bluuebunny/crossref_metadata_2025 huggingface dataset:
Student worksheet usage effectiveness based on realistics mathematics educations toward mathematical communication ability of junior high school student
Authors: Ismail R N , Arnawa I M , Yerizon Y
Published: May 2020

The purpose of this research is to examine the effectiveness of student worksheet (LKPD) based on realistic mathematics educations (RME) of class VIII of Junior High School. This is a development research with Plomp Model. The research design employs quasi experiments with Only-Posttest Control Group Design. This research took place in Public Junior High School (SMPN) Padang of class VIII. The sample is determined by purposive sampling. The treatment toward experiment group is learning by using LKPD based on RME. Meanwhile, control group is using student book according to curriculum 2013. The research instruments are test items, learning observation sheet, and learning device which had been tested for validity and practicality in the development research stage. Data analysis is conducted through t test for the mean difference test and the Scheffe test for the effectiveness of the LKPD test. The research result showed that students’ mathematical communication ability of class VIII of Junior High School (SMP) by using LKPD based on RME is better than student who uses student book. Finally, it can be concluded that LKPD based on RME is effective in improving students’ mathematical communication ability.
Forecasting of Rainfall in Sumatera Barat: Singular Spectrum Analysis (SSA) Application
Authors: Fitri F , Rahmat R , Pengestuti A D
Published: May 2020

West Sumatra has 2 peak of rainy seasons, October-November and March to May. The high intensity of rainfall causes West Sumatra has potential to floods. Precise forecasting is needed to be a reference for the government. One of the method can be used is SSA. This method is flexible because it does not require specific form of time series data, as well as parametric assumptions. Thus, accurate forecasting results is expected to be provided from the SSA method. From the forecasting process that has been done, obtained MAPE of 17% with the tracking signal value within the tolerance range.
Professionalism of teacher in geogebra software
Authors: Subhan M , Nasution M L , Armiati A , Aziz S A , Rani M M , Rifandi R , Harisman Y
Published: May 2020

Research on teacher professionalism in the learning process experiences exponential growth. One form of teacher professionalism is how teachers can use media that can make learning interesting. Geogebra is an application that can be used by teachers in learning on certain material. This research was a survey research that sees teacher interest in the use of geogebra software. Sixteen teachers from 10 junior high schools in one sub-district in one of city at Indonesia were chosen as research subjects. The training was held for five hours. When the teacher training was videotaped, observed, and interviewed. Obtained 84.76% percent of teachers gave good attention and 73. 18 % give good participation to this training.
Structural Equation Modelling: The Affecting of Learning Attitude on Learning Achievement of Students
Authors: Salma A , Fitria D , Syafriandi S
Published: May 2020

Student can obtain the high learning achievement because some factors. Those factors can appear from themselves or out of themselves. One of them is learning attitude of student. Learning attitude could be observed by some indicators. There were four indicators of learning attitudes, which were honesty, responsibility, discipline, and tolerance. The good learning attitude will give effect to learning achievement. Learning achievement is result of the learning process. There are several indicators to find out about students learning achievement. They are GPA, understanding of the concept, application and analysis. Learning achievement and learning attitude are unobserved variable, called latent variables. The method was used to analysis the latent variable in this research that was Structural Equation Modelling (SEM). It is combination from factor analysis, path analysis and regression. The aim of this research was to known affecting indicators from learning attitudes to learning achievement. The result showed that indicators of learning attitude had t-value more than 1.96 and that mean all of indicators in learning attitudes gave effect to the learning achievements.
An Analysis of student’s improvement learning outcome and student’s errors based on new man using M-APOS learning approach
Authors: Septianingsih R , Irwan I
Published: May 2020

The low learning outcomes of students in solving story questions was indicate the occurrence of problems in students. That problem is caused one of them by the mistakes of students in working on story problems. This study will see an increase in student learning outcomes and the types and causes of student errors. This type of research is a mixed method with the research design is sequential mixed method. The results of this study indicate that the probability value is 0,000 so that How is rejected or in other words there is a significant increase after learning is given using the M-APOS approach. The results of the error analysis based on the Newman procedure consist of understanding errors, transformation errors, process errors and writing error answers. Then found another error in this study is an error in writing the unit.
The Development of learning devices with realistic mathematics education based in the pharmaceutical program to improve mathematic problem-solving
Authors: Syelfia S , Armiati A
Published: May 2020

This study aims of this research to describe the value of learning devices based on the realistic mathematics education that are developed, the improved student ability to solve problem mathematically which is taught through learning devices based on realistic mathematics education developed, and the student’s response to a learning device based on realistic mathematics education developed on a pharmaceutical program for 10th grade vocational high school students. Developed learning tools consisting of the learning implement plan and the student’s worksheet. This study uses development research with the model used is Plomp (Preliminary Research, Prototyping Phase, dan Assessment Phase). The research only did until the preliminary research covered the student’s analysis. Based on a student’s observation that a student’s mathematical problem solving ability is low because the learning tools have not supported the students in improving the problem-solving ability, the learning tools that teachers use are not in accordance with the student’s skill program, only a few teachers present problems reading for practicing the mathematical skills of students. The instrument used in this research is the validity test sheet, practical test sheet, and problem solving ability test.
Analysis of students Initial mathematical communication skills in mathematics learning
Authors: Putri N D , Musdi E
Published: May 2020

This research is motivated by the low ability of students to communicate mathematical ideas, compile mathematical evidence using complete sentences, symbols, tables, and diagrams, to clarify the existing problems. This study aims to find out how the initial mathematical communication skills of students in learning mathematics, namely by giving mathematical problems related to the daily lives of students of grade VIII SMP. Problems are constructed based on indicators of communication ability and then assessed using the scoring rubric mathematical communication skills. The instrument used in the form of a preliminary test with 2 item and a sample of as many as 21 students. The results of the scoring rubric of students’ mathematical communication skills obtained in indicator 1 were 23.81%, indicator 2 was 28.57%, indicator 3 was 38.11% and indicator 4 was 14.28%. If seen from the overall results of the initial test students only get 14.28% who is able to explain with the idea of dramatic communication. The results of this initial test study was 42.85%. It indicate the need for follow-up to improve students’ communication skills.
Analysis of Student Errors in Solving Ordinary Differential Equations Based on SOLO Taxonomy
Authors: Yarman Y , Fauzan A , Armiati A , Lufri L
Published: May 2020

This study aims to describe the errors of student in solving ordinary differential equation (ODE) problems based on SOLO taxonomy. In this case there are 5 kinds of errors, namely concept errors, using data, language interpretation, technical, and making conclusions. This descriptive study involved 10 ODE research subjects. The research results obtained are the subjects of research tends to make mistakes in the five SOLO taxonomy errors. The reason is because students are not skilled in using formulas, are not thorough, and the habit of not repeating lessons.
Development of Problem-Based Mathematic Learning Model to Improve Creative Thinking Ability of Elementary Teacher Education Students, Bung Hatta University
Authors: Amrina Z , Zuzano F , Wahyuni Y
Published: May 2020

A problem-based mathematic learning model with high validity, practicality, and effectiveness is produced to improve students’ competence. The stages on developing it consist of 1) preliminary stage, 2) proto-type stage including planning, evaluation, and revision, 3) product assessment stage. The mathematic learning model based on problem was tested to the college students of PGSD Department of FKIP, Bung Hatta University involving 30 students and 3 mathematic lecturers. The instrument used in this study consisted of 1) instrument of validity appraisal, component of learning model and toolkit, 2) instrument of practicality appraisal from students and lecturers, 3) effectiveness instrument covering test result and students’ appreciation appraisal toward problem-based mathematic learning model. The result showed that problem-based mathematic learning model including syntax/learning steps, along with learning tools in term of semester learning plan and students’ worksheet was considered valid, practical, and effective.
Design learning development of a set topic based on the problem based learning on grade VII Junior High School
Authors: Kawarti Y , Armiati
Published: May 2020

This research based on reality because it is found in the research fields that a study of the learning has already been worked optimally, but the results of learning are still gained some lower minimum achievement criteria In student’s activities they do not want to ask and express their ideas or opinions, even though they often get some difficulties to solve their problems are about the expressing of learning. Teachers have low competencies in using their skill usages for learning methods, and the textbooks of the study which are not used to facilitate in the concept meanings from the materials are being learned. When they described it to their students, they will also feel the poor relation for the reality and also daily student lives. The products are gained from this research, such as, the HLT, the teachers’ books and the students’ books. That each of them They use the Plomp developed model which consists of the initial investigation phases, the prototype making and pointing phase, both of them make a discussion of the study development in this research. This is as an introduction phase. The purpose of this research wants to produce the design learning development as a set topic base on the problem based learning on the 7th at SMPN l VII Koto Sungai Sarik is validly, practically, and associatively. The data is obtained this initial stage and used to design the HLT, the teachers’ and student’s worksheet
Development of mathematical learning devices based on realistic mathematics education (RME) in senior vocational school
Authors: Andison A , Armiati A
Published: May 2020

This study is development of mathematical learning devices based on Realistic Mathematics Education (RME) in the chemical engineering expertise program in students in class XI senior vocational schools that supports valid, practical and effective problem-solving skills. This research is development research. The method used in the research is the method of developing Plomp with stages: (1) preliminary research (initial research), (2) prototyping phase (development stage), and (3) assessment phase (assessment phase). The product is a learning device. Learning tools developed include: (1) Lesson plan and (2) Student Worksheets. (1) analyzing the needs, (2) the draft development process, (3) drafting the development, (4) expert reviews and trials carried out in several stages namely (a) expert review and learning media experts, (b) analysis and revision I, (c) expert review of learning design, (d) analysis and revision II, (e) individual trials and small group trials, (f) analysis and revision III, (g) field trials: class and teacher, (h) analysis and revision IV, and (i) end product development results.
The Validity Of Learning Devices Of Cooperative Models Based On Blended Learning To Improve Learning Outcomes
Authors: Husaini A , Syarifuddin H
Published: May 2020

This study aims to produce cooperative learning tools based on blended learning that meets the validity criteria. The development research used Plomp model which consists of three phases namely the initial preliminary phase, the prototyping phase, and the assessment phase. The subjects of this study were 10th-grade Islamic senior high school student of KMM Kauman Padangpanjang. The validation sheet conducted by three mathematical education experts, one educational technologiest expert and one Indonesian language expert. Based on these results we conclud that instruments of the cooperative mathematics learning model based on blended learning is valid.
Implementation of the 21st Century Skills to High Order Thinking Students’ Mathematical in Senior High School Padang
Authors: Asmar A , Arnellis A , Sriningsih R
Published: May 2020

The purpose of this study was to describe the process and results of the development of 21st century learning tools based math problem based learning to improve high-order mathematical thinking students’ in senior high school Padang city and describe the quality of math learning tools of the 21st century based on problem based learning to improve the aspect of validity, practicality. The methods of study is a research development that is used to develop a software product math learning 21st century form of RPP and LKPD integrating 4 C which was adapted from the model Plomp. (Plomp and Nieveen, 2013: 30). Subjects tested in this study were class X SMA Padang. The data collection instrument were the sheet analysis, field notes, interview, questionnaire, and test results of learning. Data were analyzed using descriptive analysis that describes the validity and practicality of learning tools are developed. This research data analysis technique used is based on a questionnaire filled by experts then analyzed for the validity of the resulting product. Analysis of the validity of using a Likert scale. The results of the validation of the validator indicates that the device is a valid PBL based learning and practical with some characteristics such as learning devices produced have been adapted to the characteristics of Problem Based Learning (PBL). RPP and LKPD designed as a guideline for teachers in implementing the learning process is valid and practical.
Factors Affecting Academic Achievement Students’of Mathematics Department by Using Probit Regression Analysis
Authors: Amalita N , Arnellis A , Fitria D
Published: May 2020

One of the students’ academic achievement can be seen GPA, the higher the index value, the better student achievement success rate of students who obtained. Many factors affect student achievement index both internal factors and external factors. This paper described at factors that affect student achievement index of Department of Mathematics UNP who enrolled 2016 by using probit regression analysis. The results of this study are students SBMPTN, does not work while in college, and was not active in organizations on campus have the opportunity to get a better grade.
What students know about climate change? a case study of high school students in Samboja, Indonesia
Authors: Nugroho A W
Published: May 2020

Indonesia is among the top 10 highest countries in the world producing huge amount of greenhouse gases (GHG) to the atmosphere. However, climate change including its impacts might not be understandable by public in Indonesia. This is because climate change is not a crucial issue in this developing country. Education can play important roles in supporting national policies in reducing GHG in Indonesia by communicating climate change and in raising environmental awareness among people including students in schools. This study aims to determine high school students’ perceptions about climate change, to provide insights for curriculum planning to combat climate change. Furthermore, this study can also provide some strategies to the government changes by improving formal education in combating climate change. This study is conducted in the 6 selected high schools in Samboja district, Kutai Kartanegara regency, East Kalimantan province, Indonesia. Data collection was conducted from February to March 2017. Primary data is collected by using questionnaires, which are distributed to the 1st, 2nd and 3rd grade students in each selected high schools. In total there are 360 students participating in this study. Results shows that majority of students in this study have heard about climate change, however their answer are inconsistent. This indicates that these students do not fully understand about climate change. Furthermore, students also do not know about the main causes of climate change. In conclusion, climate change issues need to be elaborated in science curriculum. It is suggested that the government should introduce policies in education sectors to inform about climate change.
Budget restructuring toward utilization of carbon-based environmental services in National Parks
Authors: Nurfatriani F , Iqbal
Published: May 2020

Role of National Parks (NPs) as carbon storage has still not been well appreciated in REDD+ concept. This is because the methodology for providing incentives for reducing emissions from land sector still uses an additional approach. However, REDD+ activities have also enhanced carbon stocks and implemented sustainable forest management. Technical efforts to improve carbon stocks in NPs can be carried out in the form of utilizing carbon-based environmental services that consist of three schemes, namely: a) emission reduction scheme, b) forest carbon stock conservation scheme, and c) forest carbon stocks enhancement scheme. This study aims to analyze the budget restructure of NPs to support utilization of carbon-based environmental services in NPs. This study uses qualitative and quantitative approach with content and fiscal analysis. The results indicate that the proportion of budget related to the utilization of forest carbon services is still very small compared to the total NP’s budget (15%) in four National Parks. For this reason, restructuring budget is needed and should be based on the use of carbon-based environmental services. This will further illustrate how resource allocation must be optimized and used as a basis for providing incentives for NPs.
The application of economics in the policy formulation to manage peat swamp forests as important ecosystems in climate change
Authors: Ulya N A , Nurlia A , Waluyo E A
Published: May 2020

Forest resources can provide benefits according to their capacity if there is an efficient resources allocation. Efficient allocation requires an assessment of value of benefits for the entire economy, not just financial benefits for business entities. Currently, degraded natural peat swamp forests within production forest areas are faced with the choice of being managed as natural forests, plantations forests or converted into plantations. Financial benefits are seen as more tangible and prominent benefits than economic benefits in policy formulation. This study aims to apply appropriate economic analysis methods to formulate policies for allocating forest resources efficiently. A comprehensive cost benefit analysis framework by internalizing environmental costs is used to formulate management policy of degraded natural peat swamp forest. This research is a case study in Sungai Merang-Sungai Ngirawan Peat Hydrological Unit (PHU). The results indicate that secondary peat swamp forests are more appropriately managed as secondary natural production forests rather than if it is managed as industrial plantations or converted to plantations. The use of a science framework in the practice of policy formulation is expected to support the sustainable forest development, especially in relation to climate change.
Social forestry for improving environmental quality and community welfare: a case study of Pantar Island, Alor, East Nusa Tenggara Province
Authors: Kurniadi R
Published: May 2020

Government has attempted to involve communities in state forest management to improve environment quality as well as generate the welfare of communities around the forest. However, local communities have low participation level in social forestry programs. This research aims to examine government’s implementation on social forestry programs in Pantar Island, East Nusa Tenggara Province using interview and focus group discussion methods. The result shows that two efforts are done to accelerate social forestry programs. Firstly, Government creates some groups to apply social forestry program. Secondly, Government hires Non-Government Organization (NGO) to assist community to propose state forest and to get forest management license. However, those efforts do not work properly, Consequently environmental quality and community welfare are not improved. Based our research, it is suggested for the government to supervise communities in state forest management and increase participation of communities in social forestry program through giving benefits from social forestry programs
Study of NTFP trade policy: case of coffee and porang
Authors: Effendi R , Puspitojati T , Bangsawan I , Maryani R
Published: May 2020

Coffee and porang have been cultivated for a long time ago in forest areas in Java. Policies that support the development of coffee and porang in forest areas are estimated to be inadequate. The purpose of this study is to examine: (a) the level of policy support for the development of coffee and porang in the forest areas and (b) the suitability of coffee and porang cultivation in forest areas. This analysis uses the value of weighted indicator (VWI) method for the level of support, the scoring method for the perception and parameter indicators of forest cultivation characteristic that are different from the characteristic of agricultural cultivation for the terms of cultivation practices. The research results show that 1) support from The Ministry of LHK to the development of coffee and porang in the forest areas is limited, meanwhile the support from the Regional Government and state owned forest (Perhutani) is very high. 2), The Suitability of coffee and porang cultivation in forest cultivation are: (a) coffee and porang which are planted under forest stand thrives are relatively productive. Likewise, forest tree species are in good condition with a good canopy closures. (b) The cultivation activities do not interfere to either the protective forest or wood forest production as a life support system.
Impact of trainings on knowledge, skill, behaviour and income of farmers living around peatlands: case study in Riau Province
Authors: Rahmat M , Herawati T , Rohadi D , Winarno B
Published: May 2020

Peatlands in Indonesia have been objected to draining, burning and converting into agriculture lands causing huge greenhouse gas emissions and triggering climate change. To reduce emissions on peatland but still keep maintaining community livelihoods, farmers need to be trained with best practices on peatland uses and management. Under the Haze Free Sustainable Livelihoods Project, three trainings have been conducted, namely training on nursery and land preparation without burning, training on post harvests processing of fish and corn, and training on honeybee cultivation. The training participants are community who live in and around the Peatland Hydrological Unit of Kampar-Indragiri Rivers, Riau. An impact assessment of the completed trainings has been conducted which employe four-level evaluation model as proposed by Kirkpatrick (1994). The results indicatesthat all of the trainings improve participants’ knowledge and skill. Moreover, the honeybee cultivation training has also transformed participants’ behaviour to be more preserve and maintain nectarpollen and resin producing trees, pollen and sap. The trainings, however, are yet to affect household income although an increase of profit has been recorded on some champion participants.
Fire care community development in Batanghari District and Tanjung Jabung Timur District in Jambi Province: an overview
Authors: Budiningsih K , Setiabudi I M , Septiani AD
Published: May 2020

This study aims to describe the implementation of Fire Care Community (MPA) development and to identify related problems in Batanghari District and Tanjung Jabung Timur District, Jambi Province. For the purpose of data collection, interviewing Village Government, Brigade Fire Fighting (MA), MPA, Forest Management Unit (KPH),Technical Unit of Conservation on Natural Resources, Provincial Forestry Office, and Non-Governmental Organization are conducted. Most development of the MPA in Jambi is carried out by agencies of the Ministry of Environment and Forestry in Jambi, and several regional agencies. The obstacles on MPA development arethe limited number of personnel and budget, wide scope of work areas, and less supportive regulations. The approach that is used by these agencies in the formation of MPAs aredirectly on community groups not village institutions. This has led to deviations from the purpose of the formation of the MPA which creates a disharmonious relationship between the community and the MPA. Therefore, to strengthen better MPA management, the village approach could be an alternative for increasing the Village Government, MPA and also community in participating on fire control. This can be realized by applying a structural and participatory approach.
“Forecast” - adaptive forecast diagnostic intelligent system for vehicles
Authors: Poddubnaya A A , Keller A V
Published: May 2020

The article contains general information about promising vehicle diagnostic systems. Existing diagnostic systems, including those built into modern vehicles (MV), are not able to predict the moment of failure of components and assemblies, but only state the fact of a malfunction. To diagnose the current state and predict the residual life of the vehicle in motion mode, a mathematical model, based on machine learning technologies and data from standard additional sensors and MV detectors, is suggested. Using this approach will make it possible to forecast the defect before its actual occurrence.
Simulation based feasibility confirmation of using hybrid powertrain system in unmanned dump trucks
Authors: Kartashov A B , Skotnikov G I
Published: May 2020

The use of medium-duty vehicles (up to 50 tons) with a simultaneous reduction in technological and operational downtime, which is achieved by automated traffic control and loading and unloading systems, as well as optimization of technological maintenance modes, can be considered a new trend in the development of mining transport. The solution that meets the requirements and current development trends is the use of medium-duty unmanned dump trucks (UDT) in the interests of the Russian coal industry. An assessment of the most important performance characteristics of UDT, such as energy efficiency indicators, is considered in this research. The purpose of the research is to confirm the feasibility of using hybrid power system (HPS) in the construction of UDT. A series HPS is considered, characterized by the use of two traction electric motors: one drives the wheels of the front axle, the second drives the wheels of the rear bogie axle. The feasibility confirmation is carried out by comparing the energy efficiency and mobility of the studied vehicle with similar, equipped with other types of powertrains by simulation methods. The presented simulation results show the efficiency of HPS application in comparison with a traditional powertrain and a mechanical transmission for UDT when driving in drive cycles similar to a given one. The use of HPS allows reducing energy consumption for motion by 20-25% due to the recovery of braking energy.
Mathematical model of an electric vehicle with a non-flat battery of photovoltaic converters
Authors: Kozlov V N , Kolbasov A F , Karpukhin K E , Katanaev N T
Published: May 2020

One of the major environmental problems is emissions of CO2 and other harmful substances from motor vehicles (MV). According to the tests, the most environmentally friendly MV (measurement of emissions on MVs) are electric vehicles (EV). But a low emission level can only be ensured by the use of environmentally friendly sources of electricity used to charge EV: hydroelectric power plants, wind power plants, tidal, geothermal, wave, solar power plants, etc. However, the transmission of electric energy is connected with losses. One of the ways to use them is the application of batteries of photovoltaic converters (PVC) within the EV structure as the most suitable in terms of weight and size characteristics. The use of PVC in MV is not a new idea, but due to the increase in the efficiency of PVC, their relevance becomes more obvious. Purpose of work: development of mathematical models, scientific substantiation and rationale of the calculation method of EV energy efficiency increase by enlarging the cruising range when using PVC batteries. Research methods: methods of ground MV movement theory, system design, theory of electric circuits, mathematical modeling, etc. Results: development and scientific substantiation of the calculation method for a non-flat PVC battery within the EV structure and its effect on run or mileage change. Summary: 1) the mathematical model of EV rectilinear motion on flat non-deformable horizontal ground, suitable for the study of the processes of energy exchange between the EV and PVC batteries and the effect of these processes on the mileage, has been developed; 2) the application of the calculation method for non-flat PVC batteries to be used within the EV structure has been scientifically substantiated.
Current issues of ensuring human safety in process of vehicles operation
Authors: Gaysin S V , Koutenev V F
Published: May 2020

Based on the new cases of lung cancer registered by the World Health Organization, which number is annually increasing worldwide, development of activities and acceptance of additional emergency measures on reduction of emissions of particulate matters from wear of tyres and roadway in cities and megalopolises are necessary.

The pilot studies results are given revealing the increased level of emissions of particulate matters (PM) less than 10 microns from wear of tyres and asphalt roadway, but not from exhaust gases of the vehicles with diesel engines.
High-frequency vibration of Z-engine motor
Authors: Yamanin A I
Published: May 2020

It is shown that the high-frequency vibration of Z-engines with HCCI-process will not deteriorate compared to the four-stroke four-cylinder engine.
Basic principles of automotive modular battery management system design
Authors: Zaitsev A. , Butarovich D. , Smirnov A.
Published: May 2020

Nowadays, manufacturing of electric vehicles remains one of the most dynamically developing industries all over the globe. The issues of battery efficiency improvement by a suitable battery cell structure selection and battery control system enhancement are of the highest priority in the process of the battery design. Battery management systems (BMS) with modular structure have become the most popular as control systems in electric vehicle battery applications. The paper describes design principles of such type of BMS and necessary hardware.
Availability of the agricultural, municipal and road construction vehicle market with Russian diesel engines
Authors: Soloviev R , Cheranev S , Kolomeichenko A , Gerasimov M , Gromov V
Published: May 2020

The paper describes the enterprises that produce or produced diesel internal combustion engines for agricultural, municipal and road construction vehicles in the Russian Federation. The main emphasis is made on engines with a capacity of up to 4400 cc and a power of up to 150 kW as the most demanded for the country. The main consumers of such combustion engines are presented. It is shown that one of the main drawbacks is the impossibility of manufacturing the component base of the required quality for the organization of production of diesel engines in Russia.
Test Methods and Equipment for Assessment of Passenger Compartment Environmental Parameters of Modern and Advanced Driverless Vehicles
Authors: Saikin A M , Buznikov S E , Zhuravlev A V , Zaytseva E P , Lebedev A V , Kuznetsov D A
Published: May 2020

At the moment, no due attention is paid to the problem of ensuring environmental safety of passenger compartments of modern and advanced vehicles, including the driverless ones. The objective of this research is to analyze solutions to this social problem by developing, at this stage, of a new test method and equipment for assessment of parameters of passenger compartments of modern and advanced driverless vehicles.
Selection of the required deceleration for high-mobility wheeled vehicles with wear resistant brake systems
Authors: Kotiev G O , Gumerov I F , Stadukhin A A , Kositsyn B B
Published: May 2020

Analysis of the driving cycles of the high-mobility wheeled vehicles shows that the driver tries to provide a high speed when performing maneuvers. This results in high loads both on the powerplant and the brake system. During quick changes of the driving modes, the service brake system has to dissipate a lot of energy, which may cause overheating of its working elements and changes (deterioration) in their frictional properties or their increased wear, or even a failure of the system. The article reveals the method for selection of the required deceleration of high-mobility wheeled vehicles with wear resistant brake systems providing higher speeds and considerably lower loads on the service brake system and increased life of the frictional elements. The method is based on the generation of the driving cycle, which is close to the real-life operation conditions of the high-mobility wheeled vehicles with the use of stochastic data on the roads. Thus, driving conditions are described as realizations of random functions of such external factors as the trajectory curvature, the friction coefficient between the tire and the road, and the tire rolling resistance coefficient. The driving cycle is generated with allowance for the vehicle stability, the powerplant performance, the physiological capability of the driver to withstand accelerations, and the maximum available deceleration. By varying the vehicle deceleration we can find the dependence of the vehicle average speed on its deceleration. The data obtained during the analysis helps to select the deceleration which can be effectively provided by the wear resistant brake system without the use of the service brake system. A method for selection of the wear resistant brake system characteristics with the use of stochastic data on the driving conditions. The method allows selection of the torque – speed curves of the units of a wear resistant brake system providing required mobility of the vehicle.
Selection of the torque – speed curves for the units of a wear-resistant brake system of high-mobility wheeled vehicles
Authors: Kotiev G O , Gumerov I F , Stadukhin A A , Kositsyn B B
Published: May 2020

With the growth of the power-to-weight ratio of the modern high-mobility wheeled vehicles, the capacity of their working brake systems is no longer sufficient for operation at the high speeds owing to high thermal loads of the brakes. In order to increase the average speed of the vehicle during the long-term downslope decelerations, as well as at the intensive use of the wheel brakes it is necessary to use additional devices – exhaust and retarder brakes. This kind of devices include the exhaust brake installed inside the internal combustion engine and the transmission hydro- and electrodynamic brakes (retarder brakes). The use of an electric machine operating in generator mode for storing the braking energy in an electric storage device is also a promising option. The combination of such additional devices is called “a wear-resistant brake system”. The research is focused on the selection of the torque – speed curves of a wear-resistant brake system providing higher average speeds of the wheeled vehicles and lower loads of the working brake system. Selection of the torque – speed curves of the units of a wear-resistant brake system is carried out by the analysis of the wheeled vehicle operation in different driving cycles which are close to its real operation cycles. These cycles are usually generated for a stationary case with the use of a quasi-stationary mathematical model of the vehicle motion. In the model, the vehicle – terrain interaction is described by means of the equations of the vehicle motion including stochastically generated roads. The analysis of the vehicle operation in different driving cycles provides stochastic data on the loads of the wear-resistant brake system as a whole, which allow selecting the torque – speed curves of its units depending on their operational features. The proposed method provides selection of the required torque – speed curves of the wear-resistant brake system units: the internal combustion engine (operating in the brake mode), the electric machine, and the retarder. Selection of the parameters of the electric machine is the first step for the solution of the next important problem – selection of the required capacity of the electric energy storage device. The results of the analysis provide selection of such combination of the characteristics for each unit of the wear-resistant brake system that will ensure the required deceleration of the vehicle.
Legal regulation in the field of automated automobile transport and road tests of autonomous vehicles
Authors: Kotliarenko V I
Published: May 2020

Increase in demand for transportation services, on the one hand, stimulates development of the road network and construction of new objects of the transport infrastructure providing necessary transport system capacity, on the other hand, it stimulates development of new technologies allowing increase of human mobility, comfort and safety of vehicle driving. In these conditions, a great significance is acquired by development of intelligent transport systems (hereinafter referred to as the ITS) representing, on the one hand, means of connection, control and management built in the vehicles and objects of transport infrastructure, and on the other hand, means of control and fast decision-making based on the information received in real-time mode and available to transport operators and transport service users. ITS development has resulted in emergence of autonomous (driverless) vehicles. Considering the issues that the transport complex faces, it seems that driverless vehicles will be able to provide substantial help in solving them, for example by eliminating the human factor from transportation process. Creation of driverless vehicles is impossible without development of a unified approach to forming a legal and technical framework for their practical implementation. The abovementioned framework may be divided on a provisional basis into regulatory technical and legal ones. In the process of creating driverless vehicles, development testing on public roads is of great importance. Such tests cannot be replaced by research at closed proving grounds where it is impossible to recreate the whole range of rapidly changing driving conditions of the actual use. The existing legal framework in the Russian Federation and in a number of foreign countries allows testing highly automated and fully automated vehicles on public roads.
Adaptation of a universal method for assessing the strength and durability of suspension elements applicable to an unmanned vehicle
Authors: Nazarkov I , Bokarev A , Bakhmutov S V
Published: May 2020

Ensuring the required vehicle life is one of the most important global engineering challenges. Checking the fatigue life, first of all, is carried out separately for components, electronic and mechanical systems of the car by the bench test method, and the next step is to check the fatigue life of the car assembled by the road test method. The most urgent task is to check the strength and durability of the car chassis in the early stages of design. Currently, the mandatory and classic approach of all leading automakers when designing a car at the stage of a technical project is to apply the methodology for checking the vehicle’s steering suspension device and its power structure on multi-channel stands, and the hub assembly verification methodology is separately applied. [1] This paper describes the basic principles of the hub assembly methodology checking to be applied to any motor vehicle. The aim of this work is to demonstrate the versatility of the developed methodology for assessing the strength and durability of suspension elements. Substantiated adaptation (adjustment) of the forced load cycle of a passenger car of class M1, M2 is offered to an unmanned vehicle.
Real-time diagnostic complex of automated car active safety system unit
Authors: Dygalo V G , Keller A V
Published: May 2020

The article is concerned with the created variety of methods of drivegear active safety car system test. The analysis of factors of electronic control stability system test is displayed, as well as main disadvantages and test factors, characteristics and general terms. The system description is indicated, which gives opportunity to test active safety system. In the same way, it is possible to solve the problem of timely risk detection for key components, assemblies, and vehicle systems. And if in the traditional Driver-Car system an experienced driver can “feel” a possible malfunction, then an unmanned car has nothing but its own systems. In this case, it becomes obvious that on-board equipment is needed that monitors the state of the braking system and ABS in real time. As described above, the existing on-board diagnostic equipment does not provide the necessary information. The introduction of an additional diagnostic complex will allow tracking and detecting system failures. This system can be used with a “digital twin”
Vibration analysis of the F-segment car exhaust system
Authors: Popov V S , Gavryushin S S , Nadareishvili G G , Yudin S I
Published: May 2020

The paper considers the problem of improving the comfort and environmental friendliness of a modern f-segment car with an internal combustion engine by reducing the noise and vibration levels of the exhaust system. Gas-dynamic and mechanical excitations from the car engine and road surface cause vibrations in the exhaust system, which are transmitted through the body and the bracket structure to the body causing discomfort of the driver and passengers. To reduce the negative impact, when designing the exhaust system, it is necessary to ensure such a location of the exhaust system suspension elements that will meet the maximum operation requirements for the vibration comfort. An important task is to build a numerical experiment for the entire assembly structure to determine the nature of the similar systems loading. The solution of the above tasks is aimed at the insurance of specific strength and durability of both the entire system as a whole and the most important support elastic elements. This calculated study is of practical importance not only for reducing the vibration load of car exhaust systems and the car body, but also for improving the vibro-acoustic comfort of passengers.
Classification of tablesemantically binary relevant information for drivers in highly automated vehicles
Authors: Savchenko V V , Litarovich V V
Published: May 2020

The search for ways to solve the problem of transfer control to the driver in highly automated vehicles, involves the development of new methods and adaptation of known under the solution of the problem. The development of the method of monitoring the perception of semantically binary relevant information by the driver implies the identification of sources of significant information and classification of semantically relevant information for drivers coming from ADAS, ITS and the dashboard. Determination the driver’s time to response to the relevant information and the subsequent analysis will allow in real time, during the execution of the algorithms of the activity on the management of the highly automated vehicle, without using the additional equipment, to monitor and update the particular driver’s database containing quantitative values that characterize a number of its professionally important qualities, in automatic mode, with the use of cloud servers. The obtained results are focused on the solution of the problem control transfer to the driver in highly automated vehicles, when the vehicle’s onboard systems cannot support further “unmanned” mode of control and the vehicle is not within a specific operational design domain.
Identifying of project manager competence factors in managing EPC projects in Indonesia
Authors: Mairizal  , Edrizal  , Ismail Mohammad , Zin Rosli Mohamad
Published: May 2020

The rapid development of the industry by enhancing the development of power plants, fertilizers, oil & gas operated by integrated construction companies or Engineering, Construction and Construction (EPC) companies, where EPC companies are required and have experience in planning and developing industrial projects. The higher technology and the sophistication of the design process that demands more need for skilled Human Resources i.e. Project Manager to handle and complete these projects. Project manager is responsible for the overall success of delivering the owner’s physical development in cost constraints, schedules, quality, safety and environmental requirements. Therefore, they play an important role not only in the operating activities of engineering construction companies but also in the development of infrastructure in each country including Indonesia. Two stages of factor analysis were conducted on competence factors than the International framework of Project Manager Competences Development Framework and competence factor based on the basic theory of competence. There are 105 competence factors appeared from its analysis. All factors have validated by experts from the National Association of Design and Development of Indonesia (GAPENRI) as the Unity that manages EPC companies in Indonesia, Project Management Institute (PMI) Indonesian Chapter and Indonesian Project Management Specialist (IAMPI).