bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi-vehicle mixed formation driving method based on fuzzy decision
Authors: Guo Peng , Hua Yiding , Wang Tong , Gong Jinfeng
Published: March 2021

This paper presents a multi-vehicle driving method based on fuzzy decision. Fuzzy decision-making is used to realize the process of multi vehicle merging to observe how he turns and joins other teams successfully. Establish the multi-vehicle driving fleet model, and initialize its relevant data, mainly including the speed of multi vehicle driving, the distance between vehicles in the multi vehicle driving fleet and the location from the intersection. Establish the model and data of the vehicle to be inserted into the multi vehicle driving team, mainly including its speed, the position of the vehicle to the intersection, and the intersection of the queue jumping is a fixed T-junction, and the whole process of fleet merging is implemented The method proposed in the paper can be applied in practice.
The Influence of Different Finals Ending on the Pronunciation Airflow of Syllables Based on Cooperative Pronunciation Theory
Authors: Wang Jing , Li Yonghong , Liu Zeguo
Published: March 2021

Based on the theory of coarticulation, this paper studies whether different endings of stops and affricate vowels in syllable structure affect the pronunciation airflow. Through the analysis of the data, we can see that the stop initial syllable at the back of the pronunciation part is longer than the stop initial syllable with the same vowel in the same position. No matter whether the stop or affricate is the initial, the average air velocity of the syllable with the ending of the front nasal is higher than that of the syllable with the opening syllable and the last nasal sound.
Data Wealth Mining Based on Text and Time
Authors: Liu Jie
Published: March 2021

In this paper, online sales strategies for microwave ovens, baby pacifiers and hairdryers in Amazon are studied based on sentiment analysis and opinion mining. Firstly, we analyze and quantify star ratings, reviews, and helpfulness ratings based on the corresponding factors, and give one mathematical model for the evaluation of product. Secondly, we identify and discuss time-based measures and patterns within each data set to analyze whether the reputation of the product is rising or declining. Finally, we predict the goods that may be potentially successful or failing taking all indicators into consideration, and put forward suggestions on important design features that would enhance product desirability.
Design and Research of MCU applied in UAV Data Acquisition System
Authors: Zhang Hua , Wang Jiachen , Sun Yingying , Wang Wei
Published: March 2021

To meet the requirements of high real-time performance and long endurance of UAV data acquisition system, this paper designs a MCU, which integrates ADC, embedded memory and other key modules into a single MCU chip, so as to reduce the impact of interconnection communication between hardware units. High speed, low power consumption and high anti-interference performance are obtained for acquisition system.
An automation tool for exporting structure models from Revit to Tekla Structure
Authors: Ma Jie , Ding Siwen , Zhang Dehai , Li Yue
Published: March 2021

BIM modeling process currently faces a significant exchange issues since there is a need for conversion of intelligent building models between various design applications. Right now, Autodesk Revit and Tekla Structures, as the most popular BIM applications, in which compatibility issues were noted since many projects are facing the difficulties when a building model was converted from Revit to Tekla. Although Industrial Foundation Class (IFC), as a promise open file format which enables the possibility of exchange of models between different design applications, an exchange of models with IFC may cause compatibility issues where parts of building information can be lost or relocated. This study aims to develop a plug-in application for converting building models from Revit to Tekla by using API interface. To test the plug-in tool, a 34-storey high-rise residential building model is exchanged from Revit and Tekla with IFC and the plug-in application. The results showed the plug-in application performed better than IFC method in terms of accuracy and efficiency.
Simulation and Optimization of Protection Mothod for Large Surface Vessels
Authors: Li Jinfeng , Sun Bingcheng , Zhang Jiang
Published: March 2021

In order to determine the main protection parts of the protective structure of large surface vesselss, a model of acoustic wake homing underwater vehicle entering the position and course of wake based on probability distribution is established. Also, a simulation system of acoustic wake homing underwater vehicle based on simulation method is designed on the basis of wake acoustic simulation model, underwater vehicle acoustic homing detection model and trajectory model. On this basis, the hit area of acoustic wake homing underwater vehicle is simulated, and the protection mothod of large surface vessels is optimized. This method can be used to realize the lightweight design of vessels and improve its protection ability.
Numerical Simulation of Wave of Oil Storage Platform for Large Concrete Foundation
Authors: Ni Xiaochang , Zhang Wenwen , Zhang Lianli , Li Zhigang
Published: March 2021

In this paper, the hydrodynamic characteristics of a large concrete foundation oil storage platform under wave action are simulated by using the three dimensional wave sink IHFOAM developed by OpenFOAM. It mainly simulates the wave high,the envelope diagram of the maximum pressure value, and the force characteristics of the platform such as the combined force and bending moment under two working conditions. And draw relevant conclusions, provide optimization suggestions for the design layout scheme, and provide reference for other similar structure calculations.
Research on Application of emojies in network customer service
Authors: Gu Ming
Published: March 2021

Emojies in online shopping, online customer service is widely application. Through the investigation of Internet consumers and network service personnel, this paper from the frequency of use, attitudes, preferences and other describes the network consumer, customer service personnel to use emojies status, through the score analysis, for customer service staff in working process using emojies recommendations: positive use of emojies and use emojies are less, pay attention to the frequency of use of emojies, in the form of written words + emoticons to consumers, emojies should be placed at the end of the sentence.
Research on the Application of Models Based on Mathematical Theory in the Analysis of Building Structures
Authors: Yang Shufen , Huang Xinyao
Published: March 2021

With the development of urbanization, the demand for various high-rise buildings is also increasing. The stability and safety of the building structure are an important issue. This article uses various mathematical models to analyze high-rise buildings, studies how to analyze high-rise structures and theoretically provides support for the analysis of high-rise structures.
Simulation Design of Wearable Device Based on Intelligent Interaction Concept
Authors: Yan Jun , Han Xiaoran
Published: March 2021

The intelligent interactive concept as the center, on the basis of the problem of drinking water container, with dressing device of portable items as bottled water way to resolve the problem, through the market similar products from the aspects of capacity, material, carrying way investigation and study, analysis of intelligent interaction design in the application of high-end products embody the characteristics of humanization, intelligent, timeliness, and combine with products created by efficient and convenient. In addition, the feasibility of intelligent interaction in wearable devices with portable items is verified through their intelligence, humanization, timeliness and material requirements. On this basis, through the simulation of functions and forms in wearable devices that can carry items, the intelligentization, humanization and timeliness of the concept of intelligent interaction are analyzed and illustrated with examples.
Research on Reliability Analysis Method Based on Dynamic Fault Tree
Authors: Chen Han , Chen Ling , Zhang Yongfa
Published: March 2021

Due to the development of digital technology, digital I&C systems have replaced analog I&C systems and become the mainstream I&C systems for nuclear power plants and marine nuclear power plants. However, there is still a lack of effective and recognized analysis methods for the reliability analysis of digital I&C systems. Based on the commonly used dynamic fault tree analysis method for dynamic system reliability analysis, this paper uses Markov transition matrix to achieve quantitative analysis. Reliability analysis of the digital I&C system, through the improved dynamic fault tree analysis method, provides an effective analysis method for the reliability analysis of the digital I&C system.
Research on Trim Simulation and Flight Test of a General Electric Aircraft
Authors: Li Yadong , Zhang Zijun , Zhang Junyao
Published: March 2021

In order to study the stable flight of an electric aircraft in the whole flight speed range, taking the manned electric aircraft as an example, the method and principle of Longitudinal Trim for high aspect ratio aircraft are presented. Based on the wind tunnel test data, the torque produced by different gravity centers and tension lines as input parameters, and ignoring the influence of lateral and heading parameters, the three-degree-of-freedom motion equation of the aircraft is established, the difference of the performance parameters before and after the trim state is analyzed, which reflects the flight characteristics of the aircraft in a comprehensive way, and is compared with the flight test data. The simulative simulation data and the flight test data are in good agreement and have certain feasibility, it provides a reference for analyzing the performance parameter modification of other high aspect ratio electric aircraft in the future.
Computational Model of Cultural Preservation based on Cellular Automata
Authors: Shu Zeliang , Zhang Xinmiao , Jiang Hanlin
Published: March 2021

The competition and integration of cultures is an unavoidable trend in the context of globalization, and immigration behavior has significantly accelerated the process of cultural transmission and integration. Cultural change is an evolutionary process in a complex social system. At present, scholars in this field mainly use the complex network model, Axelrod’s cultural communication model, and cellular automata model to simulate the evolution of culture. The process of. Among them, the cellular automaton is a mathematical model with discrete time, space, and variables. Based on the above characteristics of the model, the affected population can be divided into small rectangular units, and time can be divided into units at the same time. Effectively simplified the simulation process.
Reliability Analysis of Zipline Project in A Mountainous Eco-tourism Scenic Spot
Authors: Guo Yanhui , Yang Yi , Yang Zhiquan , Ao Fuxing
Published: March 2021

In order to study the reliability and safety of the zipline project of an ecological cultural tourism scenic spot, Zhenxiong County, Zhaotong City, Yunnan Province, based on the field investigation and data collection, the three-dimensional model of the project is constructed by Midas civil, and the reliability of the zipline structure under pedestrian load is calculated. The calculation results show that after the completion of the zipline, the overall maximum combined displacement is concentrated in the middle of the span, the displacement is small, and the overall combined displacement of the zipline decreases to both ends of the tower; under the action of human load, the stress of the zipline and the cable tower increases, and the displacement of the main components also increases obviously, but it is within the acceptable range as a whole. The research results provide a reference for the normal operation of the project.
Three Dimensional Cellular Automata Sand Castle construction Model Based on Step Factor
Authors: Zhang Siwei , Zhou Yichen , Zhou Xi
Published: March 2021

It seems that everyone has the experience of making sandcastles on the leisure beach. In order to know how to build a beautiful and sturdy beach castle, this article simulates and analyzes the process of sand castles being eroded by water, and obtains some factors that extend the life of sand castles. First, we model the waves. Simplify the waves into a sine wave. Using calculus and fluid mechanics, the water wave impact force on a particle on the sand castle was calculated. Second, we model the sandcastle. Discretizing time, space, and state, we innovatively introduce the concepts of friction and impact into the model, and propose a new Three-dimensional Cellular Automaton model combined with step factors. We consider each gravel or water molecule as a cell, and simultaneously introduce the moving probability and collision probability to describe the moving trend and collision between the gravel cells, respectively. In order to effectively describe the loss of sand castles in the waves, the gravel cells that are in direct contact with the water cells will receive an impact force calculated by the first model. According to the law of large numbers, we use enough cells to simulate the erosion of sandcastles by the waves. It was found that within a certain range, the farther from the ocean and the more the total gravel, the stronger the anti-erosion ability of the sand castle.
Dynamic characteristics of piezoelectric jetting dispenser with a double spring recovery system
Authors: Deng Junjun
Published: March 2021

Piezoelectric jetting dispenser is widely used in microelectronic packaging field. The amplification mechanism with flexible hinge is often used in the piezoelectric jetting dispenser. Because the dynamic performance of the dispenser is affected by the deformation of flexure hinge, a model using rigid body amplification mechanism and double spring recovery is proposed in this paper. The mathematical model of the recovery system is established and the dynamic analysis is carried out. The working characteristics of piezoelectric ceramics are analyzed. With the increase of load stiffness, the maximum output force increases and the maximum output displacement decreases. With the decrease of needle stroke, the pressing force between the needle and the nozzle increases. Based on the double spring recovery system, the ADAMS simulation model is established, and the influence of the pre-compression of the double springs on the pressing force between the needle and the nozzle is studied.
Existence and Uniqueness of Solutions for Some Basic Stochastic Differential Equations
Authors: Qi Putong
Published: March 2021

Stochastic differential equation (sde) has plenty of applications on economic and physics. However, how to find the explicit solution usually remains a serious trouble. In this paper, we aim to study the uniqueness and existence of the stochastic differential equations. To this end, we used the Ito formula and the Lipschitz condition. As a result, we found that the Lipschitz condition is a sufficient condition for a stochastic differential equation to have a unique solution. If the Lipschitz condition can be proved by calculating the index, then it is possible to find the numerical solution.

Research on the stochastic differential equation has gained much attention after the finding of the Ito formula. The Ito formula illustrates the chain rule of a semi-martingale. Due to the difficulty in obtaining the explicit solution, one primary problem is whether there exists a unique solution. One approach to solve this problem is the use of Lipschitz condition, which is used in the ordinary differential equations.
Research on Platform Environment Simulation Platform Based on Station Status Monitoring and Information Processing Technology
Authors: Gao Yang , Sun Jiangfeng , Li Xi
Published: March 2021

Analysis the in-depth application and acquisition status of low-voltage power line broadband carrier, and establish a database of typical station characteristics based on the nature of user load, communication combination mode, and geographical distribution. Combining with the characteristic information database of typical station areas, research the station environment simulation technology and simulation platform based on multi-mode configuration information fusion. Analysis and research HPLC to deepen application function verification and HPLC expansion functions, develop personalized detection schemes, establish HPLC communication units to deepen application performance quality evaluation, and improve the level of regional HPLC deep application.
Research on Distribution Path of Single-center Medical Rescue Materials
Authors: Han Lu , Ding Yong , Lin Haijiao
Published: March 2021

Reasonably planning the vehicle’s distribution path can effectively improve the distribution efficiency of the distribution center. This article takes the distribution of medical rescue materials as an example. Under the conditions of meeting the needs of hospital and the loading capacity of the vehicle, with the goal of the shortest distribution route, an optimization model is established and the model is solved with the help of MATLAB to obtain an optimized distribution route plan. The two schemes are compared and analyzed before and after the optimization. The results show that the optimized scheme can effectively shorten the distribution path and increase the full load rate of the vehicle.
Design and Simulation of a Portable Copper Tubes Induction Brazing Tool for PV System Application
Authors: Kamil Hanan , Hamdan F. , Abbas Fadhil , Abdulbaqi Isam M.
Published: March 2021

This paper presents the design and simulation of a portable induction heating brazing tool. This tool is intended to be very lite, flexible and low price. It is an application of a singlephase Push-Pull as a DC-AC inverter to achieve the high frequency, high voltage suitable for induction heating applications. Two types of power supplies proposed for the welding tool the first is a portable battery, and the second is a photovoltaic panel. The Finite Element Analysis (FEA) applied to study the induction coil design and the welding process using ANSYS programming package, while MATLAB programming package used for simulating the power supply. The achieved results prove the visibility of this tool.
The diversity of Gastropoda in grati lake district pasuruan east java
Authors: Susilo V E , Suratno  , Dewi M I P , Mujiono N , Subchan W , Prihatin J
Published: March 2021

Freshwater gastropods are benthic fauna whose live under the water surface or attached to the bottom rocks of the river, pond, or lake. Ranu Grati is a freshwater lake located in District Pasuruan, East Java. Information on gastropod community from this lake is still scarce. We surveyed Ranu Grati from November 2019 until February 2020 to find out the gastropod’s diversity. We found 118 individual gastropoda consist of five families and six species. Gastropod’s community in Ranu Grati was classified as moderate (H ′= 1,415). Morphology of each species will be discussed briefly in this paper.
Analysis volcano deformation for determining location of the pressure source, hypocentre and magma supply as disaster mitigation efforts: case studies in Merapi volcano
Authors: Basid A , Mahardika I K , Subchan W , Astutik S
Published: March 2021

Various disaster mitigation efforts due to volcanic earthquakes and volcanic eruptions are carried out to reduce the risk of casualties and damage to infrastructure. One such effort is to conduct volcanic deformation studies. The results of this deformation study include estimating the position of the hypocenter, the pressure source, and the magma supply volume, so that the volume of material released during the eruption can be estimated. With the Mogi Model approach to analysis the Tiltmeter data on the eruption of Merapi Volcano in 2016, the estimated hypocentre is at a depth of about 1,100 to 2,440 m and the depth of the pressure source is about 2,345 m below the peak of Merapi with a magma supply volume of 21.81 million m3. With the same model approach from GPS data on the 2010 eruption, the results show that the hypocentre is at a depth of about 1,100 to 2,500 m below the peak of Merapi The source of magma pressure is at 2,200 m below the peak of Merapi and the volume of magma supply before the eruption is 15 million m3. These two results indicate that the depth of the pressure source causing surface deformation originates from shallow magma and is consistent with the seismicity analysis of Merapi in the same period.
Application of 2D resistivity from geoelectrical methods with dipole dipole configuration for identification of land slides in Citeko Village, Cisarua, Bogor District, West Java
Authors: Parwatiningtyas D , Astuti R Y , Hartoyo P
Published: March 2021

At present, many methods are used to discussed about landslide problems, especially regarding the slip field from the perspective of a one-disciplinary or multidisciplinary approach. One of the approach is using the 2D resistivity geoelectrical method. This research has been carried out to identify landslide and slip fields in Citeko Village, Cisarua District, Bogor Regency using the dipole-dipole resistivity configuration on geoelectrical method. Measurements were made in three passes with 235 metress in length and 5 metress in electrode distance. Data were processed using Res2dinv software, and the results showed that in the study, area lithology of its subsurface rocks was detected, including alluvium and sand layers, weathered material, up to volcanic rocks. Then, there are also clay layers, silt clay layers, and sandstones. The slip fields could be analyzed like a clay layer with resistivity values ranging from 42.3 Ωm−1 to 155 Ωm−1, and its position was in line 1 and line 2, with a depth of 8.5 metres - 16.4 metres. It also identified in line 3 at the depth of 16.4 metres. Then, based on the interpretation of resistivity 3D modeling with Rockworks software from geoelectric data, it shows that the direction of the landslide tends to be centered towards the Northwest to the West, this is also supported by visual observations in the field.
An evaluation model for the implementation of an electronic learning system in high school on Pramuka Island, the Thousand Island DKI Jakarta
Authors: Sardjono W , Selviyanti E , Tohir M , Mukhlis M
Published: March 2021

In line with the development of information systems and technology today, which has entered the era of the industrial revolution 4.0, the learning process in high schools also develops by utilizing information systems and information technology platforms by developing electronic learning systems or often called e-learning. For the successful implementation of e-learning, it is important to know what factors and indicators can be used to build a performance evaluation model., so that the implementation strategy can be determined in a future that is sustainable and superior in competition. The method used to process data is a factor nalysis method, whereas to construct an evaluation model of a number of factors obtained, the regression mpdel is used. The results of the analysis produced 5 (five) new factors, namely a culture of change, a knowledge management system, the latest information, the dissemination of knowledge, and the development of teaching materials.
Validity of learning devices of buffer solution material based on dilemma stories to increase students’ sustainability awareness
Authors: Winarti A , Nahraniah  , Iriani R
Published: March 2021

Awareness of protecting the environment continuously or called sustainability awareness should be built through education. This study intent to develop learning devices based on dilemma stories in Buffer Solution subject matter to improve students’ sustainability awareness. Through the dilemma stories, students’ critical thinking skills and problem solving were trained. The research method used the 4D model. The research subjects consisted of 5 validators and 5 high school students to test readability. Because of the COVID-19 pandemic, the data collection using questionnaire conducted online by email and whatsapp. To test the validity and readability of student worksheet and the dilemma story sheet developed, the CCVLES (Constructivist Chemistry Values Learning Environment Survey) questionnaire and Aiken’s content validation sheet were used. Analysis of the data used descriptive. The results showed that the learning devices developed were valid with an average score of validity of 0.93. The criteria for the dilemma stories according to the CCVLES are very good with a score of 84.4. The student worksheet developed was quite interesting. From the results of the research it can be concluded that the learning devices are valid and can be used in learning Buffer Solution Chemistry with the aim of increasing students’ sustainability awareness.
The students’ interaction in mathematics collaborative learning, caring community, and jumping task
Authors: Hobri  , Murtikusuma R P , Oktavianingtyas E , Susanto  , Putri I W S
Published: March 2021

Collaborative Learning (CL) is one of Student Centred Learning method. CbL is main aspect in Lesson Study for Learning Community (LSLC). In application, it is combined with Caring Community (CC), and Jumping Task (JT). CL, CC, and JT is very important to build students’ self confidence and their ability. Data is collected by questionaire, interview, and observation. This study is done in Mathematics Learning in Junior High School. CL that integrate with JT is done by 4 steps : (1) lecturer build group with 3-4 members, (2) lecturer give task to students, that is write research topic, (3) one student present their idea in his/her group, and other students discuss and give some solutions, (4) lecturer and students discuss about the research topic, problems and solution. The result if this research is analyzed in 4 aspects, that is, description and quality of CL that integrate with JT, description and quality of CC, quality of students’ self confidence, and students’ ability. First, the quality of CL is high. Groupis designed by 3-4 members, with JT, that what is give, what is problem, and thier solution. Quality of sstudents presentationis high, process of presentation their idea in his/her group is systematic and clear, and process of discussionis very good. Discussion between teacher and students about the research topic, problems and solution is high. Second, quality of CC is very high. The meaning of CC is communication between students, especially, from higher level student to lower level student.
Profile of high school students science literacy in east java
Authors: Suroso J , Indrawati  , Sutarto  , Mudakir I
Published: March 2021

Various efforts must be made by the government in the education sector in the 21st century and industrial era 4.0 so that students have the life skills needed is to implement integrated education starting from the family, school and community environment through literacy cultural habituation. Several studies have shown low attainment of scientific literacy. A high level of scientific literacy can improve the quality of education so that it can compete with other countries. This study aims to describe the level of scientific literacy of high school students in East Java. The method used in this research is descriptive quantitative. The data collection technique was in the form of a written test. The research variable is the science literacy ability of high school students in the content aspect. Samples were taken using purposive sampling. Overall, the average percentage of the results of high school students’ scientific literacy skills in East Java based on the aspect of science content is in the low category. The level of students’ understanding of basic science concepts is still low or weak, so that students are less able to apply and interpret data, even though the form of the problem is simple. The cause of the low ability of students is in expressing the content of the discourse given and interpreting the data in the form of pictures, tables, diagrams and other forms of presentation. In addition, there are limitations to the students’ ability to express thoughts in written form, reasoning skills, reading accuracy is still low, and students are not used to connecting information in the form of text and then expressing it in the form of new expressions to answer given test questions.
Metacognitive skills of students with high mathematical abilities in solving contextual problems
Authors: Pathuddin  , Bennu S
Published: March 2021

This study aims to explore the metacognitive skills of students with high mathematical abilities in the mathematics education study program at the Faculty of Teacher Training and Education in the University of Tadulako in solving contextual problems. The process of student metacognition is determined by providing a number of contextual problems that must be solved, then explored in stages by thinking aloud and unstructured interviews. It aims to explore students’ metacognitive skills in solving contextual problems. The results of data analysis show that students with high mathematical abilities in solving contextual problems involve their metacognitive skills.
The implementation crocodile physics simulation media on senior high school student’s scientific works skills in the materials of momentum and collisions
Authors: Prastowo S H B , Subiki  , Kamali M W
Published: March 2021

This research aimed to describe the ability level of scientific work skills and find out an increase in the students’ ability of scientific work skills when using crocodile physics simulation media. The research method used was descriptive qualitative. The research subjects were 35 students of class X MIPA 2 of SMAN Jenggawah. Data collection tools used in the form of the results of the assessment of practicum worksheets 1 definition of momentum and practice worksheets 2 of the law of conservation of momentum. Based on the results of research conducted obtained; first, the ability of students’ scientific work skills when using crocodile physics simulation media shows that students are highly skilled in formulating problems, formulating hypotheses and communicating data. Students have skilled abilities in applying concepts, formulate variables and define operational variables. Whereas the indicators analyze the data and make conclusions having sufficient skilled enough. Second, there is an increase in the ability of students’ scientific work skills from practicum 1 to practicum 2 when using crocodile physics simulation media on all indicators. For indicators to formulate variables and analyze data based on trendline lines in microsoft excel in the form of slope lines or gradients between the two graphs there is a relatively small increase in ability.
Teaching conceptual models in engineering research with mathematical model approaches
Authors: Aurachman R
Published: March 2021

In the field of social sciense generally uses a conceptual model as an initial hypothesis of research. But in the field of technology and engineering, objects of study or research can be modeled in a more appropriate form. This research proposes the application of mathematical modeling approaches in the process of designing conceptual models. Using this approach it is hoped that researchers and students will understand more accurately the interrelationships between variables so that appropriate solutions can be proposed. The diagram that we recommend are influence diagram with the enhancement using stock and flow diagram, and causal loop diagram. The modelling process can be supported by System Dynamics Software.
Enhancing students’ ability to solve word problems in Mathematics
Authors: Emanuel E P L , Kirana A , Chamidah A
Published: March 2021

Word problems are the most important thing in learning in Indonesia. Most of the students met the problems. This research aims to enhance the students’ability in the difficulties of students in solving word problems in social arithmetic. This research is qualitative. Researchers collected data through tests, interviews, and documentation. Data analysis techniques included data collection, data reduction, display (data), and concluding. The results showed that the difficulties in solving word problems in social arithmetic were difficulties in understanding the problems, namely the inability of students to translate the problem that is not able write down what is known and asked; difficulties in transformation, i.e. the inability of students to determine the formula for solving arithmetic problems social; difficulties in the settlement process, namely the inability of students in students perform arithmetic operations to solve the social arithmetic problem. Factors which causes students difficulty that is lazy to read too long questions, difficult to digest words in a problem, lack of student interest in learning mathematics, a way of learning for students who tend to memorize the material so the concept does not clear, students rarely practice the questions, do not understand the counting operations well, motivation low learning, a less conducive classroom, and learning strategies.
Health perception and commuting choice: a survey experiment measuring behavioral trade-offs between physical activity benefits and pollution exposure risks
Authors: Fan Yichun , Palacios Juan , Arcaya Mariana , Luo Rachel , Zheng Siqi
Published: March 2021

Previous literature suggests that active commuting has substantial health benefits. Yet, in polluted regions, it can also cause additional health risks by increasing riders’ pollution exposure and raising their inhalation rate. We examine the effect of perceived air pollution on stated commuting choices using an on-site survey experiment for 2285 non-automobile commuters in Zhengzhou, a heavily polluted city in central China. We integrate a sequential randomized controlled trial in a survey where individuals in the treatment group received tailored information on their commuting-related pollution exposure, based on our 2 week peak-hour pollution monitoring campaign across transportation modes in the city. We find that travelers in Zhengzhou have already adopted pollution prevention actions by favoring indoor commuting modes on polluted days. Individuals receiving personalized pollution exposure information by mode further decrease active commuting by 8.4 percentage points (95% CI: 5.1, 11.6), accompanied by a 14.7 percentage points (95% CI: 10.7, 18.3) increase in automobile commuting. Travellers make sub-optimal, overly risk averse choices by reducing active commuting even for trips where epidemiological research suggests the exercise benefits outweigh pollution exposure risks. This pollution avoidance tendency significantly attenuates the effect of policies encouraging active commuting. Our findings show the intricately intertwined relationships between the public health targets of promoting active lifestyles and reducing pollution exposure, and between individual pollution avoidance and societal pollution mitigation.
Direct radiative forcing of biomass burning aerosols from the extensive Australian wildfires in 2019–2020
Authors: Chang Dong Yeong , Yoon Jongmin , Lelieveld Johannes , Park Seon Ki , Yum Seong Soo , Kim Jhoon , Jeong Sujong
Published: March 2021

In 2019, an unusually strong positive Indian Ocean Dipole spawned hot and dry weather in southeastern Australia, which promoted devastating wildfires in the period from September 2019 to February 2020. The fires produced large plumes of biomass burning aerosols that prevented sunlight from reaching the Earth’s surface, and in this way elicited regional radiative cooling. We estimated the direct aerosol radiative forcing (ARF) resulting from these wildfires, based on Moderate Resolution Imaging Spectroradiometer space-based data and an empirical relationship from AErosol RObotic NETwork ground-based data collected in biomass-burning regions. The wildfire-derived air pollution was associated with an aerosol optical thickness of >0.3 in Victoria and a strongly negative ARF of between −14.8 and −17.7 W m−2, which decreased the surface air temperature by about 3.7 °C–4.4 °C. This is of the same order of magnitude as the radiative cooling from volcanic eruptions. Although the atmospheric lifetime of biomass-burning aerosols is relatively short (about a week), the Australian wildfire pollution plumes extended across the Pacific Ocean to South America. Since climate change is expected to lead to more frequent and increasingly intense fires in many regions worldwide, the consequent biomass burning aerosols may become a significant radiative forcing factor, which will need to be accounted for in climate model projections for the future.
Disease burden and excess mortality from coal-fired power plant emissions in Europe
Authors: Kushta Jonilda , Paisi Niki , Van Der Gon Hugo Denier , Lelieveld Jos
Published: March 2021

We studied the contribution of coal-fired power plant (CPP) emissions (SO2 and NOx) to air pollution levels and annual excess mortality by cardiovascular and respiratory diseases in Europe, based on fine particulate matter (PM2.5) concentrations computed with a regional atmospheric chemistry-transport model. The health burden of European CPP emission-induced PM2.5, estimated with the Global Exposure Mortality Model, amounts to at least 16 800 (CI95 14 800–18 700) excess deaths per year over the European domain. We identified an underestimation of the emissions magnitude and correcting for it doubles CPP-attributed annual excess mortality to 33 900 (CI95 33 000–37 600) per year. Due to the non-linearity of exposure-responses, especially at relatively low concentrations, these estimates represent lower limits of possible health benefits for the EU-28 states. CPP emission phase-out would avoid 18 400 (CI95 16 000–20 500) excess deaths annually assuming background PM2.5 levels of 10 μg m−3, 25 500 (CI95 22 600–28 200) per year if pollution levels from other sources are reduced by 50% in parallel, and 105 900 (CI95 89 900–121 700) deaths by drastically reducing anthropogenic pollution from other sources to 2.4 μg m−3 that represents the threshold for health impacts. Depending on the emission scenario, large health gains can be achieved from the phase-out of CPP emissions, which calls for coordinated air pollution control strategies at the European level.
A review of indirect N2O emission factors from artificial agricultural waters
Authors: Webb Jackie R , Clough Tim J , Quayle Wendy C
Published: March 2021

Nitrous oxide (N2O) produced from dissolved nitrogen (N) compounds in agricultural runoff water must be accounted for when reporting N2O budgets from agricultural industries. Constructed (‘artificial’) water bodies within the farm landscape are the first aquatic systems that receive field N losses, yet emission accounting for these systems remains under-represented in Intergovernmental Panel on Climate Change (IPCC) emission factor (EF) guidelines and global N2O budgets. Here, we examine the role of artificial waters as indirect sources of agricultural N2O emissions, identify research gaps, and explore the challenge of predicting these emissions using default EFs. Data from 52 studies reporting dissolved N2O, nitrate (NO3), and EFs were synthesised from the literature and classified into four water groups; subsurface drains, surface drains, irrigation canals, and farm dams. N2O concentration varied significantly between artificial waters while NO3 did not, suggesting functional differences in the way artificial waters respond to anthropogenic N loading. EFs for the N2O–N:NO3–N concentration ratio were highly skewed and varied up to three orders of magnitude, ranged 0.005%–2.6%, 0.02%–4.4%, 0.03%–1.33%, and 0.04%–0.46% in subsurface drains, surface drains, irrigation canals, and farm dams, respectively. N2O displayed a non-linear relationship with NO3, where EF decreased exponentially with increasing NO3, demonstrating the inappropriateness of the stationary EF model. We show that the current IPCC EF model tends to overestimate N2O production in response to NO3 loading across most artificial waters, particularly for farm dams. Given their widespread existence, there is a need to: (a) constrain their global abundance and distribution; (b) include artificial waters in the global N2O budget, and (c) expand the study of N processing in artificial waters across a geographically diverse area to develop our biogeochemical understanding to the level that has been achieved for rivers and lakes.
Carbon cycling in mature and regrowth forests globally
Authors: Anderson-Teixeira Kristina J , Herrmann Valentine , Banbury Morgan Rebecca , Bond-Lamberty Ben , Cook-Patton Susan C , Ferson Abigail E , Muller-Landau Helene C , Wang Maria M H
Published: March 2021

Forests are major components of the global carbon (C) cycle and thereby strongly influence atmospheric carbon dioxide (CO2) and climate. However, efforts to incorporate forests into climate models and CO2 accounting frameworks have been constrained by a lack of accessible, global-scale synthesis on how C cycling varies across forest types and stand ages. Here, we draw from the Global Forest Carbon Database, ForC, to provide a macroscopic overview of C cycling in the world’s forests, giving special attention to stand age-related variation. Specifically, we use 11 923 ForC records for 34 C cycle variables from 865 geographic locations to characterize ensemble C budgets for four broad forest types—tropical broadleaf evergreen, temperate broadleaf, temperate conifer, and boreal. We calculate means and standard deviations for both mature and regrowth (age < 100 years) forests and quantify trends with stand age in regrowth forests for all variables with sufficient data. C cycling rates generally decreased from tropical to temperate to boreal in both mature and regrowth forests, whereas C stocks showed less directional variation. Mature forest net ecosystem production did not differ significantly among biomes. The majority of flux variables, together with most live biomass pools, increased significantly with the logarithm of stand age. As climate change accelerates, understanding and managing the carbon dynamics of forests is critical to forecasting, mitigation, and adaptation. This comprehensive and synthetic global overview of C stocks and fluxes across biomes and stand ages contributes to these efforts.
Accidents that Occurred at Nuclear Power Plants in 1952-1972
Authors: Barbin N M , Titov S A , Kobelev M
Published: March 2021

The article describes the main causes of emergencies at nuclear power plants. For the twenty-year period from (1952-1972), reviewed and described in which countries and at which nuclear power plants accidents and incidents occurred. The main objects of emergencies are considered. It was determined that more accidents occurred at NRX reactors.
The Use of the Expert Method in Solving the Issues of Choosing the Instrumentation of the Procedure for Controlling Production Factors
Authors: Borisova A V , Finochenko T A , Finochenko V A
Published: March 2021

Ensuring safety at work largely depends on the quality of research on the factors of the working environment and the assessment of working conditions carried out at the workplace. The scientific paper deals with the problem of equipment for testing laboratories that control harmful production factors. In the absence of an integrated approach to the selection of instrumentation, when equipping a laboratory, there are costs associated with unjustified financial costs and incomplete functionality of the purchased equipment. At present, there are no convenient methods for practical use of choosing the instrumental support for instrumental control of harmful and hazardous production factors. To solve this problem, an approach is proposed to the choice of measuring equipment for measuring harmful production factors, which is based on the method of expert assessments. The results of studies of the application of the expert method to determine the possibility of using a group of devices for assessing physical and chemical factors in the control and monitoring system of harmful factors at the workplaces of a machine-building enterprise are presented. Information on the implementation of the obtained results of the implementation of the expert methodology in the selection of instrumentation in the management system of testing laboratories performing work in the field of labor protection and environmental safety is presented. Based on the results of the implementation, it can be concluded that the proposed approach to the selection of instrumental equipment based on the expert method is universal.
Characteristics of Agricultural Lands, the Estimation of Yield of Grain and Leguminous Crops Varieties and Parameters of Their Adaptability in the Tyumen Region
Authors: Sapega V A
Published: March 2021

The priority task of the agricultural sector of the Russian Federation is the production of food grain. The article describes the characteristics of agricultural lands for 2004-2018, the area of sowing and yield of the grain and leguminous crops for 2014-2018, as well as the assessment of yield and adaptive potential of the main varieties of the grain and leguminous crops for 2017-2019 in the Tyumen region. On average, in 2004-2018, the total area of agricultural lands amounted to 2352.6 thousand hectares, and the area of the field – 1119.1 thousand hectares. The time dynamics showed an increase of the total area of agricultural lands and a decrease of the area of the field. The area of sowing of the grain and leguminous crops averaged 689.4 thousand hectares in 2014-2018, and the average yield was 2.06 tons/ha. The leading grain crop is spring wheat. The average sowing area of spring wheat was 402.9 thousand hectares with an average yield of 1.95 tons/ha. The variability of grain and leguminous crops yield ranged from small to significant, while coefficient of yield stability ranged from 1.0 (winter wheat) to 5.3 (winter rye). The largest average yield of spring wheat was observed in the middle-early variety Tyumenskaya 25 (5.21 t/ha) and middle-season variety Aviada (5.00 t/ha), in the spring barley – Abalak (4.69 t/ha), in the oats – Foma (6.07 t/ha) and peas – Thomas (4.37 t/ha). In general, all varieties of grain and leguminous crops were characterized by low stress resistance, and their yield variability ranged from small to significant. The index of ecological plasticity of the majority of varieties was equal to and close to one, which characterizes them as plastic, i.e. the change in their yield fully corresponds to the change in growing conditions. The variety of spring wheat Tyumenskaya 25 was the best in terms of general adaptive ability (GAA = 0.20), the variety of spring barley – Abalak (GAA = 0.15), the variety of oats – Foma (GAA = 0.20) and the variety of peas – Thomas (GAA = 0.18). The variety of the spring barley Abalak (GAA = 0.15; Cv = 6.6%) and the pea variety Thomas (GAA = 0.18; Cv = 5.3%) were the best varieties combining a high level of general adaptive ability with a small yield variability.
Vein-rock in the «Dark kingdom» Marble Deposit (South Ural) and their Possible Connection with Gold Ore Mineralization
Authors: Georgievskiy A F , Bugina V M , Kotelnikov A E , Georgievskiy A A , Mahinja E , Gamil’ton Z A
Published: March 2021

During the geological training of RUDN students in the Miass district of the Chelyabinsk region, one of the abandoned open stone quarry for the extraction of crushed marble was studied. Examination of the walls of the stone quarry revealed a wide development of vein and dike bodies spatially associated with the apical part of the Syrostan granitoid massif. The noted vein and dyke complexes are accompanied by halos of skarn, greisen, and pegmatite mineralization, which allows us to consider the Dark Kingdom deposit as a promising object for identifying valuable minerals, including gold.