bluuebunny/crossref_metadata_2025_split huggingface dataset:
3-bit multilevel operation with accurate programming scheme in TiO
x
/Al2O3 memristor crossbar array for quantized neuromorphic system
Authors: Kim Tae-Hyeon , Lee Jaewoong , Kim Sungjoon , Park Jinwoo , Park Byung-Gook , Kim Hyungjin 
Published: March 2021

Abstract
As interest in artificial intelligence (AI) and relevant hardware technologies has been developed rapidly, algorithms and network structures have become significantly complicated, causing serious power consumption issues because an enormous amount of computation is required. Neuromorphic computing, a hardware AI technology with memory devices, has emerged to solve this problem. For this application, multilevel operations of synaptic devices are important to imitate floating point weight values in software AI technologies. Furthermore, weight transfer methods to desired weight targets must be arranged for off-chip training. From this point of view, we fabricate 32 × 32 memristor crossbar array and verify the 3-bit multilevel operations. The programming accuracy is verified for 3-bit quantized levels by applying a reset-voltage-control programming scheme to the fabricated TiO
x
/Al2O3-based memristor array. After that, a synapse composed of two differential memristors and a fully-connected neural network for modified national institute of standards and technology (MNIST) pattern recognition are constructed. The trained weights are post-training quantized in consideration of the 3-bit characteristics of the memristor. Finally, the effect of programming error on classification accuracy is verified based on the measured data, and we obtained 98.12% classification accuracy for MNIST data with the programming accuracy of 1.79% root-mean-square-error. These results imply that the proposed reset-voltage-control programming scheme can be utilized for a precise tuning, and expected to contribute for the development of a neuromorphic system capable of highly precise weight transfer.
Cosmic shear power spectra in practice
Authors: Nicola Andrina , García-García Carlos , Alonso David , Dunkley Jo , Ferreira Pedro G. , Slosar Anže , Spergel David N. 
Published: March 2021

Abstract
Cosmic shear is one of the most powerful probes of Dark
Energy, targeted by several current and future galaxy
surveys. Lensing shear, however, is only sampled at the positions of
galaxies with measured shapes in the catalog, making its associated
sky window function one of the most complicated amongst all
projected cosmological probes of inhomogeneities, as well as giving
rise to inhomogeneous noise. Partly for this reason, cosmic shear
analyses have been mostly carried out in real-space, making use of
correlation functions, as opposed to Fourier-space power
spectra. Since the use of power spectra can yield complementary
information and has numerical advantages over real-space pipelines,
it is important to develop a complete formalism describing the
standard unbiased power spectrum estimators as well as their
associated uncertainties. Building on previous work, this paper
contains a study of the main complications associated with
estimating and interpreting shear power spectra, and presents fast
and accurate methods to estimate two key quantities needed for their
practical usage: the noise bias and the Gaussian covariance matrix,
fully accounting for survey geometry, with some of these results
also applicable to other cosmological probes. We demonstrate the
performance of these methods by applying them to the latest public
data releases of the Hyper Suprime-Cam and the Dark Energy Survey
collaborations, quantifying the presence of systematics in our
measurements and the validity of the covariance matrix estimate. We
make the resulting power spectra, covariance matrices, null tests
and all associated data necessary for a full cosmological analysis
publicly available.
Silicone encapsulation of thin-film SiO
x
, SiO
x
N
y
and SiC for modern electronic medical implants: a comparative long-term ageing study
Authors: Lamont C , Grego T , Nanbakhsh K , Shah Idil A , Giagka V , Vanhoestenberghe A , Cogan S , Donaldson N 
Published: March 2021

Abstract

Objective. Ensuring the longevity of implantable devices is critical for their clinical usefulness. This is commonly achieved by hermetically sealing the sensitive electronics in a water impermeable housing, however, this method limits miniaturisation. Alternatively, silicone encapsulation has demonstrated long-term protection of implanted thick-film electronic devices. However, much of the current conformal packaging research is focused on more rigid coatings, such as parylene, liquid crystal polymers and novel inorganic layers. Here, we consider the potential of silicone to protect implants using thin-film technology with features 33 times smaller than thick-film counterparts. Approach. Aluminium interdigitated comb structures under plasma-enhanced chemical vapour deposited passivation (SiO
x
, SiO
x
N
y
, SiO
x
N
y
+ SiC) were encapsulated in medical grade silicones, with a total of six passivation/silicone combinations. Samples were aged in phosphate-buffered saline at 67 ∘C for up to 694 days under a continuous ±5 V biphasic waveform. Periodic electrochemical impedance spectroscopy measurements monitored for leakage currents and degradation of the metal traces. Fourier-transform infrared spectroscopy, x-ray photoelectron spectroscopy, focused-ion-beam and scanning-electron- microscopy were employed to determine any encapsulation material changes. Main results. No silicone delamination, passivation dissolution, or metal corrosion was observed during ageing. Impedances greater than 100 GΩ were maintained between the aluminium tracks for silicone encapsulation over SiO
x
N
y
and SiC passivations. For these samples the only observed failure mode was open-circuit wire bonds. In contrast, progressive hydration of the SiO
x
caused its resistance to decrease by an order of magnitude. Significance. These results demonstrate silicone encapsulation offers excellent protection to thin-film conducting tracks when combined with appropriate inorganic thin films. This conclusion corresponds to previous reliability studies of silicone encapsulation in aqueous environments, but with a larger sample size. Therefore, we believe silicone encapsulation to be a realistic means of providing long-term protection for the circuits of implanted electronic medical devices.
Validity of models for Dreicer generation of runaway electrons in dynamic scenarios
Authors: Olasz S. , Embreus O. , Hoppe M. , Aradi M. , Por D. , Jonsson T. , Yadikin D. , Pokol G.I. , EU-IM Team  
Published: March 2021

Abstract
Runaway electron modelling efforts are motivated by the risk these energetic particles pose to large fusion devices. The sophisticated kinetic models can capture most features of the runaway electron generation but have high computational costs, which can be avoided by using computationally cheaper reduced kinetic codes. This paper compares the reduced kinetic and kinetic models to determine when the former solvers, based on analytical calculations assuming quasi-stationarity, can be used. The Dreicer generation rate is calculated by two different solvers in parallel in a workflow developed in the European integrated modelling framework, and this is complemented by calculations of a third code that is not yet integrated into the framework. Runaway Fluid, a reduced kinetic code, NORSE, a kinetic code using non-linear collision operator, and DREAM, a linearized Fokker–Planck solver, are used to investigate the effect of a dynamic change in the electric field for different plasma scenarios spanning across the whole tokamak-relevant range. We find that on time scales shorter than or comparable to the electron–electron collision time at the critical velocity for runaway electron generation, kinetic effects not captured by reduced kinetic models play an important role. This characteristic time scale is easy to calculate and can reliably be used to determine whether there is a need for kinetic modelling or cheaper reduced kinetic codes are expected to deliver sufficiently accurate results. This criterion can be automated, and thus it can be of great benefit for the comprehensive self-consistent modelling frameworks that are attempting to simulate complex events such as tokamak start-up or disruptions.
Diffusive epidemic process in 3D: a two-species reaction–diffusion phase transition
Authors: Argolo C , Tenório V , Albuquerque S S 
Published: March 2021

Abstract
By the use of Monte Carlo simulation we study the critical behavior of a three-dimensional stochastic lattice model describing a diffusive epidemic propagation process. In this model, healthy (A) and sick (B) individuals diffuse on the lattice with diffusion constants d

A
and d

B
, respectively, and undergo reactions B → A and A + B → 2B. We determine the absorbing phase transition between a steady reactive state and a vacuum state. We obtained the order parameter, order parameter fluctuations, correlation length and their critical exponents by the use of steady state and short-time dynamics simulations. We studied three different diffusion regimes: the case of species A diffusing much slower than species B (d

A
≪ d

B
), the case of species with equal diffusion constants (d

A
= d

B
) and the case of species A diffusing much faster than species B (d

A
≫ d

B
). We found only second order transition for all three cases. We did not identify any signal of first order transition for the case d

A
> d

B
as predicted by field theory in first order approximation.
Performance of Undergraduate Students To Deal with STEM (Science, Technology, Engineering and Mathematics) Based Problems
Authors: Lubis A , Nasution AA , Hia Y. , Ritonga A 
Published: March 2021

Abstract
The type of research carried out in this article is descriptive which aims to provide an overview of students’ high-level thinking skills in solving STEM-based problems, especially Medan State University. The subjects in this study were 45 students in the first semester of the mathematics education study program. Data collection in this study was carried out by giving a pretest to students with 15 minutes and interviews. Interviews were conducted with the aim of obtaining information about how students solve the problems presented. The results of the pretest and interviews were used as material to answer the main problem in this study. In this case, the research findings suggest that the initial abilities of students generally have not been able to help them solve the STEM problems presented to them. In solving the problems given, some students tend to use trial and error methods, while others use descriptions in words or pictures.
The Mathematics Learning using Geogebra Software to Improve Students’ CreativeThinking Ability
Authors: Romaito Pinta , Safitri Islamiani , Sarida Hotna , Nisah Hairun , Uswatun  , Hasanah  , Apriani Dede , Afsari Siska , Dwichanda Olivia , Lucky Yossy 
Published: March 2021

Abstract
Creative thinking in mathematics learning is a form of thinking that has received less attention in formal education until now. Creative thinking can be improved through special modifications in mathematics learning, one of which is by using Geogebra Software. This study aims to determine students’ creative thinking skills in mathematics learning with Geogebra software. This research uses quantitative methods with Quasy Experimental Design. The subjects of this study were students of class VIII SMP N 1 Pulau Rakyat with a population of 184 students. The samples in this study were class VIII-3 as the experimental class and class VIII-5 as the control class. The data analysis technique used the normality test with the Shapiro-Wilk test and the homogeneity test with the Levene test. Followed by testing the hypothesis that is using the independent sample t-test t-test. Based on the results of the analysis and discussion of the research data, it is found that the creative thinking ability of students whose learning process uses mathematics learning with Geogebra Software is higher than those using conventional learning models. Students with mathematics learning treatment with Geogebra Software have better creative thinking skills than students with learning treatment using conventional learning models.
Effect of Giving Beetroot Juice During Submaximal Exercise Against Muscle Damage
Authors: Sinaga F A , Sinaga R N , Manalu N 
Published: March 2021

Abstract
Strenuous physical activity causes muscle damage marked by an increase in C-reactive protein (CRP) concentrations. Muscle damage caused by physical activity can be prevented or reduced by giving antioxidants and anti-inflammatory. It is known that beetroot (Beta Vulgaris L) has antioxidant and anti-inflammatory effects. The purpose of this study was to determine the effect of giving beet juice during submaximal exercise on concentrations of C - reactive protein (CRP). This type of research is an experimental study with a randomized control group pretest-posttest design. The research was conducted at the physiology laboratory of Departement of Sports Science Faculty Universitas Negeri Medan and the integrated Laboratory of the Faculty of Medicine at University of Sumatera Utara. The study used 20 futsal athletes who met the criteria. Furthermore, the sample was divided into 2 groups (experiment = 10, control = 10). The pre-test was done by checking the CRP concentrations prior to submaximal physical exercise. During one month of sub-maximal exercise program with a frequency of 3 times a week with an intensity of 80-90%, the experimental group was given 300 ml of beetroot juice one hour before submaximal exercise, while the control group was given a placebo drink. Measurement of research variables was carried out again immediately after submaximal exercise for one month. The results showed that beetroot juice supplementation at a dose of 300 ml/day in submaximal exercise significantly reduced CRP levels compared to the control group (18.00 ± 5.65 mg/L VS 74.66 ± 23.85 mg/L; p = 0.000). In conclusion, giving beetroot juice during training for one month can reduce the CRP levels that are increased in submaximal physical exercise in athletes. The decrease in CRP levels is due to the antioxidant content found in beetroot juice.
The Design of Evaluation Model Towards The Public-Service-Agency Financial Management System at Medan State University
Authors: Mansyur A , Gultom S , Ritonga W , Darwin  , Nasution A A 
Published: March 2021

Abstract
The issuance of Indonesian finance minister’s decree, No. 362/KMK.05/2018 about the designation of Medan State University as government institution that applies financial management system of public service agency, requires it to have transparant, accountable and well-organized performance evaluation model. The problem that arises in carrying out the evaluation function is the unavailability of performance evaluation model and instruments that can be used to enroll the evaluation process. Thus, this paper attempts to develop a performance evaluation model at Medan State University in achieving its vision and missions. The procedures of this study involve writing research proposal, identification of need analysis, mapping the evaluation model, development, validation, implementation, data processing, and writing report. This study yields a valid model and instruments that can be implemented as a supervisory system to the academic activites at Unimed.
Characterization of Modified Fe-Cu Nanoparticle Activated Carbon Derived of Oil Palm Empty Bunches
Authors: Zubir M , Muchtar Z , Syahputra R A , Sudarma T F , Nasution H I , Lubis R A F , Fadillah L , Sandi K 
Published: March 2021

Abstract
We prepared activated carbon from empty oil palm bunches by modifying the metal (Fe and Cu) in the structure of the activated carbon. Empty oil palm bunches obtained in Padang Bulan, Medan, North Sumatera and after washed, it mashed then heated at 500 °C for 1 minutes. For modification, activated carbon was dissolved in a 0.1 M solution of Fe(NO3)2 and Cu(NO3)2 which is heated at 60 oC for 3 hours. Activated carbon without and with modification was then characterized using XRD and SEM / EDX. The XRD results showed slighly change after modification with new peaks appearing and missing peaks. SEM images also show that the activated carbon before modification is irregular in shape, while the activated carbon after modification is more regular and homogeneous. The presence of Fe and Cu on the modified activated carbon is also evidenced by the EDX image, which shows the presence of Fe and Cu peaks when compared to activated carbon before modification which does not show the presence of Fe and Cu metals. It successful to modified Fe and Cu inside the activated carbon of empty oil palm bunches which consider to improve their adsorption properties.
Comparative Study on Au-Ag composition in Lithium Zinc Calcium Fluroborate Glasses: Nonlinear Optics Perspective
Authors: Abhiram J , Rajaramakrishna R. , Rajashekara K M , Jagannath G , Kaewkhao J. , Rajagukguk J. 
Published: March 2021

Abstract
20Li2O-15CaF2-20ZnO-45B2O3- 0.XAu-(0.5-X) Ag, (where X= 0.2, 0.3) glasses were prepared by the conventional melt quench technique and coded as 2G3S and 3G2S respectively. The idea of this current work is to check the compositional dependence on the gold and silver nanoparticles in the glass. The XRD results confirmed presence of Au-Ag (111) peak at 38.11. The Infrared spectral study confirms the presence of borate segments. The UV Visible Spectroscopic studies confirms the presence of surface plasmon resonance shoulder peak for Ag nanoparticles around 490nm and 509 nm for glass 2G3S and 3G2S which had overlapped with SPR resonance peak of Au around 603 nm for glass 2G3S and around 559nm for glass 3G2S. The nonlinear optical properties were characterized using Z-Scan experimental technique for these glasses and it suggests the Glass 3G2S exhibited better nonlinear refractive index and nonlinear absorption coefficient compared to Glass 2G3S
The Effectiveness of Stem-Oriented Project and Mini-Research Teaching Materials in Improving Student Learning Outcomes at SMP 37 Medan
Authors: Simatupang H , Hardinata A , Ningsih W , Dhani F.R , Josephin A.A , Lismayadi  
Published: March 2021

Abstract
Several STEM-oriented project and mini research teaching materials created by undergraduate students were utilized in schools as a contribution of the campus to the school. This study aims to determine the effectiveness of STEM-oriented projects and mini-research teaching materials in improving the learning outcomes of science students at SMP Negeri 37 Medan. The research approach used in this study is a development research model which refers to Thiagarajan, the 4D model. The validation of the teaching materials was carried out by content-related experts, education experts and the science teacher. The effectiveness of the teaching materials was then explored in Grade 7 students of SMP Negeri 37 Medan bydistributing pre-test and post-test as data for the analysis of N-gain calculations. The results showed that the teaching materials were very feasible as accordance to the answer of the content expert; feasible as stated by the education expert; and very feasible as mentioned by the science teacher. Additionally, the students’ responses were very good and the N-gain test result was obtained at 0.5 which is categorized within the “medium” category at the distribution stage. This indicated that the implementation of STEM-oriented project and mini research teaching materials by undergraduate science students is effective in improving the learning outcomes of Grade 7 students in SMP Negeri 37 Medan in the academic year of2020/2021.
The Development of TUDIAMIPA MOOCs as an Online Learning Solution
Authors: Febrian Didi , Sudarma Teguh Febri , W Brata Wasis Wuyung 
Published: March 2021

AbstractThe government released policies, colleges, and universities implementing teaching and learning activities from home to minimize the spread of Covid 19. The learning process is undertaken online and focuses on knowledge of life skills. MOOCs come as a distance learning system capable of covering the needs to be accomplished with life skills. MOOCs are online learning systems that can be accessed through the internet network to allow learners to perform teaching and learning activities that are not constrained by time and space. This study produces a system of MOOCs that is designed with CMS WordPress using HTML and PHP and database with a Waterfall architecture model using MySQL. Quality testing of ISO 9126 standard based applications with 4 functions. For the precision and suitability sub-features, 100% feasibility level is displayed, it is declared safe from malware, blacklisting of the website, etc. for the device’s security sub-features. The device can work well with 5 concurrent users, with an average time of 20 seconds and a performance rate of 99.78 % access. The system is considered feasible. 100% feasibility and usability level indicate very clear understanding of 84% feasibility level, meaning that the method is well accepted and easily understood by users.
Isolation and Characterization of Bacteria from River Origin in Mandailing Natal North Sumatera
Authors: Nasution Mhd. Yusuf , Ahmad Shafwan S. , Pulungan  , Prasetya Eko , Rezeqi Salwa 
Published: March 2021

Abstract
The indicator of water pollution according to microbiological standards is the presence of microbiological pollutants. To see the presence of bacteria in the waters, it is necessary to study the isolation and characterization of these bacteria. The existence of the river in the Mandailing Natal area has experienced a change in character due to gold mining activities along the river flow. The purpose of this study was to determine the types of bacteria in the river in the Mandailing Natal area of North Sumatra. This research was conducted at the Laboratory of Microbiology, Department of Biology, Faculty of Mathematics and Natural Sciences, State University of Medan. The research period was from June to October 2020. The population in this study was the water of the Batang Gadis Mandailing Natal river, North Sumatra. The sample in this study is the Batang Gadis river water around the Mandailing Natal gold mine, North Sumatra. The research was carried out by taking samples and isolating bacteria which included planting the samples on media enriching the planting of the samples on various growing media, purifying bacterial colonies and observing the morphology of bacterial colonies. The results showed that there were 6 bacterial isolates living in river waters in Mandailing Natal, North Sumatra.