bluuebunny/crossref_metadata_2025_split huggingface dataset:
Climate stresses and its impact towards food sufficiency: a case in Bantul regency Yogyakarta-Indonesia
Authors: Fitriana L , Susanto S , Ngadisih  , Setyawan C , Tirtalistyani R 
Published: February 2021

Abstract
Biomass production is influenced by climate, soil, and water. The most uncontrolled factor is climate. Climate change increases the hazard of hydrometeorological disasters such as floods and drought which influences harvest area an agricultural commodity. This study was purposed to identify and analyze the impact of climate stress on food sufficiency in Bantul Regency, at Special Region of Yogyakarta. Later, it was applied to recommend a strategy in achieving food sufficiency in Bantul. Here, dynamic modeling was applied to simulate the supply and demand for food. Rice is staple food in Indonesia, so it was selected in the simulation of food sufficiency in this study. The modeling used rice production, population, urbanization, and rice field area data released by the Statistic Agency of Bantul. The range of data was 10 (ten) years i.e 2010 to 2019. MAPE (Mean Absolute Percentage Error) was used to validate the model. The MAPE of rice production was 8.36%, so the modelling of climate stresses and its impact towards food sufficiency was accepted. This study identified that food sufficiency in Bantul would finish in 2026. The increasing crop index from 2.34 to 3.00 could extend the period of food sufficiency up to 10 years.
Assessing the emerging agribusiness entrepreneurs by using brainwave technology
Authors: Dharmawan B , Rosyad A , Mandamdari A N , Zulkifli L , Sunendar  , Silitonga L M 
Published: February 2021

Abstract
Individual attributes positively influence the success of entrepreneurs, so that it is important to be learnt by potential youths’ entrepreneurs by providing mentor from relevant business. To address this, we introduce Electroencephalography (EEG) or brainwave to investigate the attention and meditation level of students in entrepreneur skill and to develop an original approach to entrepreneurship learning about innovation. We constructed an integrated system of EEG brainwave in which each participant could be engaged in a virtual product design activity. The participant’s creative behavior, brainwave state, and the level of creativity of their virtual product observed and recorded simultaneously to understand the creative process and their creative product were evaluated afterwards. The experiment involved 20 students of agribusiness study program from different semesters. The result of the students’ exam was compared to their level of attention and meditation, then analyzed. The experiment showed that “attention” was more dominated to keep the brainwave technology work rather than to explore many entrepreneur paths explained by the teacher. Further investigation showed the difference of entrepreneur thinking’s priority before and after experiment, i.e. creativity-risk taking-decision making into risk taking-creativity-decision because students had different perceptions on how to become the successful agribusiness entrepreneurs after the experiment.
Research of recognition accuracy of dangerous and safe x-ray baggage images using neural network transfer learning
Authors: Andriyanov N A , Volkov Al K , Volkov An K , Gladkikh A A 
Published: February 2021

Abstract
The article considers the use of neural networks to solve the problem of recognizing dangerous and safe objects carried in the luggage of airport passengers. A comparative analysis is performed to define the accuracy achieved on the test sample for different convolutional neural networks. It also explores the influence of various regularizations on the accuracy of a two-class classification. The increased probability of correct recognition is achieved due to augmentation, reset weights and saturation of the network. The method of transfer training is used to increase the efficiency of the recognizer. In this case, a study was carried out for the transfer of various neural networks.
Identification of factors affecting accidents on the intercity road network
Authors: Baklanova K V , Voevodin E S , Fomin E V , Kashura A S , Cheban E P 
Published: February 2021

Abstract
This article examines the influence of various factors that affect the accident rate on the intercity road network. Ten road sections that differ in the level of accidents, traffic characteristics and geometric parameters were selected for the research. The experiment conducted with the help of specialized equipment showed that these road sections with similar parameters of the roadbed being in compliance with all standards have a strikingly different accident rate. The lack of correlation between the measured standardized indicators of road sections and the accident rate on them indicates the influence of unaccounted factors on the latter indicator, which are not considered by approved methods.
Determination of geometric characteristics of friction areas in contact of the chassis wheel with a solid support
Authors: Balakina E V , Sarbaev D S , Sergienko I V 
Published: February 2021

Abstract
Elastic wheels contain the chassis of airplanes, automobiles and other vehicles. Their tires interact with a solid supporting surface – roads and airfields. As a result of this interaction, only static friction, only sliding friction or a combination of them, depending on the mode of the wheel movement, can be present in the contact patch. The geometric dimensions and relative position of the different friction areas determine the stable, unstable or boundary movement of the elastic wheel. Purpose of work: calculation and measurement of geometric characteristics of static and sliding friction areas in the wheel-to-road contact. Determined that: the slip area appears on the longitudinal axis of the contact patch, at a distance from the center of the contact patch equal to 1/4 of the length of the contact patch, then it increases due to a decrease in the static friction area; the center of the static friction area in the contact patch moves toward the current moment by an amount proportional to the moment; the maximum displacement of the center of the static friction area corresponds to the moment maximum in terms of adhesion, and is 1/3 of the length of the contact patch.
Development of optimal modelling of thin-walled elements in the form of a shell made of composite materials
Authors: Bokhoeva L A , Baldanov A B , Chermoshentseva A S 
Published: February 2021

Abstract
The paper presents the research of the stress-strain state of a multilayer composite shell. The optimal construction of a multilayer shell made of composite materials (CM) in the ANSYS system is determined. The optimal construction of a multilayer composite shell provides maximum strength and rigidity at specified loads. An automated procedure developed for choose the angle of fiber laying in the layer. According to the calculations and constructed models, an experimental model of a multilayer shell made of laminated fiberglass manufactured. For the experimental manufacture of a multilayer shell by cold forming, the working drawings of the press-form made. We manually put the layers of shell made of fiberglass T-25 (BM) TU 6-11-380-76. We made layer-by-layer laying of layers in strict accordance with the calculation model, while observing the sizes of elements and reinforcement angles along the base in each layer. The surface of each layer is an ED-20 epoxy resin with a hardener. This approach can be widely used in the engineering and manufacture of structural elements and products from composite materials.
Influence of inertial links on the distribution of vibration amplitudes of points of the working body of a technological vibrating
Authors: Eliseev A V , Kuznetsov N K , Eliseev S V , Vuong Q T 
Published: February 2021

Abstract
Features of problems of dynamics and formation of dynamic states of working bodies of vibrating technological machines are considered. The purpose of the work is to develop a method for constructing mathematical models of vibration machines that provide the ability to evaluate, control and adjust the forms of movement of working bodies by introducing additional links into the structure of the system, forming a closed internal contour. Methods of structural mathematical modeling are used in the construction of original structural formations of their typical elements. The direction of constructive and technical solutions in the implementation of approaches to configure and adjust the structure of the vibration field of the working body is proposed. The method is implemented using the analytical apparatus of the automatic control theory. The features of dynamic states formation based on the application of transfer functions of structural mathematical models of mechanical oscillatory systems are studied. The use of transfer functions of interpartial connections for the formation of vibration fields of working bodies is proposed. Analytical relations are obtained that determine the possibility of implementing specific dynamic modes, including the decoupling of movements by individual coordinates, taking into account the features of the connectivity of movements by characteristic points of the working body, the manifestation of oscillation nodes or modes of dynamic damping. Features of using structural mathematical modeling methods in problems of dynamics of mechanical oscillatory systems with additional connections are discussed. The work is aimed at specialists in the field of theoretical and applied mechanics, machine science and mechanical engineering.
Mathematical model for studying the braking distance of a car equipped with ABS in winter conditions
Authors: Fedotov A I , Gromalova V O 
Published: February 2021

Abstract
The article aims to develop a mathematical model for analytical studies of the braking process of a car equipped with an anti-lock braking system in order to identify the relationship between the stopping and braking distances of a car and pedestrian visibility in dark winter conditions, when headlights are contaminated with anti-icing materials. The mathematical model of the braking process of a car equipped with ABS was analyzed. Experimental studies of the braking process of a car with running and disabled ABSs were carried out on winter roads. The experimental studies of headlight contamination with chemical anti-icing materials (CAIM) and changes in luminous intensity were carried out in real road conditions in winter. The results are presented in the article. The results of the experimental studies of pedestrian visibility in dark conditions with contaminated headlights are presented. The adequacy of the mathematical model of the braking distance of a car with running and disabled ABSs in winter conditions was assessed. The trends characterizing the effect of headlight contamination on the pedestrian visibility in dark winter conditions are described. The results of the study are presented in tables, diagrams and equations. The values of the stopping distance were determined at different initial braking speed rates. The visibility distance for a car with contaminated headlights was determined in dark winter conditions.
The influence of flank lands of end mills on machined surface in milling in the context of chatter
Authors: Dyadya S I , Kozlova Ye B , Tretiak V I , Kondratyuk E V 
Published: February 2021

Abstract
Reliability and cost-effectiveness are the main requirements for aircraft materials and structure components used in manufacturing of aviation engines. This defines the requirements for them. The majority of components are thin-walled and made of hard-to-machine materials: nickel and titanium alloys, heat-resistant steels. The use of such materials places restrictions on the use of certain cutting modes. During rough milling and semi-finish milling with end-mill cutters chatter occur. The vibrations deteriorate the machined surface of engine parts, tool life decreases and machine units are worn out. Different process technologies and constructive features of tools are used to decrease the intensity of chatter. The use of end mills having lands has yielded mixed results. The influence of land usage on surface condition and decrease of chatter in up-milling and down milling has been studied. The mechanism of influence on machined surface and chatter in up-milling and down milling has been determined. At the experimental stand studies were carried out on its effect on changes in the laws of motion of detail during the cutting process. It has been shown that in up-milling and down milling, a land fl
= 0.05 mm wide on the rear surface along the cutting tooth reduces the intensity of chatter has been shown. The results can be used to select the feed direction to reduce the intensity of chatter when milling thin-walled parts with end mills with a land on the rear surface along the cutting edges.
Formation of spatial responses of the optical field in the region of location of the optical antenna array
Authors: Pasternak Yu G , Safonov K S , Safonov F S , Fedorov S M , Volodko A V , Ischenko E A 
Published: February 2021

Abstract
This article describes a model of an optical antenna array operating in the mode of receiving electromagnetic waves in the frequency range 30-300 THz (in this case, the wavelength varies from 10 ☐ m to 1 ☐m). In the course of numerical experiments (to solve the system of Maxwell equations in the integral formulation, the Weiland method [31] was used) the accuracy of approximation of the spatial structure of the optical field at the points of the “virtual” antenna array elements using the auxiliary field sources method was studied. A study was also carried out on the possibility of using a virtual antenna array formed on the plane of arrangement of elements of a real array to increase the resolution of a multichannel optical system. At the upper frequency of the analyzed range of 300 THz, the wavelength is 1 ☐m. The lattice period was chosen equal to half the minimum wavelength of d=0.5 ☐m, so that it was possible to approximate the spatial distribution of the field in the space between the elements of the antenna array, in accordance with the requirement of the Kotelnikov-Shannon theorem.
Use of “virtual” antenna array methods for reduction of DO A estimation systematic error caused by the scattering of waves on mobile carrier body
Authors: Pasternak Yu G , Ashikhmin A V , Rembovsky Yu A , Fedorov S M , Razinkin K A , Antipov S A 
Published: February 2021

Abstract
Article shows that “virtual” antenna arrays can be used to effectively improve the DOA estimation accuracy of mobile direction finders. “Virtual” antenna arrays are the samples of the spatial field distribution calculated by approximation of the field near a three-dimensional scattering body that supports physical (“real”) antenna system. Signals from the outputs of the “real” array are used as input data for the approximation process. Information on the geometry and material properties of the medium is not required. This procedure can be based on the main provisions of electrodynamics (Kirchhoff-Huygens principle, the Lorenz lemma, method of equivalent currents and fields) or on the use of quasi-static approximation of the field based on the apparatus of the theory of analytic functions of a complex variable (the Cauchy integral and Laurent series). “Virtual” arrays can reduce the error caused by the carrier body without costly and labour-intensive calibration procedures.
Guidance dynamics of the optical load of a multielement manipulator
Authors: Tochilkin N E , Kimyaev A I , Sheval V V 
Published: February 2021

Abstract
The dynamic equations of a flat motion of the angular-type multielement manipulator are considered; the manipulator has the payload as an image formation device of a mobile observed object. Dynamics constraints of a manipulator-driven load via stepper motors are investigated. Nonlinear control algorithms are suggested for the tracking of an observed object via feedback actuators associations operating as one multicoupling control feedback actuator.
Using refrigeration machines and heat pumps in the cycle of oil preheating using electricity
Authors: Osintsev K V , Shishkov A N 
Published: February 2021

Abstract
Tank electric heating systems are designed to compensate for heat losses to the environment. The main way of heating technological machines in the negative ambient temperatures is electric heating. Also, electric heating serves to prevent phase changes in the energy carrier. Furthermore, it is needed to control the required viscosity and maintain the set temperatures. The problem of limited resources has always faced humanity. In the field of energy this problem is now more urgent than ever before, because every year, the planet’s hydrocarbon reserves are becoming less and less. Hydrocarbon cost is increasing, which leads to an increase in the cost of the final product. Therefore, it is necessary to use resources more efficiently, increase the efficiency of equipment, and introduce new technologies. In addition to limited resources, the problem of environmental pollution is no less acute.
Calculation of sealing pressures of shut-off valves
Authors: Pogodin V K , Belogolov Yu I , Gozbenko V E , Kargapoltsev S K , Olentsevich V A , Gladkih A M 
Published: February 2021

Abstract
The proposed algorithm for calculating the sealing pressures of the shut-off valve allows one to take into account the structural features of its components and their elements that affect the amount of sealing pressures. These parts are divided into the mounting system and sealing system. Analytical dependencies for determining the forces acting in these systems allow us to determine the force values when tightening fasteners, during pressure buildup and release, and also when exposed to temperatures. When calculating the specific structure of the shut-off valve, it is shown that the forces in its sealing system and mounting system exceed the values determined by known methods of calculation, respectively, 1.4 and 1.2 times. The magnitude of these discrepancies for different structures of shut-off valves may differ from those indicated and depends on the number of components included in the stop valve station. In this regard, the proposed calculation method allows determining not only the forces in the shut-off valve, but also the optimal number of components and connections that will ensure safe operating conditions. It is shown that the method of calculating forces in the stop valve station used in practice is a special case in which the stiffness coefficient of the stop valve station α = 1. The proposed calculation method makes it possible to more accurately determine the forces acting in the shut-off valve, the sealing conditions and the stress-strain state of the components. The introduction of the developed calculation method is connected with the development of a regulatory document on its basis to replace the existing methods of calculating the stop valve station in shut-off valves.
Method for determining the sealing forces in a shut-off valve
Authors: Belogolov Yu I , Pogodin V K , Gozbenko V E , Kargapoltsev S K , Olentsevich V A , Gladkih A M 
Published: February 2021

Abstract
The developed method for determining the sealing forces in a shut-off valve takes into account the design features of its components and their elements, which affect the amount of sealing pressure. The components and assemblies of the shut-off valve that provide the creation of sealing pressure are referred to the fastening system or the sealing system. Dependences for determining the forces acting in these systems are analytically revealed. The values of forces are determined when tightening fasteners, when increasing and releasing pressure, as well as when they are exposed to temperatures. The calculation of the specific structure of the shut-off valve shutdown showed that the forces in the sealing system of the check valve prototype are 1.4 times higher than the values obtained using known calculation methods, and the forces in the mounting system of this check valve are 1.2 times higher than the calculated values. The magnitude of the discrepancy between the calculated and actual values of the forces for different designs of shut-off valves may differ and depends on the number of components included in the station shut-off valve. The proposed method for determining the sealing forces in the shut-off valve makes it possible to determine not only the forces in the shut-off valve, but also the optimal number of components and connections that will ensure safe operating conditions. It is shown that the method of calculating the forces in the station shut-off valve, used in practice, is a special case in which the stiffness coefficient of the station shut-off valve is equal to unity. The proposed method for determining the sealing forces in the shut-off valve makes it possible to more accurately determine the forces acting on the shut-off valve, the sealing conditions and the stress-strain state of the components. To implement the developed methodology for determining the sealing forces in the shut-off valve of the stop station in the shut-off valves, it is necessary to develop regulatory documents formalizing the application of this method.
Analytical studies of bottom hole assembly dynamics in directional well while drilling with coiled-tubing system
Authors: Zainagalina L Z , Zinatullina E Ya , Safiullina A R 
Published: February 2021

Abstract
The article is devoted to the relevant topic of more accurate selection of the design of the bottom-hole assembly (BHA) with a hydraulic test stand to create the necessary axial stress on the bit during drilling with coiled tubing rigs. A mathematical model of the BHA as a dynamic system with linear coefficients during longitudinal vibrations while drilling wells with a coiled-tubing system has been developed and analytically investigated. Analytical dependencies for determining the dynamic parameters of coiled-tubing BHA by a hydraulic test stand have been refined when operating in a directional well.
Probing fast oscillating scalar dark matter with atoms and molecules
Authors: Antypas Dionysios , Tretiak Oleg , Zhang Ke , Garcon Antoine , Perez Gilad , Kozlov Mikhail G. , Schiller Stephan , Budker Dmitry 
Published: February 2021

Abstract
Light scalar dark matter (DM) with scalar couplings to matter is expected within several scenarios to induce variations in the fundamental constants of nature. Such variations can be searched for, among other ways, via atomic spectroscopy. Sensitive atomic observables arise primarily due to possible changes in the fine-structure constant or the electron mass. Most of the searches to date have focused on slow variations of the constants (i.e. modulation frequencies <1 Hz). In a recent experiment (2019 Phys. Rev. Lett.
123 141102) called weekend relaxion-search laboratory (WReSL), we reported on a direct search for rapid variations in the radio-frequency band. Such a search is particularly motivated within a class of relaxion DM models. We discuss the WReSL experiment, report on progress toward improved measurements of rapid fundamental constant variations, and discuss the planned extension of the work to molecules, in which rapid variations of the nuclear mass can be sensitively searched for.