Journal of Engineering and Technological Sciences
Not a member yet
888 research outputs found
Sort by
Evaluation of Crash Energy Management of the First-Developed High-Speed Train in Indonesia
Get PDFCrash energy management is an essential evaluation stage of passive safety systems for high-speed trains. As a part of crash energy management, crash energy absorption has been researched for the last decade. The development of its components has also been performed individually. This paper presents a numerical analysis of the configuration of an energy absorption system for high-speed trains developed in Indonesia. Three placement configurations of the energy absorption system were investigated using explicit dynamic analysis in ANSYS. Total energy absorption, deceleration pulse, and deformation length were considered in the evaluation of the numerical analysis results. The collision criteria used in this study were according to EN 15227 and CFR 238 standards. This study revealed that the existing design could fulfill the energy absorption and average deceleration pulse required by EN 15227. Nevertheless, the existing design could not fulfill the energy absorption and maximum deceleration pulse required by CFR 238. It was also indicated that by positioning the anti-climber slightly forward, changing the deformation force of the crush box, and adding an impactor, the quality of energy absorption and average deceleration pulse could be improved
Machine Learning-based Indoor Positioning Systems Using Multi-Channel Information
Get PDFThe received signal strength indicator (RSSI) is a metric of the power measured by a sensor in a receiver. Many indoor positioning technologies use RSSI to locate objects in indoor environments. Their positioning accuracy is significantly affected by reflection and absorption from walls, and by non-stationary objects such as doors and people. Therefore, it is necessary to increase transceivers in the environment to reduce positioning errors. This paper proposes an indoor positioning technology that uses the machine learning algorithm of channel state information (CSI) combined with fingerprinting. The experimental results showed that the proposed method outperformed traditional RSSI-based localization systems in terms of average positioning accuracy up to 6.13% and 54.79% for random forest (RF) and back propagation neural networks (BPNN), respectively
2-Dimensional Materials for Performance Enhancement of Surface Plasmon Resonance Biosensor: Review Paper
Get PDFSurface plasmon resonance (SPR)--based biosensors compete and excel among optical biosensors because of exceptional features such as high sensitivity, label-free, and real-time measurement, allowing the observation of molecular binding kinetics. In SPR biosensors and other biosensor techniques, surface functionalization and bioreceptor attachment are effective strategies to improve sensor performance. The application of an appropriate immobilization matrix for the bioreceptor is an essential step in maximizing the absorption of the bioreceptor on the sensor surface, thereby improving a specific target-sensor interaction. Furthermore, the materials should provide excellent optical properties to enhance the response signal. The high surface-to-volume ratio and high optical absorption of 2D materials qualify these requirements, thus promising advancements for SPR biosensors. This article reviews the recent SPR biosensor study with the use of the 2D materials family to improve the sensor performance, including graphene, transition metal dichalcogenides (TMDCs), MXene, black phosphorus (BP), perovskite, and boron nitride (BN). The materials properties and enhancement mechanisms of different 2D materials are discussed comprehensively. This review was expected to provide a future perspective and design approach for 2D materials-based SPR biosensors
Design of Magnetron Cooling Method Based on Heat Exchanger System for Microwave Heating Application
Get PDFMicrowave heating is a novel thermal recovery technique developed for heavy oil reservoirs. Particulary in deep reservoirs, it allows more effective thermal recovery to counter heat loss.. The magnetron as a microwave generator works based on cavity resonant vibrations and it needs an appropriate cooling system to avoid damage to its cavity elements. In this paper, the design of a cooling system based on a heat exchanger as well as the investigation of the proper material and coolant to fit the microwave characteristics are proposed
Self-Healing of Cracks in Concrete using Bacillus cibi with Different Encapsulation Techniques
Get PDFOne of the main challenges related to concrete is the formation of cracks, which can greatly diminish its strength and decrease its service life. Repair costs to mitigate these cracks can be high. This study investigated the use of Bacillus cibi to produce a self-healing bio-concrete capable of repairing cracks by itself through microbial activity. Bacteria were introduced into concrete by direct incorporation and encapsulating it in lightweight aggregates (LWA) and diatomaceous earth (DE). Samples of concrete cylinders were tested to quantify crack healing, compressive strength, and water permeability. The results showed that bio-concrete prepared with the LWA encapsulation method was able heal the largest crack width at 0.541 mm after 35 days of wet-dry cycle. Bio-concrete produced from bacteria with no encapsulation exhibited significant enhancement in 28-day compressive strength (57.28 MPa) compared to normal concrete (54.78 MPa) and produced the highest hydraulic conductivity recovery at 85.04% after 35 days of healing. The XRD analysis showed that the bacteria did not cause any major changes to the concrete
Simulation Model of Enhancing Performance of TCP/AQM Networks by Using Matlab
Get PDFInternet networks are becoming more crowded every day due to the rapid development of modern life, which causes an increase in the demand for data circulating on the Internet. This creates several problems, such as buffer overflow of intermediate routers, and packet loss and time delay in packet delivery. The solution to these problems is to use a TCP/AQM system. The simulation results showed that there were differences in performance between the different controllers used. The proposed methods were simulated along with the required conditions in nonlinear systems to determine the best performance. It was found that the use of optimization Department of Electro-mechanical Engineering, University of Technology - Iraq tools (GA, FL) with a controller could achieve the best performance. The simulation results demonstrated the ability of the proposed methods to control the behavior of the system. The controller systems were simulated using Matlab/Simulink. The simulation results showed that the performance was better with the use of GA-PIDC compared to both FL-PIDC and PIDC in terms of stability time, height, and overrun ratio for a network with a variable queue that was targeted for comparison. The results were: the bypass ratio was 0, 3.3 and 21.8 the settling time was 0.002, 0.055, and 0.135; and the rise time was 0.001, 0.004 and 0.008 for GA-PIDC, FL-PIDC and PIDC, respectively. These results made it possible to compare the three control techniques
