bluuebunny/crossref_metadata_2025 huggingface dataset:
Secure Electronic Voting System using Swarm Intelligence
Authors: Rasheed Manar Muwafaq
Published: September 2021

One of the important systems for society today is the electronic voting system. All the people around the world are looking for transparency and integrity, and they afraid of voting fraud. Electronic voting system is looking for confirming the true identity of a person. Fingerprint identification may be preferred over traditional methods (e.g. passwords, smart-cards) because its information is virtually impossible to steal. This paper introduces secure election system depending on swarm intelligence techniques, especially PSO and firefly algorithms. The proposed system is successful within 500 iterations for PSO to find best features for fingerprint. Best steganographic positions are found by firefly algorithm. PSO has been reduced the time for features extraction of one fingerprint from (1.1 sec) to (0.36 sec). Firefly algorithm has been raised the PSNR of the stegocovers up to (66.246-69.447)dB. The percentage matching of all bands at receiver side is 100%.
Classification of Imbalanced leukocytes Dataset using ANN-based Deep Learning
Authors: Alkrimi Jameela Ali , Hasin Rajaa Salih Mohammed , Naji Ali Zaki , George Loay E. , Tome Sherna Aziz
Published: September 2021

Nowadays, classification of imbalanced data is a major challenge in the machine learning (ML) algorithms, especially in medical data analysis, In this paper, deep learning algorithm which is the advance artificial neural network (ANN) is used for classifying five white blood cells (WBCs). Different preprocessing image techniques and algorithms are applied to isolate WBCs and segment the nucleus for the cytoplasm. Geometric, statistical and color features are extracted, the principal component analysis technique is applied to select the optimal features. The classification process has been repeated several times to tune the algorithm parameters and to find the best pattrens match through the training data in the learning process until achieve best classification accuracy. Multi-class classification results show high accuracy of more than 94% for the five types of WBCs. We evaluate the classification model using the geometric mean, Cohen’s Kappa, Receiver operating characteristic curve, Root mean squared error, relative absolute error and cross-validation techniques. The algorithm model achieves high accuracy and can conduct a multi-class classification of imbalanced datasets in terms of the above-mentioned metrics.
Studying the effect of the number of laser pulses on the structure, morphology, and optical properties for a thin film of GO-Ag nanocomposites
Authors: Al-Mousawi Mousa Muhammad Ali , Al-Nafiey Amer , Al-Dahesh Ghaleb
Published: September 2021

In this paper, studying the effect of the different numbers of laser pulses on graphene oxide -silver nanoparticles (GO-Ag NPs) thin film prepared by the pulse laser deposition (PLD) on silicon and quartz substrates. The laser using in PLD is an ND-YAG laser with a wavelength (1064 nm)m with a repetition rate of 6 Hz with a laser pulse duration (9 ns). Atomic force microscopy AFM and XRD using for analysis of the thin film, the results showed the possibility of preparing thin films with different sizes of granule and crystalline sizes on the nanoscale. Also, show that the granular size and crystal size of the nanoparticles decrease with the increase in the number of laser pulses with the constant energy. Moreover, the optical properties measurements showed that the absorbance and absorption coefficient increase with the increase in the number of pulses when the energy is constant, while the energy gap decreases with increasing the number of pulses These results were promises to producing the thin film for Graphene oxide-silver nanocomposites for different applications compatible with it.
A new green method for indirect determination of ferric ions in biological samples using Ascorbic acid as reducing agent via the development of CFIA system
Authors: Qassim Bushra B. , Hamed Luma L.
Published: September 2021

A simple, sensitive, automated and environmentally friendly FI/MZ technique was suggested for the indirect determination of iron (III) as ferric chloride in bulk and biological. These method involve the reduction of Fe (III) to Fe (II) using ascorbic acid as reducing agent, the reduced ion was reacted with 1,10- phenanthroline as a selective organic reagent to form red-orange complex, measured at λ=510 nm. The complexation ratio between matel ion with ligand was 1:3 ratio (M: L). The colored product obeyed Beer’s Law with linear ranges 1-30 and 8-75 μg/mL with detection limits 1.02, 0.28 μg/mL for batch and FIA/MZ methods, respectively. The rate of sampling was 54 sample/h, the %RSD less than 2% and the recovery was about 99%. The developed technique was simply and low cost with high throughput, it provides the use of an aqueous medium as carrier of chemicals in flow system that is nontoxic and causes no pollution, thereby belonging to green chemistry. The proposed procedure can be successfully applied to estimate the content of Iron (III) in biological samples. The results of estimation are satisfactory as compared with those given by a reference method, showed the new method to be accurate and precise at the 95% confidence level.
Imaging of Surface Plasmon Resonance for Nano Material of Different Shapes
Authors: Mohammed S.H. , Shanan N.S.
Published: September 2021

The studies of Surface Plasmon Resonance SPR have focused on novel materials (gold and silver ). In this paper, four kinds of samples have been prepared also the system of plasmonic imaging with objective lens to excite the SPR our samples. The hot spot images for our different samples proved that the blue wavelength (405nm) can be excite the SPRs better than the green wavelength (532nm) for silver samples and the green wavelength can be excite the SPRs better than the blue wavelength for gold samples, also the increasing in consternation of AgNWs due to increasing in width of Gaussian hot spot.
Application of New Transform “Complex SEE Transform” to Partial Differential Equations
Authors: Mansour Eman A. , Mehdi Sadiq A. , Kuffi Emad A.
Published: September 2021

The complex SEE integral transform subsidiaries is inferred, and its pertinence exhibited utilizing diverse halfway differential conditions. In this paper, we track down the specific arrangement of these conditions.
Preparing and Studying the Combination of ZnS/rGO Nano Composite by Laser Ablation Method
Authors: Jawad Wasan H. , Jader Mohammed J.
Published: September 2021

The mixed compound zinc sulfide (ZnS/rGO) nanoparticles were synthesized by the physical method laser ablation From there, the crystal structure and crystallite size of X-ray diffraction (XRD) particles were determined (D =8.35nm). The optical properties have also been studied by the visible ultraviolet absorption spectrum. Where the graphen oxide was prepared by a hummer method, after mixing it with zinc sulfide, and it was formed as a Nano composite by using the Neodymium-Yak laser (1064 nm) with the pulsed laser energy of 800 mJ and 600 pulse at a frequency of 6 Hertz in room temperature, thus generating an ionic plasma that contributed to the formation of nanoparticles. Several measurements were made on the sample, such as FTIR, to find out the constituents of the Nano composite and Energy gap is 4.942ev to calculate from UV-Visible by Tuac plot, also, determine the averge Green size (25.2nm) from XRD by using the Scherer equation, and to take SEM tests of the compound.
Low-frequency dynamic wake meandering: comparison of FAST.Farm and DIWA software tools
Authors: Rivera-Arreba I , Eliassen L , Bachynski E E , Panjwani B
Published: September 2021

Most of the global dynamic response models used today for the design of wind turbines are based on the aero-hydro-servo-elastic analysis of one single turbine. However, research on bottom- fixed offshore wind turbines has shown that interactions among turbines in a farm influence both the power production and the structural loading. Furthermore, floating wind turbines (FWTs) are sensitive to low-frequency variations, and therefore to wake meandering perturbations. In the current work, we use the Dynamic Wake Meandering (DWM) model as implemented in DIWA and FAST.Farm, to study the low-frequency content of the meandering at a target turbine placed 8 diameters downstream. At frequencies in the range of the natural frequencies of rigid body motions of semisubmersible floaters, the two models yield different results. These differences are seen for every wind speed and wind turbine model, even though they decrease as the wind speed increases. The observed differences may affect low-frequency motions and consequently mooring system design.
Data driven case study of a wind turbine main-bearing failure
Authors: Mello Elisha de , Kampolis Georgios , Hart Edward , Hickey Daryl , Dinwoodie Iain , Carroll James , Dwyer-Joyce Rob , Boateng Ampea
Published: September 2021

This paper presents a data driven case study of two outer-race spalling faults in double-row spherical roller main-bearings, with the purpose of identifying key features and relevant measurements associated with this failure mode in wind turbine main-bearings. Supervisory data is analysed for one fault case and vibration data for the other. The aim of this work is to inform practitioners and assist in improving fault detection systems for this component.
Simplified wake modelling for wind farm load prediction
Authors: Vaal Jacobus B de , Muskulus Michael
Published: September 2021

This paper presents a simple numerical wind farm model, where pragmatic choices are made in the modelling of underlying physical processes, with the aim of making useful power production and wind turbine load estimates. The numerical model decomposes the wind farm, inspired by the approach of the dynamic wake meandering model (DWM), into simple sub-models for a single wake deficit (1D Gaussian), wake meandering (statistical), and wake added turbulence (eddy viscosity based). Particular attention is given to selecting a momentum conserving wake summation method, because of its critical role in coupling the influence of individual wakes. Results are presented to illustrate the influence that wake summation methods have on equilibrium velocity and power production in a row of turbines, for different inter-turbine spacing and inflow velocities. Comparisons against published data from the Lillgrund wind farm illustrate that the suggested modelling approach reproduces important trends observed in the field data.
Evaluation of a low-fidelity hydrodynamic modelling approach for a floating wind turbine mounted on an enhanced spar
Authors: González Guido Grassi , Urbán Albert Meseguer , Horcas Sergio González , Roqueta Laura Voltá I , Blanco Sergio Hernández
Published: September 2021

The present work revolves around the numerical simulation of floating offshore wind turbines, a promising technology for energy harnessing in deep water conditions. A reference 10MW wind turbine is studied, mounted on a commercial enhanced spar buoy, referred to as the WIND-bos platform. The focus is put on the hydrodynamic modeling. In particular, the Morison equation is used, accounting for a fixed set of coefficients. Those coefficients are initially estimated based on the literature, and subsequently calibrated through the comparison with experimental results on a scaled geometry. This allows to assess the modeling capabilities of the Morison approach, together with its challenges and limitations. Larger discrepancies between the numerical model and the experiments were assumed to be related to the geometrical particularities of the floating platform. In particular, the studied structure accounts for both large and slender members, potentially limiting the applicability of the method. It is shown that the deviations could be attributed to the frequency-variation of parameters such as the added mass, the radiation damping and viscous damping. Therefore, it is concluded that the agreement between the numerical model and the experiments could be improved by re-calibrating the coefficients for each of the studied sea states.
A computer tool for optimisation and simulation of marine operations for offshore wind farm installation
Authors: Halvorsen-Weare Elin Espeland , Fonn Eivind , Johannessen Kjetil , Kisialiou Yauheni , Nonås Lars Magne , Rialland Agathe , Thun Kristian
Published: September 2021

The installation process of offshore wind farms is complex and requires a high level of coordination, agile scheduling and systematic methods. High risks and costs are involved and especially weather conditions have an impact on the marine operations. A computer tool for optimisation and simulation of marine operations has been developed in close cooperation with a large actor in the offshore wind industry. The tool has a web-based user interface and an optimisation engine that is based on a version of a genetic algorithm and uses an agent-based simulation process to evaluate installation schedules with respect to weather risks, time and costs. The objective is to provide decision support for the early phase planning of wind farm installation by offering an efficient method for estimation of cost and time for future projects.
Comparison of concrete and steel semi-submersible floaters for 10MW wind turbines
Authors: Oh Sho
Published: September 2021

Prestressed concrete floaters are gaining growing interest for floating wind turbines, while different material properties can affect the characteristics of floater motions and the range of suitable floater geometries. In this study, a basic geometry of a semi-submersible floater for 10MW is designed, based on which sensitivity study of the material property on floater design is conducted. It was found that minimum floater pitch angles achieved by selecting the optimum floater geometries were similar for the three types of material, while larger values of geometrical variables were required for concrete floaters than for steel floaters for a floater pitch limitation. If larger wall thickness was to be required for concrete structures due to, for example, corrosion protection and crack limitation, generally larger side column width and lower hull length were required for concrete floaters. As the sensitivity of pitch angle to the wall thickness was more affected by wind excitation than wave excitation for normal concrete, it is indicated that the design space for the length of hull can be widened by combining the design with the wind turbine controller methods in the treatment of the maximum thrust force. Lightweight concrete had advantages over normal concrete in the lower center of gravity. The raw material cost of lightweight concrete was higher than normal concrete but significantly lower than steel floaters.
Gradient-based optimization of a 15 MW wind turbine spar floater
Authors: Pollini Nicolò , Pegalajar-Jurado Antonio , Dou Suguang , Bredmose Henrik , Stolpe Mathias
Published: September 2021

We discuss the optimization-based conceptual design of support structures and mooring system for floating wind turbines. A four degree-of-freedom frequency-domain model is used for the dynamic response of a spar floating wind turbine subjected to wind and wave loads. The framework allows for design optimization involving the geometrical properties of the floater and the mooring system and inclusion of long realizations of multiple load cases in the analysis. The adopted optimization approach adopted relies on analytical design sensitivities of the governing frequency-domain equations and of the design requirements. This ensures that modern gradient-based optimization algorithms can effectively be used to solve the design problem at hand. The optimization approach is applied to the design of the spar-buoy floater and its mooring system for the IEA 15 MW reference wind turbine. A post-processing approach for identifying discrete designs from predefined catalogues is also presented. The post-processing allows to transform continuous design solutions into practical ones that can be used in subsequent analyses with time domain response models for the full validation of the design solutions obtained. The numerical results highlight the capability of the approach discussed herein to provide discrete optimized designs for given design constraints and loads in few minutes requiring modest computational resources and time.
Uncertainties assessment in real-time hybrid model for ocean basin testing of a floating offshore wind turbine
Authors: Somoano Miguel , Battistella Tommaso , Fernández-Ruano Sergio , Guanche Raúl
Published: September 2021

This work analyses the accuracy of large-scale experimental testing procedure in ocean basin facility involving real-time hybrid model testing (ReaTHM) techniques. The analysis is based on a scaled concept for a 15MW floating offshore wind turbine (FOWT) supported by a concrete semi-submersible platform (ActiveFloat) developed within the framework of the project COREWIND. The real-time hybrid model considered includes a multi-fan system located at the aero-rotor interface, which permits to generate the aerodynamic loads, reducing the limitations typically given by scaled problems. In order to assess the uncertainties in the hardware in the loop (HIL) implementation, firstly we define the quantities of interest to be evaluated from all the possible sources liable to inaccuracy identified. Then, we quantify the systematic and random discrepancies of the selected mooring, platform and HIL parameters. Finally, we propagate the previously quantified errors, running simulations in OpenFAST under extremal and severe environmental load cases in Gran Canaria Island (Spain) site. Comparing the platform response and mooring tensions of these uncertainty propagations with the ones of the unperturbed simulation as a baseline case, we analyse the effect of each representative parameter. Thus, the reliability of the results in ocean basin testing is numerically assessed, depending on the design load case.
A nested multi-scale model for assessing urban wind conditions : Comparison of Large Eddy Simulation versus RANS turbulence models when operating at the finest scale of the nesting.
Authors: Tabib Mandar V , Midtbø Knut Helge , Rasheed Adil , Kvamsdal Trond , Skaslien Tor
Published: September 2021

Good understanding of micro-scale urban-wind phenomena is needed for optimizing power generation capabilities of building-integrated wind turbines and for safety of futuristic urban transport involving drones. The current work involves development of a multiscale methodology for obtaining wind fields in an urban landscape. The multi-scale methodology involves coupling three models operating on different scales namely an operational meso-scale numerical weather prediction model HARMONIE, a micro-scale model that captures terrain- induced wind influence and a super-micro scale Computational Fluid Dynamics model using large eddy simulation and RANS model to capture the building-induced wind flow. Here, we present a comparison of the wind velocity predicted by two different turbulence models (LES and RANS) that are operating at the finest scale with the measured experiment data for a realistic case of flow in vicinity of the Oslo university hospital. The reasons behind the observed better prediction of LES model are outlined, and use of such models is advocated to improve accuracy.

LES, multi-scale, wind, urban climate, drones, wind energy
A Numerical Investigation of the Geometric Characteristics of Floating Wind Turbine Wakes under Axial and Yawed Rotor Conditions
Authors: Valentin J. , Sant T.
Published: September 2021

The physics of wind turbine wakes on fixed foundations have been extensively studied through numerical modelling and measurements over the recent decades. While research initiatives in the field of floating wind turbines have increased significantly, various aspects characterising floating turbine wakes are still not well understood. This paper applies a free-wake vortex model to derive the geometric characteristics of the wake of a surging rotor under axial and yawed rotor conditions. The study examines the influence of platform motion on the wake boundaries and centreline up to four rotor diameters downstream. It is shown that floating turbine wakes experience a higher degree of perturbation as compared to those of fixed turbines. This is highly dependent on the sea state and suggests the need to develop new analytical wake models for the wind industry that are able to account the effect of platform motion on wake behaviour.
Magnetic force enhanced atmospheric plasma polishing ability to improve surface roughness of copper base materials
Authors: Chen H L , Syue S H , Chen Y L , Chen Y J
Published: September 2021

The global demand for portable miniature products has increased, which has driven the improvement of micro-component technology to meet the precision requirements of miniaturization of product sizes and higher precision of products. As the requirements for the assembly accuracy of precision components and the high quality on the surface treatment of materials, the current precision polishing is also facing a technical bottleneck. Many polishing technologies have been developed, atmospheric plasma polishing is a new polishing technology, which is applied to the precision components of the optoelectronic industry. How to improve the polishing efficiency of atmospheric plasma has become a new research topic. In this study, a non-traditional surface treatment method which low-temperature atmospheric plasma is used to precision polish the copper-based material, and added magnetic force on the surface of the copper-based material, in order to enhanced atmospheric plasma polishing ability to improve surface roughness of copper base materials. The low-temperature atmospheric plasma jet has been used; the power of plasma is 50Wand nitrogen (N2) as reaction gas. The different scanning speed of stages is 2, 5, 10, 15 and 20 mm/s, respectively. The processing time is 10min. A copper foil substrate is as select material. Observe the surface roughness variation of the copper foil substrate treated by atmospheric plasma. The results shown that when the copper foil substrate is treated with low-temperature atmospheric plasma and no magnetic force on the surface, when the scanning speed of the stage is 2 mm/min, the improvement rate of surface roughness is about 17.6%; when the scanning speed of the stage is 20 mm/min, the surface roughness improvement rate is about 5.5%. When the magnetic force on the surface is about 188 mT, the improvement rate of surface roughness is about 30.8% when the scanning speed of the stage is 2 mm/min, and the improvement rate of surface roughness is about 12.5 % when the scanning speed of the stage is 20 mm/min. From the above results, it is known that applying magnetic force on the surface of the work-piece can indeed increase and improve the polishing ability of the low-temperature atmospheric plasma.
Study on shape memory effect of hot deep-drawn NI-TI shape memory alloy sheet part
Authors: Fann K J , Chang C H
Published: September 2021

This study investigates the properties of Ni-rich Ni-Ti shape memory alloy sheet parts during and after deep drawing process at an elevated temperature, which is under a plane tensile-compressive stress state. According to the results, the sheet metal shows superelasticity and ductility at 500°C, 550°C, and 600°C. In the hot deep drawing process, the working parameters affect the result. The higher the forming temperature and the longer the holding time at the bottom dead center of the punch or the longer the ageing shape memory treatment, the greater the height of the drawn part and the lesser the springback. The results of the subsequent free recovery experiment show that the deep drawn sheet part without ageing treatment still possesses the shape memory effect. It also shows in the further constraint recovery experiment that in a wide temperature span the deep drawn sheet part possesses a different recovery load when reacting to the phase transformation of the shape memory alloy. Furthermore, the higher the forming temperature and the shorter the ageing treatment, the greater the part recovery load.
Characteristic analysis of rotating ultrasonic machining applied in zirconia grinding
Authors: Chen T H , Lee J N , Tsai M H , Fu S W , Wu Y C
Published: September 2021

This research uses rotary ultrasonic grinding technology to grind zirconia (ZrO2) ceramic. The purpose is the optimization of processing parameters for rough and fine grinding. According to Taguchi method, optimized processing parameters will be available to find and successfully verified. The objective function of rough grinding is the material removal rate (MRR), and a maximum is expected. The processing parameters can be spindle speed, ultrasonic power, feedrate, and cutting depth. The best MRR is 192mm3/s in Taguchi’s experiment, and the optimized MRR is 2.14mm3/s, which can be increased by 1.11 times.

Moreover, the objective function of fine grinding is surface roughness (Ra), which needs to find a minimum value. The control factors are spindle speed, ultrasonic power, feedrate, and the number of times of grinding. In the Taguchi experiment, the minimum roughness predicted by the fine grinding is Ra0.16, but the roughness is obtained Ra0.2 by the verification experiment. It may be that the effects of the factors are not completely independent, and there are interactions between them. The predicted value will not be completely correct via the superposition of each factor effect. It can also be found that the independence of the fine grinding speed, ultrasonic power and feed factor is not strong enough for the variation analysis. It affects the results of the prediction and confirmation experiment.
Reduction of drilled-hole fracture and burr by rotary ultrasonic machining technology
Authors: Lee J N , Wu Y C
Published: September 2021

In this paper, rotary ultrasonic machining (RUM) is introduced to process the micro-drilling on graphite and brass. The best combinations of process parameters are presented as the experimental results on this research. On the basis that graphite offers efficient electrical conductivity and low hardness, and that brass as copper-zinc alloys provides convenience for processing, fractures or edge collapses are often evident after machining. This research focuses on proposing improvements by cooperating RUM with Taguchi method, from which the optimizations of process parameters and parameter verifications can be conducted. Control factors include spindle speed of the drill-bit, peck drilling, processing feed rate, and ultrasonic power. Each factor is inspected by three levels. Quality features are determined by the fracture area.

This research reveals that the difficulty in removing shavings leads to the breakage of machining tools inside the drilled holes. Incorrect process parameters cause failure at processing the micro-drilling on graphite and brass.
Study of rotating drawing process of wire rod based on slab method and FEM simulation with constant shear friction
Authors: Tzou G Y , Chai U C , Teng H Y
Published: September 2021

The study based on the slab method and FEM simulation is to explore the wire rod drawing using rotating die. Constant shear friction is assumed at the interface between die and wire rod to explore different drawing conditions such as rotating angular velocity (ω), half die angle (α°), frictional factor (m) etc. on the influence of drawing forming characteristics. Besides, the die stress of rotating die occurred has been analyzed to realize whether the drawing die is failed or not. The axial stress, the radial stress, the drawing force, and the rotating torque can be obtained from the slab method to compare with the FEM, the error between the both models is around 8-10%. Moreover the realistic experiment is able to verify the acceptances of both models. Therefore through the study due to the rotation of drawing die, the drawing force can be reduced and the flowing of wire rod is increased.
Remote control of greenhouse hybridized with AI technique and LoRa communication
Authors: Huang W C , Chiu M C , Yeh L J , Chiu C M
Published: September 2021

To increase agriculture harvesting, an online monitoring system equipped with multiple environmental sensors which can be wirelessly transmitted to a remote port using LoRa technique is presented. In addition, to ensure food safety, a portfolio of plants using a cloud connected to the remote port is also built. Moreover, in order to explore best chlorophyll of the vegetable in greenhouse, a study in obtaining appropriate environmental parameters (i.e. air temperature, air humidity, sunshine intensity, soil humidity, soil ph, and carbon dioxide) via artificial intelligent (AI) technique is proposed. Considering the cost down of manpower fee, the automation techniques using sensors and actuators in conjunction with a micro-controller is adopted. Furthermore, in order to ease monitoring and controlling, area is divided into small zones.
The stress and strain analysis double-layer and eight-leaf backward curved impeller disc agitator
Authors: Cheng C C , Wei S P , Lin A D , Hsieh C H , Hsu C M
Published: September 2021

The mixing wing’s stress and strain value of the structure in the mixing equipment needs to be studied and discussed. The research is uses the FLUENT module to simulate the flow field state in the rotating operation of the mixing tank, the stress and strain of the mixing blade, and the modal analysis of the predicted resonance frequency. First, Fluent is uses simulate the shape of the flow field inside the stirred tank. Situation of different speeds, the deformation state of the stress, strain and total displacement of the stirring wing assembly is obtained to achieve the ANSYS fluid-solid coupling effect analysis. Finally, predict the modal appearance and failure points of the simulated stirring wing assembly at different resonance frequencies. After analysis, the rotation speed of the stirring wing is increases, it must be subjected to the centrifugal force of fluid distribution, vortex gravitation, and up and down convection agitation. The total displacement and deformation of the rigid structure of the stirring wing can be obtained. The equivalent stress and strain also adopt a progressive linear growth phenomenon.
Dependence of microstructure evolution on rolling conditions in AA1050 aluminum alloy
Authors: Wang R , Lu C
Published: September 2021

Cold rolling has often been employed to tailor the microstructure and to achieve desired mechanical properties. In this study, the formation of sub-grain and grain orientation evolution in cold rolling processed AA1050 aluminum was investigated by electron backscatter diffraction (EBSD) characterisation. The experimental results demonstrated that increasing rolling reduction facilitates the transformation from sub-boundaries to high angle boundaries within grains by accumulating misorientation, and asymmetric rolling could impose a higher equivalent plastic strain, accelerating the grain refinement. The formation of small and equiaxed grains demonstrates that asymmetric rolling with high reduction promotes the recrystallization in (112) grains and contributes to the formation of (110) fibre in aluminum.
Study of finite element analysis on tube fittings
Authors: Hsiung J C , Teng H Y , Tzou G Y , Wu J H
Published: September 2021

This study uses finite element analysis based on DEFORM-2D commercial software to explore the plastic behaviors in grip and seal of tube fittings. The tube fittings consist of tube, nut, front ferrule, back ferrule and body. The material of the tube is SUS 304 stainless steel, and the material of the tube fittings is all SUS 316 stainless steel. As the nut tightens, the back ferrule squeezes into the front ferrule while forcing the front ferrule into both the nut and the tube, which results in an effective mechanical grip and seal. The nut locking force changes with the geometry conditions of α, β, and γ in the back ferrule and the front ferrule. The results show that the nut locking force increases with the increase of the frictional factor, the back ferrule chamfer (β), and the front ferrule tilt angle (γ), however decreases with the increase of the front chamfer (α).
Effects of shot peening on the tribological properties of aluminum alloys with T6 treatment
Authors: Chang Y P , Chu L M , Liu C T , Wang J C , Chen K W
Published: September 2021

Aluminum alloy has many excellent properties such as light texture, corrosion resistance, and easy processing, etc., so it is widely used on the market. The shot peening method can effectively eliminate residual stress and increase its reverse stress, so as to achieve the purpose of anti-fatigue and prolong service life. Therefore, the effects of shot peening on the tribological properties of aluminum alloys with T6 Treatment are investigated in this study. The reciprocating friction test was carried out with three different aluminum alloy mid-plate test pieces, two different shot peening impact parameters and two different loads. Moreover, the macroscopic and microscopic methods are used to discuss the tribological performance of friction and wear. The experimental results show that the plastic deformation is formed on the surface of the material by the shot peening impact method. Although the hardness increases, it also causes inelastic and brittle properties. It can be seen that although the ball striking method can improve the performance of bending, tensile, compression and impact resistance to achieve the purpose of prolonging the service life, when repeated stress is applied, the fatigue resistance will decrease and it will not resist wear. The results will be beneficial to the future of the aerospace industry to develop more internationally competitive products.
Control design of parallel-connected PWM DC-AC converters for sustainable energy applications
Authors: Chang E C , Lin G W , Lin Y T , Mao K C , Wu R C
Published: September 2021

Parallel-connected PWM DC-AC converters bring lots of merits, such as, additional capacity of power, modularity ability, better thermal regulation, convenient maintenance, and redundancy that have found wide application in sustainable energies. We propose a control technology in which the strengths of rotating sliding manifold (RSM) as well as exponential grey model (EGM) are incorporated to derive a higher performance parallel-connected PWM DC-AC converter. The RSM makes sure that the sliding mode happens from the any starting status, nevertheless the fixed sliding manifold fails to achieve the robustness in the face of parametric variances and perturbations. Once occurring with high non-linear loads, the fluttering existing in the RSM potentially generates a great deal of output-voltage distortion in the parallel-connected PWM DC-AC converters, which deteriorates sustainable energy stability. With the aim of removing the fluttering, the EGM has optimized the RSM control gains to produce both good steady-state and transience behaviour of the PWM DC-AC converter. The potency of the control technology has been well proven in terms of designing procedure, theory analysis, simulation and experimental results.
Development of software and hardware components to the Internet of an additive manufacturing system based on vat photopolymerization technology
Authors: Zikra F , Valle M A R , Wang J C
Published: September 2021

The global competition and shifts in consumer’s demand are forcing companies to enhance their productivity by reducing the manufacturing time, cost and increasing the value of final merchandise. Recent engineering researchers find that the additive manufacturing (AM) process could be an innovative solution due to its advantages in building complex shapes using different materials. However, the lack of developing tools to automate AM equipment has limited applying this technique to fabricate products within a production system. Thus, an internet of additive manufacturing(IoAM) system for the Vat photopolymerization process is proposed. The IoAM system is composed of three components which are described. The first one is the machine hardware integrated by all the various mechanical parts of a conventional Bottom-Up DLP 3D printer managed by a control board based on IoT technology. The second element is a web interface that controls and monitors a single or an array of machines from one or multiple operators and devices. The last module is firmware, which is the intermediary between the software and hardware. Besides, it is responsible for executing the adaptive control for the printing parameters, which has allowed to speed up the manufacturing process. The geometric calibration method to overcome distortion of photomask produced by DLP and the energy calibration algorithm to solve the non-uniform energy distribution have permitted to fabricate objects with high resolution around 30um in the XY axis and 50 μm as a layer thickness.
Design and implementation of high-efficiency power inverter using adaptive nonlinear control
Authors: Chang E C , Tsai D T , Xiao Z K , Kuan W C , Wu R C
Published: September 2021

In this paper, a finite-time nonlinear control law based on adaptive grey wolf optimization (AGWO) is proposed to obtain a high-efficiency power inverter. Although sliding mode control (SMC) provides robustness against internal parametric changes and external load meddling, the system-state cannot converge to zero in a finite time. The development of a finite-time nonlinear control law (FTNCL) is offered to ensure the finite-time convergence of the system state. But the FTNCL still meets the problem of jitter, which causes harmonic distortion of the output-voltage of the high-efficiency power inverter. In order to effectively suppress the jitter phenomenon, the gain parameters of the FTNCL can be optimally tuned by using the AGWO algorithm. This proposed scheme with the combination of the FTNCL and AGWO has been realized in an actual high-efficiency power inverter operated by a digitized signal processor. Simulations and experiments in a feedback system have revealed that the proposed scheme brings the advantages of fast dynamical reaction, less steady-state error, lessened total harmonic distortion, and relieved jitter.
Optimum design and performance analysis of permanent magnet synchronous motor for vehicle
Authors: Lu Q , Liu Z S
Published: September 2021

As the core of electric vehicle, the driving motor should have the advantages of high-power density, wide speed range and small volume. Aiming at the demand of vehicle drive motor and the structural characteristics of permanent magnet synchronous motor, by using Motor Cad, a internal rotor permanent magnet synchronous motor (PMSM) was designed and analysed in detail in this paper. In order to improve the anti-demagnetization ability and power density of the motor, the rotor structure was designed as a built-in compound type. At the same time, 8 poles and pear shape stator slot were adopted to reduce the loss of the motor and improve the efficiency of the motor. The simulation model of the motor was established by the simulation software, and its various performances were analysed. The simulation results showed that the design parameters of the prototype fully meet the design requirements of vehicle motor.
Study on design and flux weakening control of direct drive hub motor
Authors: Liu Z S , Wang X F , Lu Q
Published: September 2021

The direct drive hub motor is a motor that directly combines the motor and the wheel. It is accompanied by the development of permanent magnet motor and modern control technology. Permanent magnet synchronous motor (PMSM) is especially suitable for use as hub motor use of its advantages of high efficiency, energy saving, high power and easy control. In this paper, Motor Cad software was applied to optimize the design of an outer rotor PMSM motor of a cellular power, and the simulation and analysis of air gap magnetic density and other performance were carried out. The analysis results not only verify the rationality of the motor design, but also provide a basis for the next study on flux weakening control. The design and control results show that the prototype meets the design requirements fully.
Applying deep learning to develop endoscopic imaging technology
Authors: Weng C H , Tan C Y
Published: September 2021

As an important technology means in the arena of image categorisation, deep learning has broad application prospects, to carry out research on image classification technology has important practical significance and theoretical value for promoting the development of artificial intelligence and computer vision, this article gives a comment for the application of deep learning in image designation. Analyse the research findings obtained in recent years in the domain of image determination such as medical image identification and remote sensing image recognition, discuss the development trend and existing research of deep learning in the arena of image categorisation, points out that the effective use of deep learning technology to classify large sample data, with using the supervised and unsupervised learning to designate images, how to effectively determinate medical images and strengthen the theoretical nature of the models are further directions of research in this field. This paper presents a study based on deep learning, with the aim of practical research being by using Convolutional Neural Networks to identify endoscopic groupings in datasets. The proposed method can automatically detect the features of endoscopy images under the condition recognised by the algorithms and achieve the correct and fast categorisation results.
Study on impact to blankholder of dual-mass type under preload
Authors: Fann K J , Chang C M
Published: September 2021

This study is aimed to carry out an experimental verification for the finite element model and to propose a design scheme for using a dual-mass blankholder in a stamping process to increase the press ram speed without raising the impact force, in part by generating the response surface of the process parameters, whose ranges in the finite element analysis are extended. As a result, the impact has no significant relationship to the preload and the coefficient of the springs used to connect plates, but it has a significant positive correlation with the mass of the plates and the press speed. Thus an empirical equation is found by linear regression to design a dual-mass blankholder for a stamping process. With two examples, it shows that the design scheme is indeed feasible, which could become a reference for industrial applications.
Simulation and experimental analysis of draw-thread products under different lubrication conditions
Authors: Hsia S Y
Published: September 2021

The drawing material SCM435 was attempted in this study. The experiments were carried out under three different lubricating conditions: wiredrawing powder, oil and grease to analyze its optimum stretch working conditions. In the research process, the experiment and simulation analysis of the fixed shear friction ring were used to obtain the friction coefficient under three different lubricating conditions. Then the forming software DEFORM-3D was utilized to simulate the wire drawing process under different friction coefficients to obtain the load and stress distribution required for wire drawing. The research results show that the wire drawing powder has the smallest friction coefficient and the lowest surface hardness in the experiment of the drawing material. The effective stress was generated on the wire drawing die is also the smallest of the three different lubrication conditions. Moreover, during the forming simulation of wire drawing material SCM435 on wire drawing powder or wire drawing oil, the stress of the wire drawing die will not exceed the yield strength of SKD61.
Finite element study on spinning process of an aluminium tube
Authors: Fann K J
Published: September 2021

This article aims to have a glimpse into the effect of the spinning tool parameters (focusing on its diameter, attack angle, nose radius, and feed) by applying the explicit code of the commercial finite element analysis software LS-DYNA. The preliminary results show that the greater the axial feed, the greater the loads generated in the axial, the tangential, and the radial directions. At the same time, the larger the axial feed, the more the elements are parallel to the axial direction from the inflection point to the tube opening. Furthermore, using a larger axial feed will also cause the flaring of the tube opening and make the flaring more obvious. In addition, using a larger axial feed will not only cause a greater material accumulation in front of the attack angle, but also a larger material accumulation at the tangential rear of the nose radius. Moreover, the greater the attack angle, the greater the axial load. There is no further significant effect of the corner radius of the spinning tool on the spinning load.
Establishment of the optimal predictive model of die steel SKD 11 micromilling via nanofluid (graphene)/ultrasonic atomizing minimum quantity lubrication
Authors: Huang W T , Chen L Y
Published: September 2021

This study is mainly utilized nanofluid (graphene) and ultrasonic atomization system to process SKD11 mold steel in micromilling to improve the quality of processed products, find the optimal quality characteristics, and construct an accurate prediction model. In this study, Taguchi’s robust design is adopted. The L18(21×37) orthogonal table is used to find the optimal parameter combinations for each quality characteristic, and the micromilling force and micromilling temperature are used as characteristic indicators. The control variables are the average thickness of nanographene, weight percent concentration, ultrasonic atomization amount, spindle speed, feed rate, air pressure, nozzle angle, nozzle distance. Also, a back propagation neural network (BPNN) is used to predict the micromilling processing mode. Taguchi method is used to optimize the hyper parameters in the neural network to improve the accuracy of the prediction model, reduce the input of the number of training samples, and then build a neural network prediction model that can accurately predict the quality characteristics of micromilling force and micromilling temperature. The prediction results show that the milling force parameter value error between the micromilling force model prediction and the single target optimization is 0.55%. The error between the micromilling temperature model prediction and the single-target optimization of the micromilling temperature value is 5.90%.
Safe MQTT-SN: a lightweight secure encrypted communication in IoT
Authors: Kao T L , Wang H C , Li J E
Published: September 2021

The Internet of Things (IoT) is a technology trend that has been evolving in recent years. With the development of sensing technology and communication technology, the various applications of IoT are integrated into our lives gradually. Various security issues also need to be resolved with the convenience brought to us by IoT. MQTT or MQTT-SN is a lightweight communication protocol in IoT, which is more compactly on sensor nodes with limited resources. This paper provides a secure connection and end-to-end encrypted communication method which is based on MQTT-SN. By using digital signature (ECDSA), hash function, key exchange (ECDHE), AEAD (ChaCha20-Poly1305) to achieve a safe version of MQTT-SN called Safe MQTT-SN. The Safe MQTT-SN enables an end-to-end encrypted communication between the subscriber and publisher. The implementation of these algorithms enable the Safe MQTT-SN to have good performance on sensor nodes with limited computing power. Comparing with mosquito MQTT-TLS, the handshake time of MQTT-TLS is about 56.12ms and Safe MQTT-SN is about 24.78ms on Zedboard.