bluuebunny/crossref_metadata_2025_split huggingface dataset:
Exploring the online learning response to predict students’ satisfaction
Authors: Sulisworo Dwi , Wulandari Yosi , Effendi Muh Saeful , Alias Mazni 
Published: February 2021

Abstract
Online learning is carried out as an effort to utilize information technology available in higher education institutions in anticipation of changes in the educational environment. Using appropriate technology in learning management is believed to be a drive to improve learning performance particularly in literary learning. This study aims to reveal and describe the implementation of online learning. The data was obtained based on student responses. The results of this study will be the basis for improving online learning management. This research is a qualitative descriptive study involving 42 students as respondents. There are 9 questions to determine students’ understanding and perception. The data in this research are processed qualitatively using the concept of Affinity diagram and Pareto diagram. From these diagrams, interpretation can be made by referring to the results of other researchers and relevant theories. The results of this study reveal that the main inhibiting factors in implementing online learning are the level of access to the internet, the low flexibility of the assignments submission deadline, ineffective feedback to students, and unclear instructions. In the LMS (Learning Management Systems) display, students find it is less attractive (the selection of appropriate themes of the display). However, with the online learning, the students felt that it potentially eases them in obtaining content and sending assignments/learning projects, and gives the flexibility of study time.
Building The Management System: Designs on the use of Blended Learning Environment
Authors: Musdalifah Musdalifah , Baharuddin Baharuddin , Jabri Umiyati , Elihami Elihami , Mustakim Mustakim 
Published: February 2021

AbstractThis study addressed the role of children in studying education is the use of education system. The goal of this study is to develop the international community-based research approach, which is a characteristic assessment involving non-participating observation, interviews and documentation. This research focuses on the models of teaching materials for training to use the full daily school system. The whole research focuses on the models of instructional media for learning through the use of a full day state education system. The data were analyzed to use a qualitative descriptive tool. The aim of data collection is to define teaching assessment by means of interview, review, assessment, documents and research instruments. Participants included 300 elementary school graduates, namely Sidenreng Rappang Regency, Enrekang Regency, Pinrang Regency, Barru Regency and Parepare City, South Sulawesi, Indonesia. The findings of the study showed no substantial associations between the introduction of a full day public education system, personal development, and a positive mindset. The researcher shall be allowed to examine the research questionnaire identified for this analysis and the field of activity research. On the other hand, the full days public school is substantially successful in the training program for elementary school children. Most of the functionality used in the originality of this research by the research instrument selected for the study are approved and used to understand the impact of mobile-based surveys on the character development to be significant predictors.
Analytical Effectiveness using Adobe Flash in Learning Energy Source at Primary School
Authors: Rostyawati Rima , Zulherman  , Bandarsyah Desvian 
Published: February 2021

AbstractInformation and communication technology in today’s world is developing so rapidly and bringing changes to all fields, especially in education. Learning innovations in education are carried out by teachers and students to get a fair learning process. This study aimed to determine the results of student acceptance in using interactive learning media using adobe flash on the energy source material used in the learning process in grade IV primary school. The research method used was quantitative methods with survey techniques and ADDIE development models. The initial stage of the media’s validity and feasibility test was carried out by three media experts, three material experts, and 5 class teachers from five different region schools. The number of samples in this study was 156 students from five different region schools. Data were taken using a questionnaire with a Likert scale of 1 to 5. Based on the data obtained, it showed the following values: (1) the average media expert test is (90.56%) including the criteria “Very Valid,” (2) the average material expert test score is (83.65%) including the criteria of “Very Valid,” (3) the average value of the product feasibility trial to grade IV teachers is (92%) including the “Very Valid,” and (4) the average value of product feasibility trials to users or grade IV students is (85.55%) including the criteria of “Very Good.” The conclusion was that interactive learning media using adobe flash on energy sources is very feasible and very well used in theme 9, “Kayanya Negeriku,” focusing on science lessons on energy sources in grade IV motivates students in learning. For the next research, the development model can be done in the future.
e-Learning Development on Basic Chemical Law Materials in Senior High School (SMA/MA) to Improve High Order Thinking Skill Ability
Authors: Afrianti Trayda , Zainul Rahadian 
Published: February 2021

Abstract
This research aims to develop e-learning for learning Chemistry, Law of Basic Chemistry, for Senior High Schools (SMA/MA). The method used is Borg and Gail. E-learning product development using the Moodle 3.75 application. The stage in the development of this research is the content and construct validity of the product being developed. The result obtained is an e-learning product of Basic Chemistry Laws which has very high content and construct validity. From the results of the content validation, it was obtained 0.98 each for Guidelines and information; 0.88 for Content / material; and 0.87 for Evaluation. From this section, it can be seen that the content validity has a very high interpretation. From the results of the construct validity includes guidance and information; Program Performance; and Systematics, Aesthetics and Design principles respectively 0.84; 0.84; and 0.76. This section looks very high, except for the systematic, aesthetic and design aspects which are still in the high category. These results conclude that e-learning products have very high validity to be used as learning materials for Chemistry in Senior High Schools (SMA) and Madrasah Aliyah (MA), especially in the material of Basic Chemistry Laws.
The modified drive of a metal-cutting machine with the V-belt transmission of increased resource
Authors: Krol O , Sokolov V , Tsankov P 
Published: February 2021

Abstract
The process of the design improving of the V-belt transmission for the metal-cutting machine drive according to the criterion of increased resource is considered. A three-dimensional modeling of the main motion drive structure for multi-operation machine was carried out using the applied library computer aided design KOMPAS-3D. A new approach to the parametric representation of the procedure for constructing a unified profile of a V-belt pulley based on the syntax of the APM WinMachine system is proposed. The idea of constructive change of the standard operating V-belt contour with the corresponding analytical apparatus, which provides increased drawbar power of the transmission, is proposed. Experimental researches on typical sections of V-belts, confirming the increase in the operation reliability of the belt drive have been carried out. provided that the cross-sectional area of the belt remains unchanged
Analysis of the possibilities for growing hedgehog head (Dactylis glomerata, L.) variety “Dabrava” on cinnamon forest soil. Vegetative development
Authors: Vateva Violeta 
Published: February 2021

Abstract
The soil and climatic conditions of the semi-mountainous regions are specific. One of the most important tasks in creating artificial grasslands for haymaking in such areas is the selection of suitable grass species. The aim of the experiment is to analyze the vegetative potential of hedgehog head from the variety “Dabrava” grow on cinnamon forest soil. To achieve this goal, a section of the foothills of Sakar Mountain was selected. The hedgehog head variety “Dabrava” is grown under natural conditions without irrigation. Every year is fertilization with norm N12P6K6. The analysis of the four-year research shows that the hedgehog head variety “Dabrava” grown on cinnamon forest soil has good adaptability and survival in the conditions of the Sakar region. It’s develops normally, and vegetative development begins in the first ten days of March. In the first year of sowing it develops slowly and the growth rate is the weakest. In the following years the vegetative development has a growth rate, which in ten days reaches 15 cm in the first spring undergrowth and 8.8 cm in the second summer undergrowth. The vegetation period varies in the first spring undergrowth from 60 to 82 days, and in the second summer undergrowth from 51 to 80 days. The height of the grassland in mowing maturity in the first spring undergrowth is from 61.2 to 73.2 cm, and in the second summer undergrowth is from 41.7 - 48.2 cm. The overall vegetative development, growth rate and height of the grassland are directly dependent on climatic factors.
Theoretical determination and analysis of the length of the non-working move and the width of the headland when performing fishtail turn with a rectilinear reverse move, which is not parallel to the boundary of a field with an irregular shape
Authors: Trendafilov Krasimir 
Published: February 2021

Abstract
The way of movement of the machine-tractor units in the field influences the efficiency of the performed operations. A way of movement must be chosen in which the length of the non-working moves and the width of the headland are minimal. When moving in an irregularly shaped field, the length of the non-working moves and the width of the headland depend on the angle between the direction of movement of the unit and the field boundary. In the article dependences for determining the length of the non-working move when performing open and closed fishtail turns with a rectilinear reverse move, which is not parallel to the field boundary, as well as for determining the width of the headland required for their execution are derived. It was found that the non-working move is the shortest and the width of the headland is the smallest when performing a closed fishtail turn and the direction of alternation of the working moves in the field from right to left.
Robust optimization of a deep drawing process
Authors: Paskaleva S M 
Published: February 2021

Abstract
An attempt to define a robust optimization of a deep drawing process is presented in this article, based on window of plastic deformability in the area of main deformations, which is closed between the borders of damage, corresponding to necking, fracture and wrinkling. In the previous investigations of the author, this window has been determined using Finite Element – based computer simulations for technological process of deep drawing of a cylindrical cup. The influence of the stochastic character of the control variables on the quality of the output is examined. An objective function for investigating the robustness of the process, based on the quality of the detail, using numerical simulations, is suggested. The results of the model calibration and optimization run are interpreted. The flexibility of the suggested approach, potential ways to extend it and performance issues are discussed.
A SI engine performance parameters determination for gasoline and methane operation
Authors: Dimitrov R D , Bogdanov Kr Ts , Wrobel R S , Magdziak-Toklowicz M , Andonov N A , Hristov R P , Zlateva P 
Published: February 2021

Abstract
The present paper presents a study whose objective is to determine the performance parameters of an external mixture formation and spark-ignition engine when running on methane fuel. The experiments were carried out using optimum adjusting parameters for engine operation on methane and gasoline fuels. The parameters measured and determined are: brake specific fuel consumption, mean effective pressure, brake power, thermal efficiency, volumetric efficiency and etc. over the entire engine speed range. An analysis of the obtained results is made, comparing the obtained effective parameters at the operation of internal combustion engines with alternative fuel - methane and traditional fuel - gasoline.
An analysis of the potential use of waste materials for biogas plant development
Authors: Zlateva P , Dimitrov R 
Published: February 2021

Abstract
Various industrial waste materials have great potential, especially as a substance for biogas production. The aim of the present study is to analyse the possibility of using the waste materials extracted in Northeastern Bulgaria for biogas plant development. The study indicated that the most common waste materials in Northeastern Bulgaria are in the following ratios Agricultural waste - 44%; Livestock breeding waste - 34%, Waste water - 20% and Seaweed - 2%. Individual samples of the waste materials thus grouped were also examined and biogas was produced from them, after which the density and the lower heating value (LHV) were studied. The analysis of the results showed that the highest LHV are associated with Forage waste - 27.11 MJ/kg, and the lowest one relates to Brown algae - 11.06 MJ/kg, and the density indicates the opposite tendency, with the highest figures related to Brown algae - 1.363 kg/m3, and the lowest values - to Forage waste - 0.994 kg/m3. According to the analysis, the most efficient raw material for biogas production in Northeastern Bulgaria is Forage waste, which is due to its heterogeneous content. In conclusion, Northeastern Bulgaria can be claimed to have various waste materials which are a prerequisite for establishing a biogas production plant.
Problems with the operation of automatic transmissions of AW 55-50 type
Authors: Stefanov S , Hristov R 
Published: February 2021

Abstract
The five-speed automatic transmissions of the AW 55-50 type are widely used in cars. They are used in the transmissions of Opel, Renault, Volvo, Saab, Fiat (Alfa, Lancia), Nissan and GM. Various problems are observed in their operation. Some of the problems are mechanical in nature, requiring major repairs to the transmission. A common defect is a problem in the valve body, which does not require major repairs. Only the valve body is dismantled and repaired without dismantling the entire gearbox. This the report examines characteristics of the linear pressure solenoid (electronic pressure regulator), embedded in automatic transmissions of the type AW 55-50. For this purpose, made special hydraulic fixture with electronic controls, which imitate the work of this pressure regulator under real conditions.
Outdoor vertical farming on textile substrates
Authors: Dirkes L , Massanés J D , Böttjer R , Storck J L , Ehrmann A 
Published: February 2021

Abstract
Vertical farming may solve the problem that in many regions of the world, more area would be necessary to produce food, than it is available. Especially in large cities and other densely crowded areas, vertical farming can provide an efficient and eco-friendly way to feed people. While indoor vertical farming plants are usually highly automatized, outdoor approaches are usually less professionally setup and thus often prone to drying-out, in this way disturbing of even destroying the plants grown in such setups. Here we report on semi-automated irrigation systems, combined with different textile substrates to reduce the risk of fully dried substrates, in order to make inexpensive, successful vertical farming systems available for everybody.
A study on application of the golden and Fibonacci geometry in design of fashion accessories
Authors: Ilieva Julieta , Kazlacheva Zlatina , Dineva Petya , Indrie Liliana , Florea-Burduja Elena 
Published: February 2021

Abstract
The paper presents a study of application of the golden and Fibonacci geometry in design of fashion accessories: bags, scarfs, small accessories, etc. The connection between the application of the golden and Fibonacci geometry in accessories design and sustainable fashion is one of main accents in the study. The application of golden and Fibonacci tilings, floral and animal ornaments, which are created on their base, and geometric forms in golden or Fibonacci proportions are shown. As expressors of beauty, aesthetics, and harmony, the creations on the base of the golden and Fibonacci geometry can be applied in design of fashion accessories directly, as frames, and as parts of new forms. Regardless of the way of the application, the new designs are in strong connections with the sustainable fashion: slow fashion, sustainable trends, zero waste cutting, minimal waste cutting, ecological printing, etc.
E-textile for non-invasive control of the body movement of bedridden patients
Authors: Angelova Radostina A , Sofronova Daniela 
Published: February 2021

Abstract
Decubitus ulcers or bedsores are skin injuries that are a serious medical problem, difficult to treat. They are usually the result of some tissue nutrition disorder, the most common cause being lying down. The main principle for the prevention of this disease is the frequent change of body position of the person or the use of an anti-decubitus mattress. Our study aims the creation of an e-textile for non-invasive control of the body movement of bedridden patients. The use of sensors to monitor body pressure on the mattress would provide information not only on the areas with the most active wearing for each individual but on the current state of the patient: i.e. when it is necessary to change the orientation of the mattress or change the position of the body. It is expected the product to be easy to use and low in price so as to be widely applied and to have a large social impact.
Consumption of Electric Energy in the Production of Cotton Textiles and Garments
Authors: Angelova Radostina A , Velichkova Rositsa , Sofronova Daniela , Ganev Ivaylo , Stankov Peter 
Published: February 2021

Abstract
The production of cotton textiles and garments is of substantial importance for modern society in terms of its economic effect: trade, investment, employment and earnings all over the world. The sector is characterized by substantial demand for electrical energy, alongside with other types of energy resources. The paper discusses the current situation of the production of cotton textiles and garments (import/export), together with the different types of energy, consumed by the textile industry. An in-depth analysis of the energy profile of the manufacturing processes from fibres to garments is performed. The need for a paradigm shift from linear to a circular economy in the field of textiles and clothing production is also discussed.
Industry 4.0 for fashion products – Case studies using 3D technology
Authors: Spahiu T , Manavis A , Kazlacheva Z , Almeida H , Kyratsis P 
Published: February 2021

Abstract
The Fourth Industrial Revolution is based on digitalization where virtual and physical systems of manufacturing are linked and operate together. Fashion products are of a great interest not only as items used to cover and protect the body but even to express individuality, personality and attractiveness. Due to the high interest of consumers for fashion items or products, fashion industry is one of the most important industries globally due to its effect on economic growth. As a result, companies try to invest continually on new technologies by implementing them in various processes of production. The aim of this paper is to present here the implementation of advanced technologies for various fashion products as garments, jewelery and accessories. These products are modelled, evaluated and produced by using 3D modelling software, simulation and additive manufacturing as some of the pillars of Industry 4.0 will be presented. The reduced time, waste and advantages to create, visualize and evaluate products at early stages of product creation are some of the advantages of these technologies, part of Industry 4.0 in the fashion industry.
Feasibility analysis of autonomous hybrid solar-wind system for household consumption: a case study
Authors: Pehlivanova T I , Atanasov A K 
Published: February 2021

Abstract
The constant increase of electricity prices from the power grid, rising fossil fuel prices and environmental motives make people look for opportunities to supply their homes with renewable energy independently from the grid. The easy technical feasibility of the projects and the climatic features of Bulgaria determine the solar and wind energy as the most suitable for the households. The variability of solar and wind energy predetermines their shared use in hybrid systems. Feasibility analysis of autonomous hybrid solar-wind system for household consumption was made in the article. The calculations were made for a residential building located in the village of Okop, Yambol District, Bulgaria. It has been verified if the levelized cost of energy (LCOE) of the domestic solar-wind hybrid system is in parity with the final cost of the grid electricity. Different variants of system configurations and different ways of financing were considered. The results show that for the considered place, the prices of electricity produced by autonomous hybrid systems are higher than the prices of electricity for household customers connected to the power grid. The use of standalone hybrid systems is only justified when there is no power supply from the grid. Lower average prices than those of the power grid are obtained only when building a photovoltaic plant connected to the grid.
Mathematical Simulation of Electrotechnology Characteristics of Mining Complexes
Authors: Petrov V L , Sadridinov A B , Pichuev A V 
Published: February 2021

Abstract
The article presents the results of the research and analysis of the efficiency of power consumption at tunnelling sections in coal mines. The authors established distribution laws for the shift averages of technological and specific consumption of power. Further, they recommended the criteria and principles for the assessment of the power conservation level, efficiency of mine tunneling and works execution arrangement in terms of power sustainable use by shift teams. The recommendations are provided on defining sustainable levels of the shift average power consumption and rationalizing manufacturing standard indices.
Digital transformation challenges of logistics in Bulgaria
Authors: Dragomirov N , Boyanov L 
Published: February 2021

Abstract
This paper investigates the issues of digital transformation in Bulgaria. It presents the major contemporary technologies, used in digitalization and digital transformation and then presents a methodology that evaluates the degree of digital transformation in the area of logistics. Determining the level of basic digitalization of Bulgarian logistics companies is done by developing a methodological framework that covers the main classification of information systems in the area. The indicators covered are in two groups - intraorganizational and interorganisational digitalization. The state of digital transformation is analysed, reviewing small, medium and large enterprises, following a survey within each company. The results show a big potential for the process of digital transformation in Bulgaria in logistics.