1,720,970 research outputs found
The integrated simulation and processing tool for Ground Based Synthetic Aperture Radar (GBSAR)
No full textGround-based Synthetic Aperture Radar (GBSAR) is a tremendous example of the extended applications of Synthetic Aperture Radar (SAR). GBSAR is extremely useful in human-made structure observations, terrain mapping, landslide monitoring and many more. However, the process of designing and developing the GBSAR system is rather costly and time-consuming. It would be of a great advantage for system designers to have a realistic simulation and designing tool to anticipate the results before the implementation of the final design. In this paper, we are going to present the integrated simulation and designing tool that we have developed for a generic GBSAR system. We named it iSIM v2.0
Localized mirror-like surface electropolishing and void-free submillimeter-scale electrodeposition for fabrication of watch parts with complex geometries
No full textThis project is a collaboration project between Nanyang Technological University and Seiko Manufacturing (Singapore) Pte. Ltd., a subsidiary of leading wristwatch manufacturer Seiko Watch Corporation. This project focuses on the research and development of localized electropolishing technique as an alternative polishing method to mechanical polishing in conventional watch fabrication, which is very labor-intensive, highly skill-dependent and costly. Complex features of miniature watch part of which dimensional accuracy should be kept were masked by non-conductive photoresist through a simplified photolithography process. Anodic dissolution behavior of leaded brass material in Glycerol-added phosphoric acid solution was investigated. Technical issues like adverse effect of viscous layer, removal of macroscopic defect and formation of lead particles were discussed with proposed solutions. Experiment results showed that a near mirror surface finishing could be obtained by conducting localized electropolishing on photoresist-masked watch part, suggesting a high potential of substituting mechanical polishing with electropolishing which is less dependent on human skill therefore better quality consistency and lower production cost. Process scale-up and other potential application to which the developed localized electropolishing technique could be implemented, were also discussed in this thesis. Feasibility of fabrication of void-free submillimeter scale nickel component by single additive bottom-up electrodeposition was demonstrated as well.Doctor of Philosoph
Design of a balance training machine for rehabilitation of stroke patient
No full textThis project aims to design and implement a machine that delivers a reliable balance training machine that is capable of assisting stoke patients who suffers from muscular recovery to improve their ability to balance. The machine is to provide sudden perturbation and rocking motions to simulate the effects similar to sudden braking and acceleration of transportation units and the situation of slippage. Since perturbations and acceleration is concerned, it is imperative to realize the importance of the kinematic and dynamic characteristics of the system. Hence a critical and substantial portion was dedicated to analyze them.
First phase of the project involved constitution of all the possible scenarios for a person to balance on a moving train, so as to replicate the effects to or at least near resemblance of reality. Constitution of the sudden slippage scenarios have been done as well, to ensure the “artificial” slip would provide the same feel close to a genuine slip and fall. Followed by, the collection of relevant information required to replicate the scenarios.
Second phase of the project began with the conceptual designs for the balance training machine. Modular design was adopted and the machine has been divided into 2 main modules; the split belt variable speed treadmill and the lateral perturbations assembly. Both modules are required to be able to work simultaneously without any interference to each other. Embodiment principles have been incorporated at this stage.
Third phase of the project encompasses mainly on sizing of the drive systems use in the 2 components. Drive systems were carefully designed and calculated to reach the desired results we would like to achieve. A ball screw assembly was used for the lateral perturbations and the timing belt system was used for the variable treadmill. As the budget for the project is limited, we also had to do cost estimation before we proceed to purchase our items.Our fourth and final phase of the project ends with assembly and testing of our machine. Coding are done in lab view to attain the required motion and safety features were heavily implemented to prevent accidents from happening.Bachelor of Engineering (Mechanical Engineering
Design And Experiment Of Surface Deformation Monitoring Radar
No full textGround-based Synthetic Aperture Radar (GBSAR) is a tremendous example of the extended applications of Synthetic Aperture Radar (SAR). It is well-known for its capability of producing highly-detailed images. A set of SAR images taken from the same scene can be further processed and analysed to measure the displacement or deformation that took place in the scene if any. This technique is extremely useful in surface deformation monitoring for human-made structures, landslides, avalanches and many more. The process of designing and developing the GBSAR system is rather costly and time-consuming. It would be a great advantage for the system designer to have a realistic simulation and designing tool to anticipate the result before the implementation of the final design. In this work, the integrated system simulation and signal processing tool (iSIM) has been developed for the GBSAR system. The program is developed in MATLAB equipped with various tools to assist the system designer at different stages in GBSAR design, development, system simulation, data processing, and interferometric SAR (InSAR) analysis
Preparation and Properties of Phenol Formaldehyde Poly(Vinyl Alcohol)Resin as Fibre-Reinforced Film Adhesive
Get PDFThis study aims to evaluate the chemical composition, physical and mechanical properties of fibre-reinforced composite via synthesis of resole fibre-reinforced phenolic resin binded and cured under heat and pressure to the outside metal faces. Two types of resin; phenol formaldehyde resin and poly(vinyl alcohol) resin were blended and applied on the paper’s surfaces (MG Craft Paper GSM: 50 Ribbed) and then arranged in an alternate manner for the adhesion of both surfaces resin.
A series of various phenolic resin/poly (vinyl alcohol) blend compositions were prepared through solution casting technique and characterization was done through infrared, differential scanning calorimetry, thermogravimetry analysis, viscosity measurement, tensile strength and Young’s modulus.
Prepared specimen was cured for pre-press stage for 72 hours under pressure of 25 kg cm-2 at room temperature before undergoing hot press step. The compounded samples were then hot pressed at temperature 200 ± 5 °C and pressure 100 kg cm-2 for about 30 minutes and setting duration was taken after temperature setting was achieved. After cooling, the samples were tested for various analytical and mechanical assessments such as flexural strength and flexural modulus in accordance with ASTM Standard D790-98a.
The samples were also characterized for density and moisture content, and these procedures were repeated for different parameters; curing time, curing temperature, temperature setting and pressure setting.
FT-IR study indicated that the polymer blending lead to formation of methylol groups of phenolic resin and double bonding of PVA towards strong internal bonding with paper surface, polymer blending demonstrated low resistance in miscibility via DSC, the composite displayed high shear thinning and high yield stress which resemblance liquid-like flow behaviour determined by viscometer. TGA detected the polymer blend is dispensed to the die and it has the ability to form chemical bond with the coated substrate.
Phenolic formaldehyde/poly(vinyl alcohol) blending at ratio of 5/95 showed the highest tensile strength (12705.2 Pa) and Young’s modulus (355.7 Pa). The density of the fibre-reinforced composites with aluminium sheets produced in this study was found to be a maximum at 1.74 × 103 kg m-3 (Ratio = 100/0) and pure PVA exhibit the highest moisture content with 19.19 %, this would affect the resistance to cracking of the resulting product.
However, fibre-reinforced composite with high composition loading of PF/PVA = 60/40 demonstrated the highest flexural strength and flexural modulus. Meanwhile, curing time, curing temperature, temperature setting and pressure setting of 96 hours, 25 °C, 200 °C and 120.0 kg cm-2 respectively was found to be the most economical and optimum condition for formation of fibre-reinforced composite, with excellent structural strength
Synthetic Aperture Radar Signal Simulation And Processing
No full textIn this work, a MATLAB-based software program is developed to perform SAR image formation on both simulated and actual SAR data. Generally, the software program consists of three modules, namely SAR simulation module, actual SAR data extraction module, and SAR processing module
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
