Abstract: The focus of this article is fault-diagnosis of complex mechanical parts through the process of their modal information using a multi-layer perceptron (MLP), a type of artificial neural networks (ANNs). The major contribution of this work is to formulate the problem of fault diagnosis of complex mechanical parts based on their modal information so as to be solved with use of ANNs. This method consists of three major steps: (1) Extracting natural frequencies of the part with or without faults. (2) Creating the “fault signatures” by deducting the natural frequencies of some faulty specimens from the ones of the faultless part. (3) Constructing and training a mathematical model in the form of an ANN, with information obtained in previous steps, to locate (and even further characterize) the fault. The presented method was successfully adopted to estimate the location of an under-surface mechanical fault on an automobile cylinder block and is shown to have the potential to solve more sophisticated fault diagnosis problems.

Abstract: The present investigation focuses on the design and 3D printing of a non-anthropomorphic articulated mechanical hand dedicated to dextral manipulation. A virtual dextral simulation workshop under 'Catia' and based on the functionalities that are integrated in it especially the module 'Digital Model/DMU kinematics' has been developed. Its application allows the design of a five-fingered hand inspired by existing ones, and can be mounted on a manipulator arm with six degrees of freedom. It was subsequently refined through the application of the module 'Human Builder' which manages the human grasping under 'Catia, and two cases of grasping have been successfully completed: a palmar grasping and a digito-palmar one with the possibility of the whole hand-arm to perform 'pick-and-place' tasks within a virtual environment. These simulations have proved promising as they allow considering a wide spectrum of interesting robotic tasks. The design developed in this way was 3D printed out (additive manufactured) and its commands tested. The results have been found very satisfactory.

Abstract: The aim of this research was to study the effect of variations in the throat diameter of the rocket nozzle from the review of gas pressure, exit temperature and combustion rate in the rocket chamber to obtain the optimal and non-explosive thrust of the rocket. The method used was experimental and compared each throat nozzle diameter using a thrust tester. The tested variant throat nozzles are 5mm, 6mm, 8mm, 10mm in diameter. Propellant as a constant for the test material, test results in the form of a graph of the ratio between temperature and time, pressure with time, and thrust with time. The results show that the smaller the throat diameter results in a higher nozzle temperature, higher gas pressure, and higher thrust of the rocket. But this condition cannot exceed the critical condition, because the temperature of the exit nozzle reaches the melting point of the chamber material which is made of chromium which has a melting point (melting point) of 19070C and the chamber will explode. This occurs when the throat nozzle diameter is used 5mm, but when the throat nozzle diameter is used 6 mm the peak temperature only reaches 19000C or is still below the critical point. In this condition the 6mm diameter throat nozzle provides the greatest gas pressure and thrust compared to the 8mm and 10mm diameter throat nozzles, thus the 6mm diameter throat nozzle produces the most optimal thrust specifications.

Abstract: The purpose of this study is to obtain the best front wing configuration to be applied in the student formula car. This research analyzes varieties of front wing configurations, including the application of cascade winglets feature simulated in several angles of attacks. The result showed that the best configuration is achieved using front wing model with two-element cascade winglets and extra turning vanes at 18-degree angle of attack. This research proved that installing this configuration reduces the drag force received by the front wheels by 27%. This improvement is achieved with the coefficient of lift and drag values at -1.653 and 0.283.

Abstract: The laboratory in the university is one of the learning support facilities for students. Commonly, the laboratory room loaning system still uses a conventional method, the user fills a loan book out, takes the room key, and returns it to the admin after completion. The problems often happened, such as loss of keys or no monitoring system for laboratory usage. Therefore, this study aims to integrate the Internet of Things (IoT) based door lock control system for laboratory security. The proposed system consists of a website for monitoring, an Android application as a user interface for requesting laboratory loans, an NFC reader, and NFC on smartphones access to the room. The monitoring system has features for user registration, loan applications, viewing loan schedules, and sending loan notifications. The test results show that the NFC tag is able to read and detect NFC ID from a smartphone up to 2 cm with an average delay of 0.2686 seconds. With the proposed system, it is hoped that it can provide secure access, ease in loaning laboratory rooms and a fast and controlled process.