Applied Mechanics and Materials Vol. 815

Abstract: The life cycle model of Mega Float: Floating offshore fishing terminal (FORT) for deep sea fishing industry is presented in this paper. FORT is a totally new concept of a mega float for deep sea fishing application. It is aimed at increasing productivity through reducing travelling time to fishing ground by providing critical support services such as loading and unloading and minor maintenance and repair of boat and equipment at sea close to the fishing ground. The immediate concern is surely on its life cycle cost and techno-economic viability. The system is huge and remotely located far offshore and hence the element of sustainability and environmental friendliness and safety are some of the major investment issues. Immediate cost consideration includes the relatively high initial/acquisition cost and operation and maintenance costs and the intention is to at least self-sufficient by generation income from the services offered. Therefore, hybrid algorithm of cash flow and life cost cycle is applied in FORT implementation. The new derivation of the mathematical model for FORT application is developed to life cycle assessment principle [1-3]. The algorithm requires data that could be best produced based on forecast demand and projected cost. For ease of use the lengthy algorithm will be presented in a computer-based package.

Abstract: This paper presents a review on three types of techniques in designing digital all-pass filters based on group delay. All the three methods use the same basic concept rooting back to the requirement of a stable transfer function of the filter which should be a minimum-phase type, and the denominator group delay. The most optimized of the three is chosen to be implemented in MATLAB in order to decrease the group delay variation of a 5^th order Chebyshev low-pass filter with cut-off frequency of 160 MHz. The digital transfer function of the low-pass filter is obtained from the analog transfer function by means of bilinear transformation. The sampling frequency of the digital LPF is 100 times the cut-off ffrequency to retain the response of the analog LPF. Both of the filters are then cascaded together and the overall group delays variations are analyzed. The variations of group delay shows a reduction but the price paid is the increase of the overall group delay of the system.

Abstract: In this paper, we experimentally investigated the performance of ring cavity multi-wavelength Brillouin fiber laser utilizing fiber Bragg grating which operated in the C-band wavelength region. The combination of stimulated Brillouin scattering and selective wavelengths gave a new invention in the optical fiber communication. Five different lengths of single mode fiber are used in order to get the best gain medium for stimulated Brillouin scattering effect. Up to 33 of Brillouin Stokes signals and 31 of anti-Stokes signals were obtained when 10 km fiber length was used in the laser system. The average value optical signal to noise ratio of 15 dB has been achieved. The broadening bandwidth of Brillouin Stokes signals also occurred at the center wavelength of 1550 nm based on the 3 dB bandwidth of 5 nm fiber Bragg grating.

Abstract: The development was conducted with three configurations of L-Band EDFA, L-Band EDFA utilising Single FBG and Dual Stage L-Band EDFA utilising Dual FBG. The configurations utilising the FBG using 35 meter M-12 Fibercore EDF as the gain medium to amplify the input signal power in the L-band region. The gain enhancement has shown by the Dual Stage L-Band EDFA utilising Dual FBG by injecting low input signal power of -10 dBm. The flat amplitude of OSNR at 33.358 dB was produced at injected wavelength from 1570 nm to 1605 nm.

Abstract: Three XOR photonics logic gate configurations namely semiconductor optical amplifier-Mach Zender interferometer cross phase modulation (SOA-MZI XPM), SOA-MZI cross gain modulation (XGM) and terahertz optical asymmetrical demultiplexer (TOAD) XOR are analysed and compared in terms of generated power, optical signal-to-noise ratio (OSNR) values and bit error rate (BER) signal quality. The highest generated power is possessed by the TOAD at 23.5 dBm, the SOA-MZI XPM showed the most extinction ratio or OSNR with 109.6 dB whereas the best BER is recorded in the SOA-MZI XGM at 4.42 x 10^-22.

Abstract: A new approach to designing Switched-Mode Power Supply (SMPS) for motorcycle power supply is presented. It uses an alternative way to efficiently regulate power output from a stator generator instead of using conventional Power Rectifier Regulator (PRR). Energy saving switch mode regulator shown the fuel consumption were less used compared using conventional PRR from several experiments using an alpha prototype of SMPS.

Abstract: This paper presents the design and analysis of new proposed topology micro-electro-mechanical system (MEMS) inductor. This new symmetric MEMS inductor is designed to reduce the total length of the conductor strip and hence reduce the resistance of the metal tracks. This results significant increases in the quality (Q) factor of the inductor. In this paper, the MEMS inductor is designed using CoventorWare®, which is powerful software for MEMS computer aided design (CAD), modeling and simulation. Results indicate that new symmetric inductor topology has thehighest Q-factor and it hasbeenimproved bytwo times compared to circular inductor. The analysis revealed that area of the symmetric inductor has reduced by37.5% compared to the circular inductor. Result has proved that the reduction of length of the conductor strip has reduced the resistance of the metal tracks and results in a high Q-factor inductor.

Abstract: This paper presents the linear modelling of high breakdown InP pseudomorphic High Electron Mobility Transistors (pHEMT) that have been developed and fabricated at the University of Manchester (UoM) for low noise applications mainly for the Square Kilometre Array (SKA) project. The ultra-low leakage properties of a novel InGaAs/InAlAs/InP pHEMTs structure were used to fabricate a series of transistor with total gate width ranging from 0.2 mm to 1.2 mm. The measured DC and S-Parameters data from the fabricated devices were then used for the transistors’ modelling. The transistors demonstrated to operate up to frequencies of 25 GHz. These transistors models are used in the design of Low Noise Amplifiers (LNAs) using fully Monolithic Microwave Integrated Circuit (MMIC) technology.

Abstract: Nowadays, quality control becomes an important issue in semiconductor manufacturing industry. The rate of production with respect to time gives a lot of issues in the industry. In most semiconductor assemblies, a lot of defects generated from various processes in semiconductor wafer manufacturing need to be inspected manually using human experts and this process required full concentration of the operators. This human inspection procedure, however, is time consuming and highly subjective. In order to overcome this problem, implementation of machine vision will be the best solution. This paper presents defect segmentation of semiconductor wafer image based on colour features with k-Means clustering algorithm which can be adopted in machine vision system. In this work, the segmentation process is carried out in two stages. The first stage comprised of clustering the pixels in the image based on their colour and spatial features. Then the clustered pixels are merged to a specific number of regions. The proposed approach is being evaluated using defected wafer image. The experimental results show that it can be used to segment the defect correctly. By using this method, it is possible to increase the computational efficiency since it will avoid feature extraction for every pixel in the image.

Abstract: In this paper, the performance of ring cavity Brillouin Erbium fiber laser (BEFL) within L-band wavelength region are discussed. Introducing Erbium doped fiber as a secondary gain medium into conventional Brillouin fiber laser configuration is the best alternative to maximize the Brillouin Stokes power (output power) and to sustain the gain flatness. Few parameters comprising length of fiber, pump power and tunable laser source power are varied to obtain the optimum output power. From the simulation process, a maximum Brillouin Stokes power of 54.75 dBm is produced as 16 dBm Brillouin pump power and 1480 nm pump laser are injected to the configuration.