bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiple Alfvén eigenmodes induced by energetic electrons and nonlinear mode couplings in EAST radio-frequency heated H-mode plasmas
Authors: Zhao N. , Bao J. , Chen W. , Shi T.H. , Wang Z.X. , Yan N. , Liu S.C. , Liu H.Q. , Zang Q. , Lin S.Y. , Wu X.H. , Chu Y.Q. , Wang Y.M. , Wang S.X. , Hu W.H. , Chu N. , Li M.H. , Zhai X.M. , Jie Y.X. , Jiang M. , Lin X.D. , Gao X. , the EAST Team
Published: December 2020

Multiple electromagnetic coherent modes with frequencies f ∼ 20–300 kHz and toroidal mode numbers n = 1 and n = 2 have been observed and investigated in radio-frequency heated H-mode plasmas of the EAST tokamak. The experimental results show that the two main branches of these coherent modes are driven by energetic electrons (EEs), which are produced in the processes of radio-frequency current drive and heating. Bicoherence analysis indicates that there are strong nonlinear mode interactions between the two branches (mother waves), i.e. one is in the low-frequency range of f ∼ 20–50 kHz and the other one is in the high-frequency range of f ∼ 120–250 kHz, and their nonlinear couplings can generate many harmonics (daughter waves). Both coherent modes propagate poloidally along the electron diamagnetic drift direction. The gyrokinetic eigenvalue simulations support the view that both the low-frequency and the high-frequency coherent modes observed in EAST are Alfvén eigenmode (AE) type, and the kinetic effects of background plasmas and EEs are responsible for the formation and excitation of AEs, respectively. The low-frequency coherent mode is identified as the kinetic beta-induced Alfvén eigenmode located in the edge, and the high-frequency coherent mode is radially global, which is characterized by a toroidal Alfvén eigenmode (TAE) in the core and also has the components of a kinetic TAE and ellipticity-induced Alfvén eigenmode in the outer region due to the large downshift of the Alfvén continuum gap from the core to the edge in H-mode discharges.
Non-destructive test inspection of gas metal arc welding products with clamp and heat sink treatment on low carbon steel
Authors: Wibowo H , Karyono S , Prasetya T A , Nugroho BA
Published: December 2020

Efforts to reduce the level of distortion by welding treatment need to be done, but must consider the quality of the weld, especially the weld joint area. This study aims to examine non-destructive test (NDT) on welded objects with clamp and heat sink treatment to determine the level of weld perfection and detect welding defects in order to ensure weld quality. This research was conducted with 4 welding treatment designs, include: as welded, 4-point clamp treatment (4Clamp), liquid nitrogen cooling (HS-N2) heat sink treatment, and flowing water-cooling (HS-H2O) heat sink treatment. The results showed that based on the visual test of the welding on as welded condition, 4-points clamp, and flowing water cooling heat sink treatment decided “accepted”, while the heat sink treatment with liquid nitrogen did not pass the test and decided “rejected”. The dye penetrant test results of the HS-N2 treatment detected cracks at the end of the weld surface caused by a decreasing of heat input due to the HS-N2 treatment.
Analysis of quality student practice results in shielded metal arc welding
Authors: Hargiyarto P , Syauqi K , Sugiyono S , Ardian A , Sianipar S , Nadjib LA
Published: December 2020

This study aims to describe and determine the breakdown level of the V Groove welding results of students in Shielded Metal Arc Welding practice in the 3G (Vertical Up) position based on the American Welding Society standards. This study uses a quantitative descriptive research approach to describe the quality of the welding results. The collecting data in this study uses a visual assessment checklist based on AWS standards. The research conduct in a fabrication workshop at, Department of Mechanical Engineering Education, Faculty of Engineering, Yogyakarta State University. The data analysis technique was done by visually assessing students’ welding results and averaging them then describing them. The number of samples from this study were all training participants totaling 18 students. The results of this study indicate that: overall, the pass rate of students in welding the V groove connection in the 3G position SMAW practice is still meager, from a total of 18 students, none of them passed. Most students did not pass welding in the irregular bead, free from arc stray and spatter, undercut material, weld profile, and crater cross-section. The cause of student failures is due to a lack of understanding of how to avoid welding defects.
Analysis of student satisfaction of e-learning using the end-user computing satisfaction method during the Covid-19 pandemic
Authors: Prasetya T A , Harjanto C T , Setiyawan A
Published: December 2020

The government’s physical distancing policy to prevent transmission of the covid19 virus caused changes in learning patterns from face-to-face learning to distance education. The application of distance education at Universitas Negeri Yogyakarta is one of them through e-learning. Measurement of the level of e-learning user satisfaction is an assessment of the success of e-learning itself. The method used to measure students’ level of satisfaction using e-learning is End-User Computing Satisfaction (EUCS). EUCS has five indicators, namely, Content, Accuracy, Format, Ease of Use, and Timelines. The research sample was taken using a random sampling technique. The data collection technique was carried out using a questionnaire. Data analysis uses descriptive statistical analysis and inferential statistical analysis. Based on the analysis results, the content evaluation value is 4.0300, the accuracy evaluation value is 4.0200, the evaluation value is 4.2550, the evaluation value for easy use is 4.0288, and the evaluation value for timeliness is 4.0900. The overall analysis results showed that the students were satisfied with the e-learning course in vocational learning media.
Effect of contextual approach to improve competence of engineering design and manufacturing in vocational high school 2 Depok Sleman
Authors: Ngadiyono Y , Steven S , Fikrie A , Egiansyah GYF
Published: December 2020

The aim of this research was designed to determine the effect of contextual approaches on Manufacturing and Drawing Engineering competencies in class XII students of the Metal Fabrication and Manufacturing Engineering Vocational Engineering 2 Depok Sleman and improving the competency of the Manufacturing Image Engineering course by using the contextual approach of the XII grade students of the Metal Fabrication and Manufacturing Engineering expertise program at Vocational High School 2 Depok. This research is classroom action research. Data had collected in August 2019. Subjects were 29 students in class XII TFLM A. Data collection techniques used were observation, competency assessment, and documentation. The assessment technique applied in the study uses an evaluation based on the results of the student job sheet assignments. The results of this classroom action research are applying a contextual approach to improve student learning outcomes. The increase that can occur could be seen from the results of the 1st and 2nd cycle research. Increased value of cycle one by 3.4%. In the second cycle was 5.8%.
Development of computer aided manufacturing learning module for Magelang vocational high school students
Authors: Wijanartka B S , Pramono Z H , Fikrie A , Kassyaf K M
Published: December 2020

This study aims to develop computer aided manufacturing (CAM) learning modules for students, find out the feasibility of learning modules for students, and find out student assessments of modules. The research method used is 4D (Define, Design, Develompent, Dissemination). Data collection using a questionnaire. The results showed the feasibility of teaching materials by material experts who get a percentage of 84.17% with a very decent category, from CNC learning practitioners get a percentage of 85.83% with a very feasible outcome category, and assessment of students in class XII machining at Vocational High School 1 Magelang obtained a percentage of 85.28% which is included in the very feasible category. Based on the results of the assessment by material experts, CNC learning practitioners, and student assessments, this module is included as a very feasible use as teaching material for vocational students.
Online learning readiness during the Covid-19 pandemic
Authors: Widodo SFA , Wibowo YE , Wagiran W
Published: December 2020

Online learning is one of the main alternatives to learning during the Covid-19 pandemic and the new normal period. This learning has been implemented at various levels of education with various platforms. Various studies have shown that online learning has varying effectiveness at all levels and types of education. The implementation of online learning is not supported by an in-depth study of student readiness. Student readiness in online learning can be assessed comprehensively from the aspects of equipment capability, technology skills, self-directed learning skills, motivation, and perceived usefulness
Development of teaching materials for gas metal arc welding (gmaw) practice courses
Authors: Sudiyono  , Dwi Nur Indriawan Musyono Ari , Sunyoto  , Mustamil Khoiron Ahmad
Published: December 2020

In improving the quality of human resources, one of which lies in the quality of quality education. In this case, education has a very important meaning in human life, both in the life of individuals, nations, and countries. Therefore education must be implemented as well as possible so that it is following the objectives that have been planned. The objectives to be achieved from this study are to produce teaching materials for GMAW welding practice materials, produce teaching materials that are suitable for use in GMAW welding practices, and provide an evaluation of the effectiveness of using GMAW welding practice teaching materials after being used in learning. This research method uses the Borg and Gall development research method which is simplified into four steps, namely modified (simplified) into 4 steps consisting of: (1) preliminary study; (2) product development and validation; (3) limited trial; and (4) the final product. The type of research used in this research is the development of teaching materials in the form of practice modules, job sheets, and evaluation sheets in the GMAW welding practice course. Based on the research results, the researcher can conclude that the development of teaching materials for GMAW welding practices has been implemented properly. The revised results from the experts have been applied to the modules made so that the modules can be used properly by students.
Effect grain size of sand to mould’s permeability & compressive strength, and casting products
Authors: Aminnudin  , Rohmat Aji Pradana Yanuar , Ariono Angga
Published: December 2020

Sand for mould must comply with requirements for casting moulding, this sand mould must have enough permeability and strength. Permeability is the capability to remove air from the mould cavity. Sand from volcanoes is very easy to get and costs less than silica sand. One of the sands that can be used is Mount Semeru, which has only been used as a building material. The use of volcanic sand has been using clay as a binder. In order to improve the quality of the mould, in this research, we was carried out using phenolic resins as a binder. The sand used in this research is sand from Semeru Mountain which is obtained from the Pasirian area of Lumajang Regency. The sand sizes for the mould are 20, 40 and 60 mesh, the sand sizes for the mould are 20, 40 and 60 mesh. The sand binder used is phenolic resin mixed with water with a ratio of 2 resins to 1 water. Permeability testing uses a sand mould specimen in the form of a tube in accordance with SNI 15-0312-1989 standards. The highest permeability occurs in sand moulds with a mesh grain sand 20 (321.67 cm3/minute), The highest compressive strength is found in moulds with 60 mesh (4.13 MPa).
Increase the problem solving ability through improved prior knowledge
Authors: Komarudin  , Marji  , Sutadji Eddy , Widiyanti
Published: December 2020

This study examines the contribution of prior knowledge to improving problem-solving in learning using interactive multimedia. This research is an experimental quantitative study with a sample of 38 people. The implementation process begins with giving a pretest, giving material by the researcher, practicing by the participants using an EMS (engine management system), and ending with providing a post-test. The research uses EMS as a result of the development of existing media on campus. Analysis of research data is using an independent sample t-test. The work shows that there is a significant contribution of prior knowledge to problem-solving. This study shows that prior knowledge is essential to increase problem-solving abilities. Problem-solving is an essential ability in facing the industrial 4.0 era. Prior knowledge is the overall competence of students as a result of learning activities before following the next learning process.
The influence of audio visual media on student interest: automotive clutch power train system
Authors: Suyitno  , Primartadi Aci , Jatmoko Dwi , Nurtanto Muhmamad , Ratnawati Dianna
Published: December 2020

This study aims to 1) Know the procedure for developing learning media based on audio-visual coupling system . 2) To find out the learning interest of students in the fourth semester of automotive engineering education at the Muhammadiyah University of Purworejo. 3) Make it easier for non-vocational students to understand the material of the power transfer system, especially in the 4 semester coupling system lessons at the Muhammadiyah University of Purworejo. 4) Increase students’ interest in learning about the system material transfer of personnel, especially in the clutch system lesson in semester 4 of Muhammadiyah University of Purworejo. This study uses Research and Development (R & D) with subject research undertaken is the semester students of 4th grade B Automotive Engineering Education Purworejo Muhammadiyah University as many as 39 students. The data was collected using a questionnaire to determine the feasibility of the medium used using the student response sheet and the student learning interest questionnaire using the student learning interest questionnaire. From the results of the study, it shows that : 1) the procedure for developing learning media for the coupling audio visual system includes searching for potential problems, data collection, product design, design validation, design improvement, product testing, product testing, usage trials and product revisions . 2) media instructional audio visual system coupling system suitable for use in a medium of learning. This can be evidenced from media experts who showed a mean score - an average of 3, 1 . Validation from experts who showed an average score of 3.4. The learning media for the coupling system audio-visual system also meets the quality criteria of learning media. This is shown by the student response, namely the small group trial obtaining an average score of 3.43 which includes 5 students and the large group trial obtaining an average score of 3.13. 3) In student interest in learning, it shows that with the audio visual learning media the coupling system can increase the learning interest of 4th semester students of class B at the Muhammadiyah University of Purworejo.
Project Based Learning Model to Increase the Competency of Automotive Engineering Teachers Candidates
Authors: Wakid M , Usman T , Sulistyo B
Published: December 2020

This study aims to produce a Project-Based Learning model for vocational education in practical learning in Automotive field courses. The product of this research is the PjBL learning model in the practical course of Vehicle Body Technology. In this research is carried out through the stages of preliminary studies, model development, model validation, and implementation. The research was conducted at the Automotive Workshop of the Automotive Engineering Department, FT-UNY. The subjects of this study were lecturers and students of the Automotive Engineering Department who took practical courses in Vehicle Body Technology. Model feasibility tests were carried out by practitioners from the body repair and painting industry and Vocational School teachers on the Automotive Body Engineering spectrum. This development research was conducted in February until July 2019. The product of this research is in the form of a PjBL model for vocational education in the automotive sector that has been assessed and declared fit for use as a learning model in the automotive field of vocational education. Student responses to the implementation of PjBL learning in the Vehicle Body Technology course are also very good so that this learning model is in the very feasible category.
Vocational High School Infrastructure Conditions and The Challenges in Facing The Era of Literation and Industrial Revolution 4.0
Authors: Pambayun N A Y , Sofyan H , Haryana K
Published: December 2020

Infrastructure is an important component to support the learning operational in Vocational High Schools (SMK). This is a challenge for Vocational High Schools to manage their infrastructure so that they can keep up with the developments of technology and information. This study aims to: 1) determine the condition of the infrastructure and facilities of lightweight vehicle engineering of Vocational High Schools (SMK TKR) in Yogyakarta; and 2) describe the challenges of SMK, especially SMK TKR in the field of infrastructure to face the era of literaction and industrial revolution 4.0. This research is a quantitative research with survey method and literature review. The subject of this research is the Head of TKR Department or the Head of TKR workshop from 10 State and Private Vocational Schools in Yogyakarta. Data were collected by questionnaire and analyzed using descriptive analysis techniques. The results showed: 1) There are still infrastructure facilities at SMK TKR in Yogyakarta that have not met the demands of Indonesia Minister of Education Regulation No. 40, 2008 and the demands of the Curriculum 2013 syllabus; and 2) Infrastructure and facilities at SMK TKR is very difficult to follow the technological advances responsively, because technology is developing very quickly. Collaboration with the industry and the use of technology information in learning process are important to resolve the infrastructure limitation in SMK TKR.
Multiple Sensing Method Using Moving Average Filter for Automotive Ultrasonic Sensor
Authors: Prasetyono A P , Adiyasa I W , Yudianto A , Agit S N K
Published: December 2020

Distance sensing on vehicles is a trend in the development of autonomous cars. So that the use of proximity sensors such as ultrasonic and infrared, is very important. This research paper focuses on developing a reading of 4 ultrasonic sensors simultaneously. Where the reading method is done using 4 pin echo and 4 pins trigger and 1 pin echo with 4 pin triggers. In order for better reading, the programming algorithm for each method is integrated with the moving average filter. The use of this filter is able to correct the noise that occurs when reading the distance. The test was carried out at the computer simulation stage using a microcontroller. The final results of the study obtained a very small reading error.
Developing Module of Conventional Vehicle Fuel Systems
Authors: Arif M , Sukaswanto  , Nugraha B S , Fatah A
Published: December 2020

This study aims to (1) produce a Grade XI Conventional Fuel System Module Product at SMK Muh 1 Bambanglipuro; (2) validate the feasibility of a conventional fuel system module in SMK Muh 1 Bambanglipuro. This study is a research and development (R & D), conducted at SMK Muh 1 Bambanglipuro. The approach refer to the ADDIE model consists of 5 stages; (1) analysis; (2) design; (3) development; (4) implementation; (5) evaluations. Module design validation consists of two aspects: material validation and media validation. The study involved 24 students of Grade XI of Light Vehicle Engineering (LVE) class as the product users. Data collection is carried out using a questionnaire. The data analysis technique is descriptive quantitative, confirmed to the feasibility scale table. After validation and some revisions, the final product of the module packed in 21 x 14.8 cm paper size, consists of 81 pages. The feasibility assessment of the module product score is 78.34%, considered as very feasible.
Vocational skills learning model strategies during covid-19
Authors: Kholifah Nur , Irwanto Irwanto , Ramdani Sulaeman Deni , Nurtanto Muhammad
Published: December 2020

The focus of this research is the skills learning model used by teachers, especially those who teach practical subjects. In accordance with the purpose of vocational education which says that graduates from vocational high schools are graduates who are ready to work in the industrial and business world. The purpose of this study is to describe the skills learning model strategy used by teachers when Covid-19 hit Indonesia. The research method used is a qualitative research method with a descriptive approach. Collecting data using observation, interviews, and documentation. The results obtained are: (1) teachers who teach subjects related to the practice of getting obstacles and difficulties because online learning is very influential on internet networks, (2) teachers only use online learning models using video learning media, so that the teacher only sends a learning link to students via WhatsApp Class group, (3) some students experience difficulties in learning online because the internet signal or network is not always good. (4) with the covid-19 all learning in schools is required online, so that teachers must be proficient in using technology.
The development of a pocket book as a learning resource at vocational high school
Authors: Lestari Wilujeng , Komariah Kokom
Published: December 2020

The change of education curriculum in Indonesia affects school subjects, including those taught in vocational high school’s culinary department. The addition of the fusion food material in the learning syllabus demands teachers to seek various learning resources. This study aimed to develop a pocket book on fusion food as a learning resource for vocational high school students. This was a R&D (research and development) which specifically used the 4D development model (define, design, develop, and disseminate). The research participants involved experts on learning material and media, as well as Grade 12 culinary students from state vocational high school SMKN 1 Kalasan. The data collection technique included observation, interviews, document studies, and a survey, while the data analysis technique was descriptive qualitative. The findings show that the feasibility of the fusion food pocket book is deemed very feasible as a learning resource with the average score of 88.9% from the material experts, 99.1% from the media experts, and 82.3% from the students.
Development of integrated hardware-in-the-loop (hil) test bench anti-lock brake system (abs) instrument
Authors: Nauri I.M. , Ihwanudin M. , Sumarli  , Mindarta E.K. , Harly M. , Putra A.B. , Awanggapati B. , Ismail H.
Published: December 2020

Carrying out an Antilock Brake System (ABS) testing performance for ECU-ABS software development validation in real-time by an on-road test drive is challenging. Besides, it requires more time, cost, and effort. This research aims to develop a test bench device for ABS testing performance based on hardware in the loop (HIL). HIL-based ECU-ABS testing performance offers an approach that improves the validation process, and at the same time providing potential cost, time, and energy savings. To achieve this goal, this device is created through experimental development methods and a prototype is built consisting of input/output devices that can be set out and manipulated due to the desired real braking conditions. The result of the study is an ABS test performance device equipped with a data acquisition system (DAQ) hence the parameters which are working during the test can be read, harvested, and further analyzed for the development and improvement of the ABS. The design and prototyping process employ several software (i.e. MatLab, Proteus, Ansys, C++ Compiler, and Visual Basic), hardware (asynchrony motor, speed sensors, hydraulic actuator, PCI-Card LabView, PC, LCD monitor, keyboard, printer), frame structure and flywheel, calibration utility and test space that meets NASVA standards.
Toroidal variator with hydro-gas pressure mechanism for creating a holddown
Authors: Polyakov R N , Revkov A A , Shengping F , She L I
Published: December 2020

The article presents an analysis of the existing constructions of automatic shift gearboxes (automatic transmissions) in modern cars and describes a new construction based on a toroidal variator with a hydraulically variable holddown. There is a rationale that in comparison with the traditional automatic transmissions, a new one has smaller mass- dimensions with the same possibilities of transmitting smoothly variable torque from the engine to the car wheels. The innovation of the construction consists in the mechanism for pressing the intermediate disk of the variator to the friction surfaces due to the controlled hydraulic actuator and a membrane that eliminates bulky pressing linkage in a traditional construction of the toroidal variators.
Numerical Investigation of Centrifugal Compressor Radial Inlet
Authors: Gileva L , Kozhukhov Y , Gilev K , Fateeva E , Nhan N H
Published: December 2020

Efficient compressors designs reduce the overall energy consumption of industrial buildings. The inlet chambers for turbocompressors have a significant influence on the whole stage operation. An uneven flow in the inlet of an impeller can turn up to be the cause of stage efficiency drop, and also it is able to narrow down the range of its operational stability which in turn is an essential negative factor. Currently, there is no clear methodology of the design of the inlet radial chambers which makes it difficult to design the compressor. The purpose of this work is to develop recommendations for the designing problem formulation of the centrifugal compressor radial inlet chamber and also modify the existing design method for inlet chambers. During the previous research, the most acceptable model of the inlet chamber was obtained with the help of real and numerical experiment. In this paper, different geometric parameters of the inlet chamber are changed and then calculated by means of numerical experiment. Their influence on the inlet chamber loss coefficient, relative velocity distribution and static pressure coefficient is investigated.
Numerical study of the equivalent roughness effect on the low-flow centrifugal compressor impeller characteristics
Authors: Yablokov A , Kozhukhov Y , Sadovskiy N , Danilishin A , Nguyen M H
Published: December 2020

The article presents the results of a numerical study of the effect of equivalent sandgrain roughness on the characteristics of a low-flow centrifugal compressor stage. Low-flow stages are widely used in high-pressure compressors as the last stages. These compressors are used for natural gas booster compressor stations, as well as in technological processes for the production of methanol, ammonia, high - pressure polyethylene, etc. The efficiency of the low-flow stages is lower than that of medium-and high-flow centrifugal compressors stages. Stages operate at high pressure and have low gas volume flow rates. For this reason they have narrow channels of the flow part, significant friction and leakage losses. The study was conducted in the Ansys CFX 19.2 software package. In the first part of the study, the low-flow stage numerical model is validated with the test results. Full-scale tests of the stage were carried out at the LPI-SPbPU earlie. In the second part of the study, impeller equivalent sand-grain roughness numerical study carried out. As a result, the characteristics of the stage were obtained at four different values of equivalent sand-grain roughness ks. The impeller losses were estimated. It is established that when the ks values increase, the polytropic head and efficiency values do not decrease equally over the entire characteristic. Characteristics are significantly reduced in areas of high expenditure and change slightly with minimal expenditure. The internal head coefficient varies slightly depending on ks.
To the problem of efficiency of reliability assessment of agricultural units
Authors: Klimenko N P , Ustinova N P
Published: December 2020

The theoretical analysis of the processes occurring in operation, which determine the reliability of the elements of agricultural units and machines, made it possible to develop a universal approach to the construction of mathematical models of reliability. Practical use of the proposed reliability models is advisable both for accelerated assessment and for predicting reliability at the resource design stage. This article proposes a method for assessing and predicting the reliability of a complex system, if there is information about the reliability level of a sample of its elements.
The concept of hacking growth and technological breakthrough of Russian agricultural machinery industry with the use of engineering marketing approach
Authors: Lyubanova T , Lisitsin V , Oleynikova Y , Shcherba L
Published: December 2020

The article is dedicated to the consideration of hacking growth theory in the context of technological breakthrough of Russian agricultural machinery industry with the use of engineering marketing approach. Taking into account the results of analysis of Russian agricultural machinery dynamics in recent years, the prospects and opportunities for overcoming current problems (in particular, insufficient competitiveness and technological gap) are discussed on the basis of investigation of existing approaches to technology business development. The solution is suggested which consists in creating interdisciplinary growth teams capable of developing and implementing relevant innovative solutions, as well as providing rapid spread of changes. The issues of internal transformation necessary for the adjustment of Russian enterprises to the changing external environment in the context of knowledge-based economy development are considered in the paper.
Improvement of the methodology for the design of technological transport of timber industry enterprises
Authors: Ivannikov V A , Bukhtoyarov V N , Kvitko K S , Shvyrev A N
Published: December 2020

The article deals with the formation and optimization of the technological transport system of a timber enterprise. Problems were identified in the formation of cargo flows of forest material. These include poor development of methods for designing transport systems in the timber industry and disunited transport links in the operation of the enterprise. Computer simulation allows the operator to change the parameters of the designed system to optimize it. A multi-level algorithm for designing the transport system of the LPC is also proposed, including: determining the initial parameters for the design; calculating the number of vehicles; developing a simulation model of the production process in the LPC; calculating the technical characteristics of the transport system; developing an algorithm for managing the transport system; selection of the transport system option. An analytical calculation of the use of different quantities of trucks when loading vehicles is made in order to find an economically profitable number of them. As a result, calculations were made to compare the performance of the transport system with different quantities of loading equipment. When we received them, we saw that changing the number of loaders affects the capacity of the entire transport system.
Wind power plants functioning model in the power supply system
Authors: Kapov S , Alekseenko V , Sidelnikov D , Orlyanskaya I , Likhanos V
Published: December 2020

The system of complex energy supply of various objects is considered, existing problems in the field of wind power engineering are identified, those that leave complex energy supply using renewable energy sources are analyzed, and the quality of supplied energy is assessed by the efficiency factor. The structural model of wind power plant (HPU) functioning as a subsystem in the autonomous power supply system was considered separately. Methodological bases of designing in the form of structural scheme of methodology of development and creation of rotor HPU have been developed. All stages of designing and development of a wind power plant are analyzed.
Computer-digital technique for evaluating the geometry of the interface of the weld with the base metal
Authors: Assaulenko S S , Lyudmirsky Y G , Kharchenko V Y , Chernogorov A L
Published: December 2020

On the basis of the coordinate measuring machine CMM, there is a computer-digital technique for measuring the transition radius and the angle of conjugation of the metal with the base metal φ. It allows in automatic mode, with high accuracy and reliability, to determine the above parameters of welds, which are used in calculating stress factors and in assessing the fatigue strength of welded structures.
Controlling 3-d model of two exoskeleton links with variable length
Authors: Borisov A , Borisova V , Konchina L , Maslova K
Published: December 2020

3-D models of one-link and two-link exoskeletons with variable-length links are considered. The construction of a multi-link model is done from a simple one to a complex one. The 3-D analysis of the one-link model with one fixed point is done at first. After that, the two-link model with variable-length links is considered. It has been found that increasing the number of links leads to difficulties in composing the system of differential equations of motion relating to a longer time required for building it, even if the modern systems of computer mathematics are used. The proposed link model can be used for designing the working exoskeleton or anthropomorphic robot. The exoskeleton link consists of two absolutely rigid weighty sections at the link ends and of a weightless section between them. The analytically synthesised trajectories of the exoskeleton motion are given. The problem of finding controlling torques and forces is solved numerically and the solution results are presented graphically. The application of the proposed variable-length link model to an exoskeleton will reduce the load on the User’s joints, increase the User’s comfort and the force applied by the exoskeleton operator, as well as the period of its uninterrupted operation.
Algorithms Of Using Statistical Methods in The New Software Module
Authors: Golubeva O , Mirnyy V , Pogorelova A
Published: December 2020

The article is devoted to the developed software module for statistical control of production quality allowing to use the following quality tools: Pareto chart, Shewhart control charts (map of mean values and range chart), scatter chart, control charts of the proportions P and the number of nonconforming units nP, control charts of the number of nonconformities C and the number of discrepancies per unit U, Ishikawa diagram. The article can be useful for specialists involved in statistical quality control and looking for an alternative to other software that can be introduced into the production process.
Simulation of the hydraulic system of a device with self-adaptation by power and kinematic parameters on the working body
Authors: Khinikadze T , Pershin V , Karagodskaya Y
Published: December 2020

At present, Russia has adopted a course towards the creation of intelligent machines and equipment. This also applies to mobile technological machines for road construction and municipal purposes, the difficult operating conditions of which and the complexity of the proposed technical solutions hinder the implementation of this project in practice. Therefore, the design and creation of executive devices with a self-adaptation function for this class of technology is an urgent task. Materials and methods. A device with a hydraulic drive function with self-adaptation to load and coordination of kinematic and power parameters of the main movement and feed movement of the working body of a rock drilling rig is presented. For research and design of the device based on the methods of mathematical modeling of the hydraulic drive and adaptive systems, its mathematical model is proposed. Discussion and conclusion. The mathematical model presented in the article shows the fundamental possibility of the proposed device for implementing the principle of self-adaptation in terms of load under external and internal disturbing influences during its operation.
Modification and optimization of miller – rabin simplicity test algorithm implemented by parallel computation
Authors: Cherckesova L , Safaryan O , Trubchik I , Chumakov V , Yukhnov V , Yengibaryan I
Published: December 2020

The project of modification and optimization Miller–Rabin’s simplicity test algorithm implemented by parallel computation in the programming language C# is presented, which works faster on comparison with standard iterative algorithm by 50%, which makes it easier to create the keys for such well–known encryption algorithms as RSA, DSA, etc. These methods are similar on their functionality, but have a different estimation of structural complexity that has been shown various tests. Proceeding from it, modified by authors Miller–Rabin’s algorithm realized through parallel calculations is more reliably and faster, than the standard algorithm, that is experimentally confirmed in practice.
Simulation of bending and torsion tests of non-welded and welded direct-formed rectangular hollow sections
Authors: Kukhar V , Sahirov Y , Hornostai V , Markov O , Nahnibeda M
Published: December 2020

The paper implements a method for analyzing the stress-strain state of rectangular hollow sections (RHS) by finite-element modeling (FEM) of tests for three-point bending and torsion. Design schemes, 3-D solid-state and deformable models have been developed using the automated analysis and CAD/CAE system software, made it possible to obtain equivalent stress distributions and displacements in models. A simulation of tests for RHS with a cross section of 40 mm × 50 mm, manufactured in two ways, was carried out: (a) by direct-forming of galvanized steel strips on roll-forming mill in a semi-closed section with a longitudinal gap of 0.5 mm between the edges formed on a 40 mm web (DF-RHS); (b) similar direct-forming to the closed section and next welding the edges to a longitudinal weld along the web middle of 50 mm (DFW-RHS). RHS with various wall thicknesses (t = 1.93 mm, 1.84 mm and 0.7 mm) was investigated, given the design features that depend on the manufacturing processes of structural sections. It was found DFW-RHS is stiffer by at least 50% compared to DF-RHS, which allows to savings the metal by reducing the RHS wall thickness by 62% while maintaining the same stiffness and ensuring high strength of structural section.
Stress modelling in natural foundation
Authors: Agakhanov E K , Agakhanov M K , Agakhanova R E
Published: December 2020

Modeling methods are widely used in solving problems of deformable solid mechanics. Modeling of problems in the mechanics of a deformable solid is carried out using similarity criteria. Based on the similarity criteria, the model is made, the loading conditions are determined, and the transition from the values on the model to the values of the full-scale design is performed. The similarity criteria may be obtained either from the similarity theory or with the use of the dimensional analysis. The authors use the system of equations for a mixed problem in the elasticity and plasticity theory as well as the scale method and determine the similarity criteria for modelling the stresses in the foundations of structures. They note the restrictions on the choice of similarity factors for loose soils and the possibilities of the use of centrifugal modelling for the aforesaid scale method. They also note the special features of modelling the coherent soils.
Justification and development of an adaptive algorithm for stochastic optimization of a multi-criteria process
Authors: Kulikov Vladimir
Published: December 2020

The paper considers aspects of the development of algorithms for optimizing complex systems, and also develops an algorithm for solving problems of convex stochastic programming with a non-smooth goal function. The principles of constructing adaptive procedures for adjusting the parameters of variable gradient optimization algorithms are proposed. Note that in almost any iterative algorithm, as a rule, there are parameters that require their adjustment. To control and adjust parameters, - criteria are formed that determine the quality of adjustments. At the same time, the problem of determining the best value of the adjustment parameters belongs to the same class as the original optimization problem. Usually, iterative algorithms that work in the same class of optimization problems are used to adjust the available parameters. Thus, it turns out that two algorithms work simultaneously, in the source space and in the parameter space. Since algorithms are adapted by parameters during operation, this type of algorithm is called adaptive. The current stage of development of computer technology and mathematical support requires the development of algorithms that must function successfully without the User’s participation, both in the process of solving the problem and in the process of finding a solution to the problem. The paper provides recommendations for software implementation of adaptive stochastic algorithms and construction of computational procedures for stochastic computational experiments based on them.
Estimation of the losses coefficient of the vibrational energy of the woodworking technological system
Authors: Chukarina N , Meskhi B , Beskopylny A
Published: December 2020

Domestic machine tool equipment is not worse than foreign analogues in terms of product processing accuracy, productivity and reliability. However, almost all machines (including woodworking ones) create sound pressure levels at the operator’s workplaces that significantly exceed the maximum permissible values. Compliance of vibroacoustic characteristics of technological equipment with sanitary standards is not only one of the most important ergonomic criteria, but also largely determines the competitiveness of domestic equipment. The article developed methods of acoustic calculation of metal-cutting equipment, which take into account the coefficient of losses of the vibrational energy of the source, which is a frequency-dependent parameter. Experimental results and regression relationships were obtained for steel plates of various thicknesses, rolled products of multiple configurations, for transport machines and for glazing elements. For woodworking equipment, this data is obtained only for multilayer materials. For various types of wood, at present, such studies have not been carried out, which in fact determines the relevance of the materials in this article.
Determination of the density of concrete by ultrasonic velocity
Authors: Korolkov D , Mordvinov A , Trebukhin A
Published: December 2020

This article discusses the issue of determining the density of concrete using the ultrasonic method of testing concrete structures. The article discusses traditional methods for determining the density of concrete from selected samples and using radioisotopes. The advantages and disadvantages of these methods are highlighted. The authors proposed the use of an ultrasonic method for determining the density of concrete. From the equations of the propagation velocity of ultrasonic waves in solid media, the density of the material is expressed for the case of transverse and longitudinal waves. The authors proposed to use the derived equations to determine the density of concrete during ultrasonic testing of concrete and reinforced concrete structures. The authors provide explanations for determining the parameters of concrete included in the equations. The factors that influence the determination of the ultrasound velocity are given. Using the proposed formulas, you can calculate the density of concrete structures.
Atmospheric air pollution monitoring using flying robotics
Authors: Polyakov R , Fedyanin V
Published: December 2020

This article discusses a method for detecting a source of atmospheric air pollution (for example, carbon monoxide) using flying robotic equipment. The relevance of this study is the autonomy of methods for detecting a source of pollution with a given accuracy. To achieve this goal, the scheme of a mobile instrument platform in the form of an electromechanical system and the problem of finding a source of pollution were considered. By calculation and experiment, the radius of the circle and the speed at which the maximum and minimum CO concentration will be measured were obtained, an algorithm for the method for determining the coordinates of the CO concentration source based on a mobile instrument platform was proposed.
Specific environmental risks of the Lena-Tunguska oil and gas province
Authors: Gorlenko N V , Murzin M A
Published: December 2020

Oil and natural gas make up a significant part of the global economy, and the extraction of these natural resources is an essential industry. Recently, the rate of extraction of natural resources has increased significantly, the accumulated growth in exploration and discoveries of new and previously mothballed deposits, of course, entail the huge costs for restoring the natural environment. Currently, most of the deposits are located in the northern territories, where there are additional risks to the natural environment. In addition to unfavorable climatic factors that complicate the process of extraction and restoration of land, soils of natural areas are also represented by permafrost, which complicates both the extraction process itself and the process of subsequent land restoration. The impact on the atmospheric air has its negative consequences, at present most of the negative emissions and flaring have been significantly reduced. Nevertheless, there are undoubtedly risks for workers and the living environment in mining areas. In this article, we have tried to present and calculate the environmental risks for the deposits of the Leno-Tunguska oil and gas province. The paper presents the main indicators of the impact on the environment: atmospheric air, soil (waste drilling mud and industrial waste), and the impact of harmful factors on the health of workers. Currently, this impact makes the main negative contribution. The damage is given in a specific equivalent, which gives us an equivalent impact, due to the fact that the total cost of the negative impact is divided by the volume of extracted raw materials.