bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamic characteristics of piezoelectric jetting dispenser with a double spring recovery system
Authors: Deng Junjun 
Published: March 2021

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.