bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical Solution of Magnetohydrodynamic Flow and Heat transfer of Sisko Fluid over an Exponential Stretching Sheet
Authors: Dadhich Yogesh , Jain Reema
Published: May 2020

The present work explores the numerical solution of magnetohydrodynamic (MHD) flow and heat transfer of Sisko fluid model over an exponential stretching surface. The flow is produced by the stretching of exponential surface in the presence of a uniform magnetic field. The governing equations are converted to nonlinear ordinary differential equations, using some appropriate dimensionless variables. The solution of the reduced nonlinear ordinary differential equations are found by numerical technique using bvp4c solver with MATLAB. The impact of various physical factors like magnetic parameter, material parameter, power law index & Prandtl number on the velocity and temperature profiles are shown graphically and elaborated.
Effect on structural and optoelectronic properties of Sn doping in MgSiP2-A DFT study
Authors: Khan K , Gaur A , Ahuja U , Soni A , Sahariya J
Published: May 2020

In the present paper, ab intio calculations of structural, band structure and optical properties of MgSi0.94Sn0.06P2 are studied within the framework of Density Functional Theory (DFT). The exchange correlation used to carry out all the calculations is Perdew-Burke-Ernzerhof Generalized Gradient Approximation (PBE-GGA) which is embodied in Wien2k code using Full Potential-Linear Augmented Plane Wave (FP-LAPW) method. The band structure, partial and total density of states (DOS) are computed for the supercell structure of MgSi0.94Sn0.06P2. The direct energy band gap (Eg) is found to be 1.36 eV which exhibits high optical absorption. It is observed that by adding a smaller percentage of Sn at Si Site in MgSiP2 chalcopyrite increases the band gap thus making it suitable for photovoltaic applications
Computer science development and technologies associated with industry 4.0 applied to industrial maintenance in Colombia
Authors: Dueñas Ramírez L M , Villegas López G A
Published: May 2020

The technologies associated with industry 4.0, have taken a leading role worldwide, because being globally competitive in the industrial sector depends not only on the real world but also on the digital world. This is why the predictive techniques used in maintenance and that currently employ technologies such as: internet of things, machine learning, big data, cyber physical Systems, Data analysis among others; to make their predictions they have defined a path in the continuous improvement of industrial processes and in the execution of the maintenance strategy. This work shows the most developed technologies 4.0 in Colombia used in industrial maintenance and exposes the country’s gaps in the development of these technologies and their use in different industrial sectors. This research was developed through the analysis of consolidated data in studies conducted by the private sector and the public in Colombia on technological developments in the country where it is evident that these technologies associated with maintenance are in growth stage and in a few sectors of industry have exploited the benefits of use.
Mobile and web technology to display notifications of academic events of the Universidad Francisco de Paula Santander by using the agile methodology for mobile development
Authors: Parada C J , Gómez C , Diaz N
Published: May 2020

The “Universidad Francisco de Paula Santander, Colombia” lacks a dynamic tool to give the academic community timely knowledge of events and information needs in an assertive manner and in a reasonable time. Based on the above and following the dissemination strategy designed by the “Centro de Comunicaciones y Medios Audiovisuales” to incorporate the use of technology to massify internal institutional information, is built the mobile application NotiUFPS for Android devices, which allows notifying all events that take place at the university, including the calendar of previous and academic calendar, with the compatibility of downloading information in pdf format. The application will make use of global positioning system, to send timely notifications and updated information of institutional events when the user is inside the university campus. NotiUFPS was developed using “Metodología Ágil para Dispositivos Móviles”, a methodology developed by the “Grupo de Investigación en Desarrollo e Ingeniería de Software, Universidad Francisco de Paula Santander, San José de Cúcuta, Colombia”, which consolidates development practices recognized as Scrum and XP.
Use of computer tools in small and medium-sized enterprises: Statistical model for the creation of financial value in the productive sectors
Authors: Jácome N J , Nolasco C , Hurtado-Lugo N A
Published: May 2020

This presents the use of computer tools for the evaluation of the generation of financial value of small and medium-sized enterprises in the municipality of Ocaña, department of Norte de Santander, Colombia. In this regard, since small and medium-sized enterprises are organizations that promote economic development, it became necessary, through the use of computer tools, to use a statistical model that evaluates in financial terms the value creation of the productive sectors. As a result, the research, using a descriptive and correlational methodology, established the computational tools to be used for the design of the statistical model, which will characterize the main determinants in the creation or destruction of value of the business structure by means of the variables of permanence, number of employees, and commercial activity. From the point of view of financial management, the financial structure was evaluated with the statistical model, establishing in terms of investment decisions, financing, and liquidity how these organizations are financially positioned; therefore, by means of statistical correlations, the relationship of dependence of financial management on the creation or destruction of value was determined.
Development of computer systems for urban mobility
Authors: Camargo M F , Rosado Gómez A A
Published: May 2020

The growth of cities generates displacement problems that need to be regulated and streamlined. An intelligent city uses technology in favor of citizens, automating everyday processes, through the use of electronic devices that capture, transmit and process information that allows them to make decisions, in the search to improve the quality of life of human beings in harmony with natural resources. This article presents a review of the research at the bibliographic level of the smart city concept focused on the urban mobility axis which allows knowing the technologies and processes of transition from conventional mobility to intelligent mobility where the actors of a city like vehicles, pedestrians are involved and public areas guaranteeing development and evolution in citizen services.
Learning mediated by technologies of information and communication at the basic, secondary and high-level education institutes
Authors: Calletana L B , Miguel R P , Jaime P G
Published: May 2020

The implementation of academic activities that involve new technologies of information and communication, it generates in the digital native (individual who has grown up immersed in digital technology) a significant academic perspective in the development of their skills; what leads to a learning mediated by technologies of information and communication, where these are tools used in the classroom that can contain digital documents, multimedia and even the use of reality increases; what has made the present project has a titanic impact on this educational transversality, where this type of learning leaves a mark impregnated with knowledge in each of the students. In addition, the activities implemented in the classroom means that students are interested in each subject taught and that knowledge flows spontaneously, achieving in this way the significant assimilation of knowledge and skills in any area of knowledge.
Oscillatory and asymptotic behavior of third order mixed type neutral difference equations
Authors: Kaleeswari S.
Published: May 2020

The aim of this paper is to study the oscillatory and asymptotic properties of the mixed type third order neutral difference equation of the form

Δ

(

a
n

Δ
2

(

x
n

+

b
n

x

n
−

r
1

+

c
n

x

n
+

r
2

)

)

+

q
n

x

n
+
1
−

σ
1

β

+

p
n

x

n
+
1
+

σ
2

β

=
0

. where β is the ratio of odd positive integers,

τ
1

,

τ
2

,

σ
1

and

σ
2

are non-negative integers. Examples are inserted to illustrate the main results.
Information system for decision-making support with resources allocation between geographically remote objects within a production association
Authors: Salih H S , Egorov S , Nemtinova Y , Nemtinov V
Published: May 2020

In this article, we discuss the issues of creating an information system for decision-making support for the task of resources rationing at geographically remote objects within a production association. The article contains the problem statement and the algorithm for solving the problem of redistributing quotas for production resources between separate remote objects (structural divisions) of a production association, settlement of payments between them, which allow reducing total costs for the entire association.
Functional model of barrel mixer of bulk solids
Authors: Teruchcov V , Chupshev A , Konovalov V , Rodionov Yu
Published: May 2020

The description of the researched barrel mixer with flat blades is carried out. Basing on experimental data, the authors have derived regression equations between barrel filling degree and drive power input and barrel capacity and angle of its setting, between coefficient of variation and mixing duration, between the share of the check component and barrel capacity and angle of its setting. An integrated functional model has been developed for the relationship between the main indicators of the mixer and the studied factors. Discrepancy between experimental data and calculated values of the functional model is about 15% of the calculated granularity of mixture. Inclination of the barrel at the angle of 15° to the horizontal is rational. Production of dry compound feed mixtures (with the density of 500-600 kg/m3) on farms in the existing small-capacitance mixers is irrational in view of long duration of mixing. Mixers need upgrading with the help of beaters’ construction change.
Using the hierarchical analysis method for decision making in a business activity
Authors: Zubkova T , Tagirova L
Published: May 2020

Information technology is widely used in all spheres of human activity. The choice of supplier for small businesses is one of the main tasks of the entrepreneur and has an impact on the success of his activities. For a solution of the problem of the choice of the supplier, this research proposes the use of an automated information system to implement and evaluate the characteristics of suppliers, as well as ranking them. As the mechanism of the choice of the best supplier use of a method of the analysis of hierarchies intended for a solution of problems of the choice of alternatives by means of their multicriteria rating is offered. The developed software system allows to keep records on the receipt, sale and characteristics of the goods, to carry out settlement operations and reporting documentation, as well as to select suppliers who meet all requirements of the entrepreneur, and as a result to conduct business at a higher quality level.
Influence of lead-manganese naphthenate on changes in the dynamic edge wetting angle upon spreading of styrene-acrylic dispersion
Authors: Mordasov D , Mordasov M
Published: May 2020

The effect of lead-manganese naphthenate on the change in the dynamic contact angle during spreading of a styrene-acrylic dispersion is studied. The dependences of the change in the dynamic contact angle in time are obtained for various concentrations of lead-manganese naphthenate in solution. As a result of the analysis of the experimental data, a concentration region was revealed in which the dynamic wetting angle varies in the widest range with the lowest speed compared to solutions of other concentrations. The results of the research will be used to optimize the composition of the polymer-mineral composite material and will make it possible to obtain a polymer matrix that most wetts the mineral fillers, and the resulting composite will have the greatest mobility and vitality.
Mathematical model for dynamic characteristics of automatic electrohydraulic drive for technological equipment
Authors: Sokolov V , Krol O , Romanchenko O , Kharlamov Y , Baturin Y
Published: May 2020

The paper is devoted to the development mathematical model of automatic rotary motion electrohydraulic drive for technological equipment and structural scheme of mathematical model for drive as object of automatic control. The hydraulic drive of rotary motion with volume regulation is considered. The drive contains regulated pump and unregulated hydraulic motor. The regulation of the working volume of the pump is carried out by the electrohydraulic amplifier. The transfer function of the regulating process of the pump working volume is represented by aperiodic link of the first order. The adequacy of mathematical model for dynamic characteristics of electrohydraulic drive has been confirmed experimentally by the Fisher criterion. To verify the adequacy, we compared the experimental and calculated transient processes for the shaft angular rotation velocity of hydraulic motor when applying the control signal. The mathematical model of automatic rotary motion electrohydraulic drive for technological equipment as object of automatic control was used as basis for further research on the synthesis of automatic control systems for equipment.
Active technological control of synthesis of high-active catalysts on the surface of solid electrolytes of fuel elements
Authors: Obraztsov D , Chernyshov V , Obraztsova E , Chernyshova T , Dutov M
Published: May 2020

The method of active process control of parameters of synthesized catalysts on electrolytes of solid oxide fuel cells is considered. Using the proposed method, it is possible to obtain a catalyst with a maximum active area. This leads to an increase in the power of the fuel cell. Also, due to carrying out the technological process in strict compliance with the specified optimal parameters, good adhesion of the catalyst to the surface of the solid electrolyte is achieved. It leads to extending of service life of the solid oxide fuel cells. Experimental studies using the proposed method and its measuring control system showed the possibility of obtaining catalysts with minimum deviations from the specified optimal parameters.
Development of solid oxide fuel cells using high-frequency plasma spraying technologies
Authors: Platenkin A , Chernyshov V , Chernyshova T , Dutov M
Published: May 2020

The paper describes the topical issues and the latest achievements in the development of materials with high electrochemical characteristics for single cells and small assemblies of solid oxide fuel cells (SOFC). The authors propose planar SOFC technology which includes sequential deposition of all layers of a thin-film cell on a porous metallic substrate by plasma techniques. The method allows developing porous SOFC anode and cathode, which increases the active area of electrochemical reaction, reduces the spread of technological parameters (in particular, the spread in thickness and porosity of a solid electrolyte), improves SOFC performance and reduces the mass and size of SOFC assemblies. The paper also describes the physics of plasma spraying process in individual cells and SOFC structures. The proposed method is an alternative to traditional SOFC production methods; it eliminates the necessity to use agglomeration technology or other heat treatment. Moreover, it opens up the prospects for automated continuous production process. The appropriate SOFC production equipment is developed, for stationary and mobile use. Further studies will be focused on the task of reducing the weight of SOFC assemblies, which allows using them as an auxiliary power unit for on-board power supply, for example, for cars, airplanes and spaceships.
Simulation of a gas turbine engine rotor assembly
Authors: Bolotov M , Pechenin V , Balyakin D , Pechenina E
Published: May 2020

The quality of aircraft and rocket engines depends primarily on the geometric accuracy of assembly units and parts. Mathematical models implemented in the form of computer models are used to predict quality indicators (in particular, assembly parameters). The work presents a numerical model for predicting assembly parameters of the rotors based on the use of actual surfaces of the parts obtained as a result of measurement on coordinate measuring machines and of mathematical modeling. Aircraft engine turbine rotor parts surfaces are measured on a coordinate measuring machine. Experimental assemblies of three parts were carried out. The measurement error of the parts does not exceed 5 µm, of assembly – 10 µm. Face and radial run-outs were measured for four positions of the disc and retainer in the shaft assembly, with run-outs ranging from 0.08 mm up to 0.1 mm. Calculations of face and radial run-outs of the disc with respect to the base surfaces of the shaft were made using the developed digital model. Relative deviations of the calculated values from the experimental values do not exceed 10%.
Improving student engagement by mathematics learning based on contextual teaching and learning
Authors: Mentari W N , Syarifuddin H
Published: May 2020

Student engagement is important in every learning because learning activities are not just a transfer of knowledge but also as a potential development that is owned by students. This study aims to determine the increase student’s engagement of MTs grade VIII learn based contextual teaching and learning (CTL) learning device in the form of lesson plans and student worksheets. The research design used One Group Design. The sample of this study involved students of class VIII in the 2018/2019 school year were 25 students of class VIII.1 as an experimental class. The instrument used was a student engagement questionnaire and field notes. Data were analyzed quantitatively using means and n-gain and described descriptively. The results showed that the n-gain was 0.215, which means that there was an increase in the student’s engagement learning by using CTL-based mathematics learning in the low category.
Application of Fuzzy Time Series-Markov Chain Method in Forecasting Data of Exchange Rate Riyal-Rupiah
Authors: Permana D , Fitri I A
Published: May 2020

Currency rates are one of the important indicators in the context of an economics country. The value of a country’s currency always increases and decreases in value against another country’s currency at any time. In this research, we make a model of dynamical currency rates data among Riyals and Rupiah. The data are obtained from the official website of Bank Indonesia. The aim research is to predict the currency rate between Riyal to Rupiah in the future time with the Markov Chain Fuzzy-Time Series method. The results of this research are data processing in the form of error value of the forecast used AFER and MEA methods. Those are 0.827% and Rp32.96 rupiahs respectively. The forecast value for the next 10 days are Rp3,779; p3,774; Rp.3,774; Rp3,779; Rp3,764; Rp3,760; Rp3,763; Rp3,797; Rp3,777 and Rp3,784.
Effectiveness of Mathematics Learning Tools Based on Guided Inquiry Model to Mathematical Communication Capabilities of Class VIII Students
Authors: Kurani R , Syarifuddin H
Published: May 2020

This study discussed on the effectiveness of the use of mathematical learning tools based on guided inquiry models to improve mathematical communication skills (CS) for students of grade VIII SMP. The type of development research used is the Plomp model. The study was conducted on 30 students in one class to use learning tools, then given a final test to see how many students completed the test. The results showed that 86.6% had completely exceeded the minimum completeness criteria that had been set at 70. It could be concluded that the learning tools developed in the form of RPP and SW were effective in improving students’ mathematical communication abilities so that they were suitable for use. Start your abstract here…
Needs Analysis to Develop Mathematics Teaching Material of Senior High School (SMA) Based on Problem Based Learning
Authors: Jannah M , Yerizon Y , Musdi E
Published: May 2020

Students’ ability in solving mathematical problem has optimal yet. This is due to mathematics learning provide less opportunity for the students to get involved in a challenging problem during learning process. The purpose of this research is to develop learning devices in the form of lesson plan and worksheet based on Problem Based Learning (PBL). This is a development research. The development model employed in this research is Plomp Model. This model consists of 3 phases, namely, preliminary research, development or prototyping phase, and assessment phase. In this part, the reported one is the preliminary research. The result of data analysis on preliminary research shows that: 1) Teacher is not able yet to develop learning device in order to improve students’ ability in problem solving. 2) Students’ inability to solve story problem. 3) Students are not capable to work on different question from the sample given. 4) Students are expecting to have a real life context problem on worksheet in relation with their daily life. 5) Students prefer to work on group. 6) Students who live in a rural coastal area tend to be less motivated and less active in the learning process.
The Development of Learning Devices with Realistics Mathematics Education Based in Program of Mechanical Engineering and Automotive Engineering
Authors: Huda A , Armiati A
Published: May 2020

The aim of this research is to develop the math learning devices with RME-based in mechanical engineering and automotive engineering programs for students of grade 10. The devices designed are adjusted to the students’ major. The students of mechanical engineering learn about design, construction and operation of machinery, while automotive engineering students focus on the design and construction of cars. Learning devices were designed in the form of lesson plans and students’ worksheets. The development model used in this research was Plomp model. This paper focuses on the preliminary research. The preliminary research covers needs analysis, curriculum analysis, concept analysis and students analysis. The instruments used were questionnaire sheets, interview sheets, and observations. Data analysis technique is a qualitative data analysis technique. The result of the preliminary research shows the learning devices made by the teachers were universal for all major and ignore the character of each major, neither mechanical engineering nor automotive engineering. The curriculum analysis done toward the syllabus and KD of math and the productive subjects related. The result of this preliminary research will be a guidance in prototype of learning devices that will plan.
Factors affecting students’ capabilities in analyzing by using flow proof in real analysis lectures
Authors: Helma H , Murni D
Published: May 2020

Real analysis is required for mathematicians. The competency is that students are able to analyze and think critically in solving a problem, and write their solutions in a logical statement. Students must have the definitions and theorems to solve the problems and perform a process which is often called the preliminary analysis. After that, students construct the proof based on the preliminary analysis. Based on the characteristics of the problem in real analysis, the solution given to the problem is using flow proof in composing preliminary analysis. Before the learning materials are prepared, it is important to know the characteristics of learners in following the learning of mathematics that affect the learning outcomes. There are five factors that influence the learning outcomes, namely background, interest, attitude, motivation and learning styles. The purpose of research is to determine the factors that influence learning outcomes. This research is a descriptive. The instruments are assessment sheets for students’ characteristics and test. Results are the factors that influence the learning outcomes of students directly are background and learning style.
Analysis of students’ mathematical communication skill in calculus course
Authors: Rusyda N A , Ahmad D , Rusdinal R , Dwina F
Published: May 2020

The purpose of this research is to analyse the mathematical communication skill of student by using essay test. The method of this research is a quantitative approach with descriptive. We assess the communication skill from the students who take calculus course. The results showed the percentage of achievement of mathematical communication skill indicators of students were: 1) 45.7% students can express mathematical ideas in oral or written form into images, algebraic expressions, and graphics; 2) 34.3% students can state mathematics problem in daily life into a symbol or model in mathematics; and 3) 51.4% students can interpret figures into mathematical ideas. Based on the percentage, the mathematical communication skills of students in calculus course is still low and need to be improved for further research.
Source of Self-Efficacy for First-Year College Students Based on Gender and Prior Knowledge
Authors: Yenti I N , Kusumah Y S
Published: May 2020

Self-efficacy has important role in determining the success and adjustment of first-year college students, including college students in study programs of mathematics education. The purpose of this study is to analyze the source of self-efficacy of first-year college students based on gender and prior knowledge. The research method used is descriptive. The study sample consisted of 68 students enrolled in calculus lectures and 58 students enrolled in algebra lectures. Other researchers have tested instrument of self-efficacy for there students. This study finds that a source of self-efficacy of first-year college students, namely vicarious experience and mastery experience affects more male and female students. Vicarious experience is the most dominant source of self-efficacy for each category of prior knowledge.
Development of mathematics learning devices based on realistic mathematics education for financial accounting expertise program in vocational high school (preliminary research)
Authors: Sutiaharni S , Armiati A
Published: May 2020

Financial Accounting is one of expertise programs in Indonesia Vocational High Schools. The prospective Vocational High School graduates are expected to be equipped with a great problem-solving skill which demanded in the field of working. Mathematics is the lesson that develop students’ problem-solving skill. This paper discussed development in learning devices based on realistic mathematics education for financial accounting expertise program in Xth grade Vocational High School. The research was conducted until preliminary research phase by using Plomp model. Based on the interview results conducted on Mathematics teachers in SMK N 2 Padang and SMK N 3 Padang, the writer concludes that the mathhematis learning devices commonly used by teachers are general without giving differences in the characteristics of each expertise program, specifically in financial accounting programs. Lastly, students have low mathematics problem-solving skill.
Pre-service teachers’ perception on science, technology, engineering, and mathematics (stem) education
Authors: Rifandi R , Rahmi Y L , Widya  , Indrawati E S
Published: May 2020

STEM education has become a trending topic to be discussed among educational experts. However, there is still limited data about preservice teachers’ perception about it. Therefore, the aim of this study is to describe teachers’ perception about Science, Technology, Engineering and Mathematics (STEM) education. This study is a descriptive research using survey method. The data were collected through questionnaire. The collected data was analyzed by using percentage technique. The result shows that there is positive perception among the preservice teachers about STEM education and they are agree of implementing it to educational curriculum in Indonesia.
An initial observation of learning devices and mathematical problem solving ability of senior high school students
Authors: Fitriani N , Arnawa I M
Published: May 2020

A good learning devices will deliver students to have good mathematical problem solving skills. This type of research was a descriptive research by qualitative approach. The initial observation was aimed at finding out, reviewing and explaining problem-solving ability of high school students in mathematics learning and condition of learning devices used and developed by teachers, then whether it was necessary to continue research development based on realistic mathematics education to improve the mathematical problem solving ability. The results of observations at SMAN 14 Padang and SMAN 15 Padang, can be concluded that the learning devices used do not link to real life problem that the instructional becomes meaningless. Learning devices used were still general and have not been able to facilitate the students to find their own concepts and did not help the students to improve problem solving ability. An approach that can accommodate it is a realistic mathematics education. The result needed to follow-up in form of research on development of realistic mathematics education based learning devices to improve the mathematical problem solving ability of senior high school students.
Development of learning devices based on problem based learning to improve the problem solving ability at grade VII of SMP
Authors: Ridwan M A , Armiati
Published: May 2020

The aims of this research was to produce the learning devices based ona valid Problembased learning (PBL) to improve the students’ problemsolving ability They are lesson plan and students’ worksheet. for grade VII SMP. PBL aims to involve students in solving problems using real-world problems as a context for students to learn through problem solving ability. Learning devices using a PLOMP Model consist of three stages: the preliminary investigation phase, the development phase and the evaluation phase. Learning devices are said to be valid if they meet the validity of content and construction. The result of research known that instrument used is a validation sheet containing the presentation aspects, content worthiness and material, graphic and language. Expert validation results show that learning devices meet valid criteria.
Development of learning tools based on contextual teaching and learning in fifth grade of primary schools
Authors: Yuwandra R , Arnawa I M
Published: May 2020

The goals of this study is to produce the learning tools of mathematics with a valid, practical and effective CTL approach. The developed learning tool consist of a lesson plan and a student worksheet. The development model used in this study is the Plomp model (preliminary research, prototyping phase, and assessment phase). The device created is used to improve understanding of concepts and mathematical problem solving for elementary school students. The instruments used were validation sheets, teacher, and student response questionnaires and mathematics learning achievement tests. Learning devices are said to be valid if they meet the content and construct validity. Practicality seen from the ease of use of the device. The effectiveness of the device seen from the percentage of students’ completeness of the test at least 70%. The results of the experts’ validation show that the learning device meets the valid criteria. Practicality reaches very practical criteria based on the questionnaire responses of teachers and students. The percentage of students’ completeness tests is 75%.
Learning Trajectory for Teaching Division using RME Approach at Elementary Schools
Authors: Fauzan A , Yerizon Y , Yolanda R N
Published: May 2020

The research aimed to develop learning trajectory (LT) to teach the topic of integer division based on Realistic Mathematics Education (RME) which is valid, practical and effective through research on the development of Gravemeijer & Cobb types. The trial subjects were the third-grade of elementary school students in Padang. The research was supported by data collection techniques in the form of document analysis, observation, interviews, questionnaires, and tests. Data analysis was performed using descriptive statistics and parametric statistics. The results showed that the LT developed to teach the topic of integer division using RME helped the teacher in learning. LT describes the characteristics of RME and facilitates students in a class. Besides, LT can help students to find integer division algorithms. Students are more confident in using their strategies for solving the contextual problems so that students’ mathematical problem-solving abilities also develop.
Gaps in science and policy formulation of climate change: perspective from university
Authors: Mardiastuti A
Published: May 2020

Abstract. In relation to climate change, policy formulation based on science is needed to determine further strategic actions. Unfortunately, there have been several gaps that hampered the implementation. This paper explores these gaps from a stand point of university, one of strategic partner of the government as the policy maker and regulator of climate change. The identified major gaps are: (1) no specific courses dealing with climate change, although research centers have been established; (2) insufficient number of lecturers who specialized in climate change; (3) research in climate change are long-term that requires big funding, except for carbon estimation; and (4) need to use sophisticated math modelling that requires specific skills. Climate change science is extremely complex, encompass various knowledge disciplines, developed very fast, and covering a global scale. Besides as strategic pools of expert, university lecturers also have important roles to educate students who might involve in future research and policy formulation. Therefore, these gaps need to be addressed, to produce effective policies formulation and then translating them into action programs. In addition, Indonesia needs to have a likelihood science group in climate change who will provide a regular scientific assessment to be translated into policy by the government.
Highly grass fine fuel in contributing peat fire in South Sumatra
Authors: Kurniawan A , Graham L , Applegate G , Utami S
Published: May 2020

Grass density and moisture content in peatlands are important factors in fire management and for the protection of fire prone areas. If relevant data is available, it can be used as an early warning system. In this study, a replicated trial that includes vegetation analysis of understorey species and measurement of moisture content have undertaken in 1×1 m plots, and it is used to obtain a representative image of field condition of six grasslands in Riding village and Kayulabu village, Ogan Komering Ilir, South Sumatra. Base on this study, the average grass moisture content in the wet season is 70.2%, a non-flammable condition. The grass will decrease continuously in dry season to extreme dry conditions and become highly flammable. The average grass fresh biomass in Riding village, Ogan Komering Ilir, South Sumatra is 8.6 ton/ha, equivalent to 1.3 ton/ha dry biomass which is potentially a highly flammable fine fuel. This is associated with a positively reinforcing feedback loop between burning and grazing. In dry condition, that conditions is stimulated for forest peat fire.
Mathematical model of curvilinear motion of an active road train with electromechanical transmission
Authors: Chudakov O I , Gorelov V A , Gartfelder V A , Sekletina L S
Published: May 2020

The paper presents a mathematical model of curvilinear motion of a two-unit road train consisting of a four-axle tractor with independent wheel drive and a three-axle semitrailer on non-yielding bearing surface. The model considers variation in the normal load on fifth-wheel coupling (FWC) of the tractor during motion and cornering resistance moment caused by friction between the semitrailer and FWC bolster. Using the developed software, we can examine the effectiveness of algorithms of steering systems of the tractor and trailer unit allowing for various traction combinations of road train units.
The employment of multi-criteria assessment methods in the study of road safety
Authors: Markovnina A I , Makarov V S , Belyakov V V
Published: May 2020

Intelligent driver assistance systems and traffic assistants are becoming more technological and widespread. Due to the great diversity, there is a need to compare their effectiveness in different conditions and choose a set of systems that is the most efficient and inexpensive. The article considers possible comparison criteria. Some features that are worth considering when conducting a study are identified. The analysis of statistics on road traffic accidents.
Prospects for motorization and energy markets in the context of fully autonomous vehicles spread
Authors: Ksenofontov M Yu , Milyakin S R
Published: May 2020

The report is devoted to two interrelated issues: the impact of penetration of fully autonomous cars and car sharing on the car fleets, and in combination with an increase of the share of electric vehicles on the volume and structure of energy demand. For this, forecasting tools and motorization scenarios have been developed. Forecasts for car fleet and energy demand were obtained for Russia and the largest economies in the world (China, USA, EU, India, Japan).
The choice of a performance criterion for a high-voltage battery of a vehicle
Authors: Lyubimov I A , Kurmaev R Kh
Published: May 2020

Currently, major vehicle manufacturers are working to improve environmental friendliness by introducing alternative energy in motor vehicles: vehicles with combined power plants (hybrids) based on ICE, electric vehicles based on promising current sources like electrochemical generator based on fuel elements of “hydrogen-air” and traditional electric vehicles. All of the above vehicles use High-voltage battery running. The use of batteries in hybrid vehicles and electric vehicles puts forward certain requirements for them: large specific energy capacity; high resource indicator; fairly low cost. This article seeks a criterion for the performance of a high-voltage battery used as an energy source in electric vehicles. Performed an analysis of scientific publications and experiments describing the dependence of the parameters of the battery on the temperature and operating mode of the vehicle. The main parameters are determined and an assessment of their impact on vehicle performance is carried out.
Test bench for experimental research of hybrid powertrain algorithms based on rapid control prototyping unit
Authors: Butarovich D , Smirnov A , Skotnikov G
Published: May 2020

The transition from simulation to a real object in case of developing control algorithms for complex systems can be difficult for several reasons. In particular, this process can take a long time due to the lack of hardware of control systems. One of the possible solutions is rapid control prototyping technology. This article discusses the experience of developing a test bench for research of series hybrid powertrain for a bus, in particular, the development of a test bench control system. The use of rapid control prototyping technology is described to the tasks of control system checking and debugging on real objects without hardware developing.
Development of a prototype dashboard for wheeled passenger transport
Authors: Astapenko D , Butarovich D , Smirnov A
Published: May 2020

The development of wheeled passenger transport is associated with the need to use many components from various manufacturers. All these components have parameters that should be displayed on the dashboard. In the modern world, the dashboard is the “face” of the vehicle. It should give the driver a complete picture of the vehicle condition. The information shown on the screen should be understandable and not misleading for the user, regardless of the level of his training. World trends show that the analog dashboard is being replaced by fully digital (graphical) ones. When the graphics is added, the software becomes considerably more complicated. In order to reduce the complexity of its development and to design it in parallel, a modular approach is used. For the dashboard, four software modules can be distinguished: drivers for working with the hardware, operating system, top layer software, and a graphical user interface. Modern dashboards use processors with operating systems based on Embedded Linux due to the fact that there are many ready-made drivers for the hardware for this operating system. To accelerate software development, Europian manufacturers use ready-made frameworks for working with graphics, for example, the cross-platform Qt framework. The article presents the results of the development of a prototype dashboard for wheeled passenger vehicles. The device components and necessary functionality of the product for mass production is determined.
HIL models formation principle in the design of automated vehicle braking system
Authors: Dygalo V G , Keller A V , Zavatskiy A M
Published: May 2020

The general principles of the HIL models formation in the design of an ABS-featuring vehicle braking system are considered. The proposed modular principle of compiling a mathematical model of subsystems allows improving the model by the iterative method, which makes it possible to add or remove blocks, change their mathematical content, while maintaining the composition of formal relationships for a complete description of the object. The iterative process continues until a model has been obtained to solve the problem, which can be considered the most fully reflecting the physical and temporal processes taking place in real objects. Virtual physical simulation data help to adjust model parameters, apply numerical optimization, explore alternative scenarios for controller bandwidth, test development sensitivity, and study other factors. The application of this method also makes it possible to compare different implementations of control systems on different boards, analyze the development and evaluate the trade-offs. Thus, developers will be able to verify that the embedded system works exactly as planned, before its final implementation. This technology makes it possible to combine field systems with a mathematical description of the dynamics of ongoing processes and phenomena. At the same time, the Virtual Physical Modeling Technology, unlike the commercial Hardware-in-the-loop systems, is not tied to the hardware of any particular manufacturer.
Conceptual framework on noise ranking classification in eatery places for human psycho-acoustics preferences towards acoustic comfort
Authors: Din Nazli Che , Mistar Noor Aini , Sulaiman Raha , Abdullah Zunaibi , Yahya Musli Nizam , Haron Zaiton
Published: May 2020

One of the important dining interests for focusing on smelling and tasting during dining in eatery places is having concentration or attention perceived of what we eat or drink. The dining satisfaction influenced positive behavior of return intent and recommending the eatery places to others. Higher noise level may distract the concentration for having a fine dining experience and could interrupt the ability of smelling and tasting senses. Settings in the noisy atmosphere of eatery places such as located near to a busy road, open kitchen, table layout and inappropriate decoration as well as the patrons’ conversation behavior may affect speech intelligibility. Ultimately, the long period exposure towards high decibel sound and noise affecting not only the health and wellbeing but also the social interactions and communications. It is also having a direct significant impact to human preferences on acoustic comfort during their dining. However, there is no specific classification or rating system established in Malaysia to assist the information on acoustic environment obtained in the eatery place. The aim of this paper is to identify the framework of eatery places classification in Malaysia within the context of the acoustic comfort and its performance. The main concern is to elucidate clearly different categorization of eatery places which might have significant on human psychoacoustics. Based on ongoing research, this paper will discuss on the critical literature reviews to develop a conceptual framework in classifying eatery places typologies and diners’ acoustical preferences.
Critical project manager competencies in managing highway projects in West Sumatera - Indonesia
Authors: Edrizal  , Mairizal  , Abd Majid Muhd Zaimi , Zin Rosli Mohamad
Published: May 2020

The Highway development projects currently being implemented in West Sumatra, Indonesia is important in increasing the competitiveness in the country’s economy. At the same period, it will also give a positive impression such as being able to reduce the cost of transportation, increase the quality of life, the value of use and labour productivity. The project managers play an important role in the success of the project. There is a consensus that project managers increase the likelihood of project success even though their projects face major problems. In this paper, the focus is on identifying the competency of Highway Project Managers in West Sumatera in carrying out the Project Management concept that leads to project success. Based on that and in accordance with this study, the approach used in data collection and processing is a qualitative approach. The results of the factor analysis are shown to experts, to establish that all these factors are important in development the performance of a project managed by the Project Manager. The results of the factor analysis derive 31 factors that are validated by the experts. And all these factors are crucial in determining the performance of the Project Manager.
A conceptual approach in developing a project manager’s skills framework (PMSF) for improving the performance of complex projects in Kuwait construction industry
Authors: Alshammari Faisal , Yahya Khairulzan , Haron Zaiton
Published: May 2020

The aim of this study is to establish the conceptual of project manager’s skills framework (PMSF) that is required in improving complex construction projects in Kuwait. The knowledge, skills, and experiences of the project managers in handling the various resources and processes related to project management had direct impact on the outcomes of the project. Large and complex construction project in Kuwait have been facing delayed deadlines. These escalate the cost of the project, and also negatively impact the quality of the project. The study uses mixed methodology in collecting the empirical data. The objective is to collect empirical data through survey, followed by interviews. The survey will be designed as closed-ended and using 5-point Likert scale and distributed to the project managers. The responses will then be used to carry out in-depth personal interviews with project managers currently involved in complex projects. The role of project manager as one of the most important is also understood from the findings. The literature and empirical findings are used to achieve the aim of developing the PMSF. The conceptual of Project Manager’s Skills Framework (PMSF) development is also presented.