bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary Study of Epoxy Coating Process on Basketry Inlay with 3D Printed Model
Authors: Chotiprayanakul Pholchai , Noda Atsushi
Published: October 2019

In Japan and South-East Asia Countries, Basketry is a heritage handcraft made with natural material such as bamboo strip and wheat straw. Shape and size of basketry products are depended on the basketry pattern and now FDM (Fused Deposition Modelling) 3D printer is used to a print the basketry pattern. This paper will present a bit further in epoxy coating on basketry products to make it more rigid and better shining appearance either while the coated basketry still have the 3D printing model inside as a structure or it will be taken off after coating epoxy. There are a lot of makers who try to use the 3D printed model for resin casting mold but many are fail to get the casted out of the 3D printed mold. Thus we do this preliminary study to investigate the adhesive strength of the casting epoxy resin holding on the 3D FDM printed model. An experiment was designed to find the effect of the curing time and the bamboo fiber adding for resin reinforce. In experiment, a flat dog-bone shape specimen for tensile testing is redesigned by separating into 2 identical parts and they are printed with ABS plastic filament. We glue epoxy resin on 12.5 X 10 mm. contact area in middle of the specimen. We left them cure and dry for 6, 12, and 24 hours before tensile testing then repeat the experiment again with bamboo strip added in between the contact area. The result of the experiment shows that bamboo strip reinforce and curing time affect the adhesive strength.
Fundamental Analyses and Observations of Liquid Droplet on Aluminum Surface for Heat Exchangers
Authors: Charoensuk N. , Sae-kung C. , Charoensuk J. , Hirai S. , Treetong A. , Lilavivat V.
Published: October 2019

Aluminum is one of the most popular materials in the industry because of lightweight Furthermore, the heat exchanger is using more aluminum rather than cumbersome and costly copper inside the system. Nowadays, all of the low-temperature heat exchanger fins are aluminum. However, when the heat exchanger is used for a long time the fin of the heat exchanger will accumulate contamination inside such as dust. The existence of contamination has strongly effect heat exchanger system performance. In this study, the physical of the water droplet with the different surface roughness (Ra) on the aluminum surfaces were studied. Hence, in this experiment, the liquid water droplet behaviors on the aluminum surfaces were observed by the contact angle. The interaction between liquid droplets and solid surface on the flat plate affect the contact angle of the water droplet. Liquid water droplet movements were analyzed by considering the change of the contact angle, were used to explain liquid droplet behaviors on the aluminum surface. Consequently, in this study, the liquid droplet behaviors on the aluminum surface can be used to improve the self-cleaning surface of the heat exchanger such as the air-conditioning system
Construction project team’s competencies influencing contractor business competencies
Authors: Kawesittisankhun Kittipos , Pongpeng Jakrapong
Published: October 2019

Consistent arrangement of contractor business competencies and project team’s competencies helps improve project operation efficiency. Key participants in the project team are project managers, engineers, and technicians. However, a review of existing literature reveals a lack of research on the causal relationship between project teams’ competencies and business competencies. Therefore, this study attempted to identify the relationship through survey contractors’ opinions. The data were analyzed using structural equation modeling (SEM). The results suggest the regression weighs presented in parenthesis that business competencies are influenced by the competencies of a project manager (0.50) and engineer (0.49). The study also discovered the influence of competencies among project teams; that is, technician competencies influence engineer competencies (0.87), and engineer competencies influence project manager competencies (0.55). With the causal relationship between the project team’s competencies and business competencies, contractors can suitably allocate human resources for increasing their project operation efficiency.
Computing the maximum value engineering for a building construction costs using linear programming applications.
Authors: Siripob K , Vuttichai C
Published: October 2019

Value Engineering is an effective technique for reducing costs, increasing productivity and improving quality. Value engineering is a technique directed toward analyzing the functions of an item or process to determine best value or the best relationship between worth and cost functions. Building construction costs comprises 2 major components as materials cost and labor cost. Linear Programming (LP) is a quantitative technique by means of a mathematical modeling technique designs to solve allocation problem (resource allocation) to achieve the maximum profit or lowest cost. Therefore the authors bringing the advantages of both as value engineering and linear programming combined to work together in order to be able to effectively reduced building construction costs or create maximum value engineering that can be best used in the construction projects. Aim of this paper shows the reduction of building construction cost as to achieved the targets for reducing building construction cost or maximum value engineering as much as possible that leads to efficiency of cost reduction by used of principles of value engineering to apply with using linear programming for the reduction of building construction costs based on the material costs and labor costs to serve construction resource reallocation by consideration is made only 3 type construction materials as concrete, rebar and formwork because of 3 type are main component of building construction materials.
Development of Effective Lightweight Material for Construction Building.
Authors: Jarasjarungkiat Amphon , Chuaisrinual Setsawat
Published: October 2019

Due to an increasing trend of building construction in Thailand. Lightweight concrete has been recently introduced into the structural engineering applications. This study was aimed to investigate two aspects; the first one is studying the properties of Cellular Lightweight Concrete (CLC) and verifying that the lightweight concrete satisfies Thai Industrial Standard (TIS Standard) [12]. To verify with the TIS Standard, investigated properties of CLC are dry unit weight, water absorption and compressive strength. Researcher prepared admixtures with sand cement ratio (S/C), water cement ratio (W/C) and percentage of foam to collect statistical data and analyse. Verified by the standard, specimens that pass the standard criteria will be chosen for proper applications in manufacturing of prefabricated construction materials.
Navigation of autonomous vehicle for rubber tree orchard
Authors: Kunghun Worawut , Tantrapiwat Akapot , Chaidilokpattanakul Phudit
Published: October 2019

This research has studied the navigation of autonomous vehicles in rubber tree orchards. It was emphasised on the rubber tree plantation in Thailand. Due to the high labour costs in the rubber industry and the demand for natural rubber has continued to decline over the past several years. The farmer were struggled to reduce the labour costs in production. The development of autonomous vehicle technology in rubber plantation can be a way to ease the production costs, such as reducing the amount of labour in fresh latex harvesting. This work was aimed to develop algorithm of a vision system for replacement of expensive sensors used in typical autonomous vehicles. The vision system model was implemented using only one camera installed on the vehicle to search for calibrated targets which were put on the rubber tree trunk. There were two important parameters, tree row offset and target distance, which were concerned when determining the performance of the autonomous vehicle in the rubber tree orchards. In order to evaluate the accuracy of the system, a set of experiments was conducted at a distance of 1-5 meters between the target and the camera. The results were compared between the controlled environment in the laboratory and the uncontrollable environment in the real rubber plantation.
Physical properties and calorific value of briquettes produced from Palmyra palm waste with molasses binder
Authors: Utchariyajit K , Panprasert V , Chayawat L , Jungthanasombat W , Janprom P , Choatchuang M
Published: October 2019

This work aims to produce briquette made from Palmyra palm waste using molasses as a binder. The amount of binder to charcoal ratios was studied. The physical properties i.e., density, moisture content, ash content, volatile matters, fixed carbon, calorific value and cooking efficiency were investigated. It was found that the amount of binder had a significant effect on the quality and properties of the briquette. The results showed that the amount of binder decreased with moisture content and ash content decreased while density and calorific value increase. All briquettes produced with molasses binder pass the criteria of the Thai Community Product Standard (tcps 238/2547). These results provide an alternative energy for household use.
Antioxidant activity and Total Phenolic compounds of Fresh and Blanching Banana blossom (Musa ABB CV.Kluai “Namwa”) in Thailand
Authors: Thaweesang Sarisa
Published: October 2019

Fresh and blanching banana blossom were extracted by ethanol. Fresh banana florets crude extract had the highest antioxidant activity 42.74% and IC50 were 1275.50µg/ml respectively. For blanching banana florets crude extract, The antioxidant activity and IC50 value were 41.78 and 1306.67 µg/ml respectively. Antioxidant activity of fresh banana bract crude extract and blanching banana bract crude extract were only 28.43% and 13.33% respectively. Results also showed could not evaluation of IC50 value for banana bract crude extract. However, Banana blossom able to antioxidant activity. Banana florets crude extract showed effective antioxidant activity more than banana bract crude extract (p<0.05). Blanching banana florets and fresh banana florets contained the highest total phenolic compounds were 1380.58 µg GAE/g and 1091.30 µg GAE/g respectively. While banana bract had low phenolic compounds. The food processing for consumption did not affected to total phenolic compounds. It was therefore suggested that banana florets have potential as good source of natural antioxidant.
Conversion of Sodium Lactate to Lactic acid and Sodium Hydroxide with Cation Exchange Membrane Electrolytic Cell
Authors: Sirisangsawang R , Samaikaew P , Chotiviriyavanich B , Kitchaiya P
Published: October 2019

This research conversion of sodium lactate to lactic acid and sodium hydroxide with electrolysis technique combined with cation exchange membrane (CEM). The electrolytic cell has effective membrane area of 144 cm2. Experiments were carried out by feeding sodium lactate solution which was prepared with alkaline degradation of invert sugar. This solution was feed through the anolyte. The process was studied in terms of the initial concentration of sodium lactate (i.e. 0.75, 1.20 and 1.50 M) and the applied voltage (i.e. 4, 6 and 8 volt) to assess the efficiency of separation. The results suggested that the transport of sodium ion through the membrane was proportional to the applied voltage but it was not depend on sodium lactate concentration which was used as feed. The current efficiency increased as the applied voltage increased. Conversely, the energy consumption with respect to sodium hydroxide production increased with both factors. From this experiment, it was found that the highest lactic acid recovery was 55.5% at 4 volt and initial lactate concentration of 0.75 M.
Effect of Distillation Methods on Citronella Oil (Cymbopogon nardus) Content
Authors: Phovisay S , Briatia X , Chanthakoun V , Savathvong S
Published: October 2019

Citronella grass (Cymbopogon nardus) is a permanently growing grass belonging to Poaceae grass family. Which plant is native to the tropical region, especially the south-eastern Asia regions. The Citronella oil is used wildly in industrial product as insect repellent, perfumery, cosmetic, diffusion aromatherapy and health benefit. The aim of this study was investigated the efficiency of distillation methods on citronella oil content by laboratory scale, modified alcohol boiler and extractor machine. In addition, possibility of Citronella oil was reviewed to further product development. The three distillations processing were compared on essential oil content that found the distillation method significantly influenced essential oil content (p<0.05). The extractor machine showed highest yield 6.85 ± 0.07 ml/Kg followed by laboratory scale 4.55 ± 0.31 ml/Kg and modified alcohol boiler 2.35 ± 0.16 ml/Kg. The possibility of product development was found citronella oil using on mosquito repellent is recommended at a concentrations of 5-10% and massage oil should not higher than 1.0%. The strong concentration can cause skin sensitivity. Therefore, the optimized concentration should be observed in product development, and value investing. \
Evaluation and Improvement of Unscheduled Removal Component Reliability Calculation Method with No Fault Found (NFF) Shop Finding Results
Authors: Suciati F K , Suwondo E
Published: October 2019

The test results of the removed aircraft components are classified into No Fault Found (NFF), Real Reason Conform (RRC) and Other Defect Found (ODF). Corrective actions will be taken on findings that are classified as RRC and ODF, while for the NFF category no action will be taken. In the MRO XYZ, for the NFF category, the age of the component during the removal is included into the failure data. Moreover, the reliability calculation in the MRO XYZ uses the 2-parameters Weibull distribution. These will result in unrepresentative reliability calculation. Therefore, it is necessary to evaluate the method. The research compares the results of the reliability calculation between the 2-parameters and the 3-parameters Weibull distributions by applying them to several part numbers data. Furthermore, the reliability calculation using the 3-parameters Weibull is also applied to the data where the NFF category is not included the failure data. The location parameter, γ, is calculated using the Muralidhar method. The research also develops an excel VBA macro-based tool for reliability calculation. The results of the reliability calculation show that there is a significant difference of the failure rate between using the 2-parameters and the 3-parameters Weibull distribution. The failure rate calculated by using the 3-parameters Weibull distribution for the data where NFF category is not included into the failure data show a significant different as compared to the method used by the MRO XYZ, where the difference is affected by the percentage of NFF items in the failure data.
Developing new aviation management postgraduate program in responding to Industry 4.0: Key findings from multistages-multilevels market study
Authors: Ghafar N H , Rahman N A A , Mohammad M F N , Shah M Z , Hassan F
Published: October 2019

Most aviation related academic programs in Malaysia were designed centred around the aerospace engineering and aircraft engineering technologies. However, the emergence of Industry 4.0 demands aviation talents especially the non-management aviation practitioners such as aircraft engineers and other technical personnel to equip themselves with certain management-related skills. Hence, there is a pressing need for an advanced industry-driven and practitioners-based academic program in aviation management suits for various categories of aviation practitioners. The aims of this study are to explore the employability prospective of aviation managers (first stage); to examine the Industry 4.0-related management skills needed by aviation companies (second stage); and to analyse the personal development intention of individual practitioners (third stage). This study employed multistage-multilevel analysis on a single-case market study in a Malaysian aviation technical training university. Findings from this study are segregated into three levels. At the industry level, it is concluded that there is a brighter employability prospect of aviation managers at least until 2030. At the organizational level, there is an urgent need for the aviation professionals to upgrade themselves with managerial skills relevant to the Industry 4.0 such as data driven scenario planning, big data analysis, and collaborative decision making. At the individual practitioner’s level, finding indicates that there is an increasing awareness among the individual aviation professional in particular the technical and engineering professional to engage in personal development in aviation management at postgraduate level. The key contribution of this case study is that, through multistages and multilevels analysis, it not only expands the robustness of the market study on new postgraduate program development but also able to incorporate the perspectives of different aviation stakeholders group i.e. the aviation industry, aviation organizations, and individual aviation talents. This multistage-multilevel model can facilitate university’s policy makers to design future industry-based and practitioners-driven development program meant for industry practitioners.
Optimization of an Annular Combustion Chamber for Micro Turbo Jet System
Authors: Habibi F I , Hartono F , Prayogo H
Published: October 2019

This Annular combustion Chamber is designed for micro turbo jet engine. Combustion chamber is positioned in between compressor and turbine of turbojet. Combustion chamber is designed to increase enthalpy without significant pressure loss. Existing combustion chamber is designed by conventional method of trial and error. To further increase its performance then a optimization is needed. The geometry of the combustion chamber is optimized to maximized efficiency, minimized Pattern Factor, minimized pressure loss and lower temperature on the combustion wall. Varying Parameter is chosen based on Sensitivity Analysis with Spearman Correlation method to choose influential changes on geometry. After sampling process with Latin Hypercube Sampling (LHS) method and followed by interpolation with Kriging method, the combustion chamber then optimized using Multi Objective Genetic-Algorithm (MOGA). Performance of the combustion chamber then evaluated by numerical simulation. The combustion chamber will be chosen if it fulfilled pressure loss and temperature on wall criteria. Final design give better performance with a little increase in efficiency and good Pattern Factor.
The design of noise attenuation for gas turbine GTS 22 engine
Authors: Pinandhita L R , Hartono F , Prasetiyo I
Published: October 2019

Nowadays, awareness of global society to the green concept where life should be in harmony with nature has been increasing. One of the ideas in the green concept is to reduce excessive sound exposures or noise. Within this context, gas turbine GTS 22 engine is one of mechanical system that generates a very high sound pressure level. Hence, it is instructive to develop noise controls for the gas turbine in order to have acceptable sound pressure level. This research is focused on the design of muffler as noise control treatment after carefully analyzing the dominant noise spectrum of the gas turbine. In this paper, numerical approach is employed to design the muffler. The results are then validated by experimental ones. Moreover, noise reduction (NR) is used to assess the muffler performances. The design of muffler in this research contains all of combination treatment: area cross section expansion chamber, perforated system (micro perforated panel), porous material, partition chamber and concentric tube. The chosen final design of muffler is combination treatment design where NR 38.77 dB is present. This NR leads to sound pressure level of 80.82 dB or 68.95 dBA exist after the muffler applied on the exhaust of gas turbine. The deviation of experimental results compared to numerical ones is 7.14% in average. Moreover, the pressure drop (ΔP) of the muffler is only 0.4042% which is acceptable to keep the mechanical performance.
Health Condition Evaluation of Servo Turret Based on Time Sequence Signal Feature Map
Authors: Chen W Z , Chen F , Ma T , Xu B B
Published: October 2019

The health condition of servo turret depends machining quality of CNC lathe. Performance tests of servo turret are taken to evaluate the health condition and overall status during its service life. This paper selects the core signals during one tool change-cutting cycle from multichannel physical signals and describes the performance of tool change-cutting cycle by defining a series of feature matrixes. In order to clearly and visually express the health condition of different working stages and tool position, a multidimensional features map is designed according to the combination of different time sequence feature matrixes. The above method is applied on a servo turret test platform which is equipped to acquire abundant signals. The result shows that the feature map clearly defines the health condition with one easily interpreted picture instead of unarranged signals. The proposed method provides a new idea of feature selection and visual expression, which can be an instructive tool for health evaluation and fault isolation.
Effect of Reacting Temperature on the Microstructure and Electronic Property of Self-ordered TiO2 Nanotube Arrays
Authors: Yan Jiangyi
Published: October 2019

At present, with the rapid development of nanoscience, nanotubes have become an important part of nanomaterials. As a new type of multifunctional semiconductor nanotube material, the self-ordered TiO2 nanotube arrays (TNTs) have excellent optical and electrical properties, and they have a very wide application prospects in modern industrial fields. By using the method of anodic oxidation, the specific influence of reaction temperature on the microstructure and electrochemical properties of TNTs under the condition of acid system was investigated by the way of controlling variables. The results show that the lengths of TNTs and the thickness of the barrier film decrease with increasing temperature, and which is opposite in the radius and tube wall thickness. Additionally, in electrochemical properties of TNTs, the equivalent electrochemical impedance and crystallinity usually decrease with increasing of the temperature.
The Preparation of Highly Transparent Layered Double Hydroxides (LDHs)-Poly(Methyl Methacrylate) (PMMA) Nanocomposites Sheets by Batch Cell Polymerization Method
Authors: Joonlapak K , Wiwattanakul P , Jirathampradhab T , Akhadejdamrong T , Wongariyakawee A , Srikhirin T
Published: October 2019

Enhancement polymer properties using various clay nanocomposites has been interesting in polymer technology. Herein, a preparation of transparent layered double hydroxides/poly methylmethacrylate (LDHs/PMMA) nanocomposites sheet was achieved by batch cell polymerization. Nanometre-sized MgAl-LDHs in toluene showed well dispersed suspension and was translucent, indicating delamination of LDHs stacks. To prepare PMMA-LDHs nanocomposites, the delaminated MgAl-LDHs in toluene was mixed with methymethacrylate oligomer in order to form slurry of dispersed LDHs in PMMA pre-polymer. The LDHs/PMMA nanocomposites sheet was subsequently prepared using batch cell polymerization at 60oC for 5 hours in water bath and it was then post curing at 80oC for 30 minutes. The optical properties of MgAl-LDHs/PMMA nanocomposites were strongly depending upon a dispersion behaviour of MgAl-LDHs.
Chip Geometry Modelling of 2-Dimension Ultrasonic Vibration Assisted Machining (2D UVAM) on Micromilling Machine With End Mill
Authors: Kiswanto Gandjar , Johan Y R , Poly  , Ko T. J.
Published: October 2019

The needs of miniaturized products have increased a lot in this ever-changing world. This makes the micromanufacturing technologies develop fast in order to keep up with this higher needs and to meet the required quality of a product. One of the developed technologies is ultrasonic vibration assisted machining (UVAM). UVAM is different than conventional machining because of the way the cutting tool move relative to the workpiece. This different cutting phenomenon produces a different chip geometry than the conventional machining. The purpose of this paper is to give an understanding through chip geometry models about how UVAM can be a better cutting method rather than conventional milling. MATLAB is used in order to do the modelling of theoretical chip geometry. The approach used in this study is by calculating where the cutting tool edge is in a given unit of time before and after the ultrasonic vibration is induced to the workpiece in X-Y dimension. A characteristic in the cutting edge called the bottom cutting edge angle is also considered. By comparing the two chip geometries, some benefits that UVAM gives are explained.
The Effects of Cutting Parameters to the Surface Roughness in Low Speed Machining of Micro-milling of Titanium Alloy Ti-6Al-4V
Authors: Kiswanto Gandjar , Mandala A , Azmi M , Ko T. J.
Published: October 2019

The demand for micro-scale products is increasing rapidly in various fields of industries such as electronics, bio-medical, optical industry, and so on. Titanium alloys especially Ti-6Al-4V is one of the commonly used in bio-medical industries because of its biocompability properties. However, poor surface quality in terms of surface roughness commonly occurs because of unappropriate cutting parameters to machine this hard to cut material. This study aims to investigate the influencing machining parameters to produce micro-products with a low level of surface roughness in Titanium Alloy (Ti-6Al-4V) material using a miniaturized micro-milling machine. Experiments carried out by micromilling process with variations in low rpm spindle speed and feed rate with a constant depth of cut using a carbide cutting tool of with a diameter of 1 mm. The machining results in the form of a 4 mm slot with a depth of 10 μm, which then measures its surface roughness. It was found that as the feed rate increases, the surface roughness also accordingly increases. On the other hand, the surface roughness decreases as the spindle speed increases.
Development of Langevin Piezoelectric Transducer-based Two Dimensional Ultrasonic Vibration Assisted Machining (2D UVAM) on 5-axis Micro-milling Machine
Authors: Kiswanto Gandjar , Poly  , Johan Y R , Ko T. J. , Kurniawan R
Published: October 2019

The purpose of this study is to design and develop a Two-Dimensional Ultrasonic Vibration Assisted Micro-milling (2D UVAMM) system. Two-dimensional ultrasonic vibrations produced by 2D UVAMM are used to vibrate the workpiece in the micro-milling process. The system is developed using the principle of two Langevin piezoelectric transducers which have the ability to produce ultrasonic vibrations with small vibration amplitude. Process of 2D UVAMM design optimization was done by modal simulation using Finite Element Analysis method. Both Langevin piezoelectric transducers are designed to have symmetrical and asymmetrical vibration modes with the same natural frequency, so that elliptical pattern vibrations can be generated on the workpiece. The 2D UVAMM system operates at a natural frequency of 24 kHz and has an estimated total displacement on the normal and tangential axes respectively 0.766 μm and 0.382 μm. Two power sources with frequency of 24 kHz, phase difference of 90 degrees, and peak-peak voltage of 212 volt were supplied by an ultrasonic generator to excite both of the Langevin piezoelectric transducers. To confirm the developed 2D UVAMM system, experiments were conducted to compare the surface roughness of Aluminum 6061-T6 through micro-milling with conventional method and with additional of the 2D UVAMM system.
Innovative and rapid design for I2C (inter-integrated circuit) interface communication of FPGA chips
Authors: Shieh Cheng Shion
Published: October 2019

A new design flow is proposed to greatly improve the efficiency and accuracy of the HDL program design. This paper successfully completes the FPGA (Field-Programmable Gate Array) chip’s external communication I2C interface design of new design flow not traditionally one. FPGA chip is often used in mobile phones, military, aerospace or other industries. Even INTEL and Microsoft and other large companies have begun to acquire FPGA-related companies, showing its importance. But the FPGA language is written in the Hardware Description Language (HDL) which is a mechanical engineering staff obstacles. Therefore, this article makes use of the MATLAB / SIMULINK tool, which is familiar with the engineering staff, to complete the FPGA chip’s I2C interface design. The advantage is that the functional simulation and HDL program can be completed at the same time, do not have to perform the function after the simulation before designing HDL program. The traditional design wastes many times to revise back and forth between function simulation and HDL program design. Finally an experimental illustration is proposed to verify the proposed design of the I2C communication interface for an HDL program on the read and write experiments of Electrically-Erasable Programmable Read-Only Memory (EEPROM).
Evaluation of side resistance of driven precast concrete piles
Authors: Marcos M C , Chen Y-J
Published: October 2019

This study critically evaluates the axial side resistance of driven precast concrete (PC) piles. A wide range of load test data are classified into drained and undrained databases and subsequently used in the investigation. Each database is further divided into: (1) compression and uplift loading and (2) round and square cross sections. Measured and predicted results are both applied to examine the representative analytical models, including the alpha (α), beta (β), and lambda (λ) methods. The statistical results show that the range of values of the empirical coefficient α is wide. The predicted results of the β method are underestimated in drained loading, but they are reasonable in undrained loading. The relationship between λ and pile depth is also developed. Based on the analyses, the relative merits of the three analytical models are established, and designs for analyzing the side resistance of driven PC piles are recommended.
Solar radiation prediction based on random forest of feature-extraction
Authors: Liu J , Cao M Y , Bai D , Zhang R
Published: October 2019

In order to use solar energy efficiently, the accurate prediction of solar radiation is extremely important. The aim of this paper is to discuss and build the solar radiation prediction model, and an efficient method based on improving random forest is proposed in here. The random forest regression model is created for predicting solar radiation. The nine variables are taken as input of the original model, and the solar radiation as the output. The original data is normalized using Min-Max method and is mapped to the values in the range of zero to one. The large amount of radiation data has been dealt with univariate feature extraction. The classifier of the random forest tree is constructed by characteristic factors that can influence solar radiation, and the optimal parameters of the model are selected by the OOB error analysis. The relationship between M-try and OOB can be obtained by computing of the R platform. Hence, a prediction model of improved random forest solar radiation based on feature extraction has been described. Under the specific area of solar radiation forecast, the studies have been done, and the solar radiation is analyzed and compared with the different prediction methods. The simulation results prove the validity of the improved method; the root mean square error is reduced and the precision of prediction is improved. It is significant for the prediction of the amount of solar radiation under complex environment and the effective use of photovoltaic power generation.
Tree of life – intelligent environment system station design
Authors: Chen Po-Chuan , Fang Jiunn
Published: October 2019

The three elements essential for life are sunshine, air, and water. This is an undeniable fact, but with advancements in technology, amenities such as electricity, smart phones, and the internet have become the urban versions of these essential elements for life. Most people living in cities desire constant connectivity. This connectivity requires significant electricity and access to a high-speed internet connection. The purpose of this research is to design a wind turbine system modelled after the shape of a tree with the blades built inside the tree. The power generated by the tree will be stored in a power bank located inside a station adjacent to the tree and will be available to the public. Additionally, there will be WLAN antennas built inside the tree branches to provide wireless internet signals. Finally, the electricity produced will be green energy, which will help us achieve the goal of eco-friendly but intelligent life.
Economic manufacturing quantity model with machine breakdown and deteriorating production process
Authors: Chen Chung Ho
Published: October 2019

In this study, the author proposes a jointly setting model for determining the process mean and economic manufacturing quantity (EMQ) under the machine breakdown and deteriorating production process. The system addresses the corrective maintenance, preventive maintenance, and allowable shortage. The quality loss of conforming product is considered and Taguchi’s asymmetric quadratic quality loss function is used for evaluating the product quality. The optimal process mean and economic manufacturing quantity are jointly determined by minimizing the total expected cost of product per unit time including the set-up cost, holding cost, corrective maintenance cost, preventive maintenance cost, shortage cost. A solution procedure is devised to obtain the optimal solution and the sensitivity analysis of key parameters is conducted to investigate the effect on the optimal solution.
Research on harmonic suppression ability of active power filter
Authors: Shen X , Shu H C , Cao M
Published: October 2019

The system control model of double resonance injection hybrid active power filter (DIHAPF) and mathematical model of voltage source inverter with controller was established based on the structure and operating principle of DIHAPF. The injection branch features were analyzed including the static reactive power compensation capability and dividing capability of harmonic voltages. Stability and harmonic suppression capacity of DIHAPF was analyzed simultaneously. The influence of the parallel resonant circuit resonant frequency to system performance was discussed in detail. Furthermore, the method of designing the resonant frequency of parallel resonant circuit was proposed. The simulation model of DIHAPF was established and simulated on PSIM 6.0 taking nonlinear loads as harmonic current sources. A 6kV DIHAPF experiment prototype controlled by TMS320F28335 was built. Simulation and experimental results prove the validity of the analysis in this paper.
A review of reconstruction research for the lost gearing of antikythera astronomical calculator
Authors: Lin Jian Liang
Published: October 2019

This paper presented a review for the reconstruction research of the Antikythera mechanism, the mechanical calculator was made around the end of second century BC in ancient Greece. Under the concluded design specifications and constraints, all possible conceptual designs of the lost mechanical structures subject to the standard of technology and science at that time were synthesized based on a systematic design procedure. This oldest astronomical calculator excavated in 1900-1901 can display the solar, lunar and planetary motions, indicate the date of Egyptian calendar, calculate the luni-solar calendars and periods, and predict the eclipses by its interior gear trains. The structures for the solar and the planetary motions are completely lost in the excavation. Without surviving evidence, restoring the lost structures by computer tomography or X-ray detection is unfeasible. Here, the author applied a design procedure with four steps, which is based on the reconstruction design methodology of lost ancient machinery. Historical archives for reconstructing Antikythera mechanism are built based on historical records, ancient astronomy, ancient astronomical instruments, as well as the kinematic and mechanism analyses of gear trains. After identifying input conditions, three and two design specifications respectively for the solar and the planetary motions are concluded and their feasible designs are synthesized by the design procedure. For each design, the equations of teeth counting are derived based on the analysis of gear ratios. Finally, the possible teeth of gears are generated and then a new reconstruction design of Antikythera mechanism with complete interior structure is built through the constraints of space and assembly. These synthesized designs form a database of reconstruction work, and one of them can be the original structure. Once new evidence is discovered, these reconstruction designs can help archaeologists decode this mechanism further.
Comparison and validation of surface topography segmentation methods for feature-based characterisation of metal powder bed fusion surfaces
Authors: Newton Lewis , Senin Nicola , Smith Bethan , Chatzivagiannis Evangelos , Leach Richard
Published: October 2019

Feature-based characterisation, i.e. the characterisation of surface topography based on the isolation of relevant topographic formations (features) and their dimensional assessment, is a developing field of surface texture metrology. Feature-based approaches provide dimensional assessments of individual features (area, width, height, etc) as well as statistical properties of feature aggregations (e.g. mean, standard deviation, etc), which may be more intuitive or related to functionality. For powder bed fusion surfaces, a commonly investigated feature of interest is the particles or spatter present on the surface. In this work, we address segmentation, a necessary step of feature-based characterisation, where the measured surface topography is spatially partitioned into regions to isolate the targeted features from their surroundings. Three topography segmentation methods are investigated: morphological segmentation on edges, contour stability analysis and active contours. To perform the comparison, three powder bed fusion surfaces obtained at differing build orientations (0°, 30° and 90°) and measured using focus variation microscopy are subjected to the three segmentation approaches - optimised to isolate spatter and particles on the surface. The comparison of the segmentation methods focuses on performance in feature identification (i.e. the capability to correctly detect the presence of features) and performance in feature boundary determination (i.e. the capability to correctly trace the boundaries of each feature). Results show that no segmentation method is consistently superior for all test cases, but the comparison approach is useful to explore and optimise segmentation alternatives for feature-based characterisation scenarios.
Ohmura’s extended electrodynamics: longitudinal aspects in general relativity
Authors: Keller Ole , Hively Lee M
Published: October 2019

Jiménez and Maroto ((2011) Phys. Rev. D 83, 023514) predicted that free-space, longitudinal electrodynamic waves can propagate in curved space-time, if the Lorenz condition is relaxed. The present work studies this possibility by combining and extending the original theory by Ohmura ((1956) Prog. Theor. Phys.
16, 684) and Woodside’s uniqueness theorem ((2009) Am. J. Phys.
77, 438) to general relativity. Our formulation results in a theory that applies to both the field- (E, B) and potential- (Φ, A) domains. We establish a self-consistent, longitudinal wave-propagation theory for the microscopic longitudinal part of the electric field (E

L
). We first show that the product of the parameters used previously for the extension of classical electrodynamics can be expressed as a superposition of microscopic displacement modes, which are confined to the energy shell, ∣ω∣ = cq. We then show that nonlinear electrodynamic mixing allows creation of longitudinal waves in the near-field region of a source. A propagator approach gives substantial physical insight into the emission process.
Origin of exceptional magneto-resistance in Weyl semimetal TaSb2
Authors: Kumar P , Sudesh  , Patnaik S
Published: October 2019

We study magneto-transport properties in single crystals of TaSb2, which is a topological semimetal. In the presence of magnetic field, the electrical resistivity shows onset of insulating behaviour followed by a plateau at low temperature. Such resistivity saturation is generally assigned to topological surface states but we find that aspects of extremely large magneto resistance and resistivity plateau are well accounted by classical Kohler’s scaling. In addition, magneto-resistance in TaSb2 shows non-saturating field dependence. Evidence for anomalous Chiral transport is provided with observation of negative longitudinal magneto-resistance. Shubnikov-de Haas oscillation data reveal two dominating frequencies, 201 T and 455 T. At low temperature, the field dependence of Hall resistivity shows non-linear behaviour that indicates the presence of two types of charge carriers in consonance with reported electronic band structure. Analysis of Hall resistivity implies extremely high electron mobility.
The study of alpha particle induced reactions on bismuth-209 isotopes using computer code COMPLET
Authors: Asres Yihunie Hibstie , Mathuthu Manny , Beyene Ermias Yitayew
Published: October 2019

Calculations of the excitation function of 209Bi (α, n)212At, 209Bi (α, 2n)211At and 209Bi (α, 3n)210At reactions have been focussed on alpha induced reaction. Energy ranges of alpha particles were taken into computations as 10 MeV to 70 MeV. The objective of this study is to compare the computed results with the experimental data existing in the literature for each reactions. The calculated 209Bi(α,xn) reaction cross-sections were computed using computer code COMPLET and were then compared with the experimental nuclear reaction data obtained from EXFOR library in the literature. This calculated data was analyzed and interpreted with tabular and graphical descriptions. Good agreement was found between the experimental and theoretical data. The results were briefly discussed within the text of this research work.
𝐶¹-regularity of planar ∞-harmonic functions—revisited
Authors: Zhang Yi Ru-Ya , Zhou Yuan
Published: October 2019

In the seminal paper [Arch. Ration. Mech. Anal. 176 (2005), 351–361], Savin proved the

C
1

C^1

-regularity of planar

∞
\infty

-harmonic functions

u
u

. Here we give a new understanding of it from a capacity viewpoint and drop several high technique arguments therein. Our argument is essentially based on a topological lemma of Savin, a flat estimate by Evans and Smart,

W

l
o
c

1
,
2

W^{1,2}_{\mathrm {\,loc\,}}

-regularity of

|

D
u

|

|Du|

, and Crandall’s flow for infinity harmonic functions.
Influence of Physical Activity on Blood Pressure in Children With Overweight/Obesity: A Randomized Clinical Trial
Authors: Aguilar-Cordero María José , Rodríguez-Blanque Raquel , Leon-Ríos Ximena , Expósito Ruiz Manuela , García García Inmaculada , Sánchez-López Antonio Manuel
Published: October 2019

BACKGROUND

The prevalence of childhood hypertension (HT) is growing exponentially, influenced by environmental factors such as foods with high salt content, sedentary lifestyles, and poor-quality food. The incidence of HT is about 10.4% in well-nourished children, but when associated with obesity or overweight, this can rise to 38% and 68%, respectively. To assess the influence of physical activity on the blood pressure (BP) of children who are overweight or obese.

METHODS

This randomized clinical trial was carried out in Granada (Spain), from October 2015 to June 2016. The sample consisted of 98 children, all of whom were overweight or obese. The intervention group (IG) (n = 49) practised physical activity and received nutritional advice, while the control group (n = 49) only received theoretical–practical sessions on nutrition. Body composition was measured, a nutritional assessment was made and BP was determined (in percentiles, to avoid the misclassification of children who are located at the extremes of normal growth).

RESULTS

Before the physical activity intervention, 85.7% of the children in the IG (with overweight/obesity) were in the 95th or higher percentile for BP, a situation representative of high BP (HT). However, by the end of the study period, this value had decreased significantly (P = 0.001), to 16.13%.

CONCLUSIONS

Childhood obesity is a risk factor for HT. Physical activity, together with nutritional advice, effectively reduces BP in children who are overweight or obese. The use of percentiles, according to age, weight, and height, is an effective means of measuring BP.

CLINICAL TRIALS REGISTRATION

This study is registered at https://www.clinicaltrials.gov (identifier NCT02779647).
Influence of Renal Transplantation and Living Kidney Donation on Large Artery Stiffness and Peripheral Vascular Resistance
Authors: Buus Niels H , Carlsen Rasmus K , Hughes Alun D , Skov Karin
Published: October 2019

Background

Vascular status following renal transplantation (RT) may improve while living kidney donation (LKD) is possibly associated with an increased cardiovascular risk.

Methods

We prospectively assessed glomerular filtration rate (mGFR, 51Chrome EDTA clearance) and intermediate vascular risk factors in terms of blood pressure (BP), pulse wave velocity (PWV), central augmentation index (AIx), excess pressure (Pexcess), and forearm vascular resistance in donors (n = 58, 45 ± 13 years) and recipients (n = 51, 50 ± 12 years) before and one year following LKD or RT.

Results

After kidney donation, mGFR decreased by 33% to 65 ± 11 ml/min/1.73m2, while recipients obtained a mGFR of 55 ± 9 ml/min/1.73m.2 Ambulatory 24-hour mean arterial BP (MAP) remained unchanged in donors but decreased by 5 mm Hg in recipients (P < 0.05). Carotid-femoral PWV increased by 0.3 m/s in donors (P < 0.05) but remained unchanged in recipients. AIx was unaltered after LKD but decreased following RT (P < 0.01), and Pexcess did not change in either group. Resting forearm resistance (Rrest), measured by venous occlusion plethysmography, increased after LKD (P < 0.05) but was unaffected by RT, while no changes were seen in minimum resistance (Rmin). ΔPWV showed a positive linear association to Δ24-hour MAP in both groups. Multiple linear regression analysis (adjusting for age, gender, and the baseline value of the studied parameter) did not detect independent effects of graft function on 24-hour MAP, PWV, AIx, vascular resistance, or Pexcess, whereas low post-donation GFR was related to higher AIx and Rrest.

Conclusions

RT reduced BP and AIx without affecting PWV, whereas LKD resulted in increased PWV and Rrest, despite unchanged BP.