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Perangkaan perdagangan luar negeri Malaysia Ogos 2022
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Jangkaan hayat ketika lahir mengikut negeri, Malaysia, 2012-2022
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Statistik jangka hayat, Malaysia 2022
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MEMS pressure sensor for gait analysis
No full textMaster of Science in Microelectronic Systems Design EngineeringPressure sensor plays an important role in many applications, especially in gait analysis.
The focus of this dissertation is to design a pressure sensor to be applied onto the shoe
insole. The piezoelectric effect is used to study the performance of the pressure sensor.
This sensor is characterized by having a transduction element made of a piezoelectric
material. Piezoelectric can be explained as one that produces an electric charge when a
mechanical stress is applied. In this study, COMSOL Multiphysics 5.1 is used to design
and simulate the piezoelectric pressure sensor. Two main piezoelectric materials, Lead
Zirconate Titanate, PZT and Zinc Oxide, ZnO used as a surface layer of the circular
diaphragm pressure sensor. Five different pressures of 10kPa, 1MPa, 2MPa, 3Mpa and
4MPa are applied onto the surface of the pressure sensor and compared with three
different thickness parameters. The performance of the sensor studied based on the Von
Mises stress, surface total displacement and electric potential produce on the pressure
sensor design. An overall results focus on the maximum thickness of 60um with applied
pressure of 4MPa. The result shows that surface total displacement will be high when
the pressure applied were increased, but decreased in thickness of piezoelectric material.
The surface total displacement obtained for PZT and ZnO are 1.79 x 10 -3 um and
1.09 x 10 -3 um . Then, the Von Mises stress shows that when the applied pressure is
increased, the stress produces also increased but the thickness parameter must be
decreased. ZnO produces a greater effect or higher stress compared to PZT as ZnO
produces 5.24MPa compared to PZT that only produce 4.11MPa. An electric potential
between the materials shows that output voltage increased when the pressure increased
with decreasing of the thickness. The higher electric potential produce is 15.9848V
come from the material ZnO while PZT only produce 2.7659V with the same pressure
applied. As conclusion, both materials can be applied in this design as it followed the
pressure sensor specifications
Design and development of sequential algorithm (SeQ) code for OCDMA system
No full textMaster of Science in Communication EngineeringPresents a method for development of a new novel in optical code for Optical
Code Division Multiple Access (OCDMA) system using Spectral Amplitude Coding (SAC).
The proposed code is called Sequential Algorithm (SeQ) code. From theory, the proposed
method is to construct optical codes with a combination of tridiagonal matrix and identify
matrix code. This SeQ code is constructed with simple code construction for any number of
users and weight, various cross correlation and having minimum code length. SeQ code has
been designed with cross correlation is equaling to zero and one due to the effects of Multiple
Access Interference (MAI) thus to prevent from overlapping of spectra from each users.
These codes are easy to construct, simple and have better noise performance compared with
existing optical codes such as Flexible Cross Correlation (FCC), Dynamic Cyclic Shift
(DCS), Modified Frequency Hopping (MFH) and Modified Double Weight (MDW) code.
The requirement in OCDMA systems to enhanced performance of BER is the reason why
these codes has been designed. The performances of SeQ code has been done via theoretical
analysis and simulated performances analysis via utilizing commercial simulation software,
Optisystem by OptiwaveTM. The performance of the systems was characterized by referring
the Bit Error Rate (BER), signal-to-noise ratio (SNR), bit rate and effective received power.
This research finds strong performance of SeQ code when compared between theoretical and
analysis performance and the result was proportional each other. Therefore, SeQ code has
enhanced the OCDMA system better than existing codes
