bluuebunny/crossref_metadata_2025 huggingface dataset:
Reynolds Number Effect Investigation of Shock Wave on Supercritical Airfoil
Authors: Xu Xin , Liu Da Wei , Chen De Hua , Wang Yuan Jing
Published: April 2014

The supercritical airfoil has been widely applied to large airplanes for sake of high aerodynamic efficiency. But at transonic speeds, the shock wave on upper surface of supercritical airfoil may induce boundary layer separation, which would change the aerodynamic characteristics. The shock characteristics such as location and intensity are sensitive to Reynolds number. In order to predict aerodynamic characteristics of supercritical airfoil exactly, the Reynolds number effects of shock wave must be investigated.The transonic flows over a typical supercritical airfoil CH were numerically simulated with two-dimensional Navier-Stokes equations, and the numerical method was validated with test results in ETW(European Transonic Windtunnel). The computation attack angles of CH airfoil varied from 0oto 8o, Mach numbers varied from 0.74 to 0.82 while Reynolds numbers varied from 3×106 to 50×106 per airfoil chord. It is obvious that shock location moves afterward and shock intensity strengthens as Reynolds number increasing. The similar curves of shock location and intensity is linear with logarithm of Reynolds number, so that the shock location and intensity at flight condition could be extrapolated from low Reynolds number.
Undersea Observatory Platform Shape Design and Sinking Calculation Based on Fluent
Authors: Hong Yun , Liu Yi Sheng
Published: April 2014

In order to research the drag force and balance characteristics of undersea observatory platform during the sinking process. The effect base in different shape and arrangement on the flow field are studied with the help of Fluent, the relationship that how shape and arrangements of base influences drag force and balance characteristic are studied. The results show that pressure drag is the main component of the whole drag force. Round pie base suffer the least drag force, adopting the arrangement that put a round pie base at each vertex of hexagon, undersea observation platform would maintain good stability during the sinking process.
Nonlinear Analysis of Stochastic Heave Motion for Truss Spar
Authors: Shen Wen Jun , Tang You Gang , Liu Li Qin
Published: April 2014

Applying the Path Integral Solution Method, the stochastic heave motion of Truss Spar platform was studied in this paper. Taking a platform for example, probability density function of stochastic heave motion amplitude was calculated under the conditions of different wave excitations. The results show that, the changing process of probability density function in the time domain has an obvious periodicity. As the increasing of external excitation, the heave motion amplitude and speed both increases. Meanwhile, as the increasing of excitation amplitude, the probability density function of heave motion has a more pronounced periodicity.
Analytical Investigation on Optimum Member Angle of Lattice Truss Structures
Authors: Kim Sang Woo , Kim Dae Yong
Published: April 2014

Metallic sandwich panels based on lattice truss structure have been developed for a wide range of potential applications with their lightweight and multi-functionality. The study focused on the analytical approach to investigate compression and shear characteristics of pyramidal and tetrahedral truss unit cells. With various unit cell models which have the same weight per unit area but different member angle, analytical solutions for effective stiffness and strength have been predicted and compared with each other. The results showed that there are the most optimal core configuration to maximize effective mechanical properties.
Water Desalination System: Experimental Study on the Performance of a Multi-Stage Still
Authors: Zahia Tigrine , Hanane Aburideh , Randha Bellatreche , Djamila Zioui , Mohamed Abbas
Published: April 2014

This paper deals with engineering investigation and equipment design of a new multi-stage distillation system. The facility was designed in UDES center with the objective of increasing its productivity and improving its efficiency. Distillation device consists one of important process to produce fresh and clean water from brackish water that is abundant in many remote areas of south Algeria. In general, the production rate of the conventional solar still shows a daily production of 5 l/m2d which depends strongly on the material used and equipment design together with different factors. In comparison, Multi tray still mounted with four stages is more profitable in term of the output than a simple still. The various results, from which the effect of the boiler temperature Tb is presented in the range 75°C<Tb<95°C. The obtained results show that the first tray of the system produces about 33 liters of fresh water per day when the temperature of the evaporator efficiency is fixed at 96°C. Determinations of the output of each tray of the still are presented in this study. In fact, experimental data suggests that the tray number have a limit number to achieve a highest throughput with a most compact system. The analysis of the distilled water showed that its quality was within the international standards. We notice that water desalination with multi stage equipment is a good solution for a better output.
Investigation and Analysis on Energy-Saving Status in Building Lighting in China, Japan and Korea
Authors: Jiang Jia Li , He Xiao Yang , Zhang Yun Cui , Fang Yuan , Xiao Wei Hao , Zou Nian Yu , Okhee An , Miyamoto Masako , Inoue Youko , Kunishima Michiko
Published: April 2014

As global energy crisis is growing, energy-saving in architecture becomes more and more important. In addition, residential lighting especially living room lighting is an important part of energy consumption. In order to create green building, this paper analyzes energy-saving status based on joint investigations across China, Japan and Korea. It has been also compared the differences about energy-saving awareness and the selections of lighting equipments. The investigation results about residential lighting energy situation are reference to make proposals on lighting energy efficiency and quality improvement.
Preparation of High Solid Content Polyurethane Emulsion with Sulfonate Hydrophilic Chain-Extending Agents
Authors: Wei Xiao Li , Zhang Fa Xing
Published: April 2014

A series of novel stable polyurethane emulsion with high-solid-content and low-viscosity were prepared by self-emulsification. They were prepared by the reaction of poly (tetrahydrofuran-co-oxidation of propylene) glycol (Ng210), isophorone isocyanate (IPDI) with 1,2-dihydroxy-3-propanesulfonic acid salt (DHPA) as hydrophilic chain-extending agents. Influence of the content of DHPA on properties of polyurethane emulsion and film were analyzed .The results show that obtained emulsion were multivariate distribution in particle size and were spherical particles by measurement of grain size and electron microscopic photo. It is noticed that with increasing content of DHPA and, average particles diameter of polyurethane emulsion became smaller, poly-dispersion became narrower and solid-content became bigger. when the content of DHPA is 7%, solide-concent of emulsion reaches 61%. In addition, Polyurethane emulsion are endowed stability of emulsion are good at high temperature and low temperature as well as storage stability.
Using MATLAB and COMSOL Multiphysics for Optimization of the Model of Underground Thermal Processes at Old Mining Dumps
Authors: Ozana Stepan , Pies Martin , Hajovsky Radovan
Published: April 2014

The paper deals with the use of MATLAB and COMSOL Multiphysics environments for solution of optimization problem regarding underground thermal processes occurring at the old mining dumps affected by subsurface endogenous fires. It gives the description of measurement system and physical setup of the experimental borehole used to provide the real measured data for the model with the aim of its verification. The optimization problem is defined and solved by proposed computational technique that uses both MATLAB and COMSOL Multiphysics with the LiveLink tool that integrates these environments. Results of the optimization help to evaluate the total or relative heat power of the mass within mining dump.
Analysis of Temperature and Heat Flow Characteristics in Underground Tunnel
Authors: Xie Hai Min , Li Mao De
Published: April 2014

This paper summarizes the two methods which are experimental research and numerical simulation to thermal environment of the tunnel. Then the latest developments of the thermal environment research at home and overseas are introduced. At last a simplified model of thermal environment of underground tunnel is established. Through CFD software, the radial temperature distribution of tunnel surrounding rock and the axial temperature distribution of air at winter and summer conditions are obtained which provide basis for further research on thermal environment of underground tunnel.
Introduction of Respirable Air Conditioner Based on the Principle of Gravity Circulation
Authors: Yang Dong , Wen Qing Mei , Zhang Cong Ju , Liu Xue Ting , Wei Shi Jun
Published: April 2014

According to the existing problems of conventional air conditioning system, this paper presents a new form air-conditioning based on the principle of gravity cycle, analyze its merits and drawbacks and application area, to provide a theoretical basis for the popularization and application of the new air conditioning form.
Heat Transfer Analysis of Groundwater Flow for Ground Heat Exchangers in the Multi-Borehole Field of Ground Source Heat Pump under the Intermittent Operation
Authors: Zhang Can Can , Yu Yue Jin
Published: April 2014

In order to analyze the influence of groundwater flow on ground heat exchangers with different arrangements, with a project in Nanjing the access temperature field in the multi-borehole field was simulated after the ground source heat pump system had been performed for a year. Simulation results show that the access temperature is higher in the ground surrounding the borehole than the center of the corresponding borehole, thus forming a thermal barrier surrounding the borehole. Groundwater flow helps relieve temperature imbalance owing to the imbalance of heating and cooling load. The performance of the ground heat exchangers is better in staggered arrangement than in aligned arrangement. In the borehole field, the boreholes upstream have thermal interference on those downstream. And the extent of thermal interference depends on the direction of the groundwater flow when the locations of the boreholes are fixed in the borehole field.
Numerical Modeling of the Flow and Pollutant Dispersion in Street Canyons with Ground Thermal Effect
Authors: Zhang Ning Bo , Kang Yan Ming , Zhong Ke , Liu Jia Ping
Published: April 2014

Thermal stratification affects the flow in and above urban street canyons. Such thermal effect is often not noticed, and can lead to pessimistic or optimistic results of the air quality in urban street canyons under calm conditions and low wind speeds. A three-dimensional CFD model is applied to simulate the flow patterns and particle concentrations in a street canyon under different aspect ratios and ground thermal conditions. The model is validated by the experimental data found in the literature. The simulation results are used to evaluate the flow and pollutant dispersion properties in the canyon. The results show that the ground thermal conditions can significantly affect the ventilation performance of the street canyon, which improves with the increased temperature difference (ΔT) between the ambient air and the ground of the canyon. The increased ΔT enhances the buoyancy induced secondary flow in the street canyon and hence reduce the particle concentrations in the canyon, with this influence more pronounced for small street widths.
Thermodynamic Effects on Hydrate Formation in Deepwater Pipeline
Authors: Abbasi Aijaz , Hashim Fakhruldin Mohd
Published: April 2014

Hydrate formation has long been a challenge for flow assurance in deepwater natural gas pipelines. Hydrates are formed when natural gas is brought into contact with water usually at low temperature and high pressure in deepwater pipelines. The pressure is relatively high in deepwater pipelines, so it is entirely possible to meet the hydrate formation conditions and pose a significant operational and security challenge. This study provides a means to ascertain the thermodynamic properties for hydrate formation in a deepwater gas pipeline. The thermodynamic properties are to be assumed between the similarity of the hydrate formation and the isothermal adsorption in a deepwater pipeline. The study aims to develop a correlation for calculating the hydrate formation pressure, temperature and fugacity of a gas mixture. The correlation is based on the gas hydrate formation temperature and pressure with and without inhibitors. This study also provides a hydrate prediction phenomena associated with gas condensation in deepwater pipelines and it will improve the ability to predict the thermodynamic properties of hydrate formation.
Empirical Analysis on Peasant Households' Willingness of Using Solid Biomass Fuel
Authors: Ma Long Bo
Published: April 2014

The energy crisis and worsening ecological environment has become the biggest threats to human life. Using solid biomass fuel can effectively relieve these hazards. According to empirical analysis on peasant households' willingness of using solid biomass fuel, the results show that age、education and incomes of the farmers' families, energy satisfaction ,energy policies, farmers for solid biomass fuel concept cognitive degree, farmer's awareness of environmental protection and safety consciousness biomass fuel for farmers to buy solid has significant influence. Therefore it is suggested that implementing energy subsidies and strengthen the concept of product positioning that can expand propaganda in solid biomass energy and promote the impact peasant biomass fuel industry development of solid.
The Experimental Study of Floor Heating for Solar House
Authors: Jing Yu Feng , Ding Guo Zhong , Miao Jia Jiang , Ou Chang Kai , Tan Jun Yi
Published: April 2014

Constructing a solar house with a solar vacuum tube heat collector to produce hot water , and using hot water to drive the low-temperature floor heating system for heating. The test results indicate that the indoor average temperature (IAT) would be 7.62°C under the condition of no solar radiation and the outdoor average temperature (OAT) at 2.17°C, ,and then it carried on the heating compensation system, the IAT reaches to 16.35°C when setting the heating water flow is 0.1m/s ,inlet water temperature is 45°C,at 5°Ctemperature difference; When the average intensity of solar radiation is 62W/m2 and OAT is 5.15°C, the IAT is 12.74°C, at the same heating conditions , the IAT reaches 19.74°C by floor heating, and it can control the indoor temperature in a comfortable area ,so the floor heating system has a clear effect on the peak load shifting of house heating.
A Novel Change Detection Method Using Independent Component Analysis and Oriented-Object Method
Authors: Li Xiao Chun , Jia Chun Yang , Li Wei Hua
Published: April 2014

hrough analyzing problems brought on change detection methods of high-resolution remote sensing images, a novel change detection algorithm is proposed. First, feature images of image’s objects extracted using oriented-object method serve as data of input vector to estimate sub-space for Independent Component Analysis(ICA), which can improve effect of noise suppression, simultaneously, a new algorithm using self-adapted weight is proposed in order to extract image’s object, which optimizes processing method on oriented-object deeply；new partitioning scheme using undecimated discrete wavelet transform(UDWT) overcomes effectively prominent problem which shrinking of the size of input vector becomes leads to unprecisely estimation of sub-space for ICA. Compared with typical algorithm, such as ICA and UDWT, simulation results show that new algorithm improves robust and veracity of change detection for high-resolution images greatly.
Visual Pop-Can Detection Method Based on AdaBoost
Authors: Lin Xin Yi , Xue Yan Bing , Guo Bao Hong
Published: April 2014

This paper puts forward a visual method of detecting pop-cans based on AdaBoost Algorithm. This method, is basing on the idea of AdaBoost Algorithm, and we use Haar Feature and LBP Feature to extract pop-can characteristics respectively. Finally we compare the differences of the training processes and the experiment results between these two detectors. It shows that these pop-can detectors that are trained by this visual method have high detection rate and speed.
Research on Method of Metro Monitoring Model Based on Grey Prediction Algorithm
Authors: Liu Mao Hua , Sun Xiu Bo
Published: April 2014

Grey prediction model is a model to predict the trend maturely, its application in the subway safety monitoring is of great significance. Set up by MATLAB software to complete the grey prediction model, and take the surface monitoring point for example, Comparing the prediction value with the actual measured value, analysis by the accuracy, obtain the trend of surface change around the subway station.
Design and Simulation of Polarized Neutron Reflectometry at CARR
Authors: Liu Rong Deng , Liu Yun Tao , Chen Dong Feng , Li Tian Fu
Published: April 2014

In order to make best use of the neutron flux, a polarized neutron reflectometry with vertical sample geometry is simulated by Vitess package based on Monte Carlo method. The results prove that the neutron flux gain up to a factor reaches 4.3 and the vertical neutron angle divergence is proved, when the optimal tilting angle of the vertically focusing geranium monochromator is 1.3°. At last the optimal separations of horizontal blades of slit packages are optimized. The parameters can be an instruction for polarized neutron reflectometry construction or project analysis in the future.
Relationship between Foamability and Nanoparticle Concentration of Carbon Dioxide (CO2) Foam for Enhanced Oil Recovery (EOR)
Authors: Mohd T.A.T. , Shukor M.A.A. , Ghazali Nurul Aimi , Alias N. , Yahya E. , Azizi A. , Shahruddin M.Z. , Ramlee N.A.
Published: April 2014

Foam stability can be uttered in foamability measurement and bubble size dispersal. The higher the foamability, the more stable it is. The addition of nanosilica particle to the foam system will further improve the rigidity of the lamellae interface by providing stickiness force between foam lamellae and its surface, halting the film thinning and prevent it from rupture. This paper aims to investigate the stability of CO2 foam with addition of nanoparticle, to find the optimum surfactant and nanoparticle concentration that achieved higher foam stability, to determine the relationship between the foamability and the nanoparticle concentration within the carbon dioxide foam system and also to analyze the effect of crude oil on foam stability. For this experiment, foam generator was used. The concentrations of surfactant were prepared at ranges from 500 ppm to 5000 ppm. The foam stability test was conducted at constant pressure, temperature and flowrate. The nanoparticle was used with set of different concentrations such as 1000 ppm, 3000 ppm and 5000 ppm. It was found that the increases in both surfactant and nanoparticle concentration have boosted up the stability of the foam produced from 92% to 100% foamability and foam durability extended to maximum of 5 hours. The optimum concentration of both surfactant and nanoparticle was 5000 ppm. It is important to determine the relationship between foamability and nanoparticle concentration, so that foam stability, mobility and the morphology of the foam produced can be forecasted with the newly breakthrough nanoparticles technology.
Numerical Simulation of Fractured Rock Slope with Shear-Slip Behavior
Authors: Gao Qin , Wang Gui He
Published: April 2014

The development of shear-slip cracks and motion trend of fracture water were presented for discussing the shear-slip behavior and analyzing the stability of fractured rock slope under hydraulic action. Seepage behavior of epigenetic cracks and the positions of slip or collapse were also investigated by monitoring pore water pressure using DEM. The analysis method of discrete element simulation for fractured rock slope was proposed. The results of numerical simulation indicated that interpenetrating fractures are more likely to be slip planes.
Characterization of Heavy Metal Contaminated Wastewater Using a Coaxial Sensor and Electromagnetic Wave Reflection Technique
Authors: Puangngernmak N. , Chalermwisutkul S.
Published: April 2014

Industrial wastewater control is an important issue for protection of the environment. Liquid characterization using radio frequency signal is an interesting approach for selective detection of heavy metal contaminants in industrial wastewater. A simple sensor based on open-ended coaxial structure filled with the liquid under test is proposed. Liquid samples for the experiments are copper, zinc and nickel solutions with various concentrations of 1, 10, 100 and 1000 mg/liter each. From the measurement results using a vector network analyzer (VNA) in combination with the proposed sensor, the concentration of a specific contaminant can be determined by the magnitude of the measured reflection coefficient in a frequency range lower than 2 GHz. Applying a capacitive model of the sensor, complex permittivity of the liquid under test can be calculated from the measured reflection coefficient. Obvious relationship between the imaginary part of complex permittivity and the concentration of contaminant in a frequency range lower than 2 GHz was observed. The type of contaminants in the liquid samples can be identified by the position of the resonant peaks when the magnitude of reflection coefficient is plotted in the spectrum. The frequency range for contaminant’s identification lies between 2 and 3 GHz.
Development of a Railway Track Displacement Monitoring by Using Digital Image Correlation Technique
Authors: Iryani Lenny , Setiawan Hery , Dirgantara Tatacipta , Putra Ichsan Setya
Published: April 2014

To avoid an unnecessary catastrophic accident due to a failure of a railway track, it is important to have a reliable condition monitoring system for the railway track. The integrity of the railway track can be assessed by monitoring the displacement field of the track, which can then be used to determine the strain and stress field. By knowing the stress history of the track and the S–N curves of the track material, the remaining life of the railway track can be predicted. In the present work, a simple system to monitor and record the displacement field of the railway track has been developed by using Digital Image Correlation (DIC) technique. The set–up to monitor the displacement field of the railway track was developed using a high speed video camera of Nikon J1 to capture the image of the railway track when the train passing through. The DIC technique was then employed off line to measure the displacement field of the 2D image captured. The results showed that the full field displacement measured by using DIC technique gives a good agreement compared to the finite element results. The full field displacement can be used to calculate the strain-stress field, and later on the remaining life assessment can be conducted based on the results.
Research on Underwater Binocular Camera Calibration and Distortion Analysis in Current Disturbance
Authors: Pang Yong Jie , Wang Di , Huang Hai , Sheng Ming Wei
Published: April 2014

The camera calibration is the basis of the binocular stereo vision technology. The purpose of the stereo calibration camera is to obtain the camera internal and external parameters and distortion coefficients. However, disturbances such as current are usually accompanied with the static water in the actual operation environment of underwater binocular cameras, which may cause further coefficients distortion. Therefore it is necessary to carry out the binocular calibration experiment in the flow disturbance. The camera distortion is analyzed both in static water condition and flow disturbance state. The analysis results indicate that the calibration methods used in this article is verified and the obtained parameters and distortion coefficients are accurate and reliable.
Video Copy Detection Based on Principal Component Analysis
Authors: Hou Yan Yan
Published: April 2014

Content-based video hashing was proposed for the purpose of video copy detection. Conventional video copy detection algorithms apply image hashing algorithm to either every frame or key frame which is sensitive to video variation. In our proposed algorithm, key frames including temporal and spatial information are used to video copy detection, Discrete cosine transform (DCT) is done for video key frame and feature vector is extracted by principal component analysis ( PCA ). An average true positive rate of 99.31% and false positive rate of 0.37% demonstrate the robustness and uniqueness of the proposed algorithm. Experiments indicate that it is easy to implement and more efficient than other video copy detection algorithms.
Alternative Working Electrode for the Determination of the Antioxidant Content by Electrochemical Techniques
Authors: Liu Chen Yao , Yu Wei Wei , Huang Yun Guang , Wang Na Na , Zhu Li Ping , Luo Zong Chang , Zhu Zhi Ping
Published: April 2014

T501 is an antioxidant widely used in transformer oil. The content of T501 in transformer oil can be detected by electrochemical techniques, however, in the process of condition optimizing for electrochemical measurement, people haven’t done in-depth study the effect of working electrode on T510 antioxidant electrochemical measurement. This paper mainly introduced the alternative working electrodes for the determination of the antioxidant content. Through researching the electrochemical properties of T501 antioxidant by the electrochemical workstation, it is confirmed that the graphite electrode is the best working electrode in the electrochemical measurement of T501 antioxidant content.
Model Reduction and Controller Design of a DC-DC Converter
Authors: Wang Lin Bing , Liu Jia Jia , Chen Hai Fei , She Yue , Wang Yang Zhou
Published: April 2014

The reduced-order small-signal model and controller design of a two-transistor forward converter（TTFC）are presented in this paper. First, the small-signal circuit model and transfer function of control to output are found for the TTFC. Then by finding dominant energy poles of the transfer function, the model reductions are performed and the controller design of the converter is simplified. The effective of the proposed model reduction and controller design are demonstrated by bode plots and experimental results.
An Automated-Switching Precision Decade Capacitor
Authors: Hsu Jimmy C. , Gong Jeng , Huang Chih Fang
Published: April 2014

A new automated-switching precision decade capacitor for applications in industries was designed and tested. By using coaxial microwave switches, the automated-switching precision decade capacitor can be automatically set by electrical TTL signals controlled by a computer. To prevent capacitance from drifting caused by variations of ambient temperature, the internal temperature of the automated-switching precision decade capacitor was effectively kept constant using a temperature-controlled oven with sufficiently thermal isolation. Furthermore, to fulfil the compact-size requirement for using at a high frequency, SMD capacitors with NP0 dielectric were used. The temperature stabilities and linearity of the automated-switching precision decade capacitor are presented in this paper.
Preparation of Hydroxyapatite Composite Coatings with Interlayer of TiO2 and its Corrosion Behaviors
Authors: Liang Cheng Hao , Wang Shu Sen , Huang Nai Bao , Wu Bo
Published: April 2014

Hydroxyapatite (HAP) composite coatings with interlayer of TiO2 on Ti6Al4V alloy were prepared by microarc oxidation and electrochemical potentiostatic method. Platelet adhesion test and electrochemical behaviors of the HAP coatings were investigated in platelet-rich plasma, Ringer's solution, Tyrode's solution and human blood at 37°C. The HAP coating was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD). TiO2 coating has round ostioles on the surface with the element of O, Na, Al, Si and Ti. The HAP coating has sheet-like, column-like and batten-like crystal with the Ca/P 1.6689. The biocompatibility of HAP coating was better than the initial coating. The results indicated that the HAP coating had better characters of anticorrosion and biocompatibility.
The Wireless Sensor System Based on the Chip of STM32 and SH79F32
Authors: Qi Chen Jie , Wang Hong Wei
Published: April 2014

In this thesis, we take STM32F103R8T6 as main chip, SH79F32 as auxiliary chip, the temperature sensor of DS18B20 as collection tools, wireless transceiver based on nRF905 as communication tool, and reach the function of wireless sensor networks. Through Altium Designer Release 10 to conduct schematic design and draw PCB, and then solder circuit boards, use the software of Keil to design process, to realize wireless sensor communication between different microcontrollers, after that ,complete the design and production of wireless sensor communications platforms.
Data Acquisition and Wireless Data Transmission of Lightning Electromagnetic Field
Authors: Du Gai Hong , Tian Yang Meng
Published: April 2014

The paper briefly reviews the domestic and overseas lightning electromagnetic field data acquisition system, and the data transfer rate and data transfer approaches of lightning. Lightning data transfer approaches includes the conventional transmission systems of data collection, and three data transmission means which including the use of power system network to transmit data, the use of the Internet to transmit data and the use of satellite communications to expand the range of distribution.
Signal Integrity Analysis of High-Speed Differential Vias
Authors: Zhao Ling Bao , Chen Qing Hua
Published: April 2014

In modern electronic systems, data rate is keeping increase, and Gbps becomes common, designing for reliable signal integrity becomes more and more important. In the high speed borad/package design, discontinuities are big concerns of signal integrity. A variety of sources lead to discontinuities and every source ought to be carefully treated. The signal via is one source of discontinuity that should not be overlooked. Vias can add jitter and reduce eye openings that can cause data misinterpretation by the receiver. This paper detail the antipad, pad and excess via stub effect on the vias. In each case, the impedance mismatch at the via transition can be minimized by optimizing a few parameters such as antipad radius, pad radius and excess via stub. The impacts of these parameters are investigated with the help for a full-wave 3D electromagnetic simulator.
Investigation of Melting Current in Glass Tube Fuses
Authors: Ketthanom Chitphong , Chaijumrus Chaichana
Published: April 2014

This paper presents a study of melting current in the commercial glass tube fuses to determine the duration of melt, maximum melting current and maximum power consumption of the fuse in a blowing circuit. A microcontroller is used as a device to measure and collect the values of current, voltage, and power consumption. In the experiments, the glass tube fuses rated of 0.5 A, 1 A, 2 A, 3 A, 5 A, 10 A, 15 A, and 20 A were used. The experimental results show that the melting time were approximately 0.05 s, 0.07 s, 0.11 s, 0.13 s, 0.18 s, 0.20 s, 0.28 s, and 0.40 s; the maximum of melting current were approximately 0.66 A, 1.17 A, 3.81 A, 13.77 A, 20.80 A, 25.05 A, 26.66 A, and 29.96 A; the maximum of blowing voltage were approximately 12.25 V, 12.25 V, 12.30 V, 12.15 V, 12.10 V, 12.29 V, 12.10 V and 12.20 V; and the maximum of blowing power consumption were approximately 7.53 W, 14.22 W, 45.57 W, 158.49 W, 224.38 W, 242.21 W, 230.63 W and 283.68 W respectively.
An Optimized Combination of Frequency Domain Adaptive Equalizers
Authors: Leng Ke Cheng , Bie Cheng , Gong Xi , Xu Ran , Guo Ye Cai
Published: April 2014

In order to overcome the defects of the high computational loads and selecting the threshold of mean square error (MSE) for time domain decision-directed constant modulus blind equalization algorithm (DD+CMA), a frequency domain parallel decision multi-modulus blind equalization algorithm based on frequency domain MMA(FMMA) and frequency domain LMS (FLMS) algorithm is proposed. The proposed algorithm is composed of the FMMA and FLMS, and the FMMA and FLMS run automatically in soft switching parallel manner. In running process, it is not necessary to selecting the threshold of the MSE. Moreover, the computational loads can be reduced by circular convolution in the frequency domain signals instead of linear one of the time domain signals. Simulation results show that performance of the proposed algorithm outperforms the FLMS and the FMMA algorithm.
The Impedance Characteristics of ELF Line-Current Antenna over Inhomogeneous Anisotropic Ground
Authors: Liu Chao , Wang Bing , Xu Hong Qiang , Liu Yun Long
Published: April 2014

The impedance of a horizontal Extremely low frequency (ELF) line-current antenna is studied. A new analytic expression for calculating a grounding resistance in any shape of ground screen in a two-layer earth is proposed, model adapted to a bed-rock with high resistivity. Its calculated accuracy has a significant improvement compared with previous literature. The radiation resistance of an ELF line-current antenna over inhomogeneous anisotropic ground is researched. The effect of anisotropy of the ground conductivity on radiation efficiency of an ELF line-current antenna is analyzed. The obtained results have important purpose in engineering design of ELF horizontal antenna path.
Multiband Antenna Formed of Superimposed Compressed Loops
Authors: Sivaraks Jesada , Malisuwan Settapong
Published: April 2014

A compressed multiple band loop antenna that has multiple superimposed compressed loops. Each compressed loop is formed from numerous segments arrayed in multiple diverse directions so that the enclosed area of that loop and the overall size of the antenna are decreased. Multiple loops are arrayed and superimposed to provide multiple frequency bands of operation and are used to broaden the useful bandwidth of individual-bands. The small size of the compressed antenna facilitates its use in small mobile communications devices requiring internal antennas that operate in close proximity to conductive surfaces. Multiple loops are arrayed in several configurations that include nested and non-nested loops as well as closely located and spatially separated superimposed loops.
Hardware Implementation of Modeling Frequency Coded Serial Communication for Eurobalise Using ASK Module
Authors: Ehkan Phaklen , Zakaria Fazrul Faiz , Razalli Mohammad Shahrazel , Fuad Fairul Afzal Ahmad , Warip Mohd Nazri Mohd , Yuen Lam Chee
Published: April 2014

This paper discusses about the modeling of frequency coded serial communication for the application of Eurobalise on hardware-based field programmable gate array (FPGA). The transceiver consists of FPGA and the ultra-high frequency (UHF) band amplitude shift keying (ASK) module. In the convention interface of the ASK transceiver module with the digital controller, noise has introduce into the channel. The noise in the output of ASK receiver has distorted the transmitted data causing the throughput of the wireless channel to be decreased. When the ASK module interfaces with the FPGA device, the noise from the output of the ASK receiver causing the receiving FPGA retarded. The purpose of the frequency coded serial data is to provide continuous specific frequency pulse train to the ASK transmitter. The original serial bit stream is then modulated in the pulse train with different frequency corresponding to the bit’s logic level. This technique has made the output of the ASK receiver to produce a very clean signal with extremely less noise. Hence, the receiver’s FPGA able to capture all the transmitted data accurately across traditional disciplinary boundaries, including computer hardware, algorithms, electronics interfacing and application domain.
Research on Inverse Form Innovation Design for ATSE with Dual Power Supply
Authors: Yang Hong , Zhang Zhe , Luo Ya
Published: April 2014

In order to promote improvement in the applicability, quality and economic rationality for ATSE with dual power supply, the design method based on the notion of inverse form is proposed in this paper. The component-based inverse form innovation design concept for ATSE with dual power supply is discussed by theoretical analysis and applicable study with two examples, after this paper expresses the importance of product innovation design, including innovation design of ATSE with dual power supply. Especially, ATSE innovation design process with component-based inverse form is researched in detail. Next, some useful and basic advices on how to optimize ATSE products by the notion of inverse form are stated. At the same time, this paper also points out that the structure of ATSE product becomes more reasonable by appropriate use of the innovation design method with inverse form.
Proposed Control Method of Doubly Fed Induction Generator Rotor Side Converter Based on System Frequency Regulation
Authors: Zakieldeen Elhassan , Tang Yi , Li Yang
Published: April 2014

With the more penetration of wind power based on the DFIG wind turbine to the grid, there is increasing significance for controlling output power in order to meet power system requirements and to participate the frequency regulation in the power grid. This paper is presented proposed control method of DFIG implemented in the RSC using system frequency coordinated control. In this study, the GSC is controlled by using modified vector control method while the RSC is controlled by adjusting the rotor dq-axis currents. The quadrature axis current controls by using the active power generating from the frequency deviation and DFIG store kinetic energy, whereas the direct axis current is controlled by using grid reactive power. Moreover, this power is also used as a main parameter besides rotor speed to control the pitch angle blade in the turbine side. To confirm this method study, the system operation is conducted at steady state and transient modes, and the simulation results were carried out using PSCAD software program. The simulation results show that the voltage of DFIG is very stable, and the system frequency response has been improved. Furthermore, this study realized a full rated value of rotor speed and stable operation of DFIG active power at a steady state besides a good transient response. Moreover, the pitch angle control provided adequate control action at dynamic mode to decrease turbine torque hence to lead to safety transient mode operation.
Modeling and Simulation of Improved Vector Control System for PMSM
Authors: Wang Xi Juan , Zhou Tao , Feng Jing Xiao , Pei Yu Peng
Published: April 2014

In the AC control system, vector control theory is very popular as it makes the AC motor achieve the performance as perfect as DC motor [1]. In the paper, the vector control theory is briefly introduced, and then a vector control system model is builded in the matlab/simulink, and the SVPWM technique is adopted. The results show that the improved vector control sytem of PMSM has a excellent performance.
A Model Predictive Control Method for Bidirectional DC-DC Converter in the ZVS Condition
Authors: Li Po , Huang Di Bin , Zhang Yi Ru
Published: April 2014

The bidirectional DC-DC converter can achieve energy storage and transfer by adjusting the magnitude and direction of the current, which is widely used in the DC interconnect micro-grid system and battery energy management system. In the current tracking control of the bidirectional DC-DC converter, the switching loss can be significantly reduced under the Zero Voltage Switching (ZVS) condition. In this situation, the paper firstly establishes the model of switching progress. Considering the ZVS constraints, the model can be described as piecewise linear equations. Secondly, based on the piecewise model, the model predictive controller is constructed. By solving a constrained optimal problem, the switching time forecast in the ZVS condition is obtained to realize the current tracking. Moreover, the derivation of boundary conditions is presented. Finally, a simulation is presented to validate the proposed model and control method.
Study on Problem of Sensorless PMSM Parameters Identification
Authors: Wang Hua Jun , Fan Yao Kai
Published: April 2014

In the Signal-collecting in Sensorless PMSM Parameters Identification research appeared Voltage signal and Current signal are not common ground. In-depth study the problem and solved it. In order to solve the problem that Voltage signal and Current signal are not common ground, using Linearity of coupler element, Through the optical coupling element not only achieve a high and low pressure isolation and through a series of analog circuit to achieve the output terminal to the common ground. Input pressure value falls below the voltage data acquisition card allows the range of values. We verify the validity of this approach by multisim simulation software to.
Research on Optimization Design of Low-Voltage Circuit Breaker Power System
Authors: Ding Jian Bo , Li Hu , Cao Jiang Dong
Published: April 2014

A parametric model of a kind of low-voltage circuit breaker was set up by virtual prototyping technology software ADAMS, and the simulation of the low-voltage circuit breaker system’s dynamic characteristics was successfully run to confirm the parametric model. Because it was easy for contact heads to produce arc during closing, the power spring system was designed and researched in order to obtain the parametric sensitivities. Based on the difference of parametric sensitivities, the rotational angular velocity of the moving contact heads was regarded as the objective function, and the optimization design of circuit breaker power system was completed. Optimized system ensured reliable contact and shortened the arc time of the static and dynamic contact heads during closing, avoiding phenomenon as rebound repeatedly beating of the contact heads, continued arcing and temperature sharp rising, etc. The analysis had guide significance for improving the safe reliability and operating life of the low-voltage circuit breaker, and provided a good platform for the further produce development and optimization design.
Analysis of the Characteristics of PMSG Tidal Current Power Generation System Using PMSG and Water Tunnel
Authors: An Won Young , Lim Hyung Taek , Lee Seok Hyun , Lee Cheon , Kim Gun Su , Jo Chul Hee
Published: April 2014

In order to analyze the characteristics of tidal current power generation system, we measured the output power according to the stream velocity by a water tunnel system and a simulation in MATLAB/Simulink. The water tunnel system consisted of impeller tidal flow transducer and permanent magnet synchronous generator (PMSG) with rotor in the water. The simulation consisted of PMSG, the tidal current turbine, and Back-to-Back converter. Also, we simulated the characteristics of output power according to the change of blade radius and velocity.
Fault Diagnosis Method for Power Network Based on Combinational Cross Entropy Algorithm
Authors: Bian Li , Bian Chen Yuan
Published: April 2014

A new method of fault diagnosis for power networks by using the combinatorial cross entropy (CCE) algorithm is proposed. The research contents in this paper mainly contain the two parts: transmission network fault diagnosis and distribution network fault location. For transmission network, the optimization model is built by considering the relationship among fault elements, action information of protective relays and circuit breakers. For distribution network, constructing fault location model according to the logic relationship between fault current and equipment condition. The optimal solution of two models are solved by CCE algorithm, then fault element (s) in transmission network and fault section (s) in distribution network can be identified by the optimal solution. Various fault conditions are simulated in test system and the results show that conclusions obtained by proposed method are correct, which prove CCE algorithm diagnose fault effectively.
Trust and Power Factor Regulation Based Power Control Scheme for High Penetration Photovoltaic
Authors: Gao Yang , Mao Jing Li , Zhang Bi Ling , Zhou An Shi , Liu Yong
Published: April 2014

While lots of works have been done regarding low penetration photovoltaic (PV), high penetration PV has not been well investigated in the literature, especially the issues such as supply reliability and power utilization efficiency. In this paper, we first present a modified microgrid model for high penetration PV. Within the architecture of the proposed microgird, we then design a trust based active power matching scheme for efficient power usage. Power factor regulation is also used to keep the microgird running steadily. Finally, simulation results are shown to verify the effectiveness of the proposed scheme.
Wartime Nuclear Power Plant Security Protection Research
Authors: Du Nai Juan , Shen Yue Guo
Published: April 2014

Nuclear power as an important energy which benefits human being,is being more and more widely used in many countries all over the world. Under the condition of information war, threat to nuclear power plant security from precision weapon and terrorist attack is serious. This paper analyzes major threats nuclear power plant be facing to in wartime such as obvious exposure symptoms, limited own protections and large impact on the war potential. Then several main methods are discussed to strengthen safety protection of nuclear power plant. Firstly, strive to improve the early warning ability of nuclear power plant. By this means, more time can be obtained to make nuclear power plant protection to prepare. Secondly, counterattacks, interference and disguise simultaneously should build another effective barrier. In the last, it is considered that research on protection and rescue of nuclear power station should be strengthened also.
The Research on the Design Method of Micro Grid Operation Control Strategy Based on the Analysis of the Typical Example
Authors: Wang Nan , Tan Hong , Shi Shan Shan , Yuan Zhi Qiang
Published: April 2014

Abstract: Analyzing the rules of microgrid operation based on the design principle and engineering philosophy, and then defining seven microgrid operation states included: grid-tied state, and/off state, off-grid state, off/and state, fault state, power-latch state and shutdown state. Based on these seven modes, the different control strategy will be set out. These seven strategies can be integrated and be used to control the microgrid together. So we can gain the maximum efficiency of the microgrid through that above. At the same time, the appropriate control mode will be selected to guarantee the microgrid can be switched from one mode to another smoothly.. Above all, the microgrid can operate reliably through the integrated control strategy.
The Effect of Power Supply of LED Lamp
Authors: Kerdlap Patiphan
Published: April 2014

This paper presents the effect of power supply of LED lamp for external lighting are compares with electrical performance, electrical energy saving, illuminance, and the effect of harmonics noise from each power supplies on external lighting with LED. By designing and construct a linear power supply by the full wave rectifier circuit by bridge diode type and switching power supply by buck converter. The result that, the full wave rectifier circuit by bridge diode type was consumed higher power less than buck converter but lower effect of harmonics noise. In additional, as a result will be important data to the education develops and the next research.