Testing of behavior bias

This study aims to (i) test the behavior bias of gamblers fallacy occurs at the time of uptrend and downtrend conditions; (ii) test the behavior bias of halo effect occurs at the time of uptrend and downtrend conditions; and (iii) test the behavior bias of familiarity effect occurs at the time of uptrend and downtrend conditions. The number of samples in the study was as many as 41 people. The test equipment used is One-Sample t-Test and Paired t-Test by using statistical package for social scientists (SPSS) as a static test tool. The results of this study show that: (i) Gamblers' fallacy that occurs when the uptrend condition is greater than when the condition is downtrend; (ii) Halo effect that occurs when the uptrend condition is greater than when the downtrend condition; (iii) Familiarity effect that occurs when the uptrend condition is greater than when the downtrend condition.

Field Tests on Bearing Characteristics of Large-Diameter Combined Tip-and-Side Post Grouted Drilled Shafts

This paper presents a field study on the axial behavior of four large-diameter drilled shafts embedded in coarse sand. The grouting and loading test procedures were reported. The bearing capacity of shafts (TS1 and TS2) and grouted drilled shafts (TS3 and TS4) were herein determined by the bi-directional static test and top-down load test, respectively. The enhancement mechanism of bearing characteristics of the grouted shafts was discussed in detail. The test results indicate that the bearing characteristics and load transfer mechanisms of the test shafts were significantly affected by the quantity of pressurized cement slurry and the mechanical properties of the soil surrounding the shafts. Furthermore, the tip resistance of shaft can be mobilized more rapidly and fully after grouting, the side and tip resistance are mobilized in a more synchronized and coordinated manner due to the pre-mobilization of the grouted cement. Additionally, the standard penetration test (SPT) prediction model was introduced to calculate and predict the SPT blow counts of soil after grouting. The results show that the post grouting has a more obvious improvement on the strength of cohesionless soil.

Design and development of an automated robot for collecting latex cups in rubber plantation

The main reason for robots in agriculture are saving the time and energy required for performing repetitive tasks and increasing the productivity. The turnover rate in rubber plantation is high and youngster nowadays refuse to work in this industrial. This project aims to build a small-scaled automated robot prototype for collecting latex cups in hopes to reduce the dependency of labor in collecting latex. It was fabricated by using 3D printer and consists of transmission system, linear actuator robotic arm and a storage tank. It was analyzed through static test and balance test for mechanical stability. The robot developed can perform auto-navigation with proper calibration on the transmission at flat terrain, and able to control the 3 Degree of Freedom (DoF) robotic arm on the prototype to grab the latex cup smoothly. Ultrasonic sensors are used to locate the rubber trees and movements of the prototype. The robotic arm and the base are controlled by an Arduino Uno and motor driver circuit respectively. A magnetometer was implemented to ensure the prototype could move straight throughout the process. During test, the prototype was placed in front of two “rubber trees” (imitated by water bottle) to let it retrieves the model latex cups and extract the liquid inside. The results showed that implementation of magnetometer enabled the robot much more consistent in the moving direction and proper delay time used for the navigation of the robot. The prototype is able to automate basic tasks and act as fundamental design for future development.

Diagnostics of actuation system by Hadamard product of integrated motor current residuals applied to electro-mechanical actuators

The paper presents diagnostics methodology that can identify the event of occurrence of fault in the actuator or the linkage system of the flight control actuation system driven by Linear Electromechanical Actuators (LEMA). The standard data analysis like motor current signature analysis (MCSA) is good at identifying the incipient faults within the elements of the actuators in situations where-in the actuators are driving control surfaces. But in back driven cases, where-in LEMA is driven back by control surfaces, the faults outside the LEMAs are difficult to be detected due to higher mechanical advantages of transmission elements like roller screws, gear train and linkage arms scaling down their effects before reaching the motor. One such event occurred in a ground test, wherein the jet vanes were sheared when back driven by excessive gas dynamic forces. Neither the motor current nor the LEMA position feedback data has any clue of the instance of occurrence of such shearing. The case study is discussed in detail and diagnostics solution for such failures is proposed. A new methodology to pin point the event of occurrence is arrived at based on ground static test data of four independent channels. The same is reassured for its applicability using lab experiments on three samples mimicking the failure. The method's applicability is also extended for extracting events in actual flight, by comparing the flight telemetry data with the mimicked lab level (dry runs) data. The methodology uses the analysis of LEMA motor current data to arrive at the vital diagnostic information. The current data of LEMA directly cannot be interpreted due to non-stationary nature arising from variable speed and its pulsating form because of the pulse width modulation (PWM) switching, threshold voltages and closed loop dynamics of the servo. Hence the motor current is integrated using cumulative trapezoidal method. This integrated data is spline curve fitted to arrive at residuals vector. The Hadamard product is used on the residuals vector to amplify the information and suppress the noise. Further, normalizing is done to compare data across tests and samples. With this, necessary diagnostic information was extracted from static test data. The method is extended for extracting diagnostics information from actual flight using comparison analysis of, the test data in actual environment with mimicked lab level dry runs. It is also verified for applicability in faults directly driven by actuators in lab level experiments on three samples.

Emergency Separation Simulation and Damage Prediction of an Airliner under Wheel-Up Landing Condition

To predict the damage to and response of aircraft structures during wheel-up crash landing, numerical simulations were performed using a constitutive and damage model for ductile metallic materials developed in the ABAQUS/Explicit environment. The model of an entire aircraft and detailed submodels were established. The Johnson–Cook and Gurson material constitutive models were validated by conducting Hopkinson’s bar test. A drop hammer test and a static test of the fuse pins were performed to determine and verify the response and strength of the structure. The experimental and analytical results indicate that the stain rate and damage parameters significantly influence the emergency separation load, fuse pin strength, and separation sequence. The analysis results were compared with the test results, and a close agreement was found in terms of the maximum load and deformation.