bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integration of environmental education in elementary schools
Authors: Sukma E , Ramadhan S , Indriyani V 
Published: May 2020

Abstract
This study aims to determine the opinions and knowledge of teachers regarding the integration of environmental education in the learning process in the classroom for elementary school students. This research uses survey method. The instrument used was a questionnaire consisting of fifteen questions and four additional statements relating to environmental education in the learning process. The results showed that the majority of teachers agreed that it was important to integrate environmental education in the learning process for students, especially elementary school students. However, this integration still has constraints, such as insufficient time. Based on the results of the analysis shows that for elementary school level, science learning is the most likely learning to be integrated with environmental education in the learning process.
Pressure distributions on swept/unswept wings using pressure sensitive paint
Authors: Huang Y.X. , Wu H.Y. , Chung K. M. , Chang K.C. 
Published: May 2020

Abstract
Pressure sensitive paint (PSP) is an optical-based technique for full-field pressure measurements. A polymer-ceramic PSP, Ru(dpp), with a porous material is used and is applied onto a Mylar tape which affixed to the model surface of NACA 0012 and ONERA M6 wings. The PSP results agree with the data using conventional pressure measurements reasonably well.
Using Matlab real-time image analysis for solar panel fault detection with UAV
Authors: Liao K C , Lu J H 
Published: May 2020

Abstract
The main purpose of this study is to evaluate the feasibility to use Unmanned Aerial Vehicle (UAV) technology for solar panel applications and to propose a reliable, economical and fast method of fault detection. In this experiment, the UAV was used to inspect the panels of a solar farm. For this purpose, a set of tools were selected including an infrared camera and a High Definition (HD) photographic lens to scan solar panel assembly. The infrared images were immediately transmitted back with backhaul HD for analysis. The infrared image display can be roughly divided into three health conditions. The first one is the normal operation of the solar panel. In the second case, the infrared image represents an abnormal situation of the solar panel. The third one is a blurred case in which the infrared image cannot be determined to be normal or abnormal. Under this kind of situation, the Matlab® image analysis was used in this study to determine the health condition of solar panels. The results show that it is effective and efficient to use UAV to capture the thermal image and to detect different faults of solar modules. Moreover, this process is fast, low cost, and can detect defects that are not noticeable by visible light. It may provide maintenance personnel with a tool to prevent solar module failure.
Experimental measurement of anisotropic thermal conductivity of 18650 lithium battery
Authors: Huang Jian , Xu Peichen , Wang Peiyong 
Published: May 2020

Abstract
The accurate thermal conductivity of the 18650 cell is essential to the thermal management of the battery pack for electronic vehicles and aircrafts. The structure of the cell makes the conductivity anisotropic. Judged from the cell structure, the azimuthal and axial conductivity are approximately the same while the radial conductivity is much different from them. The axial conductivity of a cell is calculated by supplying an axial steady heat rate through the cell and measuring the axial temperature difference over the cell. For the radial conductivity, a steady heat rate is supplied on one quarter of the cylindrical outer surface of the cell, the heat crosses the cell radially and azimuthally to the opposite quarter of the cylindrical outer surface. The temperature difference of the two quarter surfaces is measured, and the radial conductivity of the cell is determined by adjusting the radial conductivity value with known azimuthal conductivity (equals to the axial conductivity) in an accurate CFD heat transfer simulation to match the measured temperature drop.
Fabrication and Strength Assessment of Composite Corrugated Expansion Tube
Authors: Liu J.W. , Kam T.Y. 
Published: May 2020

Abstract
A technique is proposed to develop a composite corrugated expansion tube which can achieve a prescribed axial extension when subjected to an internal pressure. The composite corrugated expansion tube was fabricated using annular carbon fabric/PU sheets via the vacuum-assisted resin transfer process. In forming the tube shape, the edges of each annular fabric/PU sheet are adhesively bound to the other two similar sheets at the outer and inner edges, respectively. A finite element model of the corrugated expansion tube is established using the shell elements of the finite element code ANSYS. To illustrate the applications of the proposed technique, the corrugated expansion tube that can sustain internal pressure of 82.73 MPa is developed and tested to verify the accuracy of the finite element model. It has been shown that compressive stresses are induced at the adhesive layers that are located at the outer edges of the corrugated expansion tube. The occurrence of such compressive stresses at the outer edge adhesive layers can increase the failure pressure of the corrugated expansion tube. The failure strength of the composite sheet dominates the incipient failure pressure of the tube. This type of failure mode makes the expansion tube design feasible for practical applications.
Improved genetic algorithm with two-level multipoint approximation for complex frame structural optimization
Authors: Ren Xingyu , Fu Jiayi , Huang Hai 
Published: May 2020

Abstract
In this paper, an improved structural topology and sizing optimization method is developed for the fast and efficient engineering design of complex frame structures where beam elements are mainly used in the structures. Discrete and continuous variables are included that the elimination or existence of beam elements are treated as discrete variables (0,1), and the continuous sizing variables of beam cross sections are considered to be continuous variables. To solve the mixed variable problem, the paper introduces a two-level multipoint approximation strategy (TMA). The first-level approximate problem is established by using the branched multipoint approximate function, which includes both two types of variables. Genetic algorithm (GA) is used to determine the absence or presence of beam members. The second-level approximate problem that only involving retained continuous size variables is made on this basis, which uses Taylor expansion and dual methods to solve the inner layer continuous optimization problem. Meanwhile, a strategy of adding a new complementary design point is adopted to expend the search scopes and improve the precision. Temporal deletion techniques are used to temporarily remove redundant constraints and local vibration modes processing techniques are used for continuum topology optimization under frequency constraints. Several representative examples are investigated to validate the effectiveness of the improved method.
Lateral Stability and Control of a Flying Wing Configuration Aircraft
Authors: Wang Yankui , Tang Xiangxi , Li Tao 
Published: May 2020

Abstract
A numerical investigation was conducted on an Unmanned Combat Air Vehicle (UCAV) model which is a moderately swept, tailless and flying wing configuration. A wind tunnel test was performed to validate the numerical results. Model forces and moments were measured using a six-component strain-gauged force balance. The computations were performed using a commercial Reynolds-Averaged Navier-Stokes (RANS) flow solver. The numerical results show that the lateral unstable of the model is caused by asymmetrical breakdown of the body vortex, and the flaps installed can induce earlier breakdown and intensity loss of the leeward vortex resulting in the enhancement of lateral stability.
Numerical simulation of dynamic multi-body separation flowfields
Authors: Han Bing , Gao Zhenxun , Jiang Chongwen 
Published: May 2020

Abstract
In this paper, three-dimensional unsteady Navier-Stokes equations coupled with six-degree-of-freedom equations are solved numerically to simulate the process of multi-body separation in the condition of high speed and high altitude. Overset grids are adopted to deal with the relative motion between two different parts. In order to study the security of separating process, the trajectories and attitudes of different parts are calculated and the characteristics of flow field during separation are analyzed carefully. Different initial angles of attack are considered during the simulation and its influence on the separation process is analyzed. The result shows that the initial angle of attack has significant impact on the flow field. Large angle of attack would cause shock/shock interactions between the two parts, threatening the safety of the separating process.
Numerical prediction of aerodynamic performance for open geometry centrifugal compressor
Authors: Kawahara Takahiro , Yamasaki Nobuhiko 
Published: May 2020

Abstract
Numerical prediction of aerodynamic performance of compressors has been widely performed by the RANS model, but there is the tendency to overestimate the work and efficiency of the impeller of a centrifugal compressor. In the RANS, we cannot analyze unsteady phenomena such as tip leakage flow. On the other hand, the LES models universal region of turbulence by performing spatial filtering operations. Since it does not include the concept of time averaging, it can be applied to unsteady calculations. In this paper we perform numerical prediction of aerodynamic performance by the RANS with the Spalart-Allmaras turbulence model and the LES with the Smagorinsky model, and reveal the unsteady phenomena, which cannot be analyzed by the RANS, by comparing each result. The CFD solver that we use is “UPACS”, which JAXA (Japan Aerospace Exploration Agency) has developed. We clarify its prediction accuracy and problem points of UPACS. The geometry data of the centrifugal compressor that we analyze is published in the papers written by Krain. The compressor is equipped with impeller with 24 full blades and vaneless diffuser. Comparing computed characteristic curves of mass-averaged total pressure, using the LES improves the overestimation of the total pressure ratio by the RANS by 10%. It seems that the LES can analyze the unsteady phenomena which the RANS cannot.
Design and implementation of a dual-antenna GPS receiver
Authors: Lin Y Y , Hsu T H , Chen T L 
Published: May 2020

AbstractIn the Global Position System (GPS) technology, the GPS receiver (GPSR) has to receive the satellite signal to locate its position in a 3D space. For the GPS applications where the GPSR carrier (vehicle) is rotating, the signal-receiving-path could be temporally blocked by the attitude of the vehicle. And, once the GPSR loses track of the signal, it takes at least 6 seconds for the GPSR to resume its positioning task. This paper proposes a novel dual-antenna GPSR system (hardware architecture and algorithms) that can solve the intermittent signal problem when the vehicle is rotating and continuing on its positioning task. Current experimental results indicate that the proposed GPSR design can successfully output its position when the vehicle is rotating at 7.5 rpm. At 22 rpm, some satellite signals remain on-lock but some do not, depending on the strength of receiving signals.
Fault diagnosis method for worm gearbox using convolutional network and ensemble learning
Authors: Hsiao J C , Shivam Kumar , Kam T Y 
Published: May 2020

Abstract
Worm gearboxes are popular across various industrial applications since they offer significant gear ratios in small installation spaces. Despite having multiple advantages, worm gearboxes are subjected to higher friction due to sliding design and are prone to damage and increased transmission error over the period of operation. Delayed diagnosis of worm gearbox degradation can lead to low-quality products and/or unnecessary production line downtime. Using vibration characteristics of worm gearbox, it is possible to determine the fault and transmission error at a given period in time. In this paper, an ensemble machine learning model is trained and deployed to monitor the transmission error of worm gearbox and classify between new, operational and old conditions. 1D CNN (one dimensional convolutional neural network) model is used to automatically extract features in vibration signal of X, Y, and Z axes and predict the relevant state of worm gear. The proposed technique uses ensemble machine learning technique fusion of features extracted by multi-layer 1D CNN for three axes vibration data. The proposed method could achieve 96% accuracy and performs significantly better than traditional sequential and ensemble machine learning models on a dataset of with 7,870 samples with 800 samples labeled as new condition, 4,740 samples as operational and 2,330 as old.
Formulation of mashed potatoes (Solanum tuberosum L.) as Tengger culinary product
Authors: Perdani C G , Wijana S , Yamin A 
Published: May 2020

Abstract
Indonesia is one of the tourist destination countries because of its natural beauty. Bromo Tengger Semeru National Park (TNBTS) is one of the destinations that becomes the main destination of tourists. In addition to natural attractions, culinary tourism can be an alternative in developing the tourism industry of TNBTS. A local cuisine has an important role to attract the hearts of tourists because they will be interested to try the local cuisine. Potato is one of the leading commodities in Ngadas Village TNBTS. The objective of this research was to obtain the optimal formulation of the mashed potato product. In this research, the linear programming was used as an optimisation analysis. The objective function was to minimise the cost of mashed potatoes production. The design of mashed potato composition was made of 4 types: formulation A (using cassava starch), composition B (using rice starch), C composition (using corn starch) and D composition (without using starch). The best treatment obtained was the addition of corn starch. Preparation of 100 g of mashed potato was made with 50 g of mashed potato, 20 g corn starch, 13 Ml water, 5 g of milk powder, 4 g of cheese and the rest were salt and pepper. The average value of the hedonic test on the addition of corn flour was 4.85 (acceptance). The cost of making 200-gram mashed potatoes was IDR 5,038.00.
Production of biodegradable package material from tofu industry byproduct
Authors: Antonius R , Simamora L L B , Setiani P , Sitorus T A , Luthfiyana H , Idris Z Y 
Published: May 2020

Abstract
Plastic has been widely used as single-use package and carrier material due to its low price, strength, practicality, and versatility. On the other hand, plastic requires a long period to naturally decompose. Nowadays, a huge number of plastic wastes have caused detrimental impacts to the global environment, hence a more environmentally benign substance of making plastic is a significant importance. This study proposed the production of biodegradable material from nata de soya, which is composed from whey waste using melt intercalation method. This environmentally-friendly substance was mainly obtained from tofu industry byproduct which is known as ‘whey’, through fermentation process using Acetobacter xylinum bacteria. Melt intercalation method was used to obtain desired texture and characteristic, the step was the fermented product mixed with chitosan, acetic acid, glycerol, and tapioca starch, with various range of concentration. The mixed component then underwent milling and drying process for finalization. As for characteristic of the materials, tested parameters include solubility, water resistance, and biodegradability in the environment. Our results showed the potential of this material to substitute the use of plastic and is applicable for versatile purposes. Water resistance was up to 95 minutes, and the material was able to be completely degraded in around 60 days.
Study of sensitivity for strain-based structural health monitoring
Authors: Herrera-Iriarte A , Alvarez-Montoya J , Sierra-Pérez J 
Published: May 2020

Abstract
One of the available methodologies for structural health monitoring (SHM) is based on strain field pattern recognition where, through the use of sensors capable of measuring strain on discrete points and machine learning techniques, it is possible to detect a damage event. In this study, strain data from fiber optic sensors (FOS), in particular fiber Bragg gratings (FBG), acquired through two experiments are used: an aluminum beam with 32 FBGs and CFRP beam provided with 20 FBGs, which serves as the main wing’s structure of an unmanned aerial vehicle (UAV). Both structures were subjected to dynamic loading for a pristine condition and later, for artificially damaged conditions. In the experiments presented in this paper the beams were provided with different amounts of sensors which were removed one by one in order to analyze the sensitivity of the damage detection methodology based on PCA to a change in the number of sensors. The results demonstrated that there are few sensors that contribute mostly to the methodology’s performance, these sensors are validated to be the ones located near the analyzed damage condition. Therefore, this study is the first step into the development of methodologies of damage localization using strains.
Probabilistic analysis of fatigue crack growth using efficient surrogate model
Authors: Chahine S , Riahi H , Bigaud D 
Published: May 2020

Abstract
In this paper probabilistic analysis of a fatigue crack growth process governed by the Walker law is performed. Sensitivity of its parameters to uncertainties related to the material properties is considered. Based on statistical analysis of experimental data, they are modelled as independent normal random variables. The effect of these uncertainties on the fatigue crack growth behaviour of Centre Cracked Plate specimen is assessed using Monte-Carlo simulations and surrogate model based on polynomial chaos expansion. An efficient truncation scheme allows to discard the high order interactions having a weak effect on the mechanical response and consequently reduce the number of finite elements calls when identifying the unknown coefficients of the polynomial chaos expansion. The statistical moments namely the mean and the standard deviation in addition to the probability density function of the mechanical response are derived with a good accuracy. The obtained results show that the fatigue crack growth life is significantly affected by the uncertainties on the material properties since its coefficient of variation reaches 21% and that it follows a log-normal distribution law.
Decision support system for quality management of cosmetic products
Authors: Shabunina O.V. , Khalyasmaa A.I. , Korelina E.V. 
Published: May 2020

Abstract
The paper describes the structure and the mathematical core of the decision support system developed by the authors for assessing the quality of cosmetic products based on machine learning approaches. The main goal of the study was to improve the system of quality control of cosmetic products, in particular, the quality of perfumes and cosmetics using intelligent methods of data processing, formalization of knowledge and experience of the experts, thus providing automatization of the decision-making process. The practical-oriented goal of the study was to obtain knowledge-supported decisions regarding the quality of the cosmetic products using the developed system of quality assessment based on intelligent methods of data processing, providing the possibility of unsupervised learning and adjustment of the developed system when changing final product characteristics.
Topological theory of physical fields
Authors: Jafari Amir , Vishniac Ethan 
Published: May 2020

Abstract
We study the topology associated with physical vector and scalar fields. A mathematical object, e.g., a ball, can be continuously deformed, without tearing or gluing, to make other topologically equivalent objects, e.g., a cube or a solid disk. If tearing or gluing get involved, i.e. the deformation is not continuous anymore, the initial topology will consequently change giving rise to a topologically distinct object, e.g., a torus. This simple concept in general topology may be employed in the study of physical systems described by fields. Instead of continuously deforming objects, we can take a continuously evolving field, with an appropriately defined topology, such that the topology remains unchanged in time unless the system undergoes an important physical change, e.g., a transition to a different energy state. For instance, a sudden change in the magnetic topology in an energetically relaxing plasma, a process called reconnection, strongly affects the dynamics, e.g., it is involved in launching solar flares and generating large scale magnetic fields in astrophysical objects. In this topological formalism, the magnetic topology in a plasma can spontaneously change due to the presence of dissipative terms in the induction equation which break its time symmetry. We define a topology for the vector field

F

in the phase space

(
x
,
F
)

. As for scalar fields represented by a perfect fluid, e.g., the inhomogeneous inflaton or Higgs fields, the fluid velocity

u

defines the corresponding topology. The vector field topology in its corresponding phase space

(
x
,
F
)

will be preserved in time if certain conditions including time reversal invariance are satisfied by the field and its governing differential equation. Otherwise, the field’s topology can suddenly change at some point, similar to a spontaneously broken symmetry, as time advances, e.g., corresponding to an energy transition.
Invited Commentary: Frontiers of Power Assessment in Mediation Analysis
Authors: VanderWeele Tyler J 
Published: May 2020

Abstract
The development of tools for power and sample-size calculations for mediation analysis has lagged far behind the development of methods. The accompanying paper by Rudolph et al. (Am J Epidemiol. 2020;189(12):1559–1567) is a helpful contribution in using simulations as a tool for power calculations for more complex methods and settings. Much work remains to be done in the development of easy-to-use packages and simple online websites for carrying out power and sample-size calculations for mediation analysis. Much remains to be learned with respect to the relative power of different methods in different settings. There will likely be feedback between these 2 important frontiers of the tools we have available and of our understanding of power when conducting mediation analysis.