bluuebunny/crossref_metadata_2025 huggingface dataset:
Mathematical Conceptual Understanding about Geometry of 8th Grade Students in Classroom Using Lesson Study and Open Approach with The Geometer’s Sketchpad
Authors: Samphantakul N , Thinwiangthong S
Published: October 2019

This research aims to analyze the Mathematical Conceptual Understanding (MCU) about Geometry in classroom using Lesson Study and Open Approach [11] with the Geometer’s Sketchpad (GSP). It used qualitative research methodology which focuses on protocol analysis through analytic description. The target group was 9 (divided into 3 groups) of 8th grade students from Kaeng Khro Wittaya School, Kaeng Khro District, Chaiyaphum Province, 2016 Academic Year. The research tools were lesson plan of Figures and Geometry Shapes with GSP, Video recorder and field note. The data included students’ problem solving protocols, students’ interviewing protocols, collaboratively lesson plan and reflection protocols, and the students’ written works. Data were analyzed by APOS framework [7]. The results were found that: 1) Posing Open-ended problems, GSP program was used for surveying details and conditions of problems. Students have the MCU in the action level, the students were able to follow the instructions, 2) Students’ self-learning, students applied the surveying details and conditions from GSP program in the 1st step to solve their mathematical problems and could have various ideas. Students have the MCU in the process level, they can draw the connection in the problematic problems as well as describe that idea in descriptive manner. They can also present and elaborate their ideas, 3) Whole class discussion and comparison, GSP program was used for expanding and comparing the students’ ideas. Students have the MCU in the object level, The students can make conclusion as well as give definitions, principles qualities to make the connection or solve the problems, and 4) Summarization through connecting students’ mathematical ideas emerged in the classroom, GSP Program was used to connect and summarize the students’ mathematical idea. Students have the MCU in the object and schema levels, the students are able to make connection of their current lesson with the other lesson such as geometry and so on.
Comparison of the capacity factor of stationary wind turbines and weather-routed energy ships in the far-offshore
Authors: Jamil Roshamida ABD , Chaigneau Alisée , Gilloteaux Jean-Christophe , Lelong Philippe , Babarit AuréLien
Published: October 2019

Offshore wind energy technology has developed rapidly over the last decade. It is expected to significantly contribute to the further increase of renewable energy in the global energy production in the future. However, even with floating wind turbines, only a fraction of the global offshore wind energy potential can be harvested because grid-connection, moorings, installation and maintenance costs increase tremendously as the distance to shore and the water depth increase. Thus, new technologies enabling harvesting the far offshore wind energy resource are required. To tackle this challenge, mobile energy ship concepts have been proposed. In those concepts, electricity is produced by a water turbine attached underneath the hull of a ship propelled by the wind using sails. It includes an on-board energy storage system since energy ships are not grid-connected. Thus, the ships route schedules could be dynamically optimized taking into account weather forecast in order to maximize their capacity factors (CF). The aim of this study is to investigate how high the capacity factors of energy ships could be when using weather-routing and compare them to that of stationary wind turbines that would be deployed in the same areas. To that end, a modified version of the weather-routing software QtVlm was used. Velocity and power production polar plots of an energy ship that was designed at LHEEA were used as input to QtVlm. Results show that capacity factors over 80% can be achieved with energy ships and stationary offshore wind turbines deployed in the North Atlantic Ocean.
Processing of sonic anemometer measurements for offshore wind turbine applications
Authors: Nybø A , Nielsen F G , Reuder J
Published: October 2019

Quality assured measurements from offshore masts may provide valuable information of the characteristics of the offshore wind field, which is of high relevance for simulations of offshore wind turbines’ dynamic response. In order to obtain these high quality data sets, a processing procedure tailored to offshore wind turbine applications must be followed. In this study, existing quality control routines applied in literature are evaluated, and a complete procedure is developed for sonic anemometer measurements. This processing procedure is applied to measurements at three heights from 16 months of measurements at FINO1. The processing procedure results in a data set of more than 6 000 30-minute periods of high quality time series showing a large variety in terms of wind speed and turbulence intensity. Together with an assessment of the stationarity, this processed data set is ready for use in offshore wind turbine research.
Experimental Investigation of a Downwind Coned Wind Turbine Rotor under Yawed Conditions: Preliminary Results
Authors: Schulz C W , Wieczorek K , Netzband S , Abdel-Maksoud M
Published: October 2019

The growing number of Floating Offshore Wind Turbine (FOWT) concepts that utilize a single point mooring and therefore rely on the self-alignment capabilities of the wind turbine (e.g. SCD nezzy or SelfAligner by CRUSE Offshore) demands an extension of the simulation methods used for their development. A crucial issue for these concepts is the accurate prediction of forces and moments, which contribute to the self-alignment. In contrast to the well-studied behaviour of torque and thrust, yaw moment and lateral forces on a rotor under yawed conditions have not been in focus of previous experimental tests for the validation of aerodynamic simulation tools. In the present work, a model turbine equipped with a 6-axis force/moment sensor to capture the complete load on the rotor is presented. A detailed study of the two-bladed model turbine’s aerodynamic behaviour under yawed conditions was carried out within a range of yaw angles between -55 to + 55° with steps of 1 – 2.5°.
Verification of Floating Offshore Wind Linearization Functionality in OpenFAST
Authors: Johnson N , Jonkman J , Wright A , Hayman G , Robertson A
Published: October 2019

The wind engineering community relies on multiphysics engineering software to run nonlinear time-domain simulations, e.g., for design standards-based loads analysis. Although most physics involved in wind energy are nonlinear, linearization of the underlying nonlinear system equations is often advantageous to understand the system properties and exploit well-established methods and tools for analyzing linear systems. Previous work in this area has focused on the development of the new linearization functionality of the open-source engineering tool OpenFAST for floating offshore wind turbines, as well as the concepts and mathematical background needed to understand and apply it correctly. This paper focuses on the verification of this new linearization functionality, which is carried out by comparing results to previous stable versions of FAST. A nonlinear time-domain simulation for a floating offshore platform is also compared to the time-domain response of the linearized state-space model. The linearized results show good alignment between OpenFAST and previous versions of FAST, as well as with the time-domain simulations, thereby showing the accuracy of the new features in OpenFAST.
How does risk aversion shape overplanting in the design of offshore wind farms?
Authors: Mora Esteve Borràs , Spelling James , van der Weijde Adriaan H.
Published: October 2019

Offshore wind farms are subjected to a maximum export capacity set in their connection agreement with the Transmission System Operator (TSO). Generators can export up to their contracted maximum export capacity, with any additional generation curtailed by the TSO. However, given the fact that the majority of the time offshore wind farms are not generating at full power, overplanting wind farms by installing a higher wind farm capacity compared to the fixed electrical infrastructure can result in better overall economics despite power output being curtailed at generations’ peaks. The objective of this paper is to provide a framework to assess overplanting in the design of offshore wind farms when the underlying variables, such as wind speed and availability rates among others, are uncertain. The paper integrates site characteristics, technology specificities and financing constraints grounded in the mathematical framework of uncertainty quantification at the heart of the decision-making process. Generally speaking, the role of determining the optimal amount of overplanting comes down to the risk appetite of the developer, which in this paper is represented by a linear combination of the risk aversion and risk neutrality setting. A case study for a commercial offshore wind farm shows a 2% optimal overplanting for a Monte Carlo simulation, whereas this is found at 4% for a double Monte Carlo loop simulation regardless of the risk appetite considered. Furthermore, overplanting the farm by any value from 2% to 8% gives a better result than with no overplanting for a risk neutral setting. This paper will be of interest to developers, policy-makers and regulatory bodies confronted with uncertainty in overplanting the design of offshore wind farms.
Winding Reinforced UHPC Sandwich Structures for Lightweight Jackets for Offshore Megastructures
Authors: Markowski J , Lohaus L
Published: October 2019

The paper presents a new type of cross-section for truss elements in an offshore construction’s sub structure framework. By combining modern materials, such as ultra-high performance concrete (UHPC) and carbon fibre reinforced polymers in a hollow section, significant weight savings compared to conventional steel structures can be achieved. An extensive experimental programme has been carried out in order to describe the construction’s load-bearing behaviour. The article presents an overview of the development process of the design, the methodological implementation of the experimental investigations and the results.
Virtual synchronous machine control for wind turbines: a review
Authors: Lu L , Cutululis N A
Published: October 2019

Virtual synchronous machine (VSM) control has been put up and developing for the past ten years, but not much work has been done specially focusing on its application on wind turbines (WTs). This paper gives a thorough review of the work that has been done until now about application of VSM control on WTs. Aspects on control schemes, energy storage (ES), frequency and voltage control capabilities, different grid conditions etc. are summarized separately. Further research work in this field is emphasized.
Numerical prediction of hydrodynamic coefficients for a semi-sub platform by using large eddy simulation with volume of fluid method and Richardson extrapolation
Authors: Pan Jia , Ishihara Takeshi
Published: October 2019

Hydrodynamic coefficients for predicting hydrodynamic loading is significant for the design of offshore wind turbine floaters. In this paper, hydrodynamic coefficients for a semi-submersible floating offshore wind turbine are investigated experimentally and numerically. In the water tank test, added mass and drag coefficients of the semi-submersible model are identified by the forced oscillation tests. In numerical simulation, large eddy simulation (LES) with volume of fluid method (VOF) is adopted to predict added mass and drag coefficients. Firstly, numerical errors in the predicted hydrodynamic coefficients are systematically studied, and Richardson extrapolation is employed to obtain the grid independent solution. The predicted added mass and drag coefficients varying with KC number are then validated by the water tank tests and the mechanism of the hydrodynamic force are clarified by vortex shedding patterns. The hydrodynamic coefficients for each element are also investigated. Finally, effect of free surface on the hydrodynamic forces is discussed and the predicted added mass and drag coefficients are compared with those obtained from the water tank tests.
Implementation of potential flow hydrodynamics to time-domain analysis of flexible platforms of floating offshore wind turbines
Authors: Oh Sho , Ishii Kimiko , Iijima Kazuhiro , Suzuki Hideyuki
Published: October 2019

In the design of supporting platforms of floating offshore wind turbines, global response analysis is essential to predict the response under various loads from wave, wind, moorings and the wind turbines. However, the literature of the global analysis of floating offshore wind turbines combining flexible modelling of the supporting platform and the potential flow theory for hydrodynamic evaluation is limited. In this study, the framework implementing the potential flow hydrodynamics to the time-domain analysis of the three-dimensional frame model was developed using modal decomposition for the hydrodynamic evaluations. The method utilized the assumption that the number of modes can be limited to those with larger contributions, which can lead to the reduction of the calculation cost. A spar-type floating offshore wind turbine was modelled to verify the implementation of the developed formulations. Results showed that the implemented method is effective in predicting the dynamic motion and deformation of floating offshore wind turbines under combined wind and wave loads. For the cases of the irregular waves, the results obtained with potential flow hydrodynamics showed smaller responses than the results from the Morison’s equation in the natural frequencies of rigid body motion, which might be attributed to the steady and low frequency external forces introduced in the Morison’s equation by considering the instantaneous position of the floater.
Spatial met-ocean data analysis for the North Sea using copulas: application in lumping of offshore wind turbine fatigue load cases
Authors: Koochekali Alahyar , Muskulus Michael
Published: October 2019

Knowledge about stochastic environmental loads and the response of the substructure are essential in fatigue damage calculations for offshore wind turbines. Site-specific and high-quality met-ocean data that contains joint measurements of wind and waves however, are not always available. An approach based on copulas was used to generate lumped joint met-ocean data in a location where only marginals (i.e., individual, univariate probability distributions) are known. Empirical copulas were calculated for different stations in the North Sea for pairs of wind speed and wave height variables. These copulas are then combined with marginals from another station to generate lumped data. The generated data is compared with the known lumped joint data, and the difference of two methods is measured. The lumped values are used to estimate fatigue damage based on simple formulas. The results show that the joint behaviour of wind speed and wave height follows a similar pattern around the North Sea. In addition, the mean difference of generated lumped wind speeds based on this technique from lumped wind speeds based on real measurements is less than 5%. The mean difference of the fatigue damage caused by the generated lumped wind speeds relative to lumped wind speeds based on real measurements is less than 5% at two locations, and less than 15% in another location. This suggests that the approach is promising for estimating joint met-ocean data at new locations in the North Sea where only marginals are available, which is of major interest for wind farm planning and design.
Tribology Effect of Copper Based Composites for High-Speed Train Braking Application
Authors: Han Xiaoming , Yang Junying , Fu Rong , Su Linlin , Gao Fei
Published: October 2019

This paper disclosed the effect of third body on tribological performance of friction pair of copper-matrix materials and H13 steel using a fixed speed test from 3.14 m/s to 31.4 m/s at 0.5MPa. Results showed that the third body increase improved and stabilized friction coefficient. When the third body decreased, the friction coefficient decreased accordingly, especially at lower speed. This was because the particle third body of low-speed was weakly bound to the matrix, so the number of particles was easy to decrease.
Mechanical Properties and Strength Prediction of Ti Microalloyed Low Carbon Steel with Different Ti Content
Authors: Ren Jiakuan , Liu Zhenyu
Published: October 2019

The effects of Ti on microstructures, recrystallization and mechanical properties of microalloyed low carbon steels were studied. Hall-Petch relationship and Ashby-Orowan equation were applied to analyse the reason for the variation of strength. The results show that the recrystallization activation energy increases parabolically as the Ti content increases. Besides, the yield strength, tensile strength and the yield ratio increase in varying degrees with the increasing of Ti content, while the elongation decreases. The fine grain strengthening makes the greatest contribution to the strength, and the precipitation strengthening of TiC particles is the main reason why the strength of test steel increases significantly when the Ti content exceeds 0.042%. In addition, the strength prediction model was established for Ti microalloyed low carbon steel. The relative error of predicted yield strength and tensile strength of Q345B steel are within ± 8% and ± 7% respectively.
Simulation Research on Vibration Cutting Mechanism of Metal Matrix Composites
Authors: Yang Liang , Xu Chunguang , Fu Bohua , Zhang Mingzhao
Published: October 2019

Particle-reinforced metal composite materials have been widely used in the industry due to their excellent abrasion resistance and high strength, but they are typical hard-to-machine materials. A finite element model of the material matrix and enhanced particles have been established by the parametric modeling in this paper. Different from the previous development process, the particle is randomly distributed in this study, so the particle distribution has been better simulated than ever. The study shows that vibration-cutting particle-reinforced composites have reduced the phenomenon of particle suspension on the machined surface compared to conventional cutting, and the high-elastic-modulus reinforcing particles have been subjected to high stress, and the matrix between the particles have acted as a stress-transmitting “channel”. When the particle’s diameter is 20μm and the volume fraction is 30%, there is a stress transmitting channel in a certain range away from the tool tip. When the cutter contacts the particles, the vibration cutting will cause the initial crack near the particle, which cut off part of the stress transmitting channels, make the stress concentrated on the tool tip and lead to the material easier to remove.
Analysis of Sulfide Morphology in Non-quenched and Tempered Steel
Authors: Zhao Menghao , Ai Kenan , Li Zhiwei , Zhang Dong , Shen Ping , Fu Jianxun
Published: October 2019

Non-tempered steel without quenching and tempering heat treatment, saving energy and protecting the environment. Sulfide form is an important indicator of its production level. To explore the gap between the levels of sulphide control in 3 steel mills, metallographic microscope, scanning electron microscope and small sample electrolysis technology were used to analysis and comparison of sulfides in non-quenched and tempered steel produced by plant A (Germany), plant B (domestic), and plant C (domestic). The ratings of Class A inclusions in the three plants are: plant A is coarse grade 2.5 and fine grade 2.0, the sulfide are short rod shape; plant B is coarse grade 2.5 and fine grade 2.5, most of the inclusions are short rods, a few are long strips, and there are inclusions with MnTe; plant C is coarse grade 2.5 and fine grade 3.0, inclusions are generally long strips. The non-quenched and tempered steel inclusions produced by plant A are evenly distributed, and the sulfide form is well controlled.
Development of CPP Based Low Temperature Heat Sealing Film Material
Authors: Xiong Ligui , Tu Zhigang , Zhang Shangxian , Zhang Liqiong
Published: October 2019

The casting polypropylene (cpp) heat sealing film was prepared by adding the homemade smooth masterbatch, in the storage period of 30 days measured the surface tension is greater than 38 mN/m, the non-corona surface friction coefficient between 0.1 ∼ 0.2, corona surface is 0.5, the longitudinal tensile strength reached 60 MPa, transverse tensile strength reached 27 MPa, the films have high surface tension, low friction coefficient, high mechanical strength properties. Measured at the same time its initial heat sealing temperature, heat sealing strength and optical properties are better than the national standard, to maintain film comprehensive properties are stable during the storage period.
Preparation of Coral-like SnO2 Hierarchical Nanostructures and Its Application in Ethanol Gas-sensing Performance
Authors: Yan Shaohui , Zhang Jie , Huang Yibo , Lu Yan
Published: October 2019

Coral-like SnO2 hierarchical nanostructures were successfully fabricated by a simple hydrothermal route. By means of a comprehensive analysis of microstructures and morphologies of the hierarchical SnO2, we found that the coral-like nanostructures were comprised of irregular nanorods and nanosheets. Considering the essential advantages of hierarchical architectures, its gas sensitivity and the formation mechanism have been further explored. The sensor response to 100 ppm ethanol is about 25 at the optimum working temperature of 240 °C, and the response and recovery time are about 17 s and 7 s, respectively. Based on the experimental results, a possible morphology-dependent sensing mechanism are speculated.
Effects of Application of BB Fertilizer on the Yield, Quality and Economic Benefits of Citrus
Authors: Huang Dongfeng , Pan Zhucai , Qiu Xiaoxuan
Published: October 2019

The effects of four different fertilization treatments [i.e., Conventional fertilization, 45% imported compound fertilizer, Sacofu compound fertilizer (N-P2O5-K2O=20-10-10), BB fertilizer for citrus (N-P2O5-K2O=19-8-13)]on yield, quality and economic benefit of Newhall navel orange were studied through three-year field plot experiment. The results showed that compared with conventional fertilization treatment, the application of Citrus BB fertilizer could not only increase the yield of Newhall navel orange by 13.65%, increase the soluble solids (TSS) content by 51.50%, soluble sugar (WSS) content by 56.64%, vitamin C (Vc) content by 8.87%, reducing the titratable acid (TA) content by 22.83%, increase the solid-acid ratio of navel orange fruit by 96.31%, sugar-acid ratio by 102.97%, but also enhance the economic benefit by 15496 yuan/hm2. Therefore, the special BB fertilizer for citrus is suitable for further popularization and application in citrus orchards on hilly red soil hills in Fujian Province and even in southern China, where the climate and soil conditions are similar to those in Fujian Province.
Taste Correction and Safety Evaluation of Rhodiola Extraction
Authors: Zhao Shouqing , Wang Shanshan , Xue Changsong , Xia Guangqing
Published: October 2019

Objective To explore tannins removal of Rhodiola extraction and evaluate its safety. Method: Content of Tannins was treated with cheese, tannins removal was used by chitosan embedding, safety evaluation was tested by acute toxicity. The pharmacodynamics were detected by in vivo and in vitro antioxidant methods. Results: 20g/L Rhodiola extraction added 1g chitosan under 50°C embedding 2h, tannis was removed effectively and taste improved greatly. The results of acute toxicity tests in mice showed that the daily dose of 29.73 g was safe on the basis of 70kg adult weight. Antioxidant activity in vitro was evaluated by DPPH, super-oxide anion and hydroxyl radical scavenging assays showed at concentration of 0.1% indicated better results, while results in vivo showed at concentration of 1.2% decreased p53, p21 gene expression. Conclusion: A reasonable process for removing tannins from were determined Rhodiola extraction and taste of Rhodiola extraction is safe under the removal extraction technique. Results of antioxidant proved that Rhodiola extraction is effective.
Modeling Design of Instrument Panel
Authors: Chen Wei
Published: October 2019

The basic requirements of instrumentation modeling, composition and layout, representation of functional areas, color, text, graphic symbols and signage, materials and coloring technology are discussed. The panel modelling should meet the following basic requirements, that is, the needs of product function, the needs of product uses, quick recognition, adaptability, artistry, and easy installation, adjustment and maintenance; The composition and layout of the panel are mainly panel composition of characteristic rectangular and panel composition of non-characteristic rectangular; The functional area of the panel can be divided into six types: wireframes, brackets, color blocks, spaces, segmentation lines and volume and surface; The color of the panel should consider its main color and matching color; Words, graphic symbols and signs on the panel, as well as the materials and coloring technology used in the panel are also factors that must be considered. The selection of materials is very important.
Research on Terrain Recognition for Gait Selection of Hexapod Robot
Authors: Zhou Xiang , Wei Wu , Gao Yong , Li Kuilin , Chen Ruidong
Published: October 2019

In order to improve the stability of the hexapod robot walking in different terrains, this paper adopts the strategy corresponding to the terrain environment and the motion gait, that is, the robot selects the gait that keeps the robot walk safer and more stable according to the identified terrain. In this paper, using the self-established data set, Terrain6, for terrain classification, the feature extraction of terrain images for hexapod robot is realized firstly based on the Convolutional Neural Networks and the transfer learning. Secondly, according to the stacking fusion method, a terrain recognition model with higher precision is obtained by integrating three terrain classification models include the support vector machine, the naive Bayes and the random forest algorithm. Finally, the experiments show that the hexapod robot selects suitable gait based on the result of terrain recognition to cross complex environment, and the stable and efficient motion of the robot verifies the validity of the research results.
Research on Optimum Laying Method for Increasing Underground Power Cable Ampacity
Authors: Pang Dan , Wu Haipeng , Dai Bin , Zhao Changpeng
Published: October 2019

When the cables are laid with equal spacing, its ampacity is limited due to the mutual heat effects. In order to increase the ampacity of the cable group, an optimum laying method with unequal spacing is proposed in this paper. The constraint function is that the temperature of all cables is lower than the upper limit, and the objective function is that the ampacity of cables is maximum. The constrained problem is transformed to an unconstrained problem by constructing a penalty function. The results show the effectiveness of the proposed method. The ratio of the increased ampacity increases with the increase of cable numbers.
Design and Implementation of HVDC System Power Automatic Control
Authors: Liu Yi , Rao Guohui , Zhang Haoran , Shao Ruibo
Published: October 2019

With the increasing number of UHVDC transmission projects in China, the design, construction, operation management and equipment manufacturing level of China’s HVDC transmission projects are also in the leading international level. But the equipment of converter station in our country is basically in operation state, and the dispatch adjusts power frequently according to various reasons. Manual power modification by operators is not only cumbersome and prone to make mistakes, but also easy to incur bad records for inquiring. In this paper, through an automatic power technology, the standard power curve of dispatching is imported into the operator control system, which runs automatically through the operator control system. The automatic power curve setting process realized by the method can reduce the manual operation, reduce the probability of misoperation, and improve the operation reliability. Operators are very satisfied with this automatic power curve, which greatly improves the efficiency of converter station.
Analysis of the dynamics of movement landing vehicle with an inflatable braking device on final stage of trajectory
Authors: Koryanov Vsevolod V. , Kazakovtsev Victor P. , Griselin Helene , Danhe Chen
Published: October 2019

For various missions that are currently being designed and planned at the present time, it is necessary to ensure reliably the stage of landing on the surface of the planet. Among the currently proposed devices that help to perform the landing of the landing vehicle, a separate interest is inflatable devices. Using inflatable device instead of rigid device has advantages, such as a small mass and a great compacity. Studies have focused on the angular motion of landing vehicles entering the atmosphere, with allowance of small asymmetries. During the descent in the atmosphere, the landing vehicle and its braking device are subjects to important perturbations, due to external environment. Thus, the inflatable device can be deformed, due to its flexibility, and the movement can become unstable. In the paper is analyzes the movement of such a landing vehicle, which uses such special devices made of inflatable devices. The paper is devoted to the analysis of movement at the final stage of landing - approaching the surface, touching the surface and further interaction with the surface. As a result, it is concluded that the most unfavorable approach to the surface, when the resulting overload is of the greatest importance.
The basic set of test problems for ODE system solvers
Authors: Manichev Vladimir , Zhuk Dmitriy , Feldman Emiliy
Published: October 2019

Known mathematical packages, MATLAB, Maple, Mathematica, MathCAD and others may get wrong, often plausible, the result of numerical solution of ODE systems with low, given by default, the requirements for mathematical accuracy of the results of the numerical solution of ODE systems. Since ODE system parameters obtained usually experimental, with a low mathematical precision, so the requirements for the precision of the results of mathematical solutions of ODE systems is low (for example, in MATLAB package required precision is 0.001). The article offers a basic set of tests to assess the range of applicability of the relevant solvers. The basic set of test problems for ODE solvers systems include linear ODE systems with the known analytic solution and nonlinear systems with known graphics solution. Presented comparative results of solutions for proposed problems using MATLAB solvers and manzhuk program from a library of standard mathematical programs SADEL (Sets of Algebraic and Differential Equations solvers Library), which has been designed for reliable and accurate solving of systems of linear algebraic equations (LAE) and ODE systems. The results can be used in mathematical modeling of dynamic systems described by ODE systems.
Bearing Fault Diagnosis Using Structure Optimized Deep Convolutional Neural Network under Noisy Environment
Authors: Jin Guoqiang , Li Dongjie , Wei Ye , Hou Wenhui , Chen Huai’an , Jin Yi , Zhu Chang’an
Published: October 2019

In recent years, deep learning has been gradually applied in bearing fault diagnosis thanks to its powerful learning and representation ability. However, deep learning-based methods are usually computationally intensive and have redundant parameters. In this paper, we propose an end-to-end structure optimized deep convolutional neural network for bearing fault diagnosis using the local sparse structure. The width and depth of the network are increased and the redundant parameters are reduced while maintaining the representation capabilities and performance of the network. The local sparse structure increases the computational efficiency and reduces the risk of overfitting. The proposed method directly employed the raw signals as input without extra feature extraction with the ability that could distinguish both the bearing fault types and the corresponding severity. Experiments show that the proposed method achieves similar performance compared to the original method by using 46.47% parameters as used in the original study, even under the noisy environment.
The modeling of the efficiency in the new generation manufacturing-distributive systems based on the cognitive production factors
Authors: Omelchenko Irina , Drogovoz Pavel , Gorlacheva Evgeniya , Shiboldenkov Vladimir , Yusufova Olga
Published: October 2019

The paper envisages the analysis of the new generation manufacturing-distributive systems. The particular attention is paid to the production function as the analytic instrument allowed evaluating the interrelation between economic results of an enterprise and production factors, which includes the cognitive production factors as well. The rationale for the enlargement of the traditional production functions by means of the transfer from the multiplicative to the logistic dependence has been analyzing. The results of production function modelling on the base of the logistic dependence have been depicted on the open data of a high tech enterprise from 2009 till 2018. The results of production function modelling have shown that the usage of logistic dependence has allowed tracing more precise the transition of production factors to the other path dependency. The inclusion of the cognitive production factors has allowed evaluating their contribution to the economic results of a high-tech enterprise. This work is still in progress and the presented results are preliminary and would be added and specified by the additional research.
Sensor subsystem design for small unmanned surface vehicle
Authors: Kolev Georgii , Solomevich Ekaterina , Rodionova Ekaterina , Kopets Ekaterina , Rybin Vyacheslav
Published: October 2019

The construction of unmanned vehicles is a major trend in a modern robotics and automation. One of the promising branches is the development of unmanned boats and surface vehicles (USV). They possess the great variety of possible applications, including environmental studies, military and security issues. In this paper, we consider the design and rapid prototyping of sensory subsystem for small-sized USV. The proposed sensor system incorporates the lidar, Doppler radar rangefinder and video camera in a waterproof housing. The housing is made with additive technology and provides the efficient and rigid placement of chosen set of sensors. The circuitry and design of the sensory subsystem are given and discussed in comparison with existing solution. The prototype of the system is described and the results of its experimental testing are provided.
Application of Structural Similitude for Scaling of a Pressure Vessel
Authors: Batul Beenish , Sohail Abeera , Aizaz Ahmad , Jamil Zukhraf
Published: October 2019

Pressure vessels find their use in various fields, ranging from gas cylinders used in households for cooking, boilers for steam engines, fuselage of aircraft to solid rocket motors used in missiles and space shuttle. The design of such vessels is validated by performing tests on full scale prototypes. Mostly the testing of such vessels is cumbersome and expensive. This paper establishes the method to reduce the cost for testing the pressure vessels. The theory of similitude is studied to make the testing process easier by establishing structural similitude for a pressure vessel. Using similitude theory a scaled model of the prototype vessel is developed in such a way that when the scaled models’ responses are multiplied by a calculated scale factor, behaviour of the prototype could be predicted. By testing on the scaled down model, the cost of manufacturing is reduced. The pressure vessel considered here is representative of the pressures and materials used in high pressure applications. In this paper a 1/10th scaled model of the pressure vessel is developed using structural similitude theory. Buckingham pi-theorem technique has been used for dimensional analysis after studying parameters on which pressure vessel is designed and ANSYS software is used to validate the resulting pi-products. Complete similarity is achieved when predicted prototype results completely map on to prototype results.
Design and Manufacture of Miniature Testing Machine for Composite Materials
Authors: Nguyen Le Nhan , Van Quy HO , Nguyen Song Thanh Thao , Le Thi Hong Hieu
Published: October 2019

Today, there are many commercial test machines in industry and laboratory with many different sizes. However, their prices are high. Some laboratories made their own equipment at lower price based on their situation, demand and purpose of test. In this paper, the design of the frame structure and the operating systems, as well as the calibration of a small tensile and bending test machine for low- to medium-stiffness composite materials are presented. The construction is made of aluminum. The loading is created by an actuator which is controlled by an Arduino micro-controller. A Hocdelam USB-9090 (the same as that of NI USB-6009 but with less accuracy) data acquisition card is connected to a personal computer through an interface with load cell and strain gauge by the amplifier to record the force and the displacement during a test. The rate of loading is identified by the rate of actuator which is maintained stable thanks to the adjustment of PWM (Pulse Width Module) with Arduino. The machine is able to conduct tensile and bending tests with a loading up to 3000 N with a sensitivity of 1 N. It is possible to conduct tests on composite specimens at speeds of 1.7 ~ 300 mm/min. This machine is able to obtain results for mechanical properties which are in good agreement with the data obtained from a commercial machine, the differences are less than 5%.
Optimal Design of Mufflers Equipped with Pod and Concentric Acoustical Rings using the SA Method
Authors: Chiu Min-Chie , Cheng Ho-Chih
Published: October 2019

There has been, of recently, much research on mufflers lined with sound absorbing material. In dealing with high frequency noise emitted from venting systems, a sound absorbing material inside a tube covered with a perforated plate has been used. However, the acoustical performance of mufflers equipped with one-layer of sound absorbing material has still proved to be insufficient. In order to promote acoustic performance, a design and theoretical assessment on pod mufflers hybridized with multi-layer concentric sound- absorbing rings is proposed. By using the acoustical-lumped-method, a four-pole system matrix for evaluating the acoustic performance (STL) will emerge. During the optimization process, the simulated annealing (SA) method, which is a robust scheme utilized to search for the global optimum by imitating a physical annealing process, is used. Before dealing with a broadband noise, the STL’s maximization relative to a one-tone noise (1000Hz) is offered to confirm the SA method’s reliability. To appreciate the influence of acoustical efficiency with respect to the design parameters, an analysis of design parameters (dh: the diameter of a perforated hole; W: the width of an air channel; R: acoustic flow resistivity of the acoustic fiber; σ : the porosity of the perforated plate; Df: the thickness of the acoustic fiber; L1: the horizontal length of the sound absorbing ring) is completed. Subsequently, to bring into focus the acoustical interaction with respect to the number of air-channels (between the sound absorbing rings), three types of mufflers (mufflers A∼C) hybridized with one, two, and three air-channels have been surveyed. Results reveal that for a rectangular muffler internally conjugated with one air-channel, the maximal STL is located at the desired tone, and the acoustical performance of a cone muffler will increase if the number of air-channels internally conjugated within the cone muffler increases. Consequently, the approach used for the optimal design of the STL on pod mufflers internally equipped with multiple air-channels within a space-constrained situation can be easily assessed.
Design of Switching Power Supply for Electric Vehicles with UC3842 Chip
Authors: Hsu Wei-Tai , Chi Yong-Ke , Huang Chia-Wei
Published: October 2019

This article is applied to UC3842 as a current mode PWM generator component, which is used to construct a single-ended flyback switching power supply with DC48V input and DC12V output. For the analysis of the instability caused by the peak current control, and the slope compensation is m=0.75m2, the duty cycle is no longer interfere with the stability of the system, which can improve the anti-interference ability of the power supply.
Stable and Robust Alternating Current Power Source Control Technique Applied to Ultraprecision Machining of Aluminum Alloy Materials
Authors: Chang En-Chih , Cheng Jerry , Tsai Yuan-Chieh , Tsai Meng-Han , Li Cheng-Syuan , Wu Rong-Ching
Published: October 2019

This paper develops a stable, robust control technique for AC power sources in ultraprecision machining of aluminum alloy materials that maintains low total harmonic distortion output-voltage and fast transient under uncertain interferences. The proposed control technique associates the properties of the finite-time variable structure controller (FTVSC) with the gray Bernoulli model (GBM). The FTVSC provides finite system state convergence time with non-singular advantages, which is different from the asymptotic convergence of the traditional variable structure controller in infinite time. However, once there is a highly uncertain disturbance, there will be chatter around FTVSC. The chatter produces high voltage harmonics in the AC power source output, which reduces the stability of ultraprecision machining of aluminum alloy materials. The GBM is used to eliminate the chatter and produce a high performance AC power source. Experimental results on a high-performance AC power source show that the proposed stable and robust control technique can result in high quality AC output voltage against system uncertainties. Since the proposed control technique is easier to implement than the existing control technique, and has high-precision tracking, fast convergence speed and efficient calculation, this paper will cause an interest in researchers of related aluminum alloy materials applications.
The Structure Design and Analysis of a Parallel Kinematic Mechanism Based on Abbe’s Principle
Authors: Chu Chih-Liang , Chen Hung-Chi
Published: October 2019

The purpose of this study is to design and analysis of a parallel kinematic mechanism based on Abbe’s principle can be applied to the 3D-coordinate measuring machine. In this study is the design and analysis of the parallel kinematic mechanism, which includes the mechanism design of linear drive rod mechanism and displacement sensing position coaxial, and the intersection of the three linear drive rod mechanisms are located at the contact probe. Therefore, the design of this study improves the displacement of the linear drive rod and Abbe error resulted from the angle variation of the displacement sensor. Furthermore, the mechanism performance has been verified experimentally. Through precision tests of the machine by a laser Doppler interferometer, the linear drive rod mechanism positioning precisions are within 1μm.
1. How can we know if someone is a psychopath or is at risk of becoming one?
Authors: Viding Essi
Published: October 2019

What are individuals with psychopathy like and what are their defining features? ‘How can we know if someone is a psychopath or is at risk of becoming one?’ considers two case studies to give an idea of the developmental course of criminal psychopathy and what psychopathic personality traits look like. It discusses the Psychopathy Checklist, developed by Robert Hare in the 1980s, and explains the difference between antisocial personality disorder, sociopathy, and psychopathy. Research has shown that whether we look at criminal psychopaths, individuals with high levels of psychopathic traits in the general population, or children who are at risk of developing psychopathy, similar patterns of brain function and information processing are seen.
Lost in the museum
Authors: Nanay Bence
Published: October 2019

The Greek word aesthesis means ‘perception’ and when the German philosopher Alexander Baumgarten (1714–62) introduced the concept of ‘aesthetics’ in 1750, what he meant by it was precisely the study of sensory experiences. ‘Lost in the museum’ explains that the scope of aesthetics is far wider than that of art, high or low; it includes much of what we care about in life. It is not the job of aesthetics to tell you which artworks are good and which ones are bad or to tell you what experiences are worth having. Aesthetics is a way of analysing what it means to have these experiences. Aesthetics is, and should be, completely non-judgemental.
Efficacy of an Internet-Based Community Reinforcement and Family Training Program to Increase Treatment Engagement for AUD and to Improve Psychiatric Health for CSOs: A Randomized Controlled Trial
Authors: EÉk Niels , Romberg Karin , Siljeholm Ola , Johansson Magnus , Andreasson Sven , Lundgren Tobias , Fahlke Claudia , Ingesson Stina , Bäckman Lisa , Hammarberg Anders
Published: October 2019

Aims

Community Reinforcement Approach and Family Training (CRAFT) is a support program for concerned significant others (CSOs) to identified persons (IPs) with alcohol use disorders, with the purpose of engaging IPs to treatment and to improve CSO functioning. The purpose of the present study was to investigate the efficacy of an internet-based version of CRAFT (iCRAFT).

Methods

Randomized controlled trial comparing iCRAFT with a wait-list (WL) condition with a nation-wide uptake in Sweden. A total of 94 CSOs to a treatment refusing IP, who described the IP according to DSM-IV criteria for alcohol dependence or abuse, were included in the study. iCRAFT consisted of five weekly administered therapist-guided modules with the following content: (a) improve CSOs’ own mental health, (b) improve the CSOs skills in asking the IP to seek treatment, (c) positive communication skills training, (d) contingency management of IP drinking behavior. Main outcome measure was IPs initiative to seek treatment measured at 24 weeks. Secondary outcomes were IP’s daily alcohol consumption, CSOs mental health, quality of life and relational satisfaction.

Results

Of 94 participants, 15 CSOs reported IP treatment initiative during the study period. Of these, 10 belonged to the iCRAFT condition and five to the WL condition. The difference between conditions was nonsignificant, and the results were inconclusive. Participants in iCRAFT showed short-term improvements regarding depressive symptoms, quality of life and relational happiness.

Conclusion

This study was unable to demonstrate substantial changes in the iCRAFT program regarding IP treatment seeking or CSO mental health.