of chisel plow on corn / Maha cultivar was observed based on some technical indicators, under three plowing depth (14, 16 and 18 cm). The experiments were conducted in a factorial experiment under randomized complete block design with three replications. The 11-13% soil humidity was meaningfully best than 13-15% soil humidity in all studied parameters. For 11-13% soil humidity and 14cm plowing depth, the fuel consumption, machine efficiency, germination percentage, plant height, 1000 – weight grain, number of grains per ear and the corn productivity were 12.336 and 11.913l.ha−1 79.425 and 79.972 %;89.527 and 92.346 %; 148.85 and 153.70 cm; 218.85 and 226.58 g; 474.308 and 499.354 grain; 4.163 and 4.286t.ha−1.
Effects of different broiler flooring systems on surface temperature, air quality and carcass characters of broilers
Authors: Al-Nasseri Ahmad N.I. , Taha Ahmed T. , Khalaf Hasan Aljumaily Tareq
Published: April 2021

The present study investigated the use of perforated plastic floors with different heights in the broiler performance, surface temperature, air quality, and carcass characters of broilers. Three hundred sixty-seven day-old unsexed chicks randomly divided into 4 groups: control reared on sawdust litter in others used, plastic floors with different heights (5, 10 and 15) cm, for 2nd, 3rd and 4th treatment respectively. The first treatment (sawdust) showed significantly (P < 0.05) increase in body surface temperature, as compared to the plastic floors system treatments, and the three plastic floor treatments affected air quality, with less concentrations of ammonia and carbon dioxide compared to the sawdust. The results showed significant differences (P < 0.05) in the live relative weight, where the treatments T2, T3 and T4 were increase at the age of 35 days compared to the sawdust treatment. We suggested the perforated plastic floors could be a good alternative to promote a better quality environment and superior production rates with improved surface temperature.
Effect of variety and humidity on the loss of maize crop after shelling in shelling and drying factories of maize (Zea mays) in Iraq
Authors: AL-Aaty Y H S , Al-Jomaily A R A
Published: April 2021

In order to know effect of the variety and the optimum humidity to reduce the percentage of loss in the yield of maize during the process of shelling the maize factories, this research was conducted during the autumn season of 2011 in Hawija district, west of Kirkuk governorate, using six entered varieties (CADIZ, DKC1120, DKC1188, DRACHMA, RONALDINIO and RANT) were cultivated according to a randomized complete block design (RCBD) with three replications. The shelling was carried out at three levels of humidity (23-26%, 27-30% and 31-33%). The following characteristics were studied (number of rows in ear, number of grains per row, total yield kg/du, outturn ratio of grain yield at the three moisture levels, and the percentage of loss of grain yield at the three moisture levels). The results indicated that there are significant differences between the varieties at a probability level of 1% for all the studied traits, and the results of the means test showed the superiority of the DRACHMA variety at the best rates for all the traits studied, as it gave a yield amounted to 3708.2 kg/du, and it also gave the lowest percentage, it was 3.95% Low humidity 23-26%. The low humidity percentage also achieved the lowest rates of loss percentage during the shelling process for all varieties.