bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensitivity Analysis and Optimization of Machining Parameters Based on Surface Roughness Prediction for AA6061
Authors: Yahya Elssawi , Ding Guo Fu , Qin Sheng Feng
Published: July 2014

Surface roughness is strongly affected by machining parameters. In the past few decades, many researchers have established the relationship between the surface roughness and machining parameters, but less attention has been paid to tool shape and geometry. In addition, the number of tool flutes was ignored, which affects in vibrations and machining system. Therefore, this study first-time includes the tool flutes in addition to cutting speed, depth of cut and feed rate as independent variables. Firstly, a set of machining experiments were conducted using AA6061 as a work piece material to provide original data. Response Surface Model (RSM) adopted to establish the relationship model of surface roughness and machining parameters using Minitab 16. Based on analysis of variance (ANOVA), the results show cutter flutes has higher significant followed by feed rate, depth of cut and cutting speed which has less significant. Finally, machining parameters were optimized to desired surface roughness, and optimization prediction error has limited values between-0.02 and 0.02μm.
Study of Nonlinear Dynamics of Rotor-Bearing System Coupled with a Floating Raft Isolation Device
Authors: Zhao Wen , Li Ming
Published: July 2014

The mathematic model of rotor-bearing system coupled with floating raft isolation device is developed and its nonlinear dynamic characteristics are mainly discussed in this paper. First, on the basic assumption theory of short bearing, the nonlinear dynamic motions of the system with 4 DOF is deduced after considering the vertical and horizontal deformation and the nonlinear vibrating behaviors are analyzed such as the steady state response and its spectrum, orbit and its Poincaré map. The results show that the responses at a low speed appear single periodic motion, with increasing the speed it indicates the doubling and quasi periodic motion, etc.
Engine Fault Diagnosis Based on EEMD Difference Energy Spectrum
Authors: Pan Hong Xia , Guo Gang Xiang , Ren Hai Feng
Published: July 2014

To fault diagnosis of diesel engine, put forward a fault diagnosis of diesel engine based on EEMD difference energy spectrum of singular value and RBF. Nonstationary original acceleration vibration signal of kinds of diesel engine’s working condition is separated to several IMF and structure a Hankel matrix by the IMF for singular value decomposition, then de-noise and reconstruction one IMF on the basis of the theory of singular value difference spectrum, and use the reconstructed IMF’s energy which include fault information as the income of RBF. This method can judge the kinds of diesel engine’s working condition and fault types accurately in the experiment.
Simple Engine Exhaust Temperature Modeling and System Identification Based on Markov Chain Monte Carlo
Authors: Ye Zheng Mao , Mohamadian Habib
Published: July 2014

Even though actual composition of engine exhaust gases varies across diverse types of engines, such as gasoline, diesel, gas turbine and natural gas engines, engine exhaust temperature is always a major factor with strong impact on emission levels and catalytic converting efficiency. For spark ignition engines, exhaust temperature depends on various engine parameters, such as engine speed, engine load, A/F ratio, intake air temperature, coolant temperature and spark timing, etc. Due to complexity, it is impossible to share a unique analytical model of engine exhaust temperature. Instead, it is mostly modeled as a complicated nonlinear system. The model complexity increases significantly however accuracy cannot be guaranteed. On the other hand, a simple linear model with accurate system identification could serve as a versatile alternative to represent the engine exhaust temperature, while engine parameters are subject to model identification to be adaptable across different types of engines. Combination of linear functions in terms of dominant engine parameters of engine speed and engine load is used for exhaust temperature modeling. To identify optimal parameters, Markov Chain Monte Carlo (MCMC) is applied. The discrete-time Markov chain is introduced where the stationary probability replaces posterior density in Monte Carlo integration for numerical integration. Compared with the high order nonlinear approaches, low computation cost is involved in the simplified model. Good agreement between the model prediction data and testing results is observed. The approach could be easily extended to other types of engines.
Ablative Heat Shield Design for Reentry Vehicle Using Numerical Analysis
Authors: Tahsini Amir Mahdi , Mousavi Samaneh Tadayon
Published: July 2014

At this paper, the thermal behavior of ablative materials as heat shields for reentry vehicles is investigated numerically. A one-dimensional finite difference solver is developed to simulate governing mass and energy equations. Four ablative materials; AVCO 5026-HCG, Carbon-Phenolic, Nylon-Phenolic, and Silica-Phenolic; are considered as a heat shield material for a reentry capsule with the diameter 2.8 meter. A heat flux profile from a simulated trajectory of a reentry capsule is used for investigation the performance and essential thickness of these four ablative materials. The only restriction for this simulation is the ultimate temperature of the backup structure which is beneath the ablative heat shield. At all simulations, the final thickness is defined by reaching the interface temperature, the temperature of the border between the ablative heat shield and solid shell, to 80±0.5 degrees Celsius. In addition, the sensitivity analysis is carried out to investigate the effect of properties variations on Carbon-Phenolic’s thickness for this specific heat flux profile.
The Assessment of Material Characteristic Using Vibration Signal Analysis during Drilling Process
Authors: Inayatullah Othman , Hamid Faizal , Hon Hew Wei , Jamaludin Nordin , Abdullah Shahrum
Published: July 2014

The purpose of this paper is to assess the material characteristic by using vibration signal analysis during drilling process. Generally, material with high mechanical properties exhibits low damping capacity and vice versa. The main objective of this paper is to develop a relationship between the signal parameters and the strengths of materials. Aluminum alloy 1100, stainless steel 304, and mild steel were selected as the specimens to be drilled using CNC machine. The vibration signal was captured using a transducer and recorded using a DAQ system. The signal parameters such as maximum amplitude, vibration energy, and the RMS value were extracted using MATLAB software. From the results obtained, the graphs of signal parameters versus strength of each specimen are plotted to show their relationship. It was found that the signal parameters increased exponentially as the strengths of materials increased. Besides that, the vibration signal of the specimens are analysed and compared based on their mechanical characteristics.
Multilevel Linked Data Structure for the Multidimensional Orthogonal Packing Problem
Authors: Chekanin Vladislav A. , Chekanin Alexander V.
Published: July 2014

The actual NP-completed orthogonal bin packing problem is considered in the article. In practice a solution of a large number of different practical problems, including problems in logistics and scheduling comes down to the bin packing problem. A decision of an any packing problem is represented as a placement string which contains a sequence of objects selected to pack. The article proposes a new multilevel linked data structure that improves the effectiveness of decoding of the placement string and as a consequence, increases the speed of packing generation. The new data structure is applicable for all multidimensional orthogonal bin packing problems.
Fast Calculation of Bayesian Unconditional Cramer-Rao Bounds in Case the State-Vector is Constant
Authors: Berkovskii N.A. , Arsenjev D.G.
Published: July 2014

The effective method for Bayesian unconditional Cramer-Rao bound on condition that the unknown state-vector of a dynamical system is constant has proposed. The recurrence formula for calculating the Fisher information matrix is deduced. Our formula doesn’t follow from the well-known recurrence relations for the general case, where the state-vector varies, and has some advantages compared to them. The effectiveness of the proposed recursive method has been illustrated by applying to Вearing-only tracking.
The Coupling of RBF and FDM for Solving Higher Order Fractional Partial Differential Equations
Authors: Avazzadeh Zakieh , Chen Wen , Reza Hosseini Vahid
Published: July 2014

In this work, we describe the radial basis functions for solving the time fractional partial differential equations defined by Caputo sense. These problems can be discretized in the time direction based on finite difference scheme and is continuously approximated by using the radial basis functions in the space direction which achieves the semi-discrete solution. Numerical results accuracy the efficiency of the presented method.
A Fractal Mutation Factor Modified Differential Evolution Algorithm
Authors: Qiu Xiao Hong , Li Bo , Cui Zhi Yong , Li Jing
Published: July 2014

To get better solution by improving the mutation strategy of Differential Evolution algorithm, a fractal mutation strategy is introduced. The fractal mutation factor of the proposed Fractal Mutation factor Differential Evolution (FMDE) algorithm is simulated by fractal Brownian motion with a different Hurst index. The new algorithm is test on 25 benchmark functions presented at 2005 IEEE Congress on Evolutionary Computation (CEC2005). The optimization results of at least 10 benchmark functions are significantly better than the results obtained by JADE and CoDE, and most of the rest of the test results are approximate. This shows that FMDE can significantly improve the accuracy and adaptability to solve optimization problems.
An Identification Method to Detect the Movement of Smoke in Video
Authors: Zhu Shi Jiao , Liu Cheng Jian , Wang Qing
Published: July 2014

In this paper, a method is proposed using the motion vector in Gabor space to recognize smoke region. Smoke orbit is described as up-forward and has some similar sharp in feature space. The propose method is assessed by calculating 45,90,135 degree upward vectors , and determined the possibility of smoke region. Different images were tested using smoke video scenes, and it meets the desired expectation. The next step will be in-depth study represents a high-dimensional space .
Study on the SVM Processing Model of the GPS Monitoring Data of Coal Mine Subsidence
Authors: Zhang Jun
Published: July 2014

In order to make the GPS monitoring data of coal mine subsidence useful and effective in engineering practice, this paper tries to analyze the exceptional handling processing model of the GPS monitoring data of coal mine subsidence under the guidance of the principle of support vector machine (SVM) regression, its calculating method and the application of regression program produced by MATLAB. By comparing the result of the exceptional handling processing model established on practical measured data with the one of the polynomial function fitting, this thesis proves that the application of vector regression algorithm in studies on the exceptional handling processing model of the GPS monitoring data is highly effective.
Factors and Optimization Methods of Error in Reverse Engineering Practical Application
Authors: Li Kun , Cai Yu Jun , Liu Yu Shan
Published: July 2014

This article states the error factors in parts of data acquisition and data processing of reverse engineering, and gives optimization suggestions in practical applications. It provides a more practical method for manufacturing products closer to the samples.
Implementation of PID Controller with PSO Tuning for FES-Assisted Exercise
Authors: Yahaya S.Z. , Hussain Z. , Boudville R. , Taib Mohd Nasir
Published: July 2014

This paper describes the implementation of PID control strategy for a functional electrical stimulation (FES) in specific rehabilitation exercise known as elliptical stepping exercise. The PID controller is used to regulate the FES in controlling the knee joint torque of the paretic and non-paretic legs of the hemiplegic stroke patient during the exercise. The cadence speed error is used as the control variable and input to the PID controller. The Particle Swarm Optimization (PSO) technique is used to optimize the PID control parameters and the performance is compared to that of the manual tuning. The result shows that the system has good interaction with PID controller in completing the exercise. The result also shows that PSO is an efficient technique in optimizing the control parameters compared to manual tuning. Further investigation of the control and optimization technique will be considered in the future in order to improve the efficiency of the FES-assisted elliptical stepping exercise.
Modeling and Controller Comparison for Quarter Car Suspension System by Using PID and Type-1 Fuzzy Logic
Authors: Çakan Abdullah , Botsalı Fatih Mehmet , Tinkir Mustafa
Published: July 2014

Ensuring vehicle drive comfort and securing drive safety are the leading topics among the most interested issues for researchers in vehicle dynamics area. In this paper, a method utilizing a linear actuator is proposed for active control of the vehicle vibrations which are caused by road profile, intending to improve drive comfort and safety of road vehicles. The mathematical model belonging to the system that is evaluated as two degrees of freedom quarter car suspension system is derived by using Lagrange Equation of Motion and MATLAB/Simulink software. In addition to modeling technique, dynamic model of proposed system is created in MSC-ADAMS software and it is simulated in both Matlab and Adams programs together. Moreover two different controllers are designed, which are PID and Artificial Neural Network Based Fuzzy Logic (ANNFL) control in order to use in active vibration control simulations. Performances of the designed controllers are examined and the suitability of the designed controllers is studied by comparing their performances in case of using two different road profile functions.
CNC Routine for Manufacturing Spur Gear
Authors: Koura Omar Monir
Published: July 2014

Manufacturing of spur gears on CNC machining centers and CNC wire cutting is randomly used due to the difficulty in producing the perfect gear profile. The present paper faces this problem by developing a special cycle that can be used on both types of machines. A code for this cycles is designed to read the part program of any product and if detects the code nominated for this cycle (G77) which indicates that a gear needs to be cut, it develops the geometrical statements of the gear profile and the motion statements. It follows by writing the full code of the cycle. The validity of the designed model was verified on a CNC simulator.
Force Feedback Control of Lower Extremity Exoskeleton Assisting of Load Carrying Human
Authors: Şahin Yusuf , Botsalı Fatih Mehmet , Kalyoncu Mete , Tinkir Mustafa , Önen Ümit , Yılmaz Nihat , Baykan Ömer Kaan , Çakan Abdullah
Published: July 2014

Lower extremity exoskeletons are wearable robot manipulators that integrate human intelligence with the strength of legged robots. Recently, lower extremity exoskeletons have been specifically developed for rehabilitation, military, industrial applications and rescuing, heavy-weight lifting and civil defense applications. This paper presents controller design of a lower-extremity exoskeleton for a load carrying human to provide force feedback control against to external load carried by user during walking, sitting, and standing motions. Proposed exoskeleton system has two legs which are powered and controlled by two servo-hydraulic actuators. Proportional and Integral (PI) controller is designed for force control of system. Six flexible force sensors are placed in exoskeleton shoe and two load cells are mounted between the end of the piston rod and lower leg joint. Force feedback control is realized by comparing ground reaction force and applied force of hydraulic cylinder. This paper discusses control simulations and experimental tests of lower extremity exoskeleton system.
Numerical Investigations of Synthetic Jet Control for TAU0015 Airfoil
Authors: Xu Xiao Ping , Zhou Zhou , Wang Rui
Published: July 2014

The aerodynamic performance of TAU0015 airfoil was investigated with synthetic jet control method. The simplified mathematical model of the active flow control was established with unsteady velocity boundary condition at the specific location of airfoil surface. The aerodynamic performance was simulated with synthetic jet and the efficiency of jet momentum coefficient was conducted. The result shows that the flow control model could perform the minor jet flow characteristics and higher jet momentum coefficient result better control efficiency.
Structure Design of Climbing Snake-Like Robot for Detection of Cable-Stayed Bridge
Authors: Wei Wu , Yu Jun Xia , Lin Wei He , Mai Ri Sheng , Chen Chun Xu , He Zhen Yong , Li Zhong
Published: July 2014

In order to realize the detection of bridge cable defects, we conducted research on bridge cable climbing robot, developed a strong climbing ability and high mobility climbing snake-like robot, which is suitable for bridge cable automatic defect detection. It consists of modules with a single degree of freedom, the number of modules can flexible increased or decreased to realize manually reconstructed according to the cable’s feature. The Ultra Torque servo, lightweight aluminum mechanical components and high coefficient of friction skin in the module, enhance the robot’s climbing ability. The robot can effectively complete cable climbing and testing operations because of the modules which combined orthogonal connection with P-R connection. Design a master-slave distributed multi-level closed-loop motion control system, with battery-powered and torque limit been introduced, which enhance the robot's mobility and ability to adapt to the environment. Cable-imitate climbing experimental results prove that the robot has powerful mobility and climbing ability.
Methodology of Developing Mathematical Models for Quality Indices Control
Authors: Polyakova Marina , Korchunov Alexey
Published: July 2014

It is proposed to set the structure of metal products quality as a hierarchical tree of properties. Input and output variables and also control parameters of technological processes are represented as universal multitudes in formalization of the process of production quality indices handling in hardware industry technologies. Presence of simultaneously diversified information initiating different types of independence, is characteristic of solving problems of metal products quality indices control.
Effect of Functional Groups on Interfacial Adhesion Properties of PEEK/Carbon Fiber Composites
Authors: Yapıcı Umut , Pan Lei , Xu Fei , Cao Jia Meng
Published: July 2014

In our work, we aimed to improve the interfacial properties of the Polyetheretherketone (PEEK) polymer/carbon fiber (CF) by treating the fibers with wet chemical method, a higly oxidative chemical solutions called piranha solution and chromate solution. The changes of the surface funtional groups, chemical compositions and structures of the carbon fibers were characterized by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR),surface morphology was studied by scanning electron microscopy (SEM), mechanical interfacial properties of the composites was evaluated by means of interlaminar shear strength (ILSS) tests. The results indicated that graphitic carbon was the major carbon functional component on the carbon fiber surfaces and other functional groups were also presented, such as C–O, C-OH, C = O. Consequently, these introductions of oxygen functional groups onto the carbon fiber surfaces led to an improvement of the ILSS of the composites.
Simulation Based Multi-Criteria Assessment of Lean Material Flow Design Alternatives
Authors: Roessler Markus Philipp , Abele Eberhard , Metternich Joachim
Published: July 2014

In this article a procedure is introduced to improve transparency and reliability of results for the selection of material flow design alternatives including machine tools and other capital-intensive goods. In the design phase of material flow planning projects, key performance indicators (KPIs) for design alternatives including processing as well as intralogistics elements can be derived using simulation. Using the state of the art method in value stream design and simulation often volatile input data is taken into account only in the simulation itself, but not in the downstream comparison of alternative designs, which could lead to imprecise conclusions and therefore to wrong investment decisions. To overcome this issue and to consider variability in the whole simulation phase and a subsequent decision making process, a multi-criteria decision analysis (MCDA) with two fuzzy representations is proposed and discussed here with the aim of helping practitioners to get more competitive value streams. A further goal of the article is the comparison between both forms used for fuzzy representation. Using the design example of machine tool-intralogistics systems obtained results are discussed.
Implementation of Reconciliation Protocol Based on DSP
Authors: Liu Wei Yue
Published: July 2014

Reconciliation protocol is used in quantum key distribution to remove residual errors in qubits distilled through quantum channel. This paper introduces the implementation of reconciliation protocol in Digital Signal Processor. Memory required by the implementation is only 96K bytes. TI TMS2812 with 128K bytes off-chip memory is used for the implementation and the performance evaluation is carried out.
Evaluation of Guidance Laws Performance Sing Genetic Algorithm
Authors: Zakaria Mohamed , Ibrahim Talaat , Hafez Alaa El Din Sayed , Abdin Hesham
Published: July 2014

Several conditions affect the performance of guidance law like target parameters or delayed line of sight rate. A variable navigation ratio is used to enhance the performance of guidance law. In this paper a Genetic Algorithm is used to formulate different forms of variable gains and measure the miss distance. An optimization process is running to find the minimum miss distance. The average values and standard deviation of miss distance for all genetic algorithm individuals are calculated to measure the performance and robustness of guidance law. Two guidance laws are considered proportional navigation (PN) and differential geometry (DG). The simulation results show that the proportional navigation is superior to differential geometry performance in the presence of delayed line of sight rate.
Research on Lane Departure Warning System
Authors: Yang Hui Bao
Published: July 2014

Lane departure warning system includes lane identification and lane departure determination. Lane identification is crucial for lane departure warning system. In this paper, A linear mode which can only bring out small distance error and angle error is used to detect lane boundaries. A region of interest (ROI) appropriate is set to reduce nonessential cost of computation. According to the characteristics of lane position, we improve the Hough transform, reduce the detection and tracking transform angle and raise the speed of calculation. Parameter angle form Hough transform is used to lane departure determination, this method does not calibrate the camera and can get the lane departure rate. Experiments show that the system is well to detect and track the lane line and give alarm correctly.
Firefighting Tactics during a Fire Event at a Nightclub
Authors: Lin Cherng Shing , Lai Chih Chung
Published: July 2014

Entertainment centers are typically equipped with flammable materials. In addition, consumers (and employees) of these establishments are relatively unfamiliar with their internal environments, escape routes, and fire safety equipment. Therefore, fire hazards often result in severe casualties and property loss. In this study, Fire Dynamics Simulator was used to simulate a severe nightclub fire recently occurred in Taiwan. Data were collected from field observations and media reports to establish a numerical model for the actual fire. Important fire dynamic parameters such as temperature distribution, smoke diffusion and carbon monoxides concentration were computed using the model. The results of this analysis can be used to formulate/analyze the firefighting and rescue tactics for similar fires, which would decrease the risk of disaster occurrence and increase rescue efficiency, thereby reducing casualties and property loss.
Effect of Laser Power on Microstructure and Properties of CBN Coating by Laser Cladding on TC11 Titanium Alloy
Authors: Gao Ji , Song De Yang , Feng Jun Wen
Published: July 2014

A wear resistant coating is fabricated on TC11 titanium alloy by laser process using CBN powder as the preset materials. Microstructure, microhardness and wear properties of the coating are characterized by optional microscope (OM), scan electron microscopy (SEM), X-ray diffraction (XRD) and HV-1000 microhardness tester and the effect of different laser powers (1.2kW, 1.6kW, 2.0kW) on the three factors was studied. The experiment results show that the coating microhardness and wear resistance increases firstly and then decreases with the increasing of laser powers when the other parameters are fixed. when the laser power is smaller, the laser energy is smaller, the life of molten pool is shorter, the pores can’t discharge in time induced CBN ceramics can’t formed evenly and the interface bonding strength of coating and substrate was weak; when the laser power is bigger, the laser energy is bigger, the CBN particles can dissolved sufficiently, no crack and pores formed at the coating, but can’t obtain coating reinforced by CBN particles due to the CBN particles dissolved mostly. When the laser power was 1.6kw, the clad coating is smooth and the CBN particles distribute evenly, the microhardness reaches maximum value and the wear resistance is the best. The microhardness was up to 4200HV.
Magnetic Properties of YBCO/LCMO Superlattices with and without STO Interlayers
Authors: Yonamine Anne H. , Fedoseev Sergey A. , dos Santos Dayse I. , Pan Alexey V.
Published: July 2014

Superlattices formed of two antagonic characteristics have been broadly studied in literature mainly in order to clarify the effects of proximity and interface interactions. Here, we present a study of superlattice introducing an insulator between each superconducting and ferromagnetic layer. The electrical insulator STO, YBCO and LCMO layer are deposited by PLD method. The samples with STO show more intergrowth surface morphology, which favors the application providing better contacts between the grains. The magnetic measurements indicated higher Tc values and high anisotropy for SLs with STO, which is dependent on the relative thickness of LCMO and YBCO.
Ferromagnetic Cluster on La2FeMnO6
Authors: Barrozo Petrucio , Moreno Nelson O. , Aguiar José Albino
Published: July 2014

The structural, magnetic and electrical transport properties of La2MnFeO6bulk samples prepared by combustion synthesis have been investigated. The X-ray powder diffraction (XRD) patterns with Rietveld refinement at room temperature shows that samples prepared by combustion synthesis are formed in single phase with an orthorhombic structure space group Pnma (62). The temperature dependent magnetization shows a formation of ferromagnetic cluster at 150K with short range interactions and a long range ferromagnetic order below 75 K. The magnetic field dependence of the magnetization shows a typical paramagnetic behavior at room temperature and a ferromagnetic-like behavior at low temperatures. The low value of the magnetization at high magnetic field can indicate the formation of a weak ferromagnetism or a metamagnetic phase. Results of the temperature dependence of the resistivity show that the transport process in this material can be attributed to small polarons.
Characterization of Bi2212 Superconductor Bulk Samples by Digital Image Processing
Authors: Bigansolli Antonio Renato , da Cruz Tessie Gouvêa , de Souza Machado Francisco Romário , Rodrigues Jr. Durval
Published: July 2014

The use of superconductors of high critical temperatures in applied superconductivity leads to higher operation temperatures and economy of cryogenic fluids. High temperature superconductor materials exhibits limited transport properties due to grain boundary weak-links and anisotropy on the critical currents. The texturing development in these superconductors decreases in an efficient way the number of high-angle grain boundaries, increasing the values of critical current densities (Jc). In this research the size grain distribution characterization of Bi2212 superconductor bulk samples heat treated under the influence of an applied external magnetic field of 5T was carried out combining processing and images analysis obtained by SEM and statistical methodologies. The objective is to investigate influence of an external magnetic field applied during the heat treatment profiles on the texturing of Bi2Sr2CaCu2O8+δ (Bi2212) bulk by using complementary analytical techniques.
Photocatalytic Decomposition of Rhodamine-B Using Scandium and Silver-Modified TiO2 Powders
Authors: da Silva Douglas Washington , Manfroi Daniela Cristina , Teixeira Guilhermina Ferreira , Perazolli Leining Antônio , Zaghete Maria Aparecida , Cavalheiro Alberto Adriano
Published: July 2014

Semiconductor-mediated photocatalytic oxidation is an interesting method for water decontamination and a specially modified TiO2 is said to be a promising material. This study verified that the synthesis of 1wt%Ag modified-Sc0.01Ti0.99O1.995 powder samples prepared by Polymeric Precursor Method is capable of forming a mixture of anatase-rutile phase with high photocatalytic performance. This kind of material is found to have a lower bandgap compared to the TiO2-anatase commercial powders, which can be associated to an innovative hybrid modification. The simultaneous insertion of scandium in order to generate a p-type semiconductor and a metallic silver nanophase acting as an electron trapper demonstrated being capable of enhancing the degradation of rhodamine B compared to the commercial TiO2. In spite of the different thermal treatments or phase amounts, the hybrid modified powder samples showed higher photocatalytic activity than the commercial ones.
Structural and Magnetoelectric Properties of a New W-Type Hexaferrite (Sr0.85Ce0.15Co2Fe16O27-δ)
Authors: da Costa Andrade Bruna , Macedo Marcelo Andrade
Published: July 2014

A new W-type hexaferrite (Sr0.85Ce0.15Co2Fe16O27-δ) was synthesized through proteic sol-gel using coconut water as a solvent for the precursor salts. Structural analysis was carried out using an X-ray diffractometer (XRD). The XRD results showed that the resulting ceramic exhibited preferential orientations along the crystal planes in addition to lattice displacements. The magnetic properties evaluated using a vibrating sample magnetometer indicated a high saturation magnetization value and low coercive field and remnant magnetization values. The Curie temperature determined through differential scanning calorimetry was 473 oC. The electric resistivity value determined through complex impedance was similar to those already reported in the literature, thus promising the use of this hexaferrite in electronic and microwave device applications.
Sensitivity Analysis and Identification of Damping Parameters in the Finite Element Modeling of Piezoelectric Ceramic Disks
Authors: Alvarez Nicolas Pérez , Carbonari Ronny C. , Andrade Marco Aurelio B. , Buiochi Flavio , Adamowski Julio Cezar
Published: July 2014

Finite element method is widely used to simulate the behavior of piezoelectric ceramics; however, its application is limited by the knowledge of the material properties. The constitutive equations are well defined for low deformations (linear case) and for materials without energy losses. In the finite element formulation of piezoelectric equations, the energy losses are introduced in several ways. In this paper a methodology to adjust the damping parameters for the two most used models, Rayleigh parameters and complex constitutive equations, is presented. The simplest Rayleigh model uses only two damping constants to model the energy losses; one proportional to the mass matrix and the other proportional to the stiffness matrix. The other model uses complex values for all parameters in the constitutive equations; in this approach ten different damping constants must be determined.
Cr-Doping-Induced Ferromagnetism in CeO2-δ Nanopowders
Authors: Ferreira Nilson S. , Macedo Marcelo Andrade
Published: July 2014

The room-temperature ferromagnetism of Cr-doped cerium oxide (Ce0.96Cr0.04O2δ) nanopowders synthesized using a sol-gel process is reported in this paper. XRD and Raman spectroscopy confirm that the Cr atoms successfully displaced some of the Ce atoms in the CeO2lattice without forming any impure phases. The results also confirmed that all calcined samples exhibited a single-phase fluorite structure. The crystallite size (as confirmed by XRD) and the particle size (as confirmed by Raman spectroscopy) increased as the calcination temperature increased. Magnetic measurements indicated that the room-temperature ferromagnetism of the sample was sensitive to the calcination temperature. When the calcination temperature increased, the saturation magnetization decreased while the coercivity increased, which corresponds to less dense and larger particles. The calcined sample at 400°C exhibited superior magnetic properties with the highest saturation magnetization (Ms) of 2.5 × 10-2emu/g (Hc~ 1.27 kOe). The results of the Raman and X-ray photoelectron spectroscopies suggest that the nature of the observed room temperature ferromagnetism in the samples are likely a result of the oxygen vacancies induced by Cr-doping in CeO2.
Electrodeposition of Zinc Oxide NanoSheets on Exfoliated Tips of Carbon Nanotube Films
Authors: Antunes Erica Freire , Saito Eduardo , Pianassola Matheus , Christovam Fernando Henrique , Trava-Airoldi Vladimir Jesus , Corat Evaldo Jose
Published: July 2014

Fast growth of ZnO nanosheets on exfoliated tips of multiwalled carbon nanotube films were investigated by electrodeposition from zinc nitrate bath. Variation of electrodeposition time showed the presence of ZnO at only 25s. At 100s, the ZnO crystal size is dominated by the dimension of carbon nanotube patterns formed after wet. Longer depositions (240-480s) produced dense films but with smaller nanosheets.
Ionic Conductivity of Chemically Synthesized La0.9Sr0.1Ga0.8Mg0.2O3-δ Solid Electrolyte
Authors: Reis Shirley L. , Muccillo Eliana Navarro Santos
Published: July 2014

Strontium and magnesium-doped lanthanum gallate is a solid electrolyte with higher ionic conductivity than yttria-stabilized zirconia. This perovskite-type ionic conductor has been investigated for application as solid electrolyte in intermediate-temperature solid oxide fuel cells. In this work the La0.9Sr0.1Ga0.8Mg0.2O3-δ composition was synthesized by a soft chemistry route seeking for a more homogeneous microstructure. Densification was carried out by the conventional method and by fast firing. The ionic conductivity of sintered specimens were evaluated by impedance spectroscopy. The apparent density was about 90% and 94% for fast fired and conventionally sintered specimens, respectively. No significant difference was found for the grain conductivity of specimens fast fired at 1500 oC for 5 min and sintered by the conventional method at 1450 oC for 4 h.
Research on Matlab Simulation Output of Optical Current Transformer
Authors: Shen Tao , Hu Chao , Yang Qian Ru , Song Ming Xin , Wei Xin Lao
Published: July 2014

The theory model of the reflective optical current transformer (OCT) has been established using Jones matrix method, and the proper devices have been chose. According to the characteristics of the transformer’s output, signal processing circuits including photoelectric translating circuit, preamplifier, correlation detector, lowpass filter and ARM processor have been designed. The simulation mode was established in the Matlab environment. The simulation analysis as well as the noise analysis was carried out. Finally, the analysis of the relationship between transformer's input and output was analyzed by using function fitting method. The fitting coefficients and error were given and quadratic or quartic curve fitting was proposed.
Word Sense Disambiguation Based on Center Window
Authors: Zhang Chun Xiang , Guo Li Li , Gao Xue Yao
Published: July 2014

Word sense disambiguation is widely applied to information retrieval, semantic comprehension and automatic summarization. It is an important research problem in natural language processing. In this paper, the center window is determined from the target ambiguous word. The words in the center window are extracted as discriminative features. At the same time, a new method of word sense disambiguation is proposed and the disambiguation classifier is given. The classifier is optimized and tested on SemEval-2007 #Task5 corpus. Experimental results show that the accuracy rate of disambiguation arrives at 64.2%.
A Novel XML Document Retrieval Method
Authors: Chen Jiang Xin , Wan Li Yong
Published: July 2014

XML is a new standard for data representation and exchange, which has been widely used on the Internet. XML retrieval has caused more and more researchers concern. How to improve the retrieval efficiency has become an important study field, this paper proposes the retrieval method based on keyword weight and structure extension, which can get the middle retrieval results in accordance with calculating the keyword weight, and further to retrieval by implementing structural extension of middle retrieval results, then can get the final query results. The experiment results show that the retrieval method has high accuracy and the recall rate compared with the traditional retrieval method.
Research on Service Model Combination Method Based on Colored Petri Net
Authors: Tang Guang Yi , Yao Deng Ju , Cui Li Jie
Published: July 2014

Model-driven architecture and service-oriented architecture are popular software development methods at the present, these two methods have their own advantages and disadvantages, the proposed SOA-based Model-driven Rapid Development Architecture by combining these two methods, Using colored Petri nets’ tools to study service composition methods specifically, and described five basic logical structure of service composition through formal methods, then gave out the construction method of composite services, finally, verified the effectiveness and safety of the service composition method through the modeling.
Using Untiy 3D Game Development Platform to Develop Low Cost Online Real Estate Display System
Authors: Jiang Rui
Published: July 2014

The thermal situation in tackling the current real estate marketing cost is high, the display effect is poor, the purpose of effective communication problems such as less crowd, put forward using Untiy 3D game development platform to develop low cost online estate system method.Starting from the relevant concepts, mainly introduced how to make use of the existing 3D model technology, image processing technology, as well as Untiy 3D game development platform integration technology and so on the many kinds of virtual reality technology, complete the system, finally solve the relevant problems in real estate marketing.
The Key Technology of Designing the Universal Programmer for Freescale HCS12 Serial MCUs
Authors: Zhang Jing , Nie Zhang Long
Published: July 2014

For implementing on-line programming of Freescale HCS12 series MCU, designing a common downloading programmer which functions include chip selection, erase and write operations. Designing a database where Freescale HCS12 MCU Flash difference parameter values ​​placed, so achieving HCS12 MCU family online programming versatility. Erase and write machine codes are provided in the RAM area of Flash memory, these codes will be run at high voltage, these codes are relocated from Flash to RAM area for improving flash operation stability during the high voltage. According to BDM communication theory, we have developed a separate BDM serial communication program, the target device only receives the user code from the programmer, programmer does not need send opcode and the address information, not waiting for a command, so, increasing the erase and write speed. the programmer has the versatility and easily using.
On Normal Sequence in Abelian Group Cn⊕Cn
Authors: Zhang Hai Yan , Yang Xin Song
Published: July 2014

Electronic information technology is based on expression, storage, transmission, and process of information. Information expression is usually generalized as information coding technology, one of whose heart theories is combinatorial number theory in algebra. In the process of storing, transmitting, and processing of electronic information technology, problems about encryption and safety need to use algebra theories of group, ring, and domain. It is thus clear that algebra is very important in electronic information theory. This paper makes use of abelian group basic theory of algebra, together with combination number theory, discusses construction problem of normal sequence in of abelian group, and gives several sufficient conditions for a guess establishment of W.D.Gao.
An Improved Voice Activation Detection Method Based on Energy Acceleration Parameters and Support Vector Machine
Authors: Liu Qian , Wang Jin Xiang , Wang Ming Jiang , Jiang Pan Pan
Published: July 2014

Voice activation detection is a very important part in speech related domain. The classic voice activation detection normally depends on feature parameters in time or frequency domain, or parameters from statistical model. An improved voice activation detection method based on energy acceleration parameters and support vector machine is proposed in this paper. The energy acceleration parameters are the voice activation detection parameters in ETSI Advanced front-end feature extraction algorithm. The training period of support vector machine is based on energy acceleration parameters and manually appended class labels of each frame. In the detection period, the detection result is derived from energy acceleration parameters and Lagrange parameters calculated from training period. The experimental result shows that the false alarm rate of proposed method is greatly decreased. It has been observed that the voice activation detection proposed is better than the voice activation detection in ETSI Advanced front-end feature extraction algorithm.
Athermalization Design of Wide Field Medium Wave Infrared Optical System
Authors: Zhao Lei , Luan Zhao Hui , Xiong Yan Ling , He Li Juan
Published: July 2014

Based on the principle of passive optical athermalization, a wide field medium wave infrared optical system is designed for working at -40℃-60℃. A 320×240 focal plane array (FPA) detector as image plane is used in the system. The system has a field-of-view of 30°×22.72° and a relative aperture of f/2 at 3-5 µm with 100% cold shield efficiency. The modulation transfer function (MTF) of each field is greater than 0.6 at the Nyquist frequency and the maximum distortion is less than 3% at -40℃-60℃. The system can meet the demand of the excellent image quality. This work is valuable for athermalization design of wide field medium wave infrared optical system.
A Clock Optimization Method in the Digital Zooming of the Image Signal Processing System
Authors: Li Dong , Wang Xiao Li , Chi Si Mon , Zhao Chang Rui , Yang Bin
Published: July 2014

We address the problem of producing an enlarged picture from a given digital image (zooming). We propose a method that tries to take into account the difficulty to apply the very fast clock in the digital zooming unit of an ISP system. The ISP system hardware is realized in the FPGA and the zooming algorithm is parabola interpolation architecture. This paper presents an optimization method by using a synchronization FIFO to greatly reduce the clock frequency of the digital zooming unit, and by this the power consumption is also decreased significantly.
The Projector Calibration Based on ZHANG’s Self-Calibration Method
Authors: Yu Guang , Yu Bo Yang , Yang Shu Cai , Wen Li , Dong Wen Fei , Wang Hui
Published: July 2014

Projector calibration can be seen as a special case of the camera calibration. It can establish the relationship of the three dimensional space coordinates for points and projector image coordinates for points DMD by using a projector to project coding pattern. In camera calibration, ZHANG’s self-calibration was conducted in the maximum likelihood linear refinement. Operation process takes the lens distortion factors into account finding out the camera internal and external parameters finally. Using this algorithm to the projector calibration can solve the traditional linear calibration algorithm which is complex and poor robustness. Otherwise, it can improve the practicability of calibration method. This method can both calibrate the internal and external parameters of projector, which can solve the problem of independently inside or outside calibration.
Sonar Image Segmentation Using the Level Set Method without Re-Initialization
Authors: Liu Guang Yu , Pang Yong Jie , Bian Hong Yu , Zhao En Ming
Published: July 2014

To solve the problem that many image segmentation methods cannot be applied to forward looking sonar image accurately, an improved level set segmentation method was proposed in this paper. Firstly, the level set evolution without re-initialization was introduced. Secondly the different characteristics of forward looking sonar image from the optical image were analyzed, and we got the factors affecting segmentation. Then, to overcome these negative effects, this paper did preprocessing by morphological top-hat and bottom-hat transformation, and carried on level set method without re-initialization to construct an improved level set sonar image segmentation system. Finally, our method was compared with the traditional level set method in computer experiments. Simulation results show that it is more adapted to forward looking sonar image segmentation.
A Flat Fiber Raman Amplifier by Optimizing a Single-Wavelength Laser Diode
Authors: Ma Yu , Li Yan Chao , Liu Chun Yu , Yang Jiu Ru
Published: July 2014

Gain-flatness is one of the crucial parameters for the application of fiber Raman amplifier (FRA). To obtain the ideal gain-flatness within the wide spectrum, the devices should be optimized in a FRA system. In this article, rather than a complicated design reported in the traditional schemes, we adopt a single-wavelength laser diode to flatten the gain spectrum of FRA through optimize its pumping power and wavelength simply. The numerical results by simulation show that the gain-flatness of the designed FRA system is controlled within ±1 dB in the range of 1500 nm ~1560 nm by a laser diode with 1435 nm and 250 mW.
Research on the Method of CPM Signal Phase Smoothing Based on Different Power Sine Function
Authors: Shang Wen Jing , Zhou Sheng Guo , Wang Nan , Rublev Victor
Published: July 2014

Continuous phase modulation (CPM) signal has the advantages of high bandwidth efficiency, continuous phase, faster decay speed of power spectrum, constant envelope and so on, which is widely used in communication systems. The degree of the phase smoothing is one of main factors that affect the decay speed of CPM signal power spectrum. One method of smoothing CPM signal phase based on different power sine function as the frequency modulation function is proposed. We draw the phase trajectory of baseband signal and the normalized power spectrum by using the MATLAB software. The spectrum characteristics of the signal generated have great improvement compared with MSK signal, which reach the desired goal.