Nur Ismarrubie Zahari

Initial response of autistic children in human-robot interaction therapy with humanoid robot NAO

The overall context proposed in this paper is part of our long-standing goal to contribute to a group of community that suffers from Autism Spectrum Disorder (ASD); a lifelong developmental disability. The objective of this paper is to present the development of our pilot experiment protocol where children with ASD will be exposed to the humanoid robot NAO. This fully programmable humanoid offers an ideal research platform for human-robot interaction (HRI). This study serves as the platform for fundamental investigation to observe the initial response and behavior of the children in the said environment. The system utilizes external cameras, besides the robots own visual system. Anticipated results are the real initial response and reaction of ASD children during the HRI with the humanoid robot. This shall leads to adaptation of new procedures in ASD therapy based on HRI, especially for a non-technical-expert person to be involved in the robotics intervention during the therapy session.

Humanoid robot NAO: Review of control and motion exploration

Humanoids; a most intriguing subject to behold by both the engineers and the world at large. With the introduction of humanoid robot NAO by Aldebaran-Robotics in 2008, a performant biped robot is now available and affordable for research laboratories and the mass market. In this paper, an exploration of current trends in control methods of biped walks, behavior interface tools for motion control for NAO and imminent findings in both research areas are discussed. Future directions are for researchers to devise a unique controller with low power consumption without compromising the robots speed and robustness.

On the correlation between microstructural evolution and ultrasonic properties: a review

The characterization and optimization of the microstructures of materials pertaining to material properties is a primitive necessity to ensure the performance and service life of the materials and components. In the demand of new characterization and evaluation techniques, nondestructive ultrasonic techniques have shown a good potential to characterize the microstructures and mechanical properties of a wide variety of materials. Measurements of ultrasonic parameters such as velocity and attenuation can provide information on the structural and microstructural variations of those materials that have undergone the heat-treatment procedure. In the current review, the correlation of ultrasonic parameters with microstructural features of ferrous and nonferrous metals such as steels, aluminum, and superalloys is investigated. It is proven that ultrasonic parameters are closely correlated to the microstructural evolutions which frequently occur during the heat-treatment procedures in practical situations. To conclude, the ultrasonic measurements contribute to a feasible and accurate characterization of the materials and evaluation of their microstructures and mechanical properties in a straightforward, reliable, and fast, nondestructive manner for practical applications.

Preparation and characterization of cassava bagasse reinforced thermoplastic cassava starch

A starch-based composite film was prepared by using fibrous residual of starch extraction (cassava bagasse) as filler. Composite films were prepared through casting technique using fructose as a plasticizer and various sizes and concentrations of bagasse. The physical, thermal, tensile and structural properties of the composite film were investigated. Also, temperature variation of dynamic-mechanical parameters of cassava starch/bagasse composites was investigated by Dynamic Mechanical Analysis (DMA) test. The size and concentration of bagasse were significantly influenced the physical properties of cassava bagasse. There were also increases- in thickness, water solubility, and water absorption of cassava bagasse. There were reduction of water content and density of the film. However, there was no significant effect of adding bagasse on thermal properties. X-ray diffraction (XRD) studies indicated increase in crystallinity of the composites with increase in fiber content. SEM micrographs indicated that the filler was incorporated into the matrix. Films with a small size of bagasse showed better compact structure and homogeneity surface. On the other hand, films with big size and higher concentration of bagasse exhibited more heterogeneous surfaces. The modulus and maximum tensile strength of composite films were increased from 69.03 to 581.68 MPa and 4.7 to 10.78 MPa respectively. Addition of 6 % bagasse was the most efficient reinforcing agent owing to its remarkable physical and mechanical properties. The composites prepared by using cassava for both matrix and reinforcement increased the significance of the remaining residue of starch extraction.

Cassava/sugar palm fiber reinforced cassava starch hybrid composites: Physical, thermal and structural properties

A hybrid composite was prepared from cassava bagasse (CB) and sugar palm fiber (SPF) using casting technique with cassava starch (CS) as matrix and fructose as a plasticizer. Different loadings of SPF (2, 4, 6 and 8% w/w of dry starch) were added to the CS/CB composite film containing 6% CB. The addition of SPF significantly influenced the physical properties. It increased the thickness while decreasing the density, water content, water solubility and water absorption. However, no significant effect was noticed on the thermal properties of the hybrid composite film. The incorporation of SPF increased the relative crystallinity up to 47%, compared to 32% of the CS film. SEM micrographs indicated that the filler was incorporated in the matrix. The film with a higher concentration of SPF (CS-CB/SPF8) showed a more heterogeneous surface. It could be concluded that the incorporation of SPF led to changes in cassava starch film properties, potentially affecting the film performances.

Effect of Artificial Aging on the Microstructure and Mechanical Properties of Aluminum Alloy AA6061-T6

The properties of aluminum alloy AA6061-T6 after aging at 220°C for 0.5 – 8 h are studied by the methods of light and scanning electron microscopy and fractography. The mechanical characteristics of the alloy are determined by tensile tests.

Design concept of a new bio-inspired tactile sensor based on main pulvinus motor organ cells distribution of Mimosa Pudica plant

This paper proposed a novel concept for a new tactile sensor that is inspired by the seismonastic movement of plants. The movement of Mimosa Pudica leaf is due to the change of pressure between the upper and lower motor organ of main pulvinus. From an engineering point of view, the turgidity changes capable of reversible shape changes, thus bringing the idea of sensing and actuating concept of a new tactile sensor. The idea is to fusion the artificial cell of Mimosa Pudica as the sensing mechanism for the new bio-inspired tactile sensor. Experiments have been conducted in order to determine the volume of the upper n lower motor organ cells of main pulvinus. The aim is to view the cross section of the main pulvinus between before and after the stimulation applied which led to two experiment procedures. Experimental results show that area of upper motor organ cell is approximately 50% larger than lower part for all four samples when mechanical stimulation applied. The design concept of the bio-inspired tactile sensor is proposed.

Effect of cassava peel and cassava bagasse natural fillers on mechanical properties of thermoplastic cassava starch: Comparative study

Increased awareness of environmental and sustainability issues has generated increased interest in the use of natural fiber reinforced composites. This work focused on the use of cassava roots peel and bagasse as natural fillers of thermoplastic cassava starch (TPS) materials based on cassava starch. The effect of cassava bagasse (CB) and cassava peel (CP) content on the tensile properties of cassava starch (CS) biocomposites films was studied. The biocomposites films were prepared by casting technique using cassava starch (CS) as matrix and fructose as plasticizer. The CB and CP were added to improve the properties of the films. The addition of both fibers increased the tensile strength and modulus while decreased the elongation at break of the biocomposites films. Films containing CB showed higher tensile strength and modulus as compared to the films containing the same amount of CP. The addition of 6 % bagasse increased the modulus and maximum tensile stress to 581.68 and 10.78 MPa, respectively. Thus, CB is considered to be the most efficient reinforcing agent due to its high compatibility with the cassava starch. The use of CB and CP as reinforcement agents for CS thermoplastic cassava added value to these waste by-products and increase the suitability of CS composite films as environmentally friendly food packaging material.Increased awareness of environmental and sustainability issues has generated increased interest in the use of natural fiber reinforced composites. This work focused on the use of cassava roots peel and bagasse as natural fillers of thermoplastic cassava starch (TPS) materials based on cassava starch. The effect of cassava bagasse (CB) and cassava peel (CP) content on the tensile properties of cassava starch (CS) biocomposites films was studied. The biocomposites films were prepared by casting technique using cassava starch (CS) as matrix and fructose as plasticizer. The CB and CP were added to improve the properties of the films. The addition of both fibers increased the tensile strength and modulus while decreased the elongation at break of the biocomposites films. Films containing CB showed higher tensile strength and modulus as compared to the films containing the same amount of CP. The addition of 6 % bagasse increased the modulus and maximum tensile stress to 581.68 and 10.78 MPa, respectively. Thus,...

Parameter estimation of a closed loop coupled tank time varying system using recursive methods

This project investigates the direct identification of closed loop plant using discrete-time approach. The uses of Recursive Least Squares (RLS), Recursive Instrumental Variable (RIV) and Recursive Instrumental Variable with Centre-Of-Triangle (RIV + COT) in the parameter estimation of closed loop time varying system have been considered. The algorithms were applied in a coupled tank system that employs covariance resetting technique where the time of parameter changes occur is unknown. The performances of all the parameter estimation methods, RLS, RIV and RIV + COT were compared. The estimation of the system whose output was corrupted with white and coloured noises were investigated. Covariance resetting technique successfully executed when the parameters change. RIV + COT gives better estimates than RLS and RIV in terms of convergence and maximum overshoot.

Creep Test of Type Austenitic 316LStainless Steel at High Temperature

The aim of this study is to investigate the creep test on static loading of stainless steel materials. Theestablished creep analytical modeling was used to predict the creep life of stainless steel at high temperature. In order to conduct creep testing, the materials were subjected to constant load and high temperature at 565°Cin comparisons with different stresses at the similar temperatures.Time dependent deformation of 316L stainless steel at high temperature at different loading was investigated in this study.The variationof creep strain rates is clearly shown that the secondary creep obeyed and well agreement with a power law relationship as the constant increase creep rate till the tertiary stages of specimen test.