21 research outputs found
Morphological and Otsu Thresholding Based Retinal Blood Vessel Segmentation for Detection of Retinopathy.
Purpose: Retinal blood vessel segmentation is crucial as it is the earliest process in measuring various indicators of retinopathy sign such as arterial-venous nicking, and focal arteriolar and generalized arteriolar narrowing. The segmentation can be clinically used if its accuracy is close to 100%. In this study, a new method of segmentation is developed for extraction of retinal blood vessel.
Methods: In this paper, we present a new automated method to extract blood vessels in retinal fundus images. The proposed method comprises of two main parts and a few subcomponents which include pre-processing and segmentation. The main focus for the segmentation part is two morphological reconstructions which are the morphological reconstructions followed by the morphological top-hat transform. Then the technique to classify the vessel pixels and background pixels is Otsu’s thresholding. The image database used in this study is the High Resolution Fundus Image Database (HRFID).
Results: The developed segmentation method accuracy are 95.17%, 92.06% and 94.71% when tested on dataset of healthy, diabetic retinopathy (DR) and glaucoma patients respectively.
Conclusion: Overall, the performance of the proposed method is comparable with existing methods with overall accuracies were more than 90 % for all three different categories: healthy, DR and glaucom
High Gain of 3.1-5.1 GHz CMOS Power Amplifier for Direct Sequence Ultra-Wideband Application
This paper presents the design a power amplifier (PA) for direct sequence ultra-wideband applications using 0.13 μm CMOS technology operating in a low band frequency of 3.1 GHz to 5.1 GHz. Current-reused technique is employed at the first stage to increase the gain at the upper end of the desired band. Cascaded common source configuration with shunt peaking inductor at the second stage helps to enhance the wideband frequency while increasing the gain approximately twice the performance. The simulation results specify that high gain of 20.3 dB with ± 0.8 dB flatness, group delay variation of ±121.3 ps, and good input return loss and output return loss is obtained over desired working band. The proposed PA achieves power consumption of 27.3 mW
Simultaneous Heat and Mass Transfer in Kek Lapis Sarawak Baking
Kek Lapis Sarawak is a specialty of Sarawak.
Nowadays, energy becomes a global issue and there is call to minimize energy consumption for a better tomorrow. In cake industry, the use of oven in baking process contributes to the major energy consumption. This research aims to optimize the baking process for an efficient energy consumption. Therefore, it is very important to investigate the relationship between baking
temperature, time and cake quality so that the baking process can be optimized. Kek Lapis Sarawak baking process has been modelled and simulate using finite element method (FEM). Then, results from the model was validated with experiment. As a result, similar model of the Kek Lapis Sarawak baking process has been developed. The finding shows interdependent relationship between porosity, thermal conductivity and moisture content where higher porosity that can lead to poor thermal
conductivity
Stability of Chlorine Termination on Ge(100) and Ge(111) Surfaces
The different cleaning solution; HCl and HF solution are used to remove the suboxide and oxide component on Ge
surface. The HCl cleaning results chlorine (Cl) termination on Ge surface whereas no Fluorine (F) termination was observed just after HF cleaning. The growth of Ge oxide is studied after treated with HCl cleaning on two surface orientations; (100) and (111),
respectively in dry oxygen ambient and cleanroom air by spectroscopic ellipsometry (SE) and x-ray photoelectron spectroscopy (XPS). A clear step and terrace trend was observed for the oxidation growth of Ge (100) and Ge (111) in dry oxygen ambient
compared to in clean room air. This trend shows the difference in surface reaction of Ge oxidation as humidity varies. The stability
of chlorine termination of Ge (111) than Ge (100) explains the slower growth of oxidation in dry oxygen ambient
Effects of Post-Deposition Annealing Temperatures on the Composition of Interfacial Layer at Germanium (Ge) /Aluminium Oxide (Al2 O3 ) (Kesan Suhu Penyepuhlindapan Pasca Pemendapan ke atas Komposisi Antara Muka Lapisan Oksida Germanium (Ge)/Aluminium (Al2 O3 ))
The understanding of chemical bonding structure of high k dielectrics/Germanium (Ge) interface is upmost importance
in order to form a good quality dielectric/Ge interface in fabricating Ge metal oxide semiconductor field effect transistor (MOSFETs). In addition, there is still no detail explanation on the interfacial growth of dielectrics/Ge under the influenced of different temperature of post deposition anneal. In current work, the effects of post deposition anneal (PDA) temperature
between 400°C and 600°C on the chemical composition of interfacial layer between Ge and Al2 O3 were examined by X-ray photoelectron spectroscopy (XPS). Investigation on thermal stability and structural characteristics for gate structure of Al2 O3 dielectric grown on Ge by RF sputtering was done by analyzing X-ray photoelectron spectroscopy (XPS) spectra.
It is observed that the oxygen deficient region in interfacial layer (IL) is enhanced rather than fully oxidized Al2 O3 with increased PDA temperatures. These undesired phenomena caused shrinkage of IL at Ge/Al2
O3 interface at higher temperature of 600°C
Power Quality Improvement on Wind Energy System by Using STATCOM
Wind energy known as a cheap, clean and uncontrolled resource and becomes an important green electricity source. However, installation of wind system into an electric grid introduces the Power Quality (PQ) phenomenon. These poses great challenges leads to various control schemes and new techniques to mitigate the PQ events. This paper described the improvement of PQ events in a grid connected wind energy system by using Static Compensator (STATCOM) with a Battery Energy Storage System (BESS) at the Point of Common Coupling
(PCC). The performance of the proposed wind energy system is simulated via MATLAB/SIMULINK in power system block set
A Review on Development of Kek Lapis Sarawak’s Machine
Kek Lapis Sarawak is a beautifully decorated and flavorful cake that can be considered as the artwork of the Malays in Sarawak. There is an overwhelming demand of the Kek Lapis Sarawak in the market that consequently need for automation. This paper summarizes comprehensive reviewed patents of the current machine and journals which have similar functions and related to the current function of manual process of producing Kek Lapis Sarawak. Conceptual idea of the Kek Lapis Sarawak machine consists of three modules namely Depositor Module, Cooling and Pressing Module and Baking Module. Therefore, patents and journals that have similar functions with these modules are reviewed that look into its advantages. The disadvantages of the design also considered for future design. Hence, the crucial advantages of each module considered are namely improved production rates, increased of hygienic rating, easy to maintenance and portability of a design. The reviewed patents and journals can be considered for the development of Kek lapis Sarawak’s machine with some improvisations are needed to meet up the specific requirements of the machine