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Holographic particle image velocimetry is a promising technique to probe and characterize complex flow dynamics since it is a truly three-dimensional (3D) three-component measurement technique. The technique simply records the coherent light scattered by small seeding particles that are assumed to faithfully follow the flow and uses it to reconstruct the event afterward. Re-construction of the event is usually performed using a digital video micro-scope mounted on a 3D translation stage. The microscope records the inten-sity only which consequently results in loss of phase information. The objec-tive of this paper is to develop and apply digital holographic microscopy with the aim to recover the phase information. Digital holographic microscopy has immense potentials in microscale solid and fluid measurements as it offers the possibility of digital wavefront processing by manipulating amplitude and phase of the recorded holograms. In this paper, we have developed an off-axis digital ho.....

850 hits

Particle image velocimetry (PIV) technique in its original form is limited to in-plane two-dimensional two-component (2D-2C) displacement and velocity measurements. Although it is possible to extract the out-of-plane component through stereoscopic viewing, the useful measurement volume remains limited to a light sheet of several millimeters thick. On the other hand, integration of holographic recording in PIV (HPIV) has finally realised whole-field, three-dimensional three-component (3D-3C) displacement and velocity measurements. In comparison to in-line particle holography, off-axis particle holography offers a relatively higher signal-to-noise ratio (SNR) although it demands long coherence and high laser energy for flow diagnostics. In-line particle holography relaxes the requirements of such a system but at the expense of image (signal) degradation due to superposition of virtual image waves, the directly transmitted reconstruction wave and the real image. On this basis, off-axis se.....

764 hits

Digital holographic microscopy (DHM) is a promising tool for a three-dimensional imaging of microscopic particles. It offers the possibility of wavefront processing by manipulating amplitude and phase of the recorded digital holograms. With a view to compensate for aberration in the reconstructed particle images, this paper discusses a new approach of aberration compensation based on complex amplitude correlation and the use of a priori information. The approach is applied to holograms of microscopic particles flowing inside a cylindrical micro-channel recorded using an off-axis digital holographic microscope. The approach results in improvements in the image and signal qualities...

1511 hits

School Management System-SMS (Sistem Pengurusan Sekolah) is a system developed by Ministry of Education Malaysia in order to reduce teachers’ burden and for Educational Data Integration. SMS is a type of Management Information System (MIS) and is pivotal for efficient and effective running of schools in Malaysia. As SMS is newly introduced, no research on its use could be found yet; therefore, this research is crucial in providing information to MOE on the SMS success. The core of this research is to validate the relations of variables in DeLone and MacLean IS Success Model with teachers’ perception towards the SMS success. Several Information System Success (ISS) evaluation theories will be discussed in this research as they are essential to describing the IS Success. Using a quantitative approach, the tool (survey questionnaire) was applied in a survey at Sekolah Kebangsaan Puncak Alam (2), Selangor with 56 respondents. Data were analyzed using SPSS. Two types of statistical anal.....

1366 hits

The Global Positioning System (GPS) passed a long way of development, starting from an advanced specialized tool, to a general purpose gadget used every day in our life. There are numerous presences of GPS in new technologies, applications and consumer products especially in Smartphone's and tablets. In GPS receiver design, power consumption and localization accuracy act as critical factors that affect the GPS receiver system outcome. Theoretically, increasing the Number of Required Tracking Channels (NRTC) in the GPS baseband receiver will increase the design complexity and size. Hence, the power consumption would significantly increase. Furthermore, to improve the location accuracy of a position, more satellites should be acquired and tracked by the receiver. This requires higher number of tracking channels in the receiver. Thus, optimizing the number of tracking channels to balance the conflict among performance parameters is a difficult and challenging task. The objective of this s.....

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Computer-assisted technology plays an important role in helping to reduce risk during pregnancy, particularly serious risks associated with intra-uterine growth restriction (IUGR). Fetal gestational age estimation and fetal weight estimation are two crucial factors in evaluating fetal growth and detecting any abnormality of growth, in order to identify IUGR risk to the fetus. The estimation is made through serial measurement of fetal anatomy comprising the length, diameter and circumference of multiple segments in the fetus scanned through an ultrasound machine. The computing method helps to overcome human subjectivity in assessment that is prone to variability in measurement. Automatic measurement methods carried out by the computer can help in producing fast, accurate and reproducible measurement and assessment of the fetal anatomy. This study presents an analysis of techniques attempted by researchers in conducting automated fetal biometric anatomy measurements using ultrasound imag.....

663 hits

Human ear is an intriguing individual anatomical part of a passive, physiological biometrics systems based on the image acquired from digital cameras. The human ear has many singular features that permit the finding of particular individuals. It could be implemented as effective biometrics systems, for example, in crowd surveillance and identifying terrorist at public places such as airports, as well as controlling access to government offices. Challenges and issues faced in the field of human identification using ear detection and recognition includes problem of occlusion, varieties in illumination, and real-time implementation in accessing information from an integrated database system with higher accuracy. Research on ear detection and recognition systems have been developing in a steady rate and mostly are constrained to controlled indoor environment. Notwithstanding, other research issues incorporate; ear print criminology; ear symmetry; and ear uniqueness. This paper presents a r.....

816 hits

Automatic classification of cell types and biological products are considered crucial in the field of hematology especially for early detection of diseases when the quantity that needs to be examined is considerably large. In a previous study, a cylindrical micro-channel was employed to mimic actual blood flow in the arteriole but it was found to cause astigmatism in the reconstructed holographic particle images. Additionally, correction of the images is important to avoid false disease detection. In this paper, we describe a new application of feed-forward backpropagation neural network for classifying images of astigmatic and non-astigmatic synthetic platelets that were obtained by digital holographic microscopy. Image cropping was performed to suppress noise, followed by image normalization to reduce variation in contrast/brightness. Using MATLABTM, a two-layer neural network with two class classifier was trained with these images to compute the weights of each layer and the perform.....

543 hits