Taiwan Association of Engineering and Technology Innovation: E-Journals
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A Comparison of Automotive Waste Heat Recovery Systems
Get PDFThe purpose of this research study is to assess schemes for recovering energy that is lost via an automobile’s exhaust. Three systems for waste heat recovery, viz., (1) electric turbo-compounding, (2) organic Rankine cycles, and (3) thermoelectrics are studied. This involves detailed computer simulations of the waste heat recovery systems, integrated within a vehicle propulsion system operating over certification driving cycles. The simulations suggest that fuel economy improvements of 3-5% could be achieved by converting waste heat into useful work
A Differential Evolution Optimization Approach for Parameters Estimation of Truncated and Censored Failure Time Data
Get PDFMost practically collected datasets are plagued with issues of incompleteness and inaccuracies which will cause erroneous reliability modeling and poor maintenance decisions. This work outlines an investigation into the use of Heuristic techniques to estimate the parameters of a stochastic life distribution by using failure data with Truncation and Censoring. A Maximum Likelihood Estimation (MLE) approach was utilized in which the Log-Likelihood function is modified to account for the Truncation and Censoring factors. A Differential Evolution (DE) algorithm developed in MATLAB R2013a minimizes the Negative Log Likelihood (NLL) function and obtains optimum parameters for the 2 Parameters (2-P) Weibull distribution. Results obtained from a series of designed experimental tests generalized the relationship between the increasing levels of Truncation and Censoring individually on the β and η parameters. The impact of the modified NLL technique was examined under cases of Left Truncated and Right Censored (LTRC) data through evaluations of the MSE metric which were compared to estimations made under the normal NLL equation. Truncation and Censoring percentages were increased from 0% to 50% for testing the modified NLL approach. It is clear from the low MSE values (error) that this approach is successful at estimating the parameters closer to the true values. This approach was applied to failure data of a Gas Engine Power Generator utilized in Offshore Gas Production. The results were compared with those obtained from traditional Weibull Analysis in the ReliaSoft Weibull/Alta package.
Effects of Unsteady Aerodynamic Pressure Load in the Thermal Environment of FGM Plates
Get PDFThe effects of unsteady aerodynamic pressure load with varied shear correction coefficient on the functionally graded material (FGM) plates are investigated. Thermal vibration is studied by using the first-order shear deformation theory (FSDT) and the generalized differential quadrature (GDQ) method. Usually, in the FGM analyses, the computed and varied values of shear correction coefficient are the function of the total thickness of plates, FGM power law index, and environment temperature. The effects of environment temperature and FGM power law index on the thermal stress and center deflection of airflow over the upper surface of FGM plates are obtained and investigated. In addition, the effects, with and without the fluid flow over the upper surface of FGM plates, on the center deflection and normal stress are also investigated
An Intelligent Manufacturing System for Injection Molding
Get PDFIn recent years, the great trends of industry 4.0, internet of things (IoT), big data analytics, and cloud computing, the design and development of plastic injection molding (PIM) products has been more requested to achieve the requirements of light, thin, short, small, multi-function, high-precision, energy-saving, and obliged to fulfill a large number of customized production. To tackle this arduous challenge, effectively developing a novel PIM intelligent manufacturing system will play a crucial role. The aim of the proposed study is to carry on building an intelligent manufacturing system (IMS) for PIM industry, which is composed of three subsystems: a multiple response optimization systems of PIM, a database management system of process parameters, and a PIM real-time monitoring and control system. Firstly, the multiple response optimization systems present an intelligent optimization system to find optimal process parameters of multiple quality characteristics in the PIM process. Secondly, the database management system allows for saving the experimental data, PIM process parameter settings and quality goals. The third is a PIM real-time monitoring and control system, which establishes a graphic monitoring and control interface to real-time monitor the parameters of PIM machine and the optimal process parameter settings. The proposed PIM intelligent manufacturing systems enable the functions of real-time monitoring, process parameter optimization and database management, which can assure better PIM product quality and yield rate, effectively reduce the manufacturing cost, and promote the competition of the PIM industry in the future
On a Touch-Activated Wearable Device with Automated Location Sending Capability
Get PDFThis study proposes a device that enables a person in distress to remotely seek for help. It is a wearable device consisting of a microcontroller and a GPS-GSM module that has the capability to determine the closest police stations based on the current location of the wearer. When being triggered, it sends the current coordinates of the wearer via SMS messages to the corresponding nearest police station, and a pre-defined contact number. Afterwards, the device sounds off an alarm to fend off any threat, or to serve as an alert of your location
A Study of the Bolt Connection System for a Concrete Barrier of a Modular Bridge
Get PDFModular technology has been recently studied to reduce the construction periods in the field of bridge construction. However, this method is restricted to the pier, girder, and deck, which are the main members of a bridge, and incidental facilities such as concrete barriers have been rarely studied. Thus, in this study, the connection system of a concrete barrier for modular bridges was developed, and a static loading experiment was performed to verify the structural capacity of the proposed system. The variables of the experiment were the vertical and horizontal bolt connections and the construction method. The barrier and plate were fabricated using match casting methods in which nuts were first inserted into the plates rather than anchor bolts using the conservative method. Moreover, a comparison with the conventional in situ barrier was also performed. The experiments were conducted according to the AASHTO LRFD standard. Consequently, the specimen using the vertical bolt connection had a structural capacity that was equal to 85% of that of the conventional specimen and exhibited similar crack patterns compared with the conventional specimen. In the case of the horizontal bolt connection, the separation in the connection area occurred with the application of the initial load and this specimen exhibited a poor performance because of the increase in the separation distance with the application of the maximum load
Effect on Tool Design and Heat Input of Some Welding Parameters in Friction Stir Welded Interstitial Free Steels
Get PDFThe friction stir welding process (FSW), a new solid state welding, are widely used in automobile and aerospace industries as compared to conventional fusion welding. The tool speed (rotational and translational), traverse speed, shoulder diameter and pin diameter are mainly responsible for the heat generation in FSW which are required to be optimized. The contribution of rotational tool speed is approximately three times higher than that of translational tool speed. This paper presents derivation for maximum heat generation to obtain best optimum tool geometry (tapered or cylindrical) in FSW through mathematical model using various parameters and necessary constraints. Two models namely genetic algorithm and regression model of response have been developed to compute optimum welding parameters. The genetic algorithm optimization technique has been employed for tapered and cylindrical FSW tool whereas the regression model has been employed for cylindrical FSW tool to obtain optimum tool geometry at constant welding speed. It has been found from genetic algorithm using MATLAB and regression modelling using MINITAB-17 that the optimum parameters for effective tool design are shoulder diameter as 12 mm, pin diameter as 4 mm and tool rotation speed as 250 rpm
Multi-Response Optimization of Wire Electrical Discharge Machining for Titanium Grade-5 by Weighted Principal Component Analysis
Get PDFThis paper reports the results of research to examine the effects of cutting parameters such as pulse-on time, pulse-off time, servo voltage, peak current, wire feed rate and cable tension on surface finish, overcut and metal removal rate (MRR) during Wire Electrical Discharge Machining (WEDM) of grade-5 titanium (Ti-6Al-4V). Taguchi’s L27 orthogonal design method is used for experimentation. Multi-response optimization is performed by applying weighted principal component analysis (WPCA). The optimum values of cutting variables are found as a pulse on time 118 µs, pulse off time 45 µs, servo voltage 40 volts, peak current 190 Amp. , wire feed rate 5 m/min and cable tension 5 gram. On the other hand, Analysis of Variance (ANOVA), simulation results indicate that pulse-on time is the primary influencing variable which affects the response characteristics contributing 76.00%. The results of verification experiments show improvement in the value of output characteristics at the optimal cutting variables settings. Scanning electron microscopic (SEM) analysis of the surface after machining indicates the formation of craters, resolidified material, tool material transfer and increase in the thickness of recast layer at higher values of the pulse on time
Smartwatch/Smartphone Cooperative Indoor Lifelogging System
Get PDFIn this study, a lifelogging system is proposed for logging the daily activities of a user using a smartphone and a smartwatch cooperatively in indoor environments. The proposed system attempts to recognize a user’s activities of daily living, including sleeping behavior and various physical activities, and to estimate the user’s daily total energy expenditure (TEE) based on the recognized lifelogs. The TEE has the potential to be useful in personal healthcare management. The system includes both mobile and server systems. The mobile system consists of both a smartwatch and a smartphone used to classify ten activities, including sleeping activities, using sensors on both devices. The server system includes a database server and a set of programs to handle the collected lifelogs for users. An Android app is also developed to display the collected lifelogs and the estimated daily TEE on smartphones to assist in managing users’ health. The experimental results show that the overall average recognition rate of seven activities is 97.5% with four subjects, and the total average error for the three states of sleeping behaviors is 6.64%
Hardware Implementation of Road Network Extraction Using Simplified Gabor Wavelet in Field Programmable Gate Array
Get PDFAutomatic detection of road networks from the satellite and aerial images is the most demanded research area, and it is used for various remote sensing applications. The Simplified Gabor Wavelet based approaches are used to extract the road network automatically. In this paper, a field programmable gate array architecture designed for automatic extraction of road network using Simplified Gabor Wavelet is proposed. The hardware implementation results are compared with software implementation results. The performance measures such as completeness, correctness and quality are calculated. In the software implementation, the average value of completeness, correctness, and quality of various images are 91%, 98%, and 89% respectively. In the hardware implementation, the average value of completeness, correctness, and quality are 89%, 97%, and 87% respectively. The performance of the proposed algorithm is also proved in noisy images. These measures prove that the proposed work yields road network very resembling to reference road map.