bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Charging and Discharging Strategies of Flywheel Energy Storage System Using Permanent Magnet Synchronous Motor
Authors: Liu Xue , Jiang Xin Jian , Li Long Fei
Published: September 2013

Flywheel Energy Storage System (FESS) has become an important research field because of the energy problem. To solve the control of Permanent Magnet Synchronous Motor (PMSM) and Bi-directional power converter, both charging and discharging control strategiesthe Compound Control for charging and the Integrated Optimization Flux-Weak Control for discharging are proposed, together with the dual-loop control and simulation results. Based on these analysis and results, a high-power DSP-controlled experiment platform is set up to test the proposed strategies. Simulation and experiment results show that the FESS can run smoothly both under charging and discharging conditions so that both the strategies and the platform are effective.
Security Protocol for Electrical Remote Terminal Units
Authors: Wang Hui Ran , Ma Rui Fang
Published: September 2013

We dissected disadvantages of the existing transmission protocols and improved its performance of dada communication security. We have proposed a security communication protocol, called as RTUSec, for remote terminal units. RTUSec adds a security layer to the existing three layer model, so that the data security is improved. After analyzing advantage and disadvantage of the present algorithms of cryptography and authentication for data communication, we have designed a security mechanism with DES and HMAC to deal with security problems like spoofing during the communication between Remote Terminal Units and controlling centers.
A Combined Power Demand Forecasting Model with Variable Weight
Authors: Wang Zhi Gang , Zhou Qing Jie , Zhou Xing Hua
Published: September 2013

A combined power demand forecasting model with variable weight considering both of the impact of the macroeconomic situation and the internal development trend is proposed. The proposed model consists of regression analysis models and the trend extrapolation models. The variable weight is determined by the difference of the prediction results between the two kinds of models . Beijing's power demand forecasting illustrates the usefulness and reliability of the combined model.
Friction and Wear Performance of CF/PTFE Composites in Water Lubrication
Authors: Zhou Zi Rong , Zhou Jie
Published: September 2013

Using ring friction testing machine and metallographic and SEM on three formula of carbon fiber reinforced PFFE composite materials (CFRP) and stainless steel under water lubrication tribological properties were studied, and analyses the influence of load, grinding time on friction coefficient and wear quantity. It was found that CFRP with carbon-fiber content of 15% mass fraction and the high temperature nitride treated OCr17Ni14Cu4Nb got a friction coefficient of 0.0ll under 200N load, sliding speed of 5 m/s , which is the lowest one between all of the similar materials in domestic reporting.15 min before testing, the friction coefficient decreased with the increase of load. After 15 min, the friction coefficient basically was stabilized at around 0.011-0.014, Main wear mechanism of the CFRP material containing carbon fiber is fatigue wear, the higher the carbon fiber content, the lower the friction coefficient; the applied load increases from100N to 250N, the wear quantity increases with load decrease, starting from250 N wear increases with load increase.
A Method for Forecasting Short-Term Wind Speed Based on EMD and SVM
Authors: Dang Xiao Jing , Chen Hao Yong , Jin Xiao Ming
Published: September 2013

In this paper, a method for wind speed forecasting based on Empirical Mode Decomposition and Support Vector machine is proposed. Compared with the approach based on Support Vector machine only, the method in this paper use EMD to decompose the data of wind power into several independent intrinsic mode functions (IMF),then model each component with the SVM model and get the final value of the overall wind power prediction. Experiments show the efficiency of the approach with a higher forecasting accuracy.
Research of Generated Power Forecasting Model Based on the Fusion of Elman NN and ACOA for Photovoltaic System
Authors: Zhao Xian Jia , Wen Ling Yun , Cai Han Yu
Published: September 2013

A new generated power forecasting model based on the fusion of Elman neural networks (Elman NN) and ant colony optimization algorithm (ACOA) for photovoltaic system are presented in this paper. Elman NN owns stronger dynamic performance and calculation ability. And it can characterize complicated dynamics behavior. ACOA was used to optimize to improve the generalization performance of Elman NN model. The testing results show that new approaches can improve effectively the precision of generated power forecasting.
Development of the Load Transfer for Closing Loop Operation
Authors: Wu Zhi Wei , Ren Jian Wen , Zhou Qing Jie , Zhou Xing Hua
Published: September 2013

When there is partial failure or risk of failure in power grid, the redistribution of load in power grid means load transfer. Its necessary to choose the most optimal path from load transfer paths. In this paper, the concept of comprehensive coefficient is added to the load transfer system. The involving equipments parameters are calculated according to certain coefficient. Compare the comprehensive coefficients in these load transfer solutions to choose the optimal path. At the same time, the closed-loop factors are added to the constraint. It can avoid the system running long time with closed loop, and makes sure of which the system runs without power outage when the circuit repairs.
A Modified Statistical Model for Wind Power Forecast Considering Wind Power Output Control and its Applications
Authors: Wang Ying , Xu Yan Ping , Zhang Kai Feng , Teng Xian Liang
Published: September 2013

At present, the wind power forecast errors are mostly assumed to be normally distributed, beta distributed or Cauchy distributed. However, considering the wind power plants can actively control and regulate their output power, the wind power forecast distributions must be influenced. In this paper, a modified statistical model for wind power forecast distribution under wind power output control is established. The model can accurately reflect how the distribution changes when the wind generation is controlled. The result reveals that the reliability of wind power generation will be improved with output control. Then, based on the model proposed, some applications for wind power generation are described.
The Analysis of Strategies for Large Thermal Power Unit Frequency Control after the Breakdown of Isolated Network in Sending-End Network
Authors: Wang Hao , Wang Qing , Huang He , Zhang Yong , Song Yun Ting , Tian Jian She
Published: September 2013

As for the hidden dangers of low-frequency load shedding caused by high frequency generator tripping in isolated power grid because of the failure connection between outward transmission district grid and leadership grid, we gave an analysis to problems with high-frequency in sending network and isolated power grid, and reasons causing the unmatching between OPC and governors. Then, we adopted the measured parameters of thermal power units for the analysis of its regulating system under the isolated power grid, and discussed the regulating effect when the lower amplitude of the primary frequency was-30% and full liberalization. As for the high rate of load shedding in the sending network, this paper has put forward an optimization strategy for thermal power unit frequency control in isolated network. Release primary frequency amplitude to-30% in isolated network, measure the acceleration of rotation speed when OPC acts at the first time, calculate the tragic power of the unit and send it to AGC system. The unit quickly adjusts the power of the unit according to new AGC instruction, and stabilizes the frequency in isolated network. This strategy can help to realize the coordination between OPC and speed governor, and improve the margin of high-frequency in isolated network.
A New Reliability Evaluating Method for Distribution Network
Authors: Pang Yan Jun , Wang Qing Hao , Liu Chuan Bo , Liu Xiao , Wang Tian Shi
Published: September 2013

In order to improve the reliability evaluation to the distribution network, uncertainty factors about aging of components are considered under conventional reliability analysis of distribution system in the paper. The relationship between unavailability of aging of components and time (or limit age of components) is analyzed. Then the reliability indices are calculated by FMEA (Failure Mode and Effect Analysis). Finally distribution network reliability level is distinguished and the measures on improving the power distribution system reliability are presented.
Design and Development of a 14-Pole High-Temperature Superconducting Filter at 127.5MHz
Authors: Du Jian Chang , Ji Lai Yun , He Li Juan
Published: September 2013

A high-temperature superconducting (HTS) band-pass filter centered frequency at 127.5MHz was successfully designed and developed. The HTS filter is 14-pole, adopting compact symmetrical dual-spiral resonators. The filter was fabricated on a 3-inch-diameter 0.5-mm-thick LaAlO3 wafer with double-sided DyBa2Cu3O7 thin films. Through the low temperature test, the insertion loss of the HTS filter is under 0.1dB, the bandwidth is 20 MHz, the return loss is better than-22dB and the out-of-band rejection is greater than 80dB. The filters measurements agree well with the simulation.
Effect of Cutting Parameters on Cutting Temperature of TiAl6V4 Alloy
Authors: Sulaiman S. , Roshan A. , Borazjani S.
Published: September 2013

A Finite Element Modeling (FEM) and Simulation was Used to Investigate the Effect of Tool Rake Angle, Cutting Speed and Feed Rate on the Cutting Temperature of Tial6v4 Alloy. the Purpose of this Study was to Find Proper Cutting Parameters for Machining of Titanium Alloy where Cutting Temperature was Lowest. A FEM Based on ABAQUS Software which Involves Jonson-Cook Material Model and Coulomb’s Friction Law was Applied to Simulate an Orthogonal Cutting Process. in this Simulation Work, a Range of Tool Rake Angle from 0° to 10°, a Range of Cutting Speed from 300 m/min to 600 m/min and a Range of Feed Rate between 0.1 Rev/mm and 0.25 Rev/mm were Investigated. the Simulation Results Indicated that Increase in Rake Angle Reduces Cutting Temperature while Increasing Cutting Speed and Feed Rate Increase the Cutting Temperature.
Delamination Behaviour of Rubber-Toughened Carbon Fibre/Epoxy Composites
Authors: Wu Helen
Published: September 2013

In this study, core-shell rubber (CSR) and liquid rubber (LR) were used to modify the matrix toughness of unidirectional carbon fibre/epoxy composites. Double cantilever beam (DCB) and end notched flexure (END) tests were performed to evaluate the interlaminar fracture toughness. It was found that LR was identified to be more effective than CSR in improving GICand GIICof the composites, although fracture toughness of the CSR-modified epoxy was better than that of the LR-modified epoxy. SEM observation of post-fracture surfaces of the specimens shows that the degree of plastic deformation of matrix is well related to the rating of fracture toughness of composites for these unmodified and modified composite laminates, and is the key factor controlling the interlaminar fracture toughness of composite laminates. Further, it was confirmed that rigid fibres constrain growth of plastic zone in composites laminates, comparing with toughened bulk epoxy matrix. However, plastic zone is not limited to a single resin layer and it is capable of developing across rigid fibre layers.
Application of Chirp-Z Transformation in High Accuracy Measurement of Radar
Authors: Leng Jian Wei , Shan Chuan Bin
Published: September 2013

In theory, FMCW radar has very high distance measuring accuracy. While in practical system, the accuracy of FMCW radar is decreased due to the firm frequency sampling interval caused by using FFT to do signal processing. To solve this problem, basing on traditional FFT processing, this paper takes advantage of Chirp-Z transformation to partially detailing the main-lobe of echo wave distance frequency spectrum. Therefore, under the circumstance of smaller calculation, this method greatly has promoted the distance measuring accuracy and met the actual requirements of high accuracy distance measurement.
Method Research on Information Fusion of Reciprocating Machinery Fault Diagnose
Authors: Wang Li Yong , Li Le , Li Yang Long
Published: September 2013

The reciprocating machinery has complicated structure, various motion forms and high difficulty of fault diagnosis, now we mainly apply the multi-sensor information fusion as the effective solution. This thesis introduces the structure model of reciprocating machinery information fusion, establishes the tree diagnosis model for fault diagnosis feature information fusion of reciprocating engine, describes the fusion diagnosis steps, and puts forward the technological approaches and methods to solve fault diagnosis information fusion of reciprocating engine from the aspect of testing methods and diagnosis modeling.
Identification of Loads on Shield Tunneling Machines Based on PSO-SVM Method
Authors: Zheng Zheng , Chen Kui , Zhang Qian
Published: September 2013

The effective control of loads acting on shield tunneling machines is vital for the equipment operating security. The identification of shield machine loads is a non-linear multi-factor problem. This article proposes an identification method for shield machine loads by using the Particle Swarm Optimization (PSO) based Support Vector Machine (SVM). A PSO-SVM identification model is developed based on on-site data of a subway project. This model implements multi-parameter input related to loads, which reflects the mapping from loads to geological parameters and operating parameters during tunneling. The comparison between identification results and the on-site data verify the accuracy of the PSO-SVM method. This work can offer helpful references for the loads control.
Research on the Relationship between the Anchor Pattern Characteristics and Adhesion Based on Neural Network
Authors: Liu Shu Cong , Song Yan Xing , Li Yan Qin , Yao Zhen Jing
Published: September 2013

The anchor characteristics are important factors in the quality of surface treatment of the tube, a good anchor pattern characteristic will ensure the best adhesion between the coating and the substrate. Surface roughness, micro-roughness spacing of anchor pattern and anchor pattern depth are main factors composed of anchor pattern characteristics. Adhesion prediction model was constructed using the BP artificial neural network , according to the relationships between the adhesion and various factors , which not only can achieve nonlinear relationships with high prediction accuracy between the anchor characteristic and adhesion, but also shorten the test time and reduce testing costs.
Soft Measurement Technology and Implementation Based on PSO-SVR
Authors: Zhu Lin , Cai Tian
Published: September 2013

Aiming at the important parameters of industrial process can not be online measured by sensors, this paper proposes a soft sensor modeling method based on PSO-SVR, and analyzes the technical bottleneck of the soft measurement model applied in engineering, designs the online application system of soft-sensing model with OPC technology. This paper discusses in detail the implementation steps of exchanging data between MATLAB algorithm model and WinCC industrial control configuration platform with OPC technology. The method has the advantages of simple integration and easy to implement, has certain application value.
Stereo Vision for Bus Traffic Conflict Investigation
Authors: Battiato S. , Cafiso S. , di Graziano A. , Farinella G.M. , Giudice O.
Published: September 2013

In this paper an imaging system for bus traffic conflict investigation is presented. The system employs geo-referenced stereo sequences and tracking procedure to provide much greater information regarding pre-crash and crash events than what is currently available. The exploitation of the traffic conflict technique potentiality as a surrogate safety measure could constitute an effective tool in understanding how the driver interacts and adapts its behavior with respect to the vehicle, the road characteristics, the traffic control devices and the environment. Experiments performed on real data acquired in urban context confirm the effectiveness of the system for the traffic conflicts measurement and the driver behavior analysis.
Improved Fuzzy C-Means Based on the Optimal Number of Clusters
Authors: Feng Xue Bo , Yao Fang , Li Zhi Gang , Yang Xiao Jing
Published: September 2013

According to the number of cluster centers, initial cluster centers, fuzzy factor, iterations and threshold, Fuzzy C-means clustering algorithm (FCM) clusters the data set. FCM will encounter the initialization problem of clustering prototype. Firstly, the article combines the maximum and minimum distance algorithm and K-means algorithm to determine the number of clusters and the initial cluster centers. Secondly, the article determines the optimal number of clusters with Silhouette indicators. Finally, the article improves the convergence rate of FCM by revising membership constantly. The improved FCM has good clustering effect, enhances the optimized capability, and improves the efficiency and effectiveness of the clustering. It has better tightness in the class, scatter among classes and cluster stability and faster convergence rate than the traditional FCM clustering method.
CFD Investigation of Damper Plate Effect on Air Flow in High Speed Rotation Hard Disk Drive by Using K-E with a Partial Model
Authors: Suriyawanakul Jarupol , Tangchaichit Kiatfa
Published: September 2013

In HDD air flow simulation, the well known LES turbulent model requires large computing times and resources, including CPU, RAM and storage intensive which is not appropriate when using various variables. The effect of an air damper is studied by the k-e model with a reduced boundary due to the lower number of equations, computing time and computer resources. Firstly the RMS velocities of a partial model are compared between LES and k-e and then the reduced boundary models are compared with the partial model. The RMS velocity errors of the partial model compared with LES and k-e are less than 6 %. The mean RMS velocity errors compared with the reduced boundary model and the partial model are 3.93% at ID and 2.12% at MD position while the OD position increased to 26.5% because there is no effect from a return flow from the flex bracket and voice coil zone. Computing time of the reduced boundary and k-e model is reduced by 68.4%. In primary HDD air flow analysis, the k-e method together with a reduced model can be used to predict the effect of an air damper.
A Weighted OMP Algorithm for Compressive UWB Channel Estimation
Authors: Li Guo Zhu , Wang De Qiang , Zhang Zi Kai , Li Zhi Yong
Published: September 2013

We investigate ultra-wideband (UWB) channel estimation based on compressive sampling (CS), where the orthogonal matching pursuit (OMP) algorithm is employed to recover the channel waveform from noisy measurements. In order to boost the robustness of OMP in the presence of additive Gaussian noise (AWGN), we propose a weighted OMP (WOMP) algorithm. For a given sparse dictionary, weighting factors are assigned to the atoms and a weighted matching process is performed by WOMP. Simulation results show that the proposed WOMP is more robust than the original OMP and can be used to gain better channel estimation precision.
Artificial Fish Swarm-Based Energy-Efficient QoS Classification Algorithm to Next Generation Electric Power Communication Networks
Authors: Meng Fan Bo , Zhao Hong Hao , Zhao Qing Qi , Ma Wei Zhe , Cao Ying , Wang Lei
Published: September 2013

This paper studies the problem of QoS graded optimization in the next generation electric power communication network and proposes an energy-efficient QoS graded optimization method based on artificial fish swarm algorithm. Firstly, this paper discusses the networks model of the QoS graded optimization and describes the networks model using delay and packet loss ratio in time-variant network. Secondly, we set up the model of networks throughput and energy consumption using the characteristics of delay and packet loss ratio in time-variant network. Finally, simulation results show that our approach is effective.
Pattern Analysis of Physico-Mechanical Anti-Seismic Structure
Authors: Wang Jian Guo , Wang Xiao Yan , Zhang Chang Jun , Wang Jian Qiang , Deng Kai
Published: September 2013

Brick-concrete structures and common buildings are destroyed in strong earthquakes. Based on physical mechanics, a pattern contrast illustrates three special designs of building structure---removal of basal markets and underground garages, use of corrugated beams, adoption of trapezoid bars---that may effectively avoid damages and casualties.
A New Analytical Expression of Overall Collision Efficiency for the Water Droplet Impinging on a Cylinder
Authors: Chen Ling , Liu Rui , Cao Yong Xing
Published: September 2013

The ice amount accreting on the rotating multi-cylinders can be used to obtain the liquid water content (LWC) and the median volume diameter of water droplet (MVD) based on cylindrical icing model. In this model, the overall collision efficiency is usually calculated by Finstads (φ100) and Langmuirs formulations (φ<100). But this combined expression doesnt agree well with the numerical calculation in some case. This paper gives a new expression based on a large number of numerical calculation results, and this expression agrees better with the numerical computation than existing expression.
Perspective of Digital Architecture World
Authors: Lin Zhou
Published: September 2013

Digital technology has played a crucial role in architectural development since being introduced in. Different application of digital design software has taken the place of traditional drawing. The innovated architecture design process has promoted a trend of space complexity. Advanced digital technology also produced a new design method; the computer can generate a unique building plan through the special program directly rather than the imagination of the human brain. Besides, digital technology has a wide range of applications in exploring the future architecture development, as well as virtual reality in the scheme deliberation and demonstration. The digital architecture has broken through the two-dimensional architectural design pattern and the aesthetic consciousness of the industrial era, and pushes the building industry development greatly.
Computer Aided Process Planning for Freeform Surface Sheet Metal Features in Automotive Industry
Authors: Saleh M.A. , Hussein H.M.A. , Mousa H.M.
Published: September 2013

This paper describes computer aided process planning for a freeform surface; sheet metal features. Automotive body panels are always manufactured using thin forming sheets; the developed CAPP system consists of two modules which are feature recognition module based on STEP AP203 and a process plan module; two additional modules for automotive panel CAPP system and cost estimation module are also incorporated in the system of punch and bending operation. Stamped or punched features in generative shape design are used to design automotive panels; the generative CAPP system is written in visual basic 2008 language and implemented in several case studies demonstrated in the present work. Feature recognition of punched; stamped internal features in free form surface recognized in base of data exchange files using STEP AP203 ISO-10303-21.
Balanced Ventilation Principle in the Application of Shigetai Coal Mine Ventilation System Optimization
Authors: Wang Wen Cai , Li Ya Chen , He Chao Ping , Zhang Bo , Zhao Hui
Published: September 2013

In order to reduce Shigetai coal mine ventilation resistance of mine ventilation system, using balanced ventilation principle Shigetai coal mine ventilation resistance of mine ventilation system was analysed and balanced, and the balanced ventilation resistance measure mine ventilation resistance in 2014-2015 simulation calculation. Results suggest that balanced ventilation measures implemented in mine ventilation resistance, coal mine ventilation resistance in the next two years not only with increased ventilation line length increases, but lower. Visible, balanced ventilation of mine has better technical and economic results are obvious, merits promotion.
A Dissipative Hydrological Model and its Application in the Hotan Oasis
Authors: Huang Ling Mei , Shen Bing
Published: September 2013

Hydrological model is an essential tool that has played an important role to manage water resources. In the arid oasis plain, there is almost no runoff from the rainfall event. Water supply mainly depends on the surface runoff generated from the rainfall, snow and glaciers melting in the mountainous region. The oasis is a place where runoff components gradually disappear through evaporation, transpiration. Due to human activities, water transformation occurs frequently among surface runoff, soil water, and groundwater. Based on the oasis water cycle and monthly water balance, a dissipative hydrological model was developed to simulate the quantitative relationship among atmospheric water, surface water, soil water and groundwater. The data set collected in the Hotan Oasis was applied to calibrate the model parameters and validate the model. The results showed that the model structure is reasonable and it can be used to compute the volumes of water consumption in the oasis. By quantitatively calculating the components of water balance, we can kwon where and how much water goes and responding measures of water resources regulation would be made to facilitate the effective and efficient utilization of water resources.
Research on Model-Designing & Architecture of IOT-Based Intelligent Transportation System
Authors: Zhang Wen Ying , Wang Xi Fu , Feng Xue
Published: September 2013

The dissertation discusses the significance of this thesis of current Intelligent Transportation System forward from the present research as a starting point; secondly, by analyzing the existing problem, we describe the necessity of leading the IOT technology into ITS; finally, we can prove that the new architecture of ITS in IOT can surpass the existing Intelligent Transportation System.
The Classification of Low Permeable and Low Yield Reservoir Based on Grey Relational Clustering Analysis
Authors: Lu Yan Feng , Liao Rui Quan , Li Jun Liang
Published: September 2013

In accordance with the non-dimensional data feature of low permeable and low yield reservoir, this paper defines the distance between non-dimensional vectors and establishes a grey correlation degree quantification model of non-dimensional data series, which exploits relevance weighting method and objective weighting method to determine the comprehensive weight of classification indexes respectively and establishes a grey clustering analysis model to sort the oil wells and obtain the maximum spanning tree to classify the low permeable and low yield reservoir in a certain confidence level. The actual classification results of the two laminated production wells of Baoziwan reservoir of Changqing oilfield shows the grey relational clustering analysis of low permeable and low yield reservoir classification has extensive adaptability for non-dimensional data, and the weight is determined rationally, the method could classify oil wells under different confidence level according to different requirement, which has preferable guidance to practical problems.
An Innovative Improvement on Standard Testing Procedure for Biomaterials under Uniaxial Tension
Authors: Adull Manan Nor Fazli , Mahmud Jamaluddin , Ismail Muhammad Hussain , Arzami Nur Hanis
Published: September 2013

Numbers of standard testing procedure are available for quality control to produce reliable test results. Nevertheless, there are always areas for improvement to the existing standards. This paper for the first time introduces and assesses the use of additional marker (pin) as an alternative measuring points. This innovative idea is hoped to improve the standard testing procedure (ASTM Standard D2209-00), which covers the uniaxial tensile test for leather. Initial work includes preparing samples (Dogbone shape) according to standard. The standard testng procedure is carried out twice. The first test (stage 1) was according to the original standard and the second test (Stage 2 modified protocol) includes several initial attempts to attach the marker pins at the optimum location. Adjustments are made to ensure the marker pins attached firmly to the sample material before standard measurement of displacement and strains using the common testile test machine. tension test, generating result (Displacement and Strain). The results for both original and modifies procedure are compared. It is found that the modified procedure reduced the variation in displacement and strain measurement. By comparison, a significant reduction (63.57%) of range difference between modified and original is computed. This proves that the current modification is significant and produce better results than the original procedure, which could be beneficial for future research especially in biomaterials engineering.
Impact Toughness of Kenaf Powder, Polypropylene and Kevlar
Authors: Kamardin Nur Kamarliah , Taib Yakub Md. , Kalam Anizah
Published: September 2013

mpact and tensile properties were carried out on Kenaf Powder (K) Polypropylene (PP) reinforced with Kevlar (KV) composites plate prepared in-house using hot press technique. The effect of bonding agent, Maleic Anhydride grafted Polypropylene (MAPP), on the strength and impact toughness was also conducted. The size of kenaf powder used was limited to 100μm. The kenaf/polypropylene composite designated as KPP specimens were tested through tensile test (ASTM D 638) and izod test (ASTM D256) for 20-40% weight ratio of kenaf powder. The optimum weight ratio of KPP sample was selected and then underwent for the drop impact testing. The selected KPP sample was further reinforced with Kevlar cloths. This hybrid composite is designated as KPP/KV sample and further tested in izod impact and drop tests. The impact toughness of KPP reinforced with KV is almost 4-6 times without KV. There are also slight improvements in the impact toughness of the KPP/KV samples with MAPP.
Chatter Suppression with Magnetic Damping in Turning of Stainless Steel AISI 304
Authors: Mohammad Ummu Atiqah Khairiyah B. , Amin A.K.M.N. , Bin Ahamad Mahrodi Muhd Amir Hafiz , Arif Muammer D.
Published: September 2013

Chatter is almost an unavoidable phenomenon during machining, normally accompanied by a characteristic sharp and monotonous noise. Apart from noise pollution in the industry, chatter leaves a bad surface finish on the part and negatively influences dimensional tolerances, reduced productivity, excessive tool wear and damaged machine-tool components. Therefore, chatter avoidance is utmost importance. However, a deeper investigation into chatter formation reveals that chatter appears during metal cutting process as a result of resonance caused by interaction of the prominent natural frequencies of the system with the frequency of chip serration. This paper presents an innovative approach to chatter suppression during turning of stainless steel AISI 304 applying permanent magnet from the bottom of the tool holder to increase the damping coefficient of the tool holder, since it has been identified that the tool holder is the main vibrating component during turning. A special fixture was designed, fabricated and mounted on the carriage of a conventional turning machine Harrison M390 for holding a permanent magnet bar. The variable cutting parameters were - cutting speed, feed rate and depth of cut at constant tool overhang of 120 mm. The experiments were designed based small Central Composite Design (small CCD) based on the Response Surface Methodology (RSM) approach using DESIGN EXPERT (DOE) software. The experiments were performed under two different conditions, the first under normal conditions, while the other was under the application of magnetic field from permanent magnet located side direction of the tool holder. The experiments focused on monitoring the vibration signals using a vibration data acquisition system during turning operation. Analysis of the recorded signals in the FFT domain indicated significant reduction of chatter when a magnetic field is applied. It is apparent that a reduction of chatter amplitude will result in improved surface finish, tool life, machining accuracy, productivity, as well as reduction of operation.
Effect of Low Impact Energy on Kenaf Composite and Kenaf/Fiberglass Hybrid Composite Laminates
Authors: Salleh Z. , Hyie Koay Mei , Berhan M.N. , Taib Yakub Md. , Hassan M.K. , Isaac D.H.
Published: September 2013

Kenaf fibres recently have been a substitute material in many weight-critical applications such as aerospace, automotive and other industrial sectors. Their characteristics, such as low densities, specific strength and specific modulus are considered superior to those of metallic materials. The tensile and low velocity impact of kenaf composites and kenaf/fibreglass composites were investigated. The findings of such revealed that the tensile properties of the composites were seriously impaired even when low energy was used. As for hybrid composites, the tensile properties were hardly affected when tested with energy of below (6J). However, the tensile properties were reduced after the energy increased above (6J). Therefore, the impact damage of the composites can be predicted from measurements taken from the residual tensile strength of impacted specimens, and the damaged zones of the composites.
Modelling of Material Removal Rate in EDM of Nonconductive ZrO2 Ceramic by Taguchi Method
Authors: Sabur A. , Mohammad Yeakub Ali , Maleque M.A.
Published: September 2013

Electro discharge machining (EDM) technique, a noncontact machining process, is applied for structuring nonconductive ZrO2 ceramic. A conductive layer of adhesive copper is applied on the workpiece surface to initiate the sparks. Kerosene is used as dielectric for creation of continuous conductive pyrolytic carbon layer on the machined surface. Experiments are conducted by varying the peak current (Ip), pulse-on time (Ton), pulse-off time (Toff) and gap voltage (Vg). Correlating these variables a mathematical model for material removal rate (MRR) is developed using Taguchi method. The optimized parametric conditions are determined for higher MRR through ANOVA and signal to noise (S/N) ratio analysis. The results showed that the Ip and Ton are the significant parameters of MRR in EDM for nonconductive ZrO2 ceramic. The model also showed that MRR increases with the increase of Ip and Ton, but the process is controlled by Ip as a whole.
Wing-Fuselage Lug Stress Prediction Using Finite Element Method
Authors: Abdul Jalil Abdul Malik Hussein , Kuntjoro Wahyu
Published: September 2013

This paper describes the methodology to predict the stress level that occurs at the wing-fuselage lugs (joints). The finite element models of the wing, the wing lugs and the fuselage lugs were developed. Finite Element Analyses were performed using NASTRAN finite element software. CQUAD4 and BAR2 elements were used to represent the individual structures of the wing such as the ribs and stringers. The applied load was based on the symmetrical level flight condition. Once the load distribution acting at the wing had been calculated and applied, reaction forces at the nodes representing the wing lugs were obtained and these values applied to the lug models where the maximum stress value acting at the lugs was obtained.
Feed Rate Influence on Motion Error Characteristics of CNC Vertical Milling Machine
Authors: Ahmad Bakir Azman , Ahmad Zainal Abidin , Mohamed Mazlan , Hassan Mohd Nor Hakim , bin Ahmad Muhamad Iqbal
Published: September 2013

The increasing number of the Computer Numerical Control (CNC) machines usage in the manufacturing field appears to suggest that they are expected to be in good running condition. Machine tools such as CNC vertical milling machines are meant to produce precise work parts. Motion errors are factors which can directly affect the accuracy of the machine. This study presents an opportunity for interested parties to understand the characteristics of motion errors that exist in the CNC vertical milling machines with different feed rate settings. The purpose of this project is to find out any abnormalities apparent to the machine performance as the feed rate setting is increased. The motion errors of the CNC machines were examined by using a measuring device, namely Double Ball Bar (DBB). This equipment is designed to examine machine performance by measuring the accuracy of its movements. This device, which has two balls of identical size at the end of the bar, was mounted on a spindle and onto a special holder which is mounted on the working table. The machine is programmed to move in a circular motion, clockwise and anti-clockwise in three planes, XY, YZ and ZX. Any deviation from the standard data will represent the imperfection of the machines condition, especially mechanical components such as the slide bearing, spindle bearing or servo motor responses. By knowing the most significant error origin, the corrective countermeasures can then be carried out.
Numerical Study of Winglet Cant Angle Effect on Wing Performance at Low Reynolds Number
Authors: Mat Taib C.F. , Jaafar Abdul Aziz , Kasolang Salmiah
Published: September 2013

The study on the effect of winglet shape in wing design has been a focus of many researchers. Nevertheless, the effect of cant angle on the wing performances at low Reynolds number has not been fully explored. This paper describes the effect of a single semi-circular shaped winglet attached with a rectangular wing model to lower the drag without increasing the span of the wing. Aerodynamic characteristics for the rectangular wing (NACA 65-3-218) with and without semi-circular winglets have been studied using STAR CCM+ 4.0. This numerical analysis is based on Finite Volume Approach. Simulations were carried out on the rectangular wing model with and without winglet at aspect ratio of 2.73 and Reynolds number of 0.16 x 10 6 for various angles of attack. From the numerical analysis, wing performance characteristics in terms of lift coefficient CL, drag coefficient CD, and lift-to-drag ratio, CL/CD were obtained. It was found that the addition of a semi-circular winglet has resulted in a larger lift curve slope and higher Lift-to-Drag ratio in comparison with the case of a wing without winglet. Further investigation has revealed that a wing with semi-circular winglet with cant angle of 45 degree has produced the best Lift-to-Drag ratio, CL/CD.
A Numerical FEM Solution of Gear Root Stress in Offset Axial Mesh Misalignment
Authors: Lias Mohd Rizal , Awang Mokhtar , Rao T.V.V.L.N.
Published: September 2013

Gear offsets mesh in axial misalignment always leads to unevenness of load transferred contributing the impact of stress value and distribution along important critical path of the tooth root. Its happening due to overpress fitting when the gear is mounted onto the shaft as an interference hub fit. Current design methodology based on empirical model provide solution by approximation load factor fail to attributes in detailed regarding this phenomenon This paper determined to focus on this phenomenon in term of methodology to the stress distribution at the critical contact region of the tooth root of the gears. Pair of spur gear with real geometrical construction and condition was constructed with offset parameter. A moving load quasi-static model with a numerical FEM solution using ANSYS is presented with modification in loading variation. For verification, the stress value at the critical path of the tooth root is compared between standard high point single tooth contacts (HPSTC) loading to moving load model. As the result, a numerical FEM methodology to calculate the stress distribution of the gear tooth root in offset axial misalignment with moving load model approach is determined. The proposed method is also found reliable as an alternative solution to define an accurate load factor calculation compared to the approximation provided by the standard empirical procedure.
Impact Response of Laminated Composite Cylindrical Shell: Finite Element Simulation Approach
Authors: Sharifi S. , Almula Thamir Aunal Deen Mohammed Sheet , Gohery Scott , Sharifishourabi G. , Saed Yob , Yahya Mohd Yazid Bin
Published: September 2013

The effect of low velocity impact response on the thin laminated composite cylindrical shell with different stacking sequences was investigated. Finite element simulation using ABAQUS software was the base of the study during the analysis. The framework was to study the stress and displacement in radial and circumferential directions through finite element simulation. For simplicity, an arbitrarily picked circumferential path at where the impactor impacts the shell surface was selected. The graphs plotted based on stress and displacement variables Vs radial and circumferential directions did not show the significant changes for laminations with different stacking sequences. In addition, The 90 degree along circumferential and radial directions was found to be the critical point.
Green Polyurethane Adhesive Bonding of Aluminum: Effect of Surface Treatments
Authors: Muhammad Zain Norazwani , Ahmad Sahrim H. , Ernie Suzana Ali
Published: September 2013

Aluminum alloy 2024-T3 was treated by two different methods of surface treatments i.e. by alkaline etching and warm water treatment followed by silanization method in order to enhance the adhesive bonding. The effects of both the substrate surface condition and the adhesive properties on singlelap shear resistance were analysed. Three different formulation of polyurethane adhesive by varying the NCO:OH ratio which were prepared from polyol based on polycaprolactone (PCL)/palm kernel oil (PKO) with an aromatic and cycloaliphatic diisocyanate. Moreover, wettability tests were performed in order to evaluate the effect of all parameters mentioned above on the substrate/adhesive interaction. Surface treatment with warm water and ɣ-GPS gives better wettability and adhesive bonding compared to alkaline etching surface treatment.
Development of Gait Training System Powered by Antagonistic Mono-and Bi-Articular Actuators Using Contraction Model Control Scheme
Authors: Mat Dzahir Mohd Azuwan , Nobutomo Tatsuya , Yamamoto Shin Ichiroh
Published: September 2013

The use of Pneumatic Muscle Actuator (PMA) in medical robots for rehabilitation has changed due to the requirements for a compliant, light weight and user-friendly robotic system. In this paper, a control system for controlling the bi-articular actuators (PMA) is proposed. Based on the information obtained from the positional input data (hip and knee joint angles), a contraction model is derived using mathematical equations to determine the contraction patterns of antagonistic mono-and bi-articular actuators, and then implemented it into the control system. Anterior and posterior muscle activation levels are introduced into the model to manipulate its magnitude. There are two tests for the control system; first is with antagonistic mono-articular actuators alone; second is along with antagonistic bi-articular actuators. The contraction model control scheme was tested on a healthy subject in a robot assisted walk test, and satisfactory performance was obtained. The result showed that, the cycle time of the gait training system is improved up to 3 seconds gait cycle compared to 5 seconds gait cycle used in previous research. However, a little time shift and inertia occurred when the controller is tested at faster gait cycle time of 2 seconds and 1 second. Thus, the potential field and iterative learning control are suggested to improve the gait cycle of the system.
Robot-Assisted to Elicit Behaviors for Autism Screening
Authors: Hashim Hafizan , Yussof Hanafiah , Hanapiah Fazah Akhtar , Shamsuddin Syamimi , Ismail Luthffi , Malik Norjasween Abdul
Published: September 2013

Early screening and diagnosis of Autism spectrums is essential to determine the best means of early intervention program. Since there is no sign in biological for autism, screening and assessment must focus on the behavioral deficits. Somehow screening is not a diagnosis, but a filter that picks out children for subsequent assessment. The aim of this paper is to propose and to ignite discussion concerning robotic assisted in autism screening process to enable early diagnosis and intervention. This process combines (a) selection of an autism screening tool (b) refinement of screening subscales and (c) integration of subscales with robot action. We use Gilliam Autism Rating Scale-2 (GARS-2) inversely integrated with humanoid robot Nao to produce a counter action to elicit individual behaviours for screening and diagnosis purposes. In extracting of GARS-2, we had considered the limitation and sensitivity when a robot tries to assist in the process of screening and diagnosis. Integrating robotics into innovative treatments however highlighted the need for additional rigorous empirical studies with quantitative measurement.
Human-Robot Interaction (HRI) for Children with Autism to Augment Communication Skills
Authors: Hamid Aminullah Che , Miskam Mohd Azfar , Yussof Hanafiah , Shamsuddin Syamimi , Hashim Hafizan , Ismail Luthffi
Published: September 2013

This paper presents a case study of robot-based intervention program for children with autism. The study focuses on two-way communication between children with autism and a humanoid robot NAO. The aim of this study is to develop a set of teaching and learning modules on communication through question type conversation and song-based approach. Module developed in this study is programmed using NAOs choregraphe, being imbedded later on and perform action. Both children participating in this study can communicate verbally and have been diagnosed with mild autism. Response from this exposure shows that the human toddler-like robot can be used as a platform to augment and facilitate communication effectively with children with autism.
Input Shaper Design for Minimum over Travel
Authors: Gürleyük Sirri Sunay
Published: September 2013

nput shaping control reduces overshoot and settling time in oscillatory dynamical systems. Although its vibration eliminating ability is very successful, the controlled output cannot response quickly to a stop-now command. The controller produces a delay penalty for travel motion to perform non-oscillatory result. The delay when a system comes to the rest position is known as overtravel. In this study, an optimal solution is searched for input shapers to reduce the induced overtravel in addition to oscillation elimination. The expression overtravel is used as an extra constraint in the input shaping design process to reduce the shaper duration. Comparisons between the new shapers are given here for minimum overtravel and maximum robustness. Results show efficiency of the new shapers.