bluuebunny/crossref_metadata_2025_split huggingface dataset:
Building handicrafts for the study of the infinite dimension of linear spaces
Authors: Cohen I 
Published: June 2020

Abstract
One of the main responsibilities of the pedagogical practice is to guide the teaching process towards significant knowledge obtention. The design and implementation of learning strategies contributes to this task. The present paper shows how a teaching strategy based on the inflationary universe theory creates images of the concept of infinite dimensional linear spaces from the concrete reality of the student, thus solving one epistemological obstacle associated with the assimilation of this concept. This work is a descriptive qualitative research that follows the design research paradigm to develop a teaching experiment over a linear algebra course conformed by 18 students from the mathematics education undergraduate program of the “Universidad del Atlantico, Colombia”. The results of the present work suggest that the designed experiment is a suitable teaching tool that solves an epistemological obstacle associated with the significant learning of the infinite dimension concept of vector spaces.
Academic performance and mathematical processes under a causal model. Correlations found in three public institutions
Authors: Prada R , Fernández R , Hernández C A 
Published: June 2020

Abstract
This research implemented a model of structural equations aimed at determining the possible causal relationship between the mathematical processes mentioned in the national teachers council mathematics and academic performance in mathematics. The level of development of the mathematical processes promoted by the teacher was analyzed, in students of the fourth to seventh grades of basic education in three public educational institutions of the San José de Cúcuta, Colombia, characterized by obtaining levels of performance (respectively) in the Saber 11 tests of 2018. The sample size was 400 students enrolled in 2019. A questionnaire was proposed and validated that included sociodemographic information of students and then determined the presence and development of the various mathematical processes in classroom work. The results highlight that, of the five mathematical processes, reasoning, representation and problem solving are presented as determining variables of academic performance in students, while the processes of communication and connections are little work in the classroom by teachers. From the results obtained arises as future research, determine what teachers understand by mathematical problems? How do you promote problem solving in the classroom?
On the beginning of the morning twilight based on sky brightness measurements
Authors: Herdiwijaya Dhani 
Published: June 2020

Abstract
We present the results of 83 measurements of night sky brightness with portable photometers for five locations, namely the Bosscha Observatory, Cimahi, Bandung, Yogyakarta, and Kupang during the moonless days from years 2011 to 2018. In the first place, instead of the zenith direction, we also evaluated the night sky brightness in various angles of the zenith distances. At the beginning of the morning twilight, solar dips were significantly affected by light and air pollution. It can cause a pseudo night effect, resulting from absorption by particles of low atmospheric height, which is due to air pollution. The duration of twilight is also influenced by the pollution level. A new tool to determine the boundaries of astronomical, nautical, and civil twilight using sky brightness difference was introduced. We also recommend a preferred solar dip of 18.5° for Islamic fajr prayer in Indonesia with twilight duration at 70.5 minutes.
Impact of solar activity on Low Earth Orbiting satellites
Authors: Khodairy S , Sharaf M , Awad M , Abdel Hamed R , Hussein M 
Published: June 2020

Abstract
In the present paper, we investigate the impact of solar activity on Low Earth Orbiting (LEO) satellites. How the increase in the number of coronal mass ejections and solar flares raises the likelihood that sensitive instruments in space and will be damaged by energetic particles accelerated in these events. So, we study the effect of perturbation forces on the Keplerian orbital elements of two LEO satellites using atmosphere model NRLMSISE00. The equation of motion and the effect of all perturbation are solved by using a High-Precision Orbit Propagation (HPOP) model, with Runge-Kutta 7 method, this method was treated by Cowell’s technique. In this respect we deduce that solar activity influences the upper atmosphere; this influence is mediated through rapid geomagnetic disturbances.
Planetary systems in dense stellar environments
Authors: Kouwenhoven M B N , Flammini Dotti Francesco , Shu Qi , Xu Xiuming , Wu Kai , Pang Xiaoying , Hao Wei 
Published: June 2020

Abstract
The recent advances in observational and computational techniques allow studying the formation and dynamical evolution of planetary systems at an unprecedented level. The formation and evolution of isolated planetary systems are challenging in itself and it is more complicated by the dense environments in which stars and planets are typically born. Here, we present an overview of the internal and external processes that govern the dynamical evolution of planetary systems, and we provide a brief overview of a selection of the computational tools that are presently available to carry out realistic simulations of planetary systems in dense stellar environments.
Interior Structure of Solar-like Star τ Ceti
Authors: Mumtahana Farahhati 
Published: June 2020

Abstract
τ Ceti, a G8-V class star, has similar physical properties with our sun, even though most values are smaller and not as active as the sun. It has also been widely reviewed that this metal-poor population II star has terrestrial planetary systems, some of which are in the Habitable Zone. This paper aims to build the interior structure of τ Ceti through modeling experiments with Modules for Experiments in Stellar Astrophysics (MESA) program. The work began with the determination of several fundamental parameters obtained from previous observations of both interferometry and spectroscopy on several references, and also from basic calculations which are then used as input to build the model in MESA. Structural modeling has been carried out in accordance with current star conditions, which is in the main sequence phase. Finally, the result various physical parameters so-called stellar interior structure such as mass, luminosity, pressure, temperature, radius, and age, as well as zonal division of nuclear core (R < 0.23 R⊙,), radiative (0.23 < R⊙ < 0.54), and convective zone (0.54 < R⊙ < 0.775) were obtained.
The orbital dynamics of asteroid 469219 Kamo’oalewa
Authors: Rezky M , Soegiartini E 
Published: June 2020

Abstract
The study of orbital dynamics and evolution of Solar system small-bodies like asteroids has been conducted regularly with the latest data to ensure and update our understanding of the object’s motion, especially the ones located nearby the Earth. One of its examples is asteroid 469219 Kamo’oalewa, which currently known as an Earth Quasi-satellite (QS). In this article, we investigate the orbital dynamics of 469219 Kamo’oalewa by running an N-body numerical integration. It was calculated from its latest orbital solution at epoch JD 2458600.5 using Gauss-Radau scheme provided by IAS15 integrator, which available on REBOUND code package. We found that the co-orbital motion of the asteroid towards Earth happens during time interval (–19.7,19.5) thousand years, with QS–HS transition happening at that period. The current QS motion started 15 years ago and will be transitioning to HS at around 50 years from now. After losing its current state, it will orbit the Sun near the Earth as an Apollo asteroid. We also investigated the secular evolution of this asteroid and found the result that support its QS–HS transition nature. On some occasions like a long period of HS, we found several orbital characteristics that resemble Kozai–Lidov resonance, but it doesn’t hold long before the transition to QS resumes.
Contact forces in Brazil nut effect phenomenon of boulders on the asteroid surface
Authors: Rozzykin A Z , Dermawan B , Viridi S 
Published: June 2020

Abstract
Granular particles can be found on the asteroids in the form of regolith. Regolith is a pile of boulders and gravels that covers the surface of an asteroid and have various sizes. Brazil Nut Effect (BNE) is one of the well-known phenomena that happened in this sort of system. This phenomenon leads to occur a tendency for larger boulders to come up to the surface. Some asteroids like Eros and Itokawa show that BNE supposes to happen also in a low gravity environment. BNE in asteroid may be generated by seismic vibration that causes inter-particle collisions. The collisions are represented by contacts among particles, so that contact forces need to be counted in modeling BNE. This study aims to build a modeling of BNE in asteroid involving contact forces caused by inter-particle collisions during the seismic vibration. This study shows that contact forces have a positive role in BNE by inter-particle contacts. The contacts accommodate the system to keep larger boulders staying in the elevated height. In the model that only involves static friction (without rolling), the vector of normal forces dominates over the tangential one for the resultant forces. Uprising of the larger boulders has been observed in the simulation, but most of them are still buried underneath the smaller ones. It is predicted that a seismic vibration with large enough energy is needed to make all of the larger boulders to come up to the surface. With that result, the larger boulders observed on the surface of some asteroids nowadays are reasonably the result of BNE which caused by heavy bombardment by meteoroids in the early stage of Solar System formation that drives some high-energy seismic vibration.
Optimization of surface roughness and tool wear on AISI 4140 using coated Ni-YSZ for CNC turning process
Authors: Mohd A. , Adnan M. H. L. , Baba N. B. , Selamat Z. A. , Rose A. N. M. , Mohamed S. B. 
Published: June 2020

Abstract
Numerous type of cutting tools has been developed continuously for use in metal cutting and the coated cemented carbides are the most popular in employing many machining strategies to improve machinability of alloy steel. This paper presents on analyze of surface roughness and tool wear on AISI 4140 alloy steel using CNC lathe machine at various machining parameters such as cutting speed, feed rate and depth of cut. Experiments were conducted using Response Surface Methodology (RSM) and the interactions of machining parameters were analyzed using Analysis of Variance (ANOVA) method. Results showed that the best surface roughness parameter for Ni-YSZ coated tool is at maximum cutting speed, feed rate is minimum and minimum depth of cut which representing 0.28 μm . Whereas, for the tool wear, the best parameter is at minimum cutting speed, minimum feed rate and minimum depth of cut for producing 0.892 μm.
Utilization of Response Surface Method (RSM) in Optimizing Automotive Air Conditioning (AAC) Performance Exerting Al2O3/PAG Nanolubricant
Authors: Redhwan A.A.M. , Azmi W.H. , Sharif M.Z. , Zawawi N.N.M. , Zainal Ariffin S. 
Published: June 2020

Abstract
This manuscript examines the performance of automotive air conditioning (AAC) with the variation of the concentration of Al2O3/PAG nanolubricant, initial refrigerant charges, and compressor speed. Today, the response surface methodology (RSM) is one of the most commonly used optimization techniques for designing experimental work and for optimizing variables for a system. In this study, RSM was used to predict response parameters such as cooling capacity and compressor work. Besides, critical relationships between input and response factors will be identified using RSM. Independent variable optimization is carried out using a desirability approach to maximize cooling capacity and minimize the compressor. The results of the RSM analysis found that the optimum conditions with high desirability of 100% were at a concentration of 0.010%, cooling charge of 168 grams and compressive speed of 1160 rpm. At this optimum condition, the AAC system produces a cooling capacity of 1314 kW and a compressor work of 14.19 kJ/kg. The model predicted by RSM is accurate and has been validated in experiments with a deviation of less than 3.4%. Therefore, it can be concluded that RSM can predict optimization parameters that affect AAC performance.
Encapsulation of protein within alginate-inulin matrix for targeted drug delivery system
Authors: Hajaratul Najwa M , Norsyazwani Solehah N 
Published: June 2020

Abstract
By using sodium alginate and inulin as the core matrix, targeted release hydrogels were produced through ionotropic gelation method. As for model protein, bovine serum albumin (BSA) was chosen for in-vitro assessments. It appeared that amount of inulin had major impact on the encapsulation of BSA and also stability of hydrogels in simulated gastro intestinal fluid. The encapsulation efficiency of BSA was enhanced as the amount of inulin incorporated into the hydrogels was increased. In addition, only a little amount of BSA was released throughout 2 hours in simulated gastric fluid, SGF exposure. However, after changing into simulated intestinal fluid, SIF 100% of protein was released within 1.5 hours. Lower swelling index has been observed from alginate-inulin hydrogels in acidic condition (pH 1.2) as compared to alkaline medium, phosphate buffer (pH 7.4). This phenomenon is an indicative of pH responsive swelling activities. These hydrogels were characterized by Fourier-Transform Infared spectroscopy and Scanning Electron Microscopy for protein-excipients and hydrogels surface morphology, respectively. These developed alginate-inulin hydrogel has demonstrated high stability in acidic medium and good release efficiency at the targeted area.
Analysis of Pan-Tompkins Algorithm Performance with Noisy ECG Signals
Authors: Fariha M. A. Z. , Ikeura R. , Hayakawa S. , Tsutsumi S. 
Published: June 2020

Abstract
The Pan-Tompkins Algorithm is the most widely used QRS complex detector for the monitoring of many cardiac diseases including in arrhythmia detection. This method could provide good detection performance with high-quality clinical ECG signal data. However, the numerous types of noise and artefacts that exist in an ECG signal will produce low-quality ECG signal data. Because of this, the performance of Pan-Tompkins-based QRS detection methods using low-quality ECG signals should be further investigated. In this paper, the performance of the Pan-Tompkins algorithm was analysed in extracting the QRS complex from standard ECG data that includes noise-stressed ECG signals. The algorithm’s QRS detection reliability was tested using MIT-BIH Noise Stress Test data and MIT-BIH Arrhythmia data. The performance of the algorithm was then analysed and presented. This paper shows the capability of the Pan-Tompkins algorithms in handling noisy ECG signals.
Evaluation of Acceptability of Steering Support Method Using Impedance Control with Multiple HMIs
Authors: Hirata Takuya , Hayakawa Soichiro , Tsutsumi Shigeyoshi , Ikeura Ryojun 
Published: June 2020

Abstract
In order to realize safer driving, it is necessary to operate the driving assistance device a few seconds before the car falls into a dangerous situation, and it is necessary to improve the acceptability of the driver. Therefore, a driving support system that improves acceptability and safety is needed. In this study, we introduce multiple HMIs into the steering intervention support system introducing the impedance control of the steering torque command, we aim to evaluate safety and acceptability in this system. We use the damping ratio as an evaluation index to derive control parameters that compatible with safety and driver acceptability at the time of steering intervention assistance. We conducted experiments using driving simulation and achieve the above object in the introduction situation of HMI.
Control Techniques of Multi-Fingered Hand for Rehabilitation
Authors: Wan Faizura W.T. , Luqman M.Z.M. , Mohd Hafiz O. , Safuan Naim M. , Ahmad Armin S. , Irraivan E. 
Published: June 2020

Abstract
The use of the robotic hand today has been widely studied. So many ideas from robot designers to create different types of robots and have their functionality. Today the use of robots has been widely used everywhere such as factories, hospitals, homes, offices and others. Several factors are contributing to the increase in hand robot construction in hospitals due to the high demand in hand rehabilitation for stroke patients. In this study, there are four controllers used namely PID controller, Fuzzy Logic controller, Fuzzy-PID controller, and PID-PSO controller to find the best system response for hand applications. Appropriate control schemes should be set with various methods and parameters to enhance the system response to human hand rehabilitation.
UV Photodetector Based on p-NiO film/n-Si Heterojunction Prepared by Thermal Oxidation
Authors: Nomaan Ahlaam T. , Ahmed Naser M. , Al-Hardan Naif H. , Shiong Ng Sha , Aziz Azlan Abdul 
Published: June 2020

Abstract
In this work, p-type NiO film was grown on n-type Si substrate as UV photodetector. NiO film was prepared over n-type Si (100) through two-step method. First, metallic Ni film was deposited on Si wafer using thermal evaporator; then the film was thermally oxidized in a tube furnace at 500 °C for 3 h to get NiO film. The film revealed polycrystalline structure of cubic NiO phase as confirmed from XRD characterization. The diffraction peaks ascribed to metallic Ni film were not detected in the XRD pattern which implies that Ni film was completely converted into NiO. For photoelectric measurements of NiO/Si heterojunction, Ag metal was deposited on both Si substrate and NiO film as a contact. The current-voltage curves exhibited rectifying behaviour with ideality factor and barrier height of 25 and 0.96 eV, respectively. NiO/Si heterojunction showed appreciable photoresponse towards UV light at wavelength of 365 nm. The responsivity, rise time and fall time of the photodiode were measured as 0.16 A/W, 1.7 s and 0.85 s, respectively at bias voltage of -5 V.
Wearable Heart Rate and Body Temperature Monitoring Device for Healthcare
Authors: Abu Bakar Aslina , Rahim Sarminadira Shaikh A. , Razali Ahmad Rashidy , Noorsal Emilia , Radzali Rosfariza , Abd Rahim Alhan Farhanah 
Published: June 2020

Abstract
The Development of a wearable sensor that can monitor a heart rate and body temperature based on ESP8266 NodeMCU microcontroller is proposed in this project. To realize the system, two biomedical sensors are used which are MAX30205 and SEN11574 Pulse Rate Sensor. The sensors should be wearable to make it easy to be used by the patient. All the data that are collected from the sensors are sent via internet and displayed on a mobile apps to be observed by the guardian. MAX30205 is used to measure the temperature and SEN11574 pulse rate sensor is used to measure the heart rate. The data then will be sent through ESP8266 NodeMCU microcontroller and connected to a mobile apps via the internet. Patient can remotely send the information which are heart rate and body temperature from home to the clinic or hospital. Thus, doctors can have the patients’ health history prior to the patients visit.
IoT Based Patient Monitoring System using Sensors to Detect, Analyse and Monitor Two Primary Vital Signs
Authors: Mohamad Hadis Nor Shahanim , Amirnazarullah Muhammad Nazri , Jafri Muhammad Mahdi , Abdullah Samihah 
Published: June 2020

Abstract
This paper presents the development of patient monitoring system for two primary vital signs of body temperature and respiratory rate. The monitoring system was implemented in IoT platform and designed using Arduino Mega 2560 and ESP8266 Wi-Fi Module. Two sensor’s modules used to determine each vital sign level, which each module use temperature sensors. The purposes of this project are to design patient monitoring system that can detect the vital signs level, analyse the level of vital signs according to the patient age, provide alert for abnormal condition and also displayed the results wirelessly through android apps. This project would minimize the work load for nurses in hospital and provide much convenient method in monitoring status of each vital signs for every patient in the ward. Conventional method which requires nurse to visit every patient to record vital signs measurement is time consuming. With this system, nurses can monitor the patient status through android apps installed into any android device. Nurses or doctors can also review the previous vital sign status by downloading the data from the cloud in the excel format. Comparison on the two vital signs level obtained from this system with standard measurement equipment or manual observation shown almost similar results.
The effects of post heat treatment on ITO/AgAl/ITO/p-Si multilayer films
Authors: Isiyaku Aliyu Kabiru , Ali Ahmad Hadi , Nayan Nafarizal 
Published: June 2020

Abstract
For the past few decades, the quest for an improve indium tin oxide (ITO) films have attracted a lot of interest by scientists and industries for application in advanced optoelectronic devices. ITO/AgAl/ITO multilayer films were deposited on p-silicon (Si) substrates at room temperature by radio frequency (RF) and direct current (DC) magnetron sputtering respectively. The effects of post-heat (annealing) treatment on the structural, optical and electrical properties of the ITO/AgAl/ITO multilayer films were investigated at different temperature of 200 °C, 300 °C, 400 °C and 500 °C respectively. X-ray diffraction (XRD) results reveal an amorphous structure for the as-deposited film whereas the post annealed films show a polycrystalline and cubic bixbyite structure with preferential peaks orientation along ITO (222), Ag (111), and ITO (440) crystalline directions. Atomic force microscopy (AFM) analysis indicates a smoother surface morphology and improved grain size after post heat treatment. Ultraviolet-visible spectrophotometer measurements show a significant increase in optical transmittance spectra as the annealing temperature increases. Maximum transmittance peak of 87.2 % was obtained by film annealed at 500 °C. Four-point probe measurements exhibit a substantial decrease in sheet resistance with respect to increasing post-annealing temperature. The sheet resistance of the as-deposited film is about 7.85 Ω/sq and falls down to 3.23 Ω/sq as the post-heat temperature is increased to 500 °C. Compared to as-deposited film, the post annealed multilayer films optical and electrical properties have been successfully enhanced, fine turned and favourable for Si solar cell application.