DSpace community: 淡江理工學刊

A Fuzzy Based Adaptive Gateway Discovery Algorithm for Hybrid Multi-hop Wireless Networks

title: A Fuzzy Based Adaptive Gateway Discovery Algorithm for Hybrid Multi-hop Wireless Networks abstract: The portable devices such as mobile phones, laptops or personal digital assistants (PDAs) are used by mobile ad hoc networks (MANETs) for communication establishment in a spontaneous manner. For fulfilling the coverage requirements of future 4G we need integration of mobile ad hoc network with Internet to enhance the pervasiveness and flexibility of networks. It is necessary for mobile nodes to identify and choose an optimal gateway among multiple gateways for Internet access. Therefore, a mechanism for gateway discovery is needed. The adaptive gateway discovery can be configured by dynamically adjusting its TTL value (proactive area) on the basis of several parameters like number of active source nodes, traffic load at the gateway and link changes. Existing schemes involve inaccurate estimation of optimal proactive area, hence they suffer from large routing overhead which ultimately affects the network performance and throughput. This paper aims to develop a novel and efficient adaptive gateway discovery algorithm focusing on optimal TTL value by utilizing the potential and capability of Fuzzy logic, which makes a significant impact on routing overhead during gateway discovery. The proposed scheme also incorporates efficient handover in the situation of multiple gateways so that single gateway will not become a bottleneck. The proposed approach is evaluated using computer simulation and also analytically validated. Results show our approach outperforming existing ones.

An Efficient Adaptive Image Enhancement Method in Wavelet Domain for Handwritten Document

title: An Efficient Adaptive Image Enhancement Method in Wavelet Domain for Handwritten Document abstract: In this study, a new method, called adaptive image enhancement (AIE), is used to enhance handwritten document images, such as historical documents. An AIE method is proposed to denoise handwritten documents in a wavelet domain, which differs from others methods in two aspects: Firstly, modified contrast limited adaptive histogram equalization (MCLAHE) is used to equalize the contrast of an image by cutting the histogram at some threshold, and then equalization is used. Secondly, the image is improved by using directional discrete wavelet transform (D2 WT) enhancing for foreground and interfering strokes, respectively. As a result, this method not only removes the interfering strokes or visible watermarks in the background information, but also significantly increases the readability of handwritten document images.

Parallel Processing-Oriented Hybrid Scheduling of Virtual Machines in Cloud

title: Parallel Processing-Oriented Hybrid Scheduling of Virtual Machines in Cloud abstract: In cloud computing environment, parallel applications generally run on symmetric multiprocessing (SMP) virtual machine (VM). Since this type of application requires synchronous operations between processes/threads, all virtual CPUs (vCPUs) of a parallel VM (i.e., the VM running parallel application) should be online simultaneously. At present, relevant studies have been intensively conducted from the perspective of vCPU co-scheduling in virtual machine monitor (VMM). However, the existing co-scheduling methods have the problems of unrestricted preemptions between parallel VMs, which probably results in negative impact on the performance of parallel applications in these VMs. To address the above problems, in this paper, we first analyze the deficiencies of the existing co-scheduling approaches in virtualized environment. Then we propose an enhanced co-scheduling algorithm to improve the performance of parallel application in SMP VM.

Improving Wi-Fi Indoor-Positioning Accuracy by Using AP Selection and Adaptive Pattern Matching

title: Improving Wi-Fi Indoor-Positioning Accuracy by Using AP Selection and Adaptive Pattern Matching abstract: This study proposes a method based on access point (AP) selection and adaptive pattern-matching for Wi-Fi indoor positioning (ASAPM). In the proposed ASAPM, a box plot algorithm is used to remove received signal strength (RSS) outliers in samples received from APs in order to smooth the RSS. Subsequently, we analyzed the RSS variations for selecting the top-N APs with the least interference. Moreover, we analyzed the history of the positioning results to estimate the direction and distance of users in subsequent positions in order to reduce the pattern-matching time and computational overhead of the positioning system. The simulation results revealed that the average positioning error, average maximum positioning error, and average pattern-matching times of ASAPM were 36%, 51%, and 57% lower than the three compared strategies, respectively. These findings show that ASAPM could reduce the computational overhead; moreover, it is suitable as an indoor-positioning service for mobile devices.

Application of Transformerless High Gain DC/DC Converter for Grid-connected Offshore Windfarms

title: Application of Transformerless High Gain DC/DC Converter for Grid-connected Offshore Windfarms abstract: In this paper, operation and control of an offshore wind farmusing typical configuration is considered. Commonly, the offshore wind farms are connected to the grid using HVDC transmission system in order to decrease power losses and voltage sag. In the proposed configuration a new cascaded structure of transformerless high gain DC/DC converter is appliedinstead of a power transformer. The proposed DC/DC converter can boost voltage level and regulate DC link voltage in output of permanent magnet synchronous generator (PMSG). By adjusting DC link voltage in a suitable value, the maximum active power can be received from PMSG. The main advantage of the proposed configuration is that there aren’t anypower transformer and back-to-back converter inoutput of PMSG. The simulation results confirm good operation of the proposedconfiguration in various wind speeds. Also experimental results of the introduced prototype of the DC/DC converter show the effectiveness of this converter in high gain mode.

Experimental Study on Uniform Mobility Displacement Method for Heterogeneous Reservoir

title: Experimental Study on Uniform Mobility Displacement Method for Heterogeneous Reservoir abstract: Reservoir heterogeneity is the most important reason for low recovery and early excess water production. Experimental study on uniform mobility displacement was conducted to improve conformance and reduce water channeling for heterogeneous reservoir. The principle and mechanism were founded using a heterogeneous stratified reservoir model. For this model, injection slugs matching different permeable layers can flow simultaneously and achieve a piston-like flow. Mobility contour was proposed to screen polymer concentration. Displacement experiments were conducted in heterogeneous cores to estimate the EOR effect. The results show that uniform mobility displacement can improve oil recovery greater than polymer flooding and ASP flooding. This may provide a new EOR method to reduce water production for heterogeneous reservoir.

Convection of Cu-water Nanofluid in a Partially Active Porous Cavity with Internal Heat Generation

title: Convection of Cu-water Nanofluid in a Partially Active Porous Cavity with Internal Heat Generation abstract: In this study, the effect of internal heat generation for Cu-water nanofluid on natural convection heat transfer in a fluid saturated porous cavity with partially active walls has been numerically investigated. The governing non-dimensional Darcy-Brinkman-Forchheimer equations are solved using the finite volume approach together with SIMPLE algorithm. Benchmark results are compared with present study which furnish that the present results are to be reliable. The addition of nanoparticles produces an augmented heat transfer rate for low values of internal heat generation. On the other hand, the base fluid water induces the maximum heat transfer rate than the nanofluid for high values of internal heat generation parameter. This means that in the presence of high internal heat generation, there is no need to add nanoparticles inside the cavity to generate the augmented heat transfer rate.

A Review on Role of Processing Parameter in Determining Properties of Silicon Carbide Reinforced Metal Matrix Nanocomposites

title: A Review on Role of Processing Parameter in Determining Properties of Silicon Carbide Reinforced Metal Matrix Nanocomposites abstract: The present paper reports a review on study of various processing routes and related mechanical properties of silicon carbide reinforced Metal Matrix Nanocomposites (MMNCs). Physical and mechanical properties that can be obtained with Metal Matrix Nanocomposites (MMNCs) have made them potential candidate for use in aerospace and automobile applications. MMNCs are made by dispersing a ceramic material into a metallic matrix. MMNCs have attracted attention as a result of their low costs and enhanced properties. Various reinforcements used are carbides, nitrides, and oxides. MMNCs manufacturing can be broken into three types - solid, liquid and vapor. Solid state methods include powder metallurgy, liquid state method includes stir casting and squeeze casting whereas vapor state method includes physical vapor deposition and chemical vapor deposition. In comparison with conventional polymer matrix composites, MMNCs are resistant to fire, can operate in wider range of temperatures, do not absorb moisture, have better electrical and thermal conductivity, are resistant to radiation damage, and do not display outgassing. It is expected that the silicon carbide reinforced metal matrix nanocomposites will be a potential candidate for heavy duty applications.

Roll Stiffness Optimization for Anti-roll Bar in Interconnected Air Suspension

title: Roll Stiffness Optimization for Anti-roll Bar in Interconnected Air Suspension abstract: Lateral Interconnected Air Suspension (hereinafter referred to as Interconnected Air Suspension or IAS) tends to deteriorate vehicle roll stability on the condition of steering while travelling in high speed, so interconnection state is generally closed when lateral acceleration of car body exceeds its designed threshold (0.4 g in this paper). In this paper, a roll stiffness optimization strategy of anti-roll bar in IAS based on genetic algorithm is proposed for better roll stiffness as well as better roll angle vibration characteristics both in the state of interconnection and non-interconnection. And the strategy is used to optimize the anti-roll bar of a passenger car equipped with IAS. In the optimization strategy, weighted sum of body roll angle’s mean value and standard deviation is originally determined as the objective function based on impact sensitivity analysis, i.e. the analysis of anti-roll bar roll stiffness’s influence on body roll angle’s mean value and standard deviation. Besides, totally 6 driving conditions are considered in the optimization to make it more realistic. The optimization result shows that optimal roll stiffness of front and rear anti-roll bar is 1998 N m/deg and 1402 N m/deg respectively. The proposed optimization strategy helps to resolve the problem of how to balance vehicle roll stability and roll angle vibration characteristics under different working conditions during the process of anti-roll bar roll stiffness matching for IAS vehicles. It can also be guidance or a reference for the matching of other parameters in IAS vehicles.

Characteristics of Wind Pressures on a Cooling Tower Exposed to Stationary and Translating Tornadoes with Swirl Ratio 0.54

title: Characteristics of Wind Pressures on a Cooling Tower Exposed to Stationary and Translating Tornadoes with Swirl Ratio 0.54 abstract: Current wind-resistant design of wind-sensitive structures including large-scale cooling towers is generally carried out with respect to synoptic boundary-layer-type strong winds. A swirling tornado can produce significantly different wind pressures than conventional boundary-layer wind. This paper presents both stationary and translating tornado effects on a cooling tower in a tornado vortex simulator developed at Tongji University, China. Wind pressures acting on the external surface of cooling tower model were measured at a fixed swirl ratio (S = 0.54) in the present study. Different radial distances between a cooling tower and stationary tornado vortex center were considered. Translating tornadoes with three different translation speeds (u = 0.04 m/s, 0.12 m/s and 0.2 m/s) were simulated. The results show that a tornado vortex can produce high negative wind pressures on a cooling tower surface due to the negative pressure drop accompanying a tornado. A cooling tower exposed to a tornado experiences combined effects of pressure drop accompanying a tornado and aerodynamic flow-structure interaction.

The Building Information Modeling and its Use for Data Transformation in the Structural Design Stage

title: The Building Information Modeling and its Use for Data Transformation in the Structural Design Stage abstract: As a processing technology of data and information, building information modeling (BIM) is often used for producing digital engineering model and promoting interoperability among participants involved in the Architecture, Engineering, and Construction (AEC) industry. The real values of BIM largely depend on effective information integrating and sharing among different stages or disciplines through the whole building lifecycle. To this day, although BIM has made a substantial contribution to the Chinese AEC industry, there are still some debates on its roles. Moreover, due to the complexity of structural design process, the weak link between structural model and BIM model makes its deep application even harder. To address these issues, this paper discusses the roles of BIM from the perspective of structural engineers through comparing with the traditional CAD. Then, the BIM structural model is studied by analyzing the model conformation, design mode, and Industry Foundation Classes (IFC)-format structural model. By comparing the differences between BIM physical model and structural mechanical model, an indirect method for the data transformation from BIM model to structural analysis model is proposed. An interface is developed based on the analysis of data formats and mapping rules. Three typical cases are adopted to demonstrate the data transfer efficiency by using the interface. The case study shows that the proposed method achieves higher efficiency for the data transformation from BIM model to structural analysis model.

Mitigation of Resonance for High Speed Train-bridge Systems Considering Overhanging Beam Effects

title: Mitigation of Resonance for High Speed Train-bridge Systems Considering Overhanging Beam Effects abstract: Short overhanging beams usually exist at both ends of a simply supported bridge. As a train passes through the overhanging beams of the bridge at high speeds, the overhanging beams would be subjected to intensive vibrations, from which the dynamic response of the train-bridge system would be built up. To mitigate the amplified response of the train-bridge system due to the overhanging beam effects, an end rotational spring to restrain the relative rotations is equipped between the free ends of the adjacent beams. By the vehicle-bridge interaction finite element analysis, the numerical studies indicated that the overhanging beams play a key role in amplifying the response of the train-bridge system. Even so, the proposed end restraintscan reduce the amplified response of the VBI system significantly

CFD Simulation in Helical Coiled Tubing

title: CFD Simulation in Helical Coiled Tubing abstract: According to hydrodynamic theory, based on CFD software-Fluent, the simulation for Newtonian fluid flow in helical coiled tubing was carried out to reveal the flow characteristics and pressure gradient of the helical section. Laminar and turbulent flow with different inlet velocities are considered. The results are compared with other published correlations. The results show that maximum velocity distributes in the outer side of the coiled tubing. The velocity in turbulent flow is more uniform than in laminar flow. It is shown that the faster the inlet velocity, the greater the pressure gradient increment. CFD simulation is in close agreement with the published correlations.

Daily Peak Load Forecasting Based on Fast K-medoids Clustering, GARCH Error Correction and SVM Model

title: Daily Peak Load Forecasting Based on Fast K-medoids Clustering, GARCH Error Correction and SVM Model abstract: Safe and economic operation of power system is based on load forecasting, and how to increase forecasting accuracy is the premise of power dispatching and economic analysis. Present paper establishes SVM (support vector machine) forecasting model based on fast K-medoids clustering algorithm and data accumulative pre-processing. FKM (fast K-medoids clustering algorithm) is applied to extract similar days by dividing all samples into k clusters, and respective forecasting of k clusters can realize the forecasting of a whole object. Before inputting the data into SVM system, the original data is preprocessed by accumulation to weaken the irregularity disturbance and strengthen sequence regularity. Due to existing unexplained component in forecasting error, GARCH (generalized autoregressive conditional heteroskedasticity) model is employed to forecast the error with non-white noise. According to its results, error correction is applied to the forecasted daily peak load. The forecasting effect of the proposed model is compared with other models in the given example, which verifies that SVM model based on fast K-medoids clustering algorithm and GARCH model has the characteristic of effectiveness, superiority and universality. The accuracy of daily peak load forecasting is enhanced significantly

A Two-Fluid Model for Herschel-Bulkley Fluid Flow through Narrow Tubes

title: A Two-Fluid Model for Herschel-Bulkley Fluid Flow through Narrow Tubes abstract: A two-fluid model of Herschel-Bulkley fluid flow through tubes of small diameters is studied. It is assumed that the core region consists of Herschel-Bulkley fluid and Newtonian fluid in the peripheral region. The analytical solutions for velocity, flow flux, effective viscosity, core hematocrit and mean hematocrit have been derived and the effects of various relevant parameters on these flow variables have been studied. It is found that the effective viscosity, core hematrocit and mean hematrocit for Newtonian fluid is less than that for Bingham fluid, power-law fluid and HerschelBulkley fluid. It has been observed that the effective viscosity and mean hematocrit increase with yield stress, power-law index, hematocrit and tube radius but the core hematocrit decreases with hematocrit and tube radius. Further, it is also noticed that the flow exhibits the anomalous Fahraeus-Lindqvist effect.

Establishing the Formation Pressure Profile of Predrill Well Based on Adjacent Wells Data

title: Establishing the Formation Pressure Profile of Predrill Well Based on Adjacent Wells Data abstract: The formation pressure plays a very important role in drilling engineering. So it is of great significance to predict formation pressure before drilling. In order to solve the problem, the concept of formation matrix and wellbore matrixwere put forward. Also the method of epitaxial transplantation for the regional formation pressurewas proposed. With the concept of wellbore pressure matrix, the target wellbore pressure matrix can be builtby dealing with the adjacent wellborepressureusing the method of depth adjustment and weighted distance correction. Finally, we can obtain the formation pressure of the targetwell. Case study of Qinghai Oilfield was carried out to test the method. Through comparative analysis, the maximum relative error of the transplantation pressure and logging interpretation pressure is 4.2%. The result indicated that the accuracy and reliability of the method can meet the engineering requirement. This is conductive to designers to predict formation pressure which can provide the basis for the casing design and the selection of the drilling fluid density.

Performance Analysis of DF Relaying M2M Cooperative System

title: Performance Analysis of DF Relaying M2M Cooperative System abstract: The average symbol error probability (ASEP) of multiple-mobile-relay-based mobile-tomobile (M2M) system with decode-and-forward (DF) relaying over N-Nakagami fading channels is investigated in this paper. The moment generating function (MGF) method is used to obtain the ASEP of various modulation techniques. Then the ASEP performance under different conditions is evaluated through numerical simulations to verify the analysis. The simulation results showed that the fading coefficient, number of cascaded components, relative geometrical gain, power-allocation parameter, and number of mobile relays have an important influence on the ASEP performance.

A Routing Optimization Strategy for Wireless Sensor Networks Based on Improved Genetic Algorithm

title: A Routing Optimization Strategy for Wireless Sensor Networks Based on Improved Genetic Algorithm abstract: In order to resolve the problem of generating invalid new individual when using genetic algorithm for routing optimization in wireless sensor networks (WSNs), an improved genetic algorithm (ROS_IGA) is put forward. By considering the position and neighbors of nodes in WSNs, ROS_IGA takes reasonable crossover and mutation operation to ensure compliance with the topological of actual WSNs and the demand of communication among nodes. Furthermore, ROS_IGA takes many factors, such as the residual energy of sensor nodes, distance and energy consumption between adjacent nodes, communication delay and relay hops, into consideration to select suitable routing. So ROS_IGA increases the speed of convergence and optimizes the performance of WSNs. Finally, a simulation experiment is carried out and the experimental results show that the improved algorithm in this study can effectively finds the best routing and decreases energy consuming and also increases the network life cycle.

Estimating Rate-Distortion for Multiple Description Coding Based on Zero Padding

title: Estimating Rate-Distortion for Multiple Description Coding Based on Zero Padding abstract: In the studies related to multiple description coding (MDC), applying zero padding not only improves the spatial correlation between descriptions but also increases their sizes. However, as we pad more zeros, the spatial correlation does not improve linearly. Therefore, the distortion is not reduced as the same amount when the size increases. In this paper, we focus on how to efficiently find an acceptable trade-off between the number of padded zeros and the increase of distortion in MDC. In this paper, we propose two distortion estimations for MDC with zero padding based on spatial quincunx distribution, which are standard deviation for distortion estimation and triangular linear approximation distortion estimation (TLA-DE) to efficiently calculate the distortion for the number of padded zeros atthe horizontal direction. In order to search for the acceptable number of padded zeros, we propose two search methods, Naïve Search and Best Division Search, which are both based on the proposed rate-distortion trade-off indicator. Our experiments result show that the worst error of distortion estimation by TLA-DE is up to 18%, but the average is 5.5% with 95% confidence level. The executing time of best division search is about two times faster than that of naïve search for 11 test sequences. To sum up, we confirm that the acceptable trade-off between rate and distortion in low computational complexity can be found by using the best division search on TLA-DE.

Analysis of Heat Transfer Coefficients in Direct Contact Membrane Distillation Modules Using CFD Simulation

title: Analysis of Heat Transfer Coefficients in Direct Contact Membrane Distillation Modules Using CFD Simulation abstract: Membrane distillation (MD) isan emerging separation technology for desalination, solution concentration and waste water treatment. As a thermal driven device, heat transfer coefficients are critical to the MD performance. In this study, the transmembrane heat and mass transfers are rigorously accounted for in the computational fluid dynamics (CFD) simulation. Flat plate direct contact membrane distillation (DCMD) modules with smooth-surface and rough-surface channels as well as in co-flow and counter-flow configurations are analyzed for the desalination application. For different rough-surface channels, flow configurations and operation conditions, the simulated permeation fluxes are fairly close to the experimental results. The local distributions of heat transfer coefficients show very high values at fluid inlets. For the simulated flat plate modules, the local heat transfer coefficients fall between conventional correlations of heat exchangers with circular channels and parallel plates and the module average heat transfer coefficients are much higher than the conventional correlations. This study reveals the values and distribution characteristics of the heat transfer coefficients in DCMD modules, which is important for the design of DCMD modules.

Third-Order Sinusoidal Oscillator Using a Single CMOS Operational Transresistance Amplifier

title: Third-Order Sinusoidal Oscillator Using a Single CMOS Operational Transresistance Amplifier abstract: This paper presents the design of a compact third-order sinusoidal oscillator based on an operational transresistance amplifier (OTRA). The proposed circuit consists of a single OTRA combined with three resistors and three capacitors. A review of relevant literature revealed that this is the first study to design a third-order sinusoidal oscillator, constructed with a single OTRA and the minimal number of passive components, with independent control of the oscillation condition and frequency. This study involved a review of previous designs as well as related formulations, nonideal analyses, and sensitivity discussions regarding the proposed circuit. Because the proposed circuit features a low-impedance output, it can be applied in cascading and used without additional buffer circuits. This study conducted simulations for the proposed circuit using HSPICE, and used commercially integrated circuits (ICs) and discrete components for circuit implementation and testing to verify its feasibility. Simulation and experimental results confirmed the validity of the proposed oscillator circuit.

A Modified Method for Risk Evaluation in Failure Mode and Effects Analysis

title: A Modified Method for Risk Evaluation in Failure Mode and Effects Analysis abstract: This study proposes a modified failure mode and effects analysis (FMEA) method based on fuzzy set theory and fuzzy analytic hierarchy process (FAHP) by analyzing the limitations of the traditional FMEA. First, the fuzzy language set of severity, occurrence, and detection is set up in this method. Second, the failure mode is evaluated by a triangular fuzzy number based on the fuzzy language set. Then, the weights of severity, occurrence, and detection are determined by the FAHP. Finally, the risk priority of the failure modes is determined by the modified risk priority number (RPN). The efficiency and feasibility of the modified FMEA method are verified by using it to deal with risk evaluation of the failure modes for a compressor crankshaft.

Rainfall Landslide in Sedimentary and Sub-Metamorphic Rock an Example in Kaoping River Basin

title: Rainfall Landslide in Sedimentary and Sub-Metamorphic Rock an Example in Kaoping River Basin abstract: Many researches employed several landslide-related factors such as the slope-aspect, size, lithology etc. to study the landslide assessment. Utilizing the landslide inventory delineated by 1:5000 high resolution aerial photo, this article explored the landslide characteristics, such as the landslide area, slump direction and air current for two different rock types in Kaoping River basin during the period of 2009 Typhoon Morakot. It is found that the air current direction is the dominant factor for landslides triggered by a heavy rainfall in Kaoping River basin. The number and size of landslides in slate is larger than the sedimentary rock. This indicates the slate region in Kaoping River basin is more likely to take place landslide; however, the landslide characteristic in size distribution is similar.

Numerical Investigations of Body Tail Projectile

title: Numerical Investigations of Body Tail Projectile abstract: The unsteady compressible flow around a body tail projectile is numerically solved with a Large Eddy Simulation (LES) method, Smagorinsky-Lilly model was used as the Sub-Grid Scale (SGS). The computed results are obtained in supersonic flow regime for a viscous fluid in order to determine the aerodynamic coefficients with different angles of attack. The flow around a body tail projectile was solved as a three-dimensional flow.

Optimization Design for Screw Wash-Sand Machine Based on Fruit Fly Optimization Algorithm

title: Optimization Design for Screw Wash-Sand Machine Based on Fruit Fly Optimization Algorithm abstract: The aim of this study is to minimize the specific energy consumption of the screw wash-sand machine. Let the diameter of the screw structure, pitch, diameter of the screw axis, blade thickness, installation angle, and the speed of the screw axis be the design variables, and take the minimum specific energy consumption as the optimization objective. According to the complexity of the optimization problem in this study, the fruit fly optimization algorithm (FOA) is used to execute the optimization design of the screw wash-sand machine. The non-stationary multi-stage assignment penalty function is adopted to cope with the constrained optimization problem. To judge the stability and reliability of the optimal solution and find the sensitive factors of the optimization design, the sensitivity analyses of the objective function and constraint conditions to the design variables are carried out. By simulation, the optimized structure parameters of the screw wash-sand machine and the data of the objective sensitivity and constraint sensitivity are obtained. The simulation results show that the specific energy consumption decreases by 4.59%; the diameters of the screw structure and screw axis are sensitive factors of the optimization design.

Free Vibrations of Homogenous Isotropic Viscothermoelastic Spherical Curved Plates

title: Free Vibrations of Homogenous Isotropic Viscothermoelastic Spherical Curved Plates abstract: In this paper free vibration analysis of viscothermoelastic spherical curved plate has been presented to study the spheroidal and toroidal vibrations. The basic governing partial differential equations have been reduced to ordinary differential equations for time harmonic vibrations. Coupled systems of equations represent spheroidal vibrations, while uncoupled equation corresponds to toroidal vibrations. These uncoupled vibrations remain independent of temperature variations. Matrix Fröbenious method of extended power series has been applied to derive the formal solution of the coupled system of ordinary differential equations. The analytical results have been computed numerically for polymethyle methacrylate material. The fundamental iteration technique have been used to compute eigen values and corresponding eigen functions to represent field quantities with the help of MATLAB software. The numerical results in respect of lowest frequency, dissipation factor, stresses, displacements and temperature change have been presented graphically.

Investigation on Non-Gaussian Peak Factors for Wind Pressures on Domed Roof Structures

title: Investigation on Non-Gaussian Peak Factors for Wind Pressures on Domed Roof Structures abstract: Roof curvature and Reynolds number effect significantly define the characteristics of wind pressures on domed roof structures. Once the flow separates from the roof surface, apparent changes in aerodynamic coefficients or non-Gaussian wind-induced pressure spectra are expected. This paper investigated the non-Gaussian peak factors of wind pressure coefficients on domed roofs under a simulated suburban boundary layer flow. By estimating the higher statistic moments, skewness and kurtosis coefficients, and adopting the moment-based Hermite polynomial translation techniques, including the softening and hardening processes, comparisons were made based on the empirical and simulated results. The fairly good estimation results by translation process were demonstrated and the influence on the estimation of wind pressure extremes was discussed in a practical viewpoint.

Optimization of Biodiesel Production Using Multi-Objective Genetic Algorithm

title: Optimization of Biodiesel Production Using Multi-Objective Genetic Algorithm abstract: In this modern technological age, one of the challenges facing the transportation industry, is finding a less polluting substitute for diesel. Meanwhile, any kind of fuel due to the cetane number specified in a diesel cycle cannot be utilized. One of the alternatives for this is biodiesel which is indirectly obtained from animal fat in the presence of alcohol. Cost of biodiesel is more than that of conventional fuels; therefore, optimization of industrial production of biodiesel is with major importance. There are several methods to obtain the optimum temperature for biodiesel production process. In this paper, genetic algorithm, as one of the strongest evolutionary algorithms, has been applied to biodiesel production to obtain the best reaction parameters. Moreover, in order to have a robust optimization, multi objective genetic algorithm is employed. The achieved temperature point for maximizing biodiesel production was a wide range of temperature which can be illustrated as Pareto front to help making the final decision. This study was aimed to maximize the amount of Ester and Alcohol in this production and minimize the other products. This result can define a new strategy for industrial biodiesel production planning.

Finslerian Hypersurfaces and Generalized Change of Finsler Metric

title: Finslerian Hypersurfaces and Generalized Change of Finsler Metric abstract: In the present paper, using the field of linear frame [13], we shall considered Finslerian hypersurfaces given by generalized change of Finsler metric. The generalized change of Finsler metric is given by L = f (L, 1), 2),…, m) ), where f is any positively homogeneous function of degree one in L and 1), 2),…, m). Our purpose is to give some relations between the original Finslerian hypersurface and the other which is Finslerian given by generalized change. We have shown that generalized change makes three types of hypersurfaces invariant under certain conditions. Also, we have obtained the conditions under which this change will be a hyperplane of first, second and third kind.

Research on the Application of the Segmentation Based on Key Points in the Power Consumption of Wireless Sensor

title: Research on the Application of the Segmentation Based on Key Points in the Power Consumption of Wireless Sensor abstract: In order to reduce the power consumption of the sensor, the key points of the algorithm are proposed, which can greatly reduce the transmission data and reduce the power consumption; The Sink receives the key point sequence, and uses the piece-wise linear algorithm to fit the data, for the user to query, statistics and graphics and other operation; The empirical evidence of this algorithm fits the raw data well, Less computation, less transmission of data, is conducive to reduce the power consumption in the wireless sensor.

A 2D Hidden Markov Model for Patch-based Super Resolution

title: A 2D Hidden Markov Model for Patch-based Super Resolution abstract: Super resolution is developed to enhance the resolution of images and various kinds of learning based methods were proposed to magnify a single image. This paper presents a 2D hidden Markov model which could do super resolution by using learned image patch pair database. The image patch pairs store the correspondence relation of high-frequency information between low resolution (LR) patches and high resolution (HR) patches. For each input LR patch, the top five similar LR candidate patches in database are searched to construct a 3D cube which can then be modeled by the proposed 2D hidden Markov model (HMM). A novel 2D Viterbi algorithm is developed to find the optimal LR candidate patches that are the most compatible with each other. The resulting super resolution image could be formed by pasting back the corresponding HR patches from patch pair database according to the positions of found optimal LR patches. By objective comparisons of PSNRs/SSIMs and subjective judgment of the generated super resolution images, the proposed 2D HMM method is superior to the traditional interpolation methods and some existing state-of-the-art methods.

A New Habit Pattern Learning Scheme in Smart Home

title: A New Habit Pattern Learning Scheme in Smart Home abstract: Most of the user’s activities are consistent with their habits, therefore in this paper, we propose a new habit pattern learning scheme in smart home to better obtain user’s behavior regulations and habits, which can make the home more intellectually interact with people. By recording the operations on each electric appliance in the form of time series, we firstly find out that the habit can be classified into fixed-length habit and timing habit. Then, we propose habit extraction methods based on the corresponding activity probability and calculation formulas of the habit strength. Since different habits have different variation characteristics on habit strength and time zone, we further propose the self-learning algorithms on time zone and habit strength threshold to obtain the suitable parameters. Furthermore, by defining the association among individual habits into selection, parallel, sequence, cross and inclusion, we can obtain habit set which is a group of habits with inner correlation. In order to adapt to the habit variations, we introduce a habit change factor into the habit pattern discovery algorithm so as to follow the habit changes. Finally, we construct the experimental environment in a real smart home, analyze and calculate the operation records of electric appliances in two months. The experiment results show that the proposed habit pattern learning scheme is effective and efficient.

The Study of Rotational Ultrafiltration System for Recovery of Spent Cutting Oil from Solar Photovoltaic Cell Manufacturing Process

title: The Study of Rotational Ultrafiltration System for Recovery of Spent Cutting Oil from Solar Photovoltaic Cell Manufacturing Process abstract: The main problems of recovery cutting oil from spent waste are high viscosity of cutting oil and high content of nano-size particle. This study combined an innovative rotational circular-plate ultrafiltration membrane filter with a scraping device to recycle the cutting oil and remove particles fouling cake attached to the membrane surface, and was able to maintain cutting oil filtrate flux above 6.65 l/m2 /hr. Also, the proposed process is the practical solution for materials separation between highly viscosity liquid and fine particles even nano-size. The results show the filtrate of ultrafiltration membrane could meet the reuse requirements of less than 0.03% solid content. Analysis of blended oil characteristics under different blending ratios was conducted, showing the optimum blending ratio of recycled oil to new cutting oil was 6:4. The final production cost can be reduced over 27.4%. The process can achieve waste reuse ratio of greater than 77.2%.

Rough Classifier Based on Region Growth Algorithm for Identifying Liver CT Image

title: Rough Classifier Based on Region Growth Algorithm for Identifying Liver CT Image abstract: Over decades, liver cancer is a rising cause of death in Taiwan, and more and more researchers are concerned about detecting hepatic tumors in computed tomography (CT) images. For clinical applications in terms of diagnosis and treatment planning, image segmentation on abdominal CT is indispensable. Patients with a large number of CT images need specialist physicians to identify, and detecting tumor location correctly from many CT images has been a major challenge subsequently. Therefore, this paper proposed a novel computer-aided detection (CAD) method that had high classification accuracy for identifying tumors. The proposed method used a region growing algorithm to segment liver CT images, employed REDUCT sets to reduce attributes, and then utilized a rough set algorithm to enhance classification performance. To evaluate the classification performances, the proposed method was compared with five different classification methods: decision tree (C4.5 and REP (reduced error pruning)), multilayer perceptron, Naïve Bayes, and support vector machine (SVM). The results indicate that the proposed method is superior to the listing methods in terms of classification accuracy.

Theoretical Analysis of Wind Turbine Tower-Nacelle Axial Vibration Based on the Mechanical Impedance Method

title: Theoretical Analysis of Wind Turbine Tower-Nacelle Axial Vibration Based on the Mechanical Impedance Method abstract: Based on an established axial vibration model of the wind turbine tower-nacelle system, the mechanical impedance method was applied to construct the mechanical network diagram for the axial vibration of the tower-nacelle system. Then, the axial free vibration and forced vibration of the system were analyzed theoretically with considering the displacement impedance or admittance as the transfer function. The analysis shows: for free vibration, the system performs damped vibration with light damping, the amplitude attenuates exponentially with light damping, the system returns to the equilibrium position directly with over-damping, and the system does not generate reciprocating vibration with critical damping; for forced vibration, the amplitude of the axial displacement response is related to the frequency ratio of rotation rate. The resonance frequency does not occur at the undamped natural frequency 0. The peak value of the vibration triggered by blade mass imbalance shifts toward the high frequency direction along with the increase of damping ratio , while the peak value of the vibration triggered by tower front spoiler and pneumatic imbalance shifts toward the low frequency direction along with the increase of . If > 2 2 , the amplitude frequency has no peak value, and resonance does not occur. The analysis provides a theoretical basis for the design and control of the wind turbine tower.

High Rate Anodic Dissolution of Stainless Steel 316 (SS316) Using Nano Zero Valent Iron as Reducing Agent

title: High Rate Anodic Dissolution of Stainless Steel 316 (SS316) Using Nano Zero Valent Iron as Reducing Agent abstract: The experiments on electrochemical machining of stainless steel SS316 have been carried out according to designed experimental plan to observe the effect of nano zero valent iron (NZVI) mixed electrolyte solution on material removal rate. Dependence of material removal rate on feed rate in presence of NZVI has been determined and compared with theoretical values. These comparative investigations for MRR are given in tabular format with graphical representation. The significant effect on MRR was observed; when NZVI mixed aqueous NaCl solution was used as an electrolyte due to its high reducing characteristics. The observed experimental results were found to be quite close with theoretical results.

Research on Flip Mechanism Automatic Offline System Based on LabVIEW

title: Research on Flip Mechanism Automatic Offline System Based on LabVIEW abstract: According to the analysis of XX company’s flip mechanism production line, an automatic offline system for the flip mechanism was designed based on LabVIEW to substitute manpower. The upper computer software is developed under LabVIEW. The PCI1010 motion control card is used to gather the information of sensors to realize the real-time control of the external execution devices. Adsorption experiment shows that the system can match with the production line seamlessly and improve the production efficiency greatly. The research provides an effective method for the transformation and upgrading of the production line.

Development of 3D Feature Detection and on Board Mapping Algorithm from Video Camera for Navigation

title: Development of 3D Feature Detection and on Board Mapping Algorithm from Video Camera for Navigation abstract: In this paper, a different approach is introduced to produce comparable 3D reconstruction outcomes similar to that of working geometry method but not as computationally extensive as well as mathematically complex. An image pair, capturing the left and right view of the object or surrounding, is used as inputs. The analogy is very similar to how the human eye perceives the world. The 3D reconstruction program is broken down into two sections, with 3 MATLAB codes been written in total. First, to generate the image frames, followed by the second section, generating the 3D point cloud. In the first part of the program, 2 MATLAB codes have been written with the end result of estimated image frames between the two views which are not captured by the camera will be generated. In the second half of the program, the image pair is now processed to generate 3D point clouds containing 3D co-ordinates of the features. This techniques allows the partial reconstruction of a 3D environment by stitching together these image frames, thus creating a video of the environment as if the camera is moving from the left camera point to the right, giving the user the depth perception one would get when viewing it in real life. After which a 3D point cloud is generated, however to achieve this, the camera must first be calibrated to obtain the camera parameter with the aid of a checkerboard. The camera positions are also estimated and this is combined with the 3D co-ordinates of the features, producing the 3D point cloud. This will give the 3D co-ordinates of the features in an interactive 3D plot within MATLAB extracted from just a pair of input images.

Experimental Studies on 3D Printed Parts for Rapid Prototyping of Micro Aerial Vehicles

title: Experimental Studies on 3D Printed Parts for Rapid Prototyping of Micro Aerial Vehicles abstract: This paper presents the results of exploratory studies for facilitating the direct use of 3D printed parts in design and development of micro aerial vehicles (MAV). 3D printing processes of stereolithography and fused deposition modeling are investigated as the candidate prototyping options. Custom developed electro-chemical and mechanical processes are used to deposit thin structural nickel coatings on 3D printed test specimens and MAV parts. Residual stress and mechanical strength of coated 3D printed specimens are evaluated through experimental methods. Considerable improvement is realized in tensile and impact performance of the coated 3D printed parts. Findings from this study enable the MAV research teams to work with multiple design options and arrive at optimal solutions without severe time and cost penalties that are typically associated with conventional manufacturing procedures.

Design of a Butterfly Ornithopter

title: Design of a Butterfly Ornithopter abstract: Research on ornithopters is receiving more attention because they exhibit good controllability, maneuverability, and robustness in the natural environment. Here, we report on the design, fabrication, and experimental validation of the mid-size butterfly ornithopter, which mimics the morphology of a dead leaf butterfly. The wing flapping mechanism can support wings with a span of 565 mm and can flap the wings in a 120-degree range and at a frequency of 5 Hz. A lift force measurement and a particle image velocimetry experiment were performed to validate the performance of the ornithopter.