bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of the electric loads of residential and public buildings in urban power supply systems
Authors: Demidenko A S , Kudelina S A , Shvedov G V 
Published: March 2021

Abstract
Accurate determination of the calculated electric loads is a basis for power supply systems design. Values of the calculated loads influence parameters of the electrical grid. That is why the values of the calculated loads should not be exceeded in operation. Calculated electric loads also influence investments in the designed grid. For the most effective usage of the investments, the values of the calculated loads should not be overstated or understated. This article is about the applicability of the problem of the elaboration existing databases used in governing documents. Based on the obtained data, the analysis of the calculated electric loads of public buildings is carried out. Typical daily load graphs at the input of the apartment houses with electric stoves are given. Accurate load graphs at the input of the apartment houses are received, according to the results of measurements for various days of the week. The received load graphs are compared with given graphs from technical literature. We have found that the configuration of the up-dated load graphs of residential buildings significantly differs from the given graphs.
Critical heat flux calculation model for tubes with twisted tapes
Authors: Zakharov S V , Baidakov I L 
Published: March 2021

Abstract
A new method for calculating the heat transfer crisis in tubes with twisted tapes on the basis of the existing physical model of CHF for nucleate boiling is presented. The change of CHF in case of using twisted tapes is taken into account by introducing of correction factors to the existing model. Verification of the present model has been carried by checking out of existing experimental works with data on CHF with a total of 187 points. The model gives good agreement with the experiment in a wide range of parameters.
Control of a local energy complex with renewable energy sources
Authors: Molotov F V , Vaskov A G , Shestopalova T A 
Published: March 2021

Abstract
Local energy complexes are characterized by the fact that they do not have as many energy sources as in the Unified energy system. In this regard, it is required to comply with the standard in quality and reliability of electricity. Given the availability of renewable energy sources in the system, the instability of electricity generation must be compensated for with the help of guaranteed energy sources or storage devices. In this paper, various control algorithms for electric power sources with different guaranteed power and inertia are considered. The proposed algorithms are tested on a physical and mathematical model of a local power system.
Methodological bases of optimization of thermal insulation structures of glass furnaces
Authors: Beknazarian D V , Kanevets G E , Strogonov K V 
Published: March 2021

Abstract
In the construction of modern bathrooms of flaming glass furnaces, glass resistant refractory materials of high quality and a variety of thermal insulation materials are used, which are compounded into multi-layer thermal insulation panels, reducing heat losses. However, increasing the temperature of wall bars when applying thermal insulation sharply reduces their service life due to high-temperature physical and chemical corrosion. Such a contradiction and a wide range of insulation products, as well as various modes of glass melting and intensity of forced cooling of the outer lateral surface of the furnace requires the choice of an optimal set of thermal insulation materials under the chosen conditions of furnace operation to ensure maximum operating life of the unit with maximum efficiency.
Energy saving of high-temperature processes by intensive melt degassing
Authors: Strogonov K V , Zdarov A A 
Published: March 2021

Abstract
The paper considers the possibility of energy saving high-temperature processes for producing melt. Reducing energy consumption is ensured by a set of measures aimed at intensifying the process of degassing of the melt and increasing its efficiency. Presented are modern methods of degassing melts. The main parameters that determine the nature of the movement of gas bubbles in the melt are the Reynolds criterion and the dynamic viscosity of the melt. The viscosity of the basalt melt decreases with increasing temperature. The creation of vacuum conditions in the degassing chamber provides a multiple increase in the rate of degassing of the melt and a decrease in heat loss to the environment.
Methods for determining thermophysical properties of heat protective protections of buildings and high-temperature installations
Authors: Dolinin D A , Wu S K , Davlatov R K 
Published: March 2021

Abstract
The paper presents two methods for determining the thermal and physical properties of thermal barriers, differing in the range of operating temperatures and the object of which they are an integral part. The first method is based on a non-destructive approach to determining the thermal resistance of the external fencing of buildings, providing comfortable living conditions. The second method is based on taking into account the volumetric absorption of radiation by porous materials used in high-temperature installations, and the quasi-stationary heating mode. The presence of these two factors makes it possible to determine the absorption coefficient of a material located in the field of high-temperature radiation.
Experimental researches of atmospheric sublimation drying and analysis of economic efficiency its applications
Authors: Egorova A I , Vlasenko G P , Nechepurenko N S , Antipov A V , Popov D E , Alyautdinov A R 
Published: March 2021

Abstract
This article presents the results of experimental studies and economic analysis in the field of atmospheric freeze drying (AFD), analyzes the features of the processes of sublimation of polydisperse materials of animal and vegetable origin. Using the results of this work will reduce energy intensity and increase the efficiency of sublimation technologies in industrial production. An economic analysis of the feasibility of atmospheric freeze-drying technology is carried out according to discounted indicators. The values of the terms of the project implementation are obtained and practical recommendations on the modes and parameters of drying are given.
Stability Improvement of Asphalt Concrete Binder Course using LDPE Plastic Waste with Lignin as Coupling Agent
Authors: Afif M R , Huda T , Firdausi M F 
Published: March 2021

Abstract
Development of plastic waste as an asphalt mixture inhibited by its compatibility. In this study, the addition of weight variations modified lignin as coupling agent in Asphalt Concrete-Binder Course (AC-BC) with LDPE mixture was investigated. Asphalt, Polymer Modified Bitumen with and without lignin addition were characterized by physical analysis using Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy. While the AC-BC pavement was analyzed by mechanical analysis using marshall parameter. The addition of plastic to asphalt will form agglomeration and after lignin was added the agglomeration reduced. The reduced formation of plastic agglomeration due to lignin addition in asphalt form Van der Waals reaction was indicated by peaks alteration from 1041.77 cm−1 to 1031.11 cm−1 at the maximum addition of lignin. Moreover, the marshall stability of the AC-BC pavement was enhanced up to 89.5% at optimum lignin addition. Lignin utilization as a coupling agent of asphalt and LDPE can be a solution to the weaknesses of asphalt plastic technology while solving the plastic waste problem.
TVET Institutions’ Perspective on Implementation of Public-Private Partnerships Model in The Southeast Asia Countries
Authors: Towip  , Widiastuti Indah , Saputra Taufik Wisnu , Noviansyah Wahyu , Trianingsih Lilis 
Published: March 2021

Abstract
Youth unemployment is one of the youth problems in Southeast Asia countries. Previous studies found that one of the problems is caused by the skills gap between TVET graduates and industry needs. Strengthening the partnership between TVET institutions and industry is one of the solutions to minimize the skills gap. Many TVET institutions have established partnerships with the industry. Therefore, the present study is aimed to review the partnerships with industry from the TVET institution perspectives. Respondents from different TVET institutions (N = 129) were surveyed to investigate their perceptions of the partnerships with the industry. Quantitatively, the instrument of the survey data is analysed by using SPSS software. Qualitatively, data from open-ended participants’ responses were analysed by qualitative content analysis to explore the findings from the survey. The result showed that the implementation of public-private partnerships has a good performance and improved the skilled workforce in terms of TVET institutions’ perspectives. Other hands, the present study also explored the partnership’s performance in the subjects of demand-oriented, meet the changing skills demand, allow the industry to participate in the development and management of TVET, supported by the regulatory with the systematic framework and go along with a strategic transition from a short-term to long term objective. The areas of partnerships with industry are discussed as well.
Comparative Analysis of Hierarchical Clustering with Improve Feature for Herbs Leaves
Authors: Liantoni Febri , Prakisya Nurcahya Pradana Taufik , Aristyagama Yusfia Hafid , Hatta Puspanda 
Published: March 2021

Abstract
Plants have different leaf morphological characteristics starting from the leaf surface, leaf bone, leaf tips, leaf edges, leaf base, and even leaf color. The study of plants has been progressing rapidly. One of them is the branch of science in plant morphology. Morphological characteristics of leaves are one of the properties possessed by leaves and can be seen clearly. This morphological study learns about the structure of the plant body, especially about the edge leaf shape. This study will be done based on leaf shape. Leaf shape can be used as a reference in the classification process. The classification process requires a good data extraction feature, so it is necessary to improve the feature process at the pre-processing level. Combining the median filter and image erosion is used to improve the feature process. As for feature extraction, the seven moment invariant method is used. The classification method used for grouping is the Hierarchical Clustering. This method consists of four kinds. There are complete link clustering, single link clustering, average link clustering, and centroid linked clustering. Based on the results of experiments conducted, the use of Average Linkage Clustering method obtained clustering accuracy of 87%. It proves that the average method successfully optimizes the result by calculating any distance between points of the cluster. While the smallest accuracy results using complete linkage clustering of 81%.
Tracing Successful Online Teaching During Covid-19 Pandemic
Authors: Subarno Anton , Sulistyaningrum Cicilia Dyah , Umam Muhammad Choerul , Winarno  
Published: March 2021

Abstract
The world of education dismisses students (studying at home) to reduce the spread of the coronavirus. In such conditions, teachers are challenged to apply all their abilities and expertise so that they can continue to teach students by transferring knowledge, pedagogic abilities, and their belief in successful online learning. This study aims to explore how lecturers can conduct teaching in the midst of the Covid-19 pandemic and what they use as a medium to conduct successful online teaching. In addition, researchers also want to know how lecturers can adjust the online teaching transition. The design of this research is qualitative research using deep interview tests to explore online learning that suits current needs. The research was conducted at the department of Office Administration Education Sebelas Maret University with the head of the study program as the key informant. The data validity test used source triangulation and method triangulation. The sampling technique was purposive snowball sampling, data collection techniques used observation, interviews and documentation, and data analysis techniques used interactive data reduction, data presentation, and conclusion drawing. The results show a good connection communication network of all students and lecturers is a major aspect that must be considered in lectures even though using simultaneously online social media, e.g. You Tube, Google Classroom, Google Meet, and WhatsApp. The Covid-19 pandemic is considered a challenge and an opportunity to conduct research in the field of information and communication technology (ICT) especially on digital classroom management. The outcomes of research that can be directly utilized by the user are the output targets research whose activities are manifested in the form of community service. Community Service Program (KKN) is a tangible form of student involvement in community service.
Pseudo Thinking Process in Understanding the Concept of Exponential Equations
Authors: Muslim R I , Usodo B , Pratiwi H 
Published: March 2021

AbstractThe thought process is a very interesting thing to examine in mathematics learning. Sometimes in solving questions, students’ answers are wrong not because of the wrong thinking process, as well as correct answers, it is not certain that students understand why the process was carried out. Such conditions occur because the students’ thought processes are pseudo, meaning that the thought process that occurs is not a reflection of the real thought process. The focus in this study is students who experience pseudo thinking in understanding the concept of exponential equations. The pseudo thinking categories are grouped according to the Vinner and Subanji frameworks. Based on the research results, the students’ pseudo thinking process in understanding the concept of exponential equations was shown that most students in understanding the concept of exponential equations still memorized the formula without understanding the formula. Students only think of looking for answers quickly using formulas that have been learned. If learning only emphasizes procedures and memorization, what happens learning mathematics has no meaning. In addition to memorizing procedures, it is very risky for students to forget, students are not able to use mathematics according to the actual concept.
Reflective Abilities in Students with a High Level of Self-confidence
Authors: Hidayat N , Usodo B , Saputro D R S 
Published: March 2021

Abstract
Reflective thinking is the student’s ability to actively and carefully answer a given problem. The purpose of this study was to determine the reflective thinking ability of students with high levels of self-confidence. This research is descriptive qualitative, with the researcher as the main instrument and other supporting instruments in the form of a reflective thinking ability test, self-confidence questionnaire, and interview guidelines. The results of the questionnaire showed that there were nine grade VIII B students of SMPN 1 Pundong who had high self-confidence, two subjects in this study were selected by purposive sampling. The results showed that six out of nine students with high self-confidence were able to meet all indicators of reflective thinking. The other three students are only able to meet a fraction of the five indicators. The inability to think reflective because students are not used to linking old knowledge to be used in solving new problems, and students are also less careful in solving problems because students are unable to check the answers that have been obtained.
High School Students’ Mathematical Problem Solving Skills Based on Krulik and Rudnick Steps Reviewed from Thinking Style
Authors: Rahmah A , Mardiyana  , Saputro D R S 
Published: March 2021

Abstract
This research explains the problem solving skills of students of Grade XII MIPA SMA MTA Surakarta based on Krulik and Rudnick’s steps that are reviewed from the thinking style. This research is a qualitative study that produces descriptive data. The study began by determining the subject of the study by using a thought style questionnaire, given problem solving tasks and interviews. The results showed math problem solving skills; 1) concrete sequential student are systematically worked on and use an inductive mindset and the steps of reviewing and discussing are not implemented; 2) abstract sequential student are easy to present what is known in the question to mathematical symbol forms, collect data in detail, and manage the information obtained regularly and perform all of Krulik and Rudnick’s steps; 3) concrete random student are tend to be consistent in using guessing or experimenting strategies and work without detail and the steps of reviewing and discussing are not implemented: 4) abstract random student are fundamental differences in processing the information received and planning problem solving in a way of their own accord and doing all the steps krulik and rudnick.
The Effectiveness of Software GeoGebra to Improve Visual Representation Ability
Authors: Azizah A N , Kusmayadi T A , Fitriana L 
Published: March 2021

Abstract
GeoGebra is a mathematical software that supports learning mathematics to make it easier to visualize geometric shapes. Geography software can create geometric images that are 2 dimensional or 3 dimensional so that GeoGebra can help students to represent real geometric shapes. This research aims to view the effectiveness of GeoGebra software in improving students’ visual representation ability. This study used a one-group pre-test/post-test design pre-experiment. The sample in this ability were students of eight grades SMP Negeri Sukoharjo who studied the material of flat-sided building. The instruments used in this study were the pre-test with and post-test of mathematical representation abilities. The results showed that there was an effectiveness of using GeoGebra in improving students’ visual representation skills with the difference in the mean score of students after being given geoGebra treatment was 61.3 for the pre-test and 70.5 for the post-test.
E-book Based on Mobile Learning Used Problem Based Learning (PBL) Model to Improve Problem-Solving Ability in Statistical Material
Authors: Herdianto E N , Mardiyana  , Indriati D 
Published: March 2021

Abstract
The research aims to developed a mobile learning-based e-book that used problem-based learning (PBL) to improve problem-solving abilities in statistical materials that meets validity, practically, and effectiveness. The type is a Development Research used the Four-D model (define, design, development, and disseminate). The validation results of the material feasibility average was very good at 82% and the validation of the media was 85.92%. The results of the response questionnaire by students was 88.22% and by the teacher was 83.31%, included in the very practical category. Therefore the mobile learning-based e-book developed is valid to use in mathematics classes. The result of e-book effectiveness meets the effective criteria with the completeness study of students at 84%. From the products tested, it was concluded that the students problem-solving abilities in statistics material used mobile learning-based e-book that had been developed were better than used existing products. Thus, this mobile learning-based e-book used a problem-based learning model to improve problem-solving abilities in eighth grade of statistical material which is suitable for uses and recommended at mathematics learning.
Some applications of cloud technologies in mathematical calculations
Authors: Zhaldak M I , Franchuk V M , Franchuk N P 
Published: March 2021

AbstractThis article discusses some use of cloud technology in mathematical calculations using Remote Desktop Ulteo OVD. To use such technologies, it is enough to have access to the Internet through a suitable browser to access an open virtual desktop on a powerful remote computer and then use the resources of the remote computer (server) to solve their problems in processing various information resources – solving mathematical problems, working out texts, translating from one language to another, help on the interpretation of different terms, their origin and more. You can organize access to Ulteo OVD from two servers (Application Server (Windows 2008R2) and Session Manager Server (Linux Ubuntu)), using the Proxmox web-based virtual environment. Gran1, Gran2D, Gran3D software can be installed on the application server. The article also examines in detail some examples of the use of the pedagogical software for educational purposes Gran1. In particular, the calculation of the approximate value of the double integral; graphical two-dimensional problem solving, the so-called linear programming problems; two-dimensional problems, including convex programming – finding the smallest value of a convex downward function (or the highest convexity of a function) on a convex set of inequalities (including linear ones). However, the use in the educational process of any technology, including modern information and communication, as well as the content of training, should be pedagogically balanced, which will allow to avoid any negative effects on the formation of personality of a future member of society, his mental and physical development.
The arrangement of on-line training of master students, majoring in Mathematics for internship in technical universities
Authors: Vlasenko K V , Lovianova I V , Chumak O O , Sitak I V , Achkan V V 
Published: March 2021

Abstract
This article looks into the issue of online-training of master students, majoring in Mathematics for internship in technical universities. This study is focused on arranging students' learning activities with the help of an on-line course “Methods for teaching Mathematics to students in technical universities”. The study considers the issues that students face during the internship in technical universities and debates a possibility to factor in the students’ needs while designing the course content. The present study gives a description of the activities that students do while working with the course materials, requirements, and recommendations on facilitating the learning process through this course. Active participation of students and their contribution to discussing the course, its content and the facilitation of the learning process presume that introduction of the on-line course and its integration into the program of training master students enhances their readiness for internship.
The ICT usage in teaching mathematics to students with special educational needs
Authors: Kramarenko T , Bondar K , Shestopalova O 
Published: March 2021

AbstractIn the article, authors have considered the implication of ICT into mathematics educational strategies in the inclusive class of secondary school. The research includes also a presentation of a teacher’s tool, prepared by an author group, on the use of ICT in teaching planimetry and stochastics of children with special educational needs (SEN) in secondary schools. The research has introduced the model of implication ICT and the influence of effective strategies and methods of inclusive education on the math studying process by children with hearing disorder. The possibilities of using the method of educational projects as one of socialization directions are described. The efficiency of the distance learning was discovered that facilitates the self-representation of students with SEN.