bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect and Analysis of Cable Distributed Capacitance on Secondary Side Harmonics in Port Power Distribution System
Authors: Yang Wen Huan , Chen Hai Xu , Li Rong Gao
Published: September 2013

The power distribution system lays lots of power cable, and mainly uses variable velocity variable frequency technology with power energy feedback in modern ports, which generated much harmonics. This article mainly researches harmonics amplification caused by distributed capacitance of power cable when harmonics are generated at secondary side. By the way of basic theory of electric circuit, we analyze the mutual influence between system harmonic and distributed capacitance of power cable in port power distribution system. It is known that through analysis the power cable distributed capacitance has different influence such as enlargement, suppression or filtering etc on system harmonic, finally the theory is verified by PSCAD/EMTDC simulation.
Utilization of Albizia Wood (Albizia falcata) and Ramie Fibers as Wind Turbine Propeller Modification of NACA 4415 Standard Airfoil
Authors: Sudarsono  , Purwanto  , Soedarsono Johny W. , Munir Badrul
Published: September 2013

Ramie fibers and albizia wood, which are abundantly available in Indonesia, were used in fabricating hybrid sandwich composite for wind turbine propeller. A prototype was fabricated by modification of NACA 4415 standard airfoil, intended for low speed wind and environmental friendly operations. Hand lay-up method was applied for fabrication of this hybrid composite with one and two layers of ramie fiber. Mean volume fiber fraction (vf) of one-layer and two-layer composite are 47,12% and 44,82%, respectively. The highest measured bending stress is 30.88 MPa for two-layer composite with modulus of elasticity 2.02 GPa and bending strain 1,795%. Microstructure of this hybrid composite is unchanged significantly after 5.5 months operation. With ultimate simplicity and low manufacturing cost, hand lay-up method is suitable for small scale production.
A New High Resolution Measurement Technology of D Flip-Flop Output Signals for Measuring Frequency Difference
Authors: Dong Jin Feng , Zhang Wei Yu , Liu Hua Liu , Wei Yong
Published: September 2013

The output periods of D flip-flop mixer are variable though the periods of two input frequencies are invariable. To measure the output frequency, the conventional method is to calculate the average value of the output periods and the maximum possible absolute error is a clock period. The variation of the output periods has its own pattern of arrangement and it can provide valuable information. Measuring accuracy can be significantly improved by taking into account all the details of output periods changes. A mathematical model that describes the relationship between the input square waves and the output square waves was developed and the difference of two input frequencies can be estimated by the solution of the model. The new method is quite suitable for measuring small frequency increments of quartz crystal resonators.
Design of Driving Cycle Data Acquisition System Based on GPS
Authors: Jing Lei , Wan Ren Jun , Wei Ke Xin
Published: September 2013

The article introduces a data acquisition system based on GPS and LPC1768 microcontroller as the core and SD card as storage medium.Meanwhile,it shows hardware design and software design to realize a design of driving cycle data acquisition system
A Real-Time Multiple Acoustic Sources Localization Method Using Widely Spaced Microphone Array
Authors: Gu Tian Yi , Zhao Zhao , Wu Ya Qi , Xu Zhi Yong , Wang Jing Yi
Published: September 2013

A real-time disambiguous localization method for multiple acoustic sources using widely spaced microphone array is proposed in this paper. The observation signals in each frame are firstly discriminated utilizing conventional energy-based sound detection measurement. Using inter-microphone phase differences (IPD), as well as an iterative cluster process, the DOAs of sources can be estimated while the phase wrapping ambiguity in conventional DUET is avoided.
Analysis about Random Failure Indicator for Relay Protection
Authors: Peng Zhi Feng , Yang Ming Yu , Zhou Qing Jie , Yuan Cheng Yong
Published: September 2013

This paper puts forward a random failure indicator of relay protection, and describes the reliability of relay protection through exponential function. At the same time, the reliability model is modified and improved on the basis of actual structure. Also, a reliability function of relay protection random failure is constructed, and a method of calculating random failure reliability is proposed. Then, status of relay protection devices from some pilot substations in one region is evaluated by using the above method. The result shows that the random failure reliability of the relay protection equipment can be calculated by the method and the calculation result can actually reflect the equipment status.
Voltage Sag Source Localization Based on the Voltage Distance Function in Distribution Network
Authors: Liu Yu , Wang Jin Hao , Yang Chao Ying
Published: September 2013

To realize voltage sag source localization in distribution network, the paper proposes a function fitting method based on the least squares. Establish a voltage distance function in response to fault distance changes by the line voltage. According to the voltage distance function, combine with the bus voltage after fault to find out likely fault section and distance. Through the sorting algorithm to sort all possible results, weaken the effect of pseudo fault point on the judgment result. Finally the simulation verifies the effectiveness of the method.
A Caculation Method of Wave-Maker Mechanical Parameters Based on Matlab and Excel
Authors: Wang Shou Jun , Yang Li Bo
Published: September 2013

Wave-maker mechanical parameters play an important role in the stability of the wave systems. Accurate mechanical parameters are the key part and basic work in the design and analysis of one wave-maker. In order to meet the strength, stiffness and response time requirements, its necessary to have its stress analysed before, which is meaningful to the design of the wave-maker. According to this situation, a caculation method of wave-maker mechanical parameters based on Matlab and Excel is introduced in this paper.
Numerical Investigation of Adhesively Bonded Joints
Authors: Hasan Abad Mahmood Mokhtari , Bakhtiari Reza , Choupani Naghdali
Published: September 2013

The study focuses on using fracture mechanics to evaluate mixed-mode fracture properties of adhesively bonded aerospace material systems. As a part of experimental efforts, mixed-mode fracture tests were performed using modified Arcan specimens consisting of several combinations of adhesive, composite and metallic adherends using a special loading device. Experimental and numerical studies of mixed-mode fracture behaviour of adhesively bonded aluminum and steel were also performed using an adhesive in the aerospace industry. Finite element analyses were carried out on specimens with different adherends. Based on those analyses, many fundamental numerical results were obtained.
Recovery of Silver from Zinc Acid-Leaching Residue by Flotation
Authors: Yang Zhi Chao , Ge Ying Yong , Zhang Yuan Long , Zhao Jun Li , Zhu Kun
Published: September 2013

Through flotation recovery of Silver (Ag) from Zinc acid-leaching residue (ZALR) was investigated in this study. The study adopted the single factor and orthogonal test reveal interactions among all considerable influence factors including sodium sulphide (SS) as regulator, ammonium butyl dithiophosphate (ABD) as major collector, GC as minor collector, interaction between ABD and GC, OC as flotation carrier, and pulp density. The experimental results show the flotation of the circuit composited of one rougher, one cleaner, one scavenger and middlings being back to the next rough flotation together is practical way and that the concentrate containing Ag 10890.0g/t, recovery77.43% can be obtained from the residue (Ag grade 340g/t). The optimum roughing flotation process is: the pH value of flotation pulp is 3.0~4.0, the pulp density is about 45wt.%, ABD dosage is 900g/t, GC dosage is 50g/t, OC dosage is 2000g/t, and BK201 dosage is 100g/t.
Anatomization of Stresses on a V-12 Engine Crankshaft Vulnerable to Varying Imposed Forces
Authors: Gulzar Mubashir , Anwar Muhammad Saqib , Hussain Mudassir , Malik Muhammad Sajjad Sabir
Published: September 2013

Crankshaft is an important component of an engine with intricate geometry which converts the linear displacement of piston into rotary motion. Since the crankshaft is predisposed to massive loads during combustion cycles, so different factors like endurance has to be kept in mind while designing crankshaft. Keeping in view the above scenario, the main motive of this paper is to do the fatigue analysis so that we can analyze various factors that are affecting the service life of crankshaft.
Geometric Modeling of the Frequency of an Acoustic Detonation Pressure Wave in a Standard Spark Ignition Engine
Authors: Gulzar Mubashir , Talal Jameel M. , Tariq Sufyan , Khalid Umair
Published: September 2013

In an archetypal engine the detonation frequency is usually analyzed using an overly simplistic model, incorporating only the rudimentary parameters (modeling the combustion chamber as a right circular cylinder). The research work is to develop a broader state space geometric model to discern the detonation frequency in a standard Otto engine based on engine conformation parameters. The intent of this project is to model the detonation event using a broader state-space i.e.to build on Draper’s Acoustic Wave Pressure formula and develop a sound underlying mathematical structure manifesting the models intricacies. The mathematical structure is predicated on standard wave equation, this mathematical generality makes it a potential candidate for future investigations into developing a superposition model using acoustic wave theory.
Stability Analysis of High-Speed Railway Vehicle Based on Multibody Dynamics Analysis
Authors: Kang Ju Seok
Published: September 2013

Multibody dynamics analysis is advantageous in that it uses real dimensions and design parameters. In this study, the stability analysis of a railway vehicle based on multibody dynamics analysis is presented. The equations for the contact points and contact forces between the wheel and the rail are derived using a wheelset model. The dynamics equations of the wheelset are combined with the dynamics equations of the other parts of the railway vehicle, which are obtained by general multibody dynamics analysis. The equations of motion of the railway vehicle are linearized by using the perturbation method. The eigenvalues of these linear dynamics equations are calculated and the critical speed is found.
Failure Analysis of Aluminum Reinforced Composite Vessel
Authors: Sulaiman S. , Borazjani S. , Roshanand A. , Heydaryan S.
Published: September 2013

At this paper attempts have been made to determine the effects of internal pressure on the reinforced composite pressure vessel. Finite element analysis (FEA) along with the Tsai-Wu failure criterion was utilized to predict the failure pressure of the vessel and the optimum fiber angle orientation. Six layers of E-glass/Epoxy and Graphite/Epoxyfibers have been selected to reinforce the aluminium vessel. Fibers were oriented with six different winding angles of 300, 450, 550, 600, 750 and 900 at asymmetric fiber orientation. The commercial code ABAQUS CAE was employed to simulate the model and analyse the structure. Results were revealed that Graphite/Epoxy has higher strength in comparison with E-glass/Epoxy fiber. Also it was observed that for both composite materials 550fiber angle is the optimum winding angle. Results were compared to the experimental ones and there was a good agreement between them.
A New Chaotic System Family Dynamics Analysis and Circuit Implementation
Authors: Duan Shu Min , Wu Guo Zeng
Published: September 2013

A new three-dimensional chaotic system is presented in this paper. Some basic dynamical Properties of this chaotic system are investigated by means of Poincaré mapping, Lyapunov exponents and bifurcation diagram. The dynamical behaviours of this system are proved not only by performing numerical simulation and brief theoretical analysis but also by conducting an electronic circuit implementation. It is new physical phenomenon that the Poincaré mapping of this system is a group of parallel lines.
Sliding Mode Control for BLDC Electromechanical Actuator Based on DSP
Authors: Zhou Jun , Li Peng , Zhou Feng Qi , Gao Zhi Gang
Published: September 2013

This paper deals with the design, simulation and implementation of a digital sliding mode controller for brushless DC motor-based electromechanical actuator. Firstly, a mathematic model of the actuator is drawn from its structure. Secondly, sliding mode control algorithm with the approach to weaken chattering is designed for the system, and simulations are carried out under Matlab/Simulink environment. Thirdly, the SMC algorithm is implemented on TMS320F2812 digital signal processor platform along with extensive experiments. Lastly, results of simulation and experiment are compared and discussed, showing that the proposed approach can achieve accurate and fast position tracking in the presence of load disturbance and plant parameter variations.
Deformation Characteristic of Thin Stainless Gasket Material
Authors: Shigeyuki Haruyama , Nurhadiyanto Didik , Ushijima Kazuya , Kaminishi Ken , Chen Dai Heng
Published: September 2013

Previous studies on corrugated metal gaskets have established that the contact width, contact stress, and surface roughness are important design parameters for optimizing gasket performance. However, the metal gaskets studied previously required a high axial force for the tightening process; in addition that metal gaskets tend to corrode easily. In this study, we examined the deformation mode of a thin stainless gasket using a finite element method (FEM) analysis. A final evaluation was made using a compression examination. The analysis based on the dimension of flat and convex portion. The load, deformation mode, and contact stress were obtained through a simulation. Based on the deformation of the flat and convex portions, the deformation modes were divided into three types. The deformation mode of the thin stainless gasket material has a higher probability of deformation in mode I when the aspect ratio of the length of the flat portion to the length of the convex portion, L/D, increases.
Design of Automatic Control System Program for Overhead Crane Based on VB6.0
Authors: Leng Jian Wei , Zhao Ya Ming
Published: September 2013

this design uses the industrial PC as upper computer. The bar code positioning system encoder and laser ranging sensors are used to locate the crane 3 d coordinate position. The crane automatic control program is based on VB6.0 .This paper analyzes the problems and solutions encountered in the implementation process, finally achieves the automatic control of the crane.
Research of Simulation in the Main Circuit of Static Var Generator Based on Cascade H-Bride
Authors: Dai Xian Bin , Yuan Xiao Hua , Du Wei
Published: September 2013

This paper introduces the working principle of the research of simulation in the main circuit of Static Var Generator based on Cascade H-Bride and takes the three-phase Static Var Generator based on cascade H-Bride with rated capacity 10kVar,rated voltage 380V for example to proceed the MATLAB simulation. The research shows that the more amount of cascade H-Bride, the more number of output voltage levels in the main circuit of Static Var Generator, the smaller value of voltage waveform distortion factor, and the less harmonic content be inject in electric network, which improves power index.
Photovoltaic Power Generation Investment Decision-Making Framework Based on Real Options Theory
Authors: Fang Shuo , Liu Jun , Liu Min , Zhang Zhi , Zhou Yan Hong
Published: September 2013

In the new electricity market environment, PV project investment faces more investment risks. For photovoltaic power generation characteristics of the project and with the integrated current research, we put forward the investment decision-making framework based on real option theory; we enrich and develop the applications of real options theory about investment decisions in the electricity, there are certain theoretical and practical significances.
Research on the Hydropower Frequency Control Strategy for Power Delivery Grid Splitting
Authors: Meng Li , Wang Hao , Tian Jian She
Published: September 2013

After power delivery grid splitting off from the main power grid, there is the risk of over frequency generator tripping leading to low frequency load shedding action. Regulation characteristic of hydro-turbine speed control system for regional power grid is analyzed by using the measured parameters of hydropower. The turbine speed control effect is analyzed without lower limit of primary frequency regulation. Frequency control improvement program of hydropower generating units in isolated power system is proposed based on wide area measurement system. The scheme uses WAMS to collect power information as governor PID output lead, and to calculate power target into the speed control system.
A New Duty Cycle Control Strategy for Digital Constant-Current LED Drive Based on Buck-Boost Topology
Authors: Wang Lin Bo , He Hong Kun , Shi Lei , Yang Jin Jin , Feng Qian Ni
Published: September 2013

This paper proposes a new digital constant-current control method for high-power LED drive based on buck-boost topology. In this control system, buck-boost topology is used as the power conversion. The output voltage can be either higher or lower than the input voltage in buck-boost topology. Therefore, it solves the problem that in the buck topology the input voltage is required to be always higher than the output voltage. Furthermore, according to the input and output parameters, the duty cycle data which are used to maintain output current constant can be calculated in advance, and stored in the embedded chip. Thus, it can reduce the calculation of the embedded chip and solves the problem that the existing digital constant-current controllers need the high-speed analog-to-digital converter. In addition, in order to reduce the error generated in above calculation, the double threshold feedback circuit is used to fine-tune the duty cycle and makes the output current more steady and accurate. Meanwhile, due to adopting full-digital control, the brightness and flicker frequency of load LED can be conveniently regulated by modifying the system firmware. Therefore, this method can apply to the device of illumination, lighting decoration, visible light communication and so on.
Grid Based Path Planning Using CNN & Artificial Potential Field Method
Authors: Akter Shamina , Lee Deok Jin , Lim Shin Taek , Chong Kil To
Published: September 2013

This proposed path planning method combines cellular neural network (CNN) with artificial potential field approach. The fundamental operation based on CNN gray scale image processing and artificial potential is the additional approach for global path-planning. Every point of the environment has a potential value with respect to start and destination position. In the trajectory planning process, a minimum search of potential value of every surrounding neighbor points around a point is done and the neighbor point with the least minimum value is selected as the next location. This procedure is repeated until the goal point is reached. The advantage of using CNN based image processing with artificial potential field function in a vision system is its effectiveness in robot localization while the use of minimum potential value gives a simple yet efficient path planning method. Their feedback criterion is similar to a procedure in filtering the image and it frequently updates the information about obstacles and free path. The parallel processing properties of CNN makes the proposed method robust for real time application.
Performance Analysis of Low Complexity Multiuser Scheduling Algorithms in MIMO System
Authors: Lv Ming Xia , Lai Yan Kun , Tang Dong
Published: September 2013

The total throughput of the communication system can be maximized by allocating the common radio resource to the user or the user group having the best channel quality at a given time and the multiuser diversity gain can be obtained when multiple users share the same channel at one time. The object to select the users is to select the users with the maximum sum capacity. As for a scheduling algorithm, exhaustive algorithm can get the largest capability of the system by multi-user scheduling. However, this algorithm is quite complex hence the cost of operation to a base station has substantial increased. We compare the multiuser performance of two fast user selection algorithms with low complexity in MIMO-MRC systems with co-channel interferences. From the simulation results, these two algorithms not only decrease the computational complexity of the scheduling algorithm but also retain large capability of the MIMO system.
Cement-Sand Based Piezoelectric Smart Composites
Authors: Liu Hong Yan , Zhao Ping , Feng Chen , Sharma Rohit
Published: September 2013

In this paper, preliminary investigation of a new cement-sand based piezoelectric composite was conducted for potential structural engineering applications. PZT ceramic powder has been incorporated into cement material to form composite smart materials in earlier studies and showed promising outcome. However, the previous studies were limited to using only PZT and cement. In this study, PZT powder mixed with cement and sand, which is more realistic in civil engineering applications. The compressive strength of the composites with different PZT volume ratios was investigated. The results showed that embed PZTs increased the strength of the composites. Modified Sawyer-Tower circuit was applied to pole the composites in order to obtain the desired electrical properties of the composites. The mechanical and electrical properties of this type of new smart material had been investigated experimentally. Through a series of MTS compression tests, feasibility of using cement-sand based PZT composite materials in civil engineering is evaluated.
Research on Effect of Gravity of Wave-Maker Installing Truss on its Deformation
Authors: Wang Shou Jun , Yang Li Bo , Fu Zhen Yu
Published: September 2013

In order to meet wave accuracy and response time requirements, its necessary to have the installing truss finite element analyzed, which can bring a knowledge of the stress and deformation of the installing truss at the same time. The force acted on the installing truss should be learnt before the finite element analysis of it, including the gravity of the wave-makers, the gravity of the installing truss, the resistance of water (transmit from the wave-plate),the torque caused by the resistance and the gravity of the installing truss is one of the important factors that affect the deformation. With the method of statics analysis and harmonic analysis, this paper have a further study on the effect of gravity of installing truss on its deformation.
Ecological Security Evaluation of Coal Resource-Exhausted Cities: A Case Study of Zaozhuang City in China
Authors: Zhang Bang Hua , Zhai Hong
Published: September 2013

By means of conceptual model of pressure-state-response model and the method of analytic hierarchy process, evaluation index system of ecological environment was built. Evaluation of ecological security was quantitatively calculated based on comprehensive index method. The evaluation of development trend and diversity of ecological security was conduct in the case of a typical coal resource-exhausted city-Zaozhuang city in China. The results show that ecological security of Zaozhuang city is in good tendency with little fluctuation in 2001-2009 and ecological security indexes in various districts with different coal mining histories are of some differences in Zaozhuang city.
Ergonomics Intervention in Assembling Air Handler Panels
Authors: Loo Huck Soo , Saad Nor Hayati , Redza Mohd. Ridhwan Mohammed , Rahman Rahani Abdul , Rashid Amirul Abdul , Isa Hamidun Md.
Published: September 2013

This paper emphasizes an ergonomics intervention to fit jobs for workers in the handling of air handler panels in a manufacturing factory. Ergonomic risk factors were identified by means of qualitative and quantitative data from general survey, participative assessments, and direct observations. Ergonomics intervention via real life experiment was implemented. Post survey incorporating participative assessments and direct observations was subsequently conducted to gauge its effectiveness. This intervention comprises the introduction of a steel trolley for horizontal placing of steel panels and a mobile steel rack for vertical placing of those panels. This action-oriented study produced results which were in line with the objective of the research.
Effect of Application of a Combination of Magnets on Chatter Amplitude Reduction in Turning of Stainless Steel AISI 304
Authors: Mohammad Ummu Atiqah Khairiyah B. , Nurul Amin A.K.M. , Bin Abdul Rappat Mohd Redzuan , Arif Muammer D.
Published: September 2013

This paper presents the results of experimental investigations of vibration analysis conducted on Engine Lathe Harrison M390 using variable cutting speed, feed rate and depth of cut at constant tool overhang of 120mm as the machining parameters ascertain the effectiveness of TiN coated carbide insert in turning of hardened steel AISI 304. The experiments were designed based on the Response Surface Methodology (RSM) approach using DESIGN EXPERT (DOE) software to enhance statistical model using the capabilities of RSM to compare the effectiveness of application of a combination of a bottom and a side magnet with respect to the tool holder in terms of reduction of chatter amplitude. The experiments were performed under application of magnetic field from two permanent magnets with magnetic strength of 1200 Gauss each with one located at the bottom and the other at the side of the cutting tool with distance 1cm from the tool. The dimension of the bottom magnet was 25 x 25 x 50mm and that of the side magnet was 87 x 50 x 17mm. The vibration amplitude data for the two conditions were compared to identify the influence of magnet on chatter reduction. The results reveal that a maximum of 87% and an average of 50% reduction of chatter acceleration amplitude were achieved with the said arrangement of the magnets. Furthermore, empirical mathematical model of maximum chatter amplitude was developed for machining with magnet application to predict the cutting parameters with the lowest value of chatter amplitude and maximum material removal rate.
Case Study: The Methodology of Lean Manufacturing Implementation
Authors: Halim Nurul Hayati Abdul , Jaffar Ahmed , Noriah Yusoff , Naufal Ahmad Adnan
Published: September 2013

This paper presents a review on the actual implementation of Lean Manufacturing (LM) techniques at a manufacturing area. It focuses on the execution of flow from the beginning until the end of the implementation, types of analyses and tools applied, evaluation methods and how the company benefited from the implementation. The on-site study was conducted at an automotive assembly area, XYZ Sendirian Berhad. LM, using a set of tools, such as time study, single minute exchange of dies (SMED), standardized work, continuous flow manufacturing system (CFMS) and 5-Why analysis were successfully implemented. The flow of implementation activities was designed by referring to Toyotas 8-Step process. The results of this study showed a significant achievement in waste identification and elimination at the case study area. This successfully proves that the Toyota 8-Steps process could work well in any environment, provided the systematic and appropriate methods and tools are used. At the same time, it could also helps to organize and optimize the effectiveness of LM establishment to the company.
Embedded FBG Sensor in Aircraft Smart Composite Materials for Structural Monitoring
Authors: Ramly Ramzyzan , Kuntjoro Wahyu , Abd Rahman Mohd Kamil
Published: September 2013

This paper describes the use of embedded Fiber Brag Grating (FBG) sensor in the honeycomb core carbon fiber sandwich panel in smart composite materials for the application of monitoring the structural integrity of an aircraft. A part of vertical stabilizer was selected and reproduced using carbon fiber honeycomb core sandwich panels. The sandwich panel was fabricated in accordance to the generic sandwich structure and aviation industry standards, including the materials and also the method of construction. Using a carbon fiber from Hexcel as the face-sheet, Nomex honeycomb as the core, the sandwich panel was cured using Hysol EA9330 resin according to a standard curing process in the aviation industry. In order to make the sandwich panel as smart materials, optical sensor which has fiber bragg grating arrays, FBG, were embedded between the carbon fiber plies during the lay-out process. Using an FBG data logger and Instron 8802 Universal Testing Machine, the panel was subjected to flexural load and the FBG sensor signals were read at the load interval of 0.2 kN. From the experiment the results were taken and data was plotted and it shows that the FBG signals responded well to the load applied. In the future, the specimen will be used for further experiment for measuring strains and establishing the existence of damage in the panel.
Effects of Foam Density and Wall Thickness Interactions on the Energy Absorption Performances
Authors: Ismail Al Emran
Published: September 2013

This paper discussed the effect of foam densities and wall thickness interactions on the energy absorption performances. The studies of energy absorption capabilities are important in order to reduce injuries during vehicular collisions. In this work, three different wall thicknesses are used and different polymeric foam densities are inserted into the empty tubes. The empty and foam-filled tubes are then quasi-statically compressed and forces versus displacement curves are obtained where the area under the curves represented the energy absorption performances. In order to study the interactions between foams and wall, the crushed tubes are sectioned axially and observed. It is found that when the wall thickness was less than 2.0mm, foam densities played an important role in increasing the energy absorption capabilities. However, when the wall thickness was greater than 3.0mm, lack of influence of foam densities on the energy absorption performance was observed.
Parametric Study of Low Velocity Impact Using Finite Element Analysis
Authors: Mohd Sahri Mohd Ridhuan , Muhamad Che Muhamad Khairul Iezuadi Che , Abd Latif Mohd Juzaila , Mahmud Jamaluddin
Published: September 2013

An aircraft structural and material response is very complex when subjected to impact. It involves both elastic and plastic deformation in instant. Nevertheless, investigating this phenomenon is challenging yet interesting. Therefore, this research attempts to investigate the effect of selected parameters variation (i.e. material type, skin thickness and impact velocity) to the resulting equivalent plastic shear strain using finite element analysis (FEA). The finite element (FE) models were developed using commercially modeling and FE software to replicate an aircraft fuselage (target) and projectile according to the experimental setup and data established by other researcher [. The current study only focuses on the materials response and deformation behavior due low velocity (30 150 m/s) impact of a blunt object to a square shape target made of Al 2024-T3 and aluminum alloy 7475 (AA 7475). In all cases (parameters variation), the resulting equivalent plastic strain has been determined and compared to the established data. It is found that the currents results are very close to the actual material response measured in experiments. This proves that simulated results are validated and the study contributed some knowledge to understanding the behaviour of the structural and material response in a low impact velocity. By varying selected parameters, the impact resistivity of the structure could be improved.
Design, Manufacturing and Testing Process of Buckling and Bending Testing Machine Using Systematic Method
Authors: Putra Ichsan Setya , Nam Pham Hoang , Syamsudin Hendri , Dirgantara Tatacipta , Truong Le Xuan
Published: September 2013

In this work, a new testing machine is designed and manufactured with two main functions, i.e., buckling and bending experiment. This machine is designed for classroom demonstrations, or students working in pairs or small groups. The buckling experiment is used to show the buckling phenomenon and to determine critical buckling load for struts with pinned and clamped ends for various strut lengths. The struts for buckling test are made from aluminum alloys with section 2 mm × 20 mm and various lengths of 300mm, 350mm, 400mm, 450mm, 500mm. The bending experiment is carried out to find the flexural rigidity of a strut. The supports of strut in bending test can be changed to fixed, pinned, and rolled supports. The strut of bending test is made from aluminum alloys and common steel with section 3 mm × 20 mm and length 600 mm. Using a systematic method, the development of the machine is broken downinto 3 stages. The first stageof the systematic process is to define the specification based on requirements and objectives. In the second stage, the conceptual design is performed. It comprises the evaluation of the function to find advantages and disadvantages of the components based on the design requirements setup earlier and the comparison of the design concepts against several existing machines was made. Based on this evaluation, the final design is selected for stage 3 of the detail design stage. In this final stage, each component is designed and analyzed in detail. Based on the result of design stage, the testing machine is then manufactured in the Universitys workshop. The evaluation of the machine shows a new design that meets the requirements and objectives. The measurements of critical buckling loads and bending displacements for various strut lengths are in good agreements with analytical calculation. The margins are less than 5 percent.
The Influence of Oxygen in the Carbonization of Oil Palm Shell on Bio-Char Yield and Properties
Authors: Zailani Ramlan , Ghafar Halim , So’aib M. Sufian
Published: September 2013

The presence of oxygen from air infiltration during the carbonization process of biomass is expected to be detrimental to biochar yield and properties. Experimental study was carried out on oil palm shell in a fixed-bed pyrolyser under various oxygen concentrations ranging from 0% to 11 % by varying the nitrogen and oxygen fractions in the pyrolysing gas mixture. The two critical parameters: the bed temperature and holding time were also varied. Process optimization was carried out by Response Surface Methodology (RSM) by employing Central Composite Design (CCD) using Design Expert 6.0 Software. The effect of oxygen ratio and holding time on biochar yield within the temperature range studied were statistically significant. The optimum condition of 30.0 % biochar yield of palm shell was predicted at pyrolysis temperature of 420 °C, oxygen percentage of 2.3% and holding time of two hours. This prediction closely agreed with the experiment finding of 31.1% biochar yield.
Performance Analysis of Ground-Based Static Test for Hydrogen Fuelcell Propulsion System
Authors: Jenal Norhisyam , Kuntjoro Wahyu , Ward Thomas Arthur , Sainan Khairul Imran , Mohamad Firdaus
Published: September 2013

Combustion engines are increasingly being regarded as unsustainable in the long-term, because of their negative impact on the environment (e.g. pollution, green-house gas production, and global warming). This has generated worldwide interest in propulsion systems based on renewable alternative energy sources for the future. Fuel cell technology is a promising alternative power source because of their high specific energy, efficiency, and reliability. Hydrogen proton exchange membrane fuel cell (PEMFC) in particular produces zero carbon emissions by having only water vapor as the exhaust. Although there has been much research by automotive industries in developing fuel cell hybrid electric vehicles (FCHEV), fuel cell research for aircraft application is relatively new. Therefore, there is a pressing need for research related to development of aircraft fuel cell electric propulsion systems. Universiti Teknologi MARA (UiTM) is conducting static experiments on different configurations of fuel cell electric propulsion systems. The objective of this study is to understand the behavior of a PEMFC propulsion system under a ground-based static test. A 1 kW PEMFC was used as the main power source for a brushless DC motor electric propulsion system. The electrical characteristics, rotational speed, and thrust data were presented for two different electrical propellers. Analyses of the results were used to characterize the effectiveness of the fuel cell system and its balance of plant. The results were beneficial as a predictive method on defining the optimum electric propulsion system performance needed for future actual flight development.
Optimization of One Legged Hopping Robot Hardware Parameters via Solidworks
Authors: Rahim N.H.A. , Kassim A.M. , Miskon M.F. , Azahar A.H. , Sakidin H.
Published: September 2013

This paper discussed about simulation of one legged hopping robot via Solidworks software in order to determine the optimum hardware parameters of the hopping robot. Simulations have been done according to different variables that have been set up earlier which are crank bar length, spring length and spring coefficient. The best parameters were chosen in terms of higher and stable hopping performance. Besides that, an experiment is done to validate the parameters from the simulation. Average hopping height is discussed and overall performances of hopping height stability are proved by the normal distribution graph. As the result, the optimum parameter values for hardware of one legged hopping robot are validated.
Performance Comparison between RGB and HSV Color Segmentations for Road Signs Detection
Authors: Mohd Ali Nursabillilah , Md Rashid Nahrul Khair Alang , Mustafah Yasir Mohd
Published: September 2013

This paper compares the performance of RGB and HSV color segmentations method in road signs detection. The road signs images are taken under various illumination changes, partial occlusion and rotational changes. The proposed algorithms using both RGB and HSV color space are able to detect the 3 standard types of colored images namely Red, Yellow and Blue. The experiment shows that the HSV color algorithm achieved better detection accuracy compared to RGB color space.
An Underwater Glider for Subsea Intervention: A Technical Feasibility Study
Authors: bin Ibrahim Mohamad Faizul , Mark Ovinis , bin Shehabuddeen Kamarudin
Published: September 2013

An underwater glider is a type of autonomous underwater vehicle that moves based on small changes in its buoyancy, maneuvering using it wings as it glides through the water. These gliders, currently used in oceanographic sampling, may potentially be used to deliver payloads for subsea intervention at a lower net transport economy (NTE). Net transport economy, is a measure of the cost of transport in terms of the energy consumed per meter traveled, for each kilogram of loaded mass in air or net buoyancy underwater. The current method of payload delivery is either by using customized support vessel or remotely operated vehicle. This paper presents a technical feasibility study of extending the use of these gliders for subsea intervention, with emphasis on payload delivery. Important aspects of an underwater glider such as its volume (size), speed, wing area, wing span, operational depth and net transport economy were considered. The analysis was based on mathematical models governing existing gliders such as legacy gliders and the XRAY Liberdade. The results obtained were validated by extrapolating the present state of the art in underwater gliders to the proposed future use of these gliders, which is for payload delivery. In conclusion, the use of underwater gliders for subsea intervention is feasible based on factors considered in this study.
Stair Climbing of a Track-Driven Mobile Robot with Flipper Arm
Authors: Mahadhir Khairul Azmi , Low Cheng Yee , Hamli Hizzul , Jaffar Ahmed , Salleh Elwan , Bahari M. Saiful
Published: September 2013

On both natural and manmade terrains, the maneuverability of mobile robots has been improving. Nevertheless, stair climbing remains a challenging functionality for mobile robots. In this paper, a step-by-step stair climbing approach is proposed for a track-driven mobile robot equipped with flipper arms. The flipper arms are actuated by DC motors controlled by PID controller. Potentiometers and rotary encoders are used to provide closed loop feedbacks. Executable codes are generated using Real-Time Workshop of MATLAB/Simulink. The reference angles to be followed by the flipper arm in stair climbing are emulated and verified by real time experiments.
Performance Comparison between ANN and PCA Techniques for Road Signs Recognition
Authors: Mohd Ali Nursabillilah , Mustafah Yasir Mohd , Md Rashid Nahrul Khair Alang
Published: September 2013

This study reports about a comparison in recognizing road signs between Neural Network and Principal Component Analysis (PCA). The road sign with circular, triangular, octagonal and diamond shapes have been used in this study. Two recognition systems to determine the classes of the road signs class were implemented which are based on Feed Forward Neural Network and Principal Component Analysis (PCA). The performance of the trained classifier using Scaled Conjugate Gradient (SCG) back propagation function in Neural Network and PCA technique were evaluated on our test datasets. The experiments show that the system using PCA has a higher accuracy as compared to Neural Network with a minimum of 94% classification rate of road signs.
Optical Flow Vectors Thresholding in Assisting Heading Direction Estimation
Authors: Zainal Zairulazha , Ramli Rizauddin , Mustafa Mohd Marzuki
Published: September 2013

This paper presents a technique on how to estimate heading direction of a moving vision system such as mobile robot. The heading direction is represented by estimation angle which is generated by optical flow vectors threshold technique (OFVTT). The utilizations of optical flow field generated based on Horn-Schunck and Lucas-Kanade methods are essential in order to compute the threshold value. The performance of the proposed technique was determined through percentage of root mean square error (RMSE). Based on our experimental results, it can be ascertained that combination of Horn-Schunck method together with OFVTT shows the best performance in assisting the heading direction estimation of a moving vision system.
The Effectiveness of Operational Modal Analysis (OMA) for Detecting Saw Cut Damage in Fiberglass Reinforced Epoxy
Authors: Rahman Haizuan Abd , Mat Isa Ahmad Azlan
Published: September 2013

This study attempts to apply vibration based damage detection method specifically operational modal analysis (OMA) on fiberglass reinforced epoxy plate. OMA is used on undamaged fiber glass reinforced epoxy plate to extract the modal parameters and after which the procedure is extended to saw cut damage fiberglass reinforced epoxy plate. Both healthy and damaged composite material are tested for different boundary conditions i.e. free-free on 4 edges, 1 edge clamped, 2 edges clamped, 3 edges clamped and 4 edges clamped condition. Then result of frequency from OMA was compared analytically with finite element method. Based on the results, it shows that a high deviation between OMA and finite element method can be observed. Result of frequency from OMA was then compared with Experimental Modal Analysis (EMA) to validate the effectiveness of OMA method. It is shown that results obtained from OMA are in good correlation with results obtained from EMA.
Equilibrium Modeling in Updraft Gasifier for Refinery Sludge Gasification Using ASPEN PLUS Simulator
Authors: Ahmed Reem , Chandra Mohan Sinnathambi
Published: September 2013

The production of refinery sludge has been increasing during tank cleaning, deslugging, and wastewater treatment process. Many efforts have been done to manage the large amount of generated sludge. The gasification of sludge is the most versatile alternative or /and is one potential treatment process for power generation and syngas production. The thermodynamic of gasifier is still not well understood for refinery sludge feedstock. As far as optimising the operational conditions of gasification process is concerned, a successful simulated work is introduced by making use of ASPEN PLUS software simulator. This software was tailored and developed to describe an equilibrium model in updraft gasifier of dry refinery sludge (DRS). The textural characteristic properties of refinery sludge are shown in this paper (ultimate and proximate analysis). In the present study four parameters ( i.e. oxidation zone temperature, operating pressure, air flow rate (l/min) and equivalent ratio) were analyzed. In the present work, details of the equilibrium model are presented. This model shows a better agreement with literature model for biomass gasification. From our model results, the mass fractions yield of the desired products (CO and H2) increases as the oxidation zone temperature increases while their yield decreases after 3 bar. The desired products are found to decrease as the air flow increases while CO2 mass fraction favors high air/fuel ratio. The model results are validated by comparison with experimental data issued from the literature.
Experimental Model to Optimize the Design of Cylindrical Heat Pipes for Solar Collector Application
Authors: Idrus Fairosidi , Mohamad Nazri , Zailani Ramlan , Wirachman Wisnoe , Abdullah Mohd Zulkifly
Published: September 2013

A heat pipe is a heat-transfer device that use the principles of thermal conductivity and phase change to transfer heat between two ends at almost constant temperature. The thermal peformance of cylindrical heat pipes depends on design parameters such as dimensions of the heat pipe, material, wick structure and the working fluid. An experimental strategy was designed to study the effect of these parameters on the thermal performance of cylindrical heat pipes. The experimental design was conceived by employing the Taguchi method. The final aim of the experiments is to come up with design parameters that will yield optimum thermal performance. This paper presents an efficient design of experiment and the associated experimental setup and procedures to be carried out in order to optimize the design of cylindrical heat pipes.
Effect of Electrode Types on the Resistive Switching Behavior of Titania Thin Films
Authors: Aznilinda Zainuddin , Herman Sukreen Hana , Bakar Raudah Abu , Rusop M.
Published: September 2013

The resistive switching or memristive behavior of sputtered titania thin films sandwiched in between of three types of metal electrodes (Au, Pt and Ti) was investigated. The active region of the device consisted of two titania thin films, in which, the first layer was exposed to a plasma treatment to create the oxygen vacancies, before the deposition of the second layer. The whole active layer sputtering deposition process was conducted in a one-flow process without exposing the sample to the room ambient. From the I-V measurements, titania thin films in between Ti and Au did not show any resistive switching, but those sandwiched between Pt electrodes exhibit a noticeable memristive behavior. This may due to the metal work function of the platinum itself.