18 research outputs found
OPTIMIZATION OF MEANDER LINE ANTENNA USING ACO TECHNIQUE
Get PDFMeander Line Antenna is small size, low cost, light weight and higher efficiency antenna. Ant colony optimization (ACO) is one of the most recent techniques for approximate optimization. The inspiring source of the ACO algorithms is real ant colonies. ACO is inspired by ants foraging behavior. In this work ant colony system algorithm is used to optimize the antenna . Meander line antenna is designed using HFSS to ol and MATLAB is used to implement ACO algorithm. The structure of antenna is optimized. ACO is best adaptable technique for optimization of Mean der Line Antenna
Design And Simulation of Sierpinski Pre fractal Antenna Using HFSS
Get PDFA compact triangular patch Pre Fractal Sierpinski antenna with micro strip feed line for multiband and moderate gain antenna for portable communications systems respond to the great demand for both commerci al communications systems and military is designed with HFSS Ansoft v11 and fabricated on TEFLON. The results demonstrate that the proposed antenna with triangular slots at special positions can generate steady radiation pattern and is capable of wrapping the frequencies demanded by UWB Communication system, RFID, Wi - Fi, GSM, WiMax. Good agreement between the simulated and measured results further validates the utility of presented antenna for proposed application. For operational frequency of 2.25 GHz, 4.15 GHz and 6.25 GHz, VSWR bandwidth nearly 2.4 and return loss bandwidth up to - 15.85db has been obtained. A triangular slots and cut plays an important role in balancing resistive part and reactive part which affe cts the impedance matching. A thick dielectric substrate is helpful in increasing the bandwidth
OPTIMIZATION OF U-SLOT MICROSTRIP PATCH ANTENNA USING GENETIC ALGORITHM
Get PDFIn this work, an extensive design study of a u - slot microstrip patch antenna for dual band operation will be presented. This antenna consists of microstrip patch with U - slot. Feeding techniques namely probe - feeding and co - planar waveguide feeding have been used and the results compared. Genetic Algorithm has been used to optimize the antenna parameters. The simulated results indi cate that using co - axial feeding technique coplanar waveguide feeding results in a tremendous increase in bandwidth with Genetic Algorithm over other algorithms
DESIGN OF COMPOUND FRACTAL ANTENNA FOR MULTIBAND APPLICATION
Get PDFThis work is concerned with the investigation of two types of antenna elements that are to be used for multiband applications. The first antenna is the Fractal antenna while the second is the meander line antenna. The basic design is based on the self similarity principle of fractal profiles but uses different slot geometries. The behaviors of both type antennas are investigated such as return loss, number of iterations and radiation pattern. Compound fractal antennas have the potential to provide multi - band solution through the property of self similarity that the fractal shape poses. Compound fractal antenna is comprised of elements patterned after self similar designs. Self - similarity of the fractal shape can be translated into its electromagnetic behavior. Nowadays wireless communications systems require compact antennas which are capable of operating at different bands. Fractal geometry is being studied in order to answer those requirements
THYROID PROFILE IN PATIENTS WITH LIVER CIRRHOSIS AND ITS CORRELATION WITH SEVERITY AND ETIOLOGY OF LIVER DISEASE
No full textObjective: Liver cirrhosis is associated with various endocrine abnormalities, including thyroid dysfunction. The liver plays a crucial role in thyroid hormone metabolism, and cirrhosis may alter thyroid function tests (TFTs). This study aimed to evaluate thyroid function in cirrhotic patients and correlate it with disease severity and etiology.
Methods: A cross-sectional study was conducted on 54 patients with liver cirrhosis. Thyroid profiles (TSH, FT3, FT4) were assessed and correlated with Child-Pugh and MELD scores. Etiologies included alcohol, viral hepatitis (HBV, HCV), and non-alcoholic fatty liver disease (NAFLD). Statistical analysis was performed using SPSS v26.
Results: Thyroid dysfunction was present in 40.7% of patients, with sick euthyroid syndrome (low FT3) being the most common (29.6%). Hypothyroidism (elevated TSH) was seen in 11.1%. FT3 levels inversely correlated with Child-Pugh (r =-0.52, p<0.01) and MELD scores (r =-0.48, p<0.01). Viral hepatitis-related cirrhosis showed more thyroid dysfunction (55.5%) compared to alcoholic cirrhosis (33.3%).
Conclusion: Thyroid dysfunction, particularly low FT3, is common in cirrhosis and correlates with disease severity. Viral etiology is associated with a higher prevalence of thyroid abnormalities. Routine thyroid screening in cirrhotic patients may aid in better management
RF and Crosstalk Characterization of Chip Interconnects Using Finite Element Method
No full text132-137This paper presents new finite element method (FEM) based approach for radio frequency (RF) and crosstalk (X talk)
characterization of chip interconnects. Being based on scattering parameters (S-parameters), this approach truly and accurately
demonstrates the transmission line behavior of chip interconnects over a wideband of frequencies. To demonstrate FEM based
method, a single-line and a 3-line interconnect test structures on SiO2-Si substrate have been designed and simulated in High
Frequency Structure Simulator (HFSS). The RF and crosstalk characterization of chip interconnect materials Copper (Cu),
doped multilayer Graphene Nanoribbon (DMLGNR), and neutral multilayer Graphene Nanoribbon (NMLGNR) have been
demonstrated in terms of transmission coefficient Sij &Smn from 1 to 1000 GHz. The single-line three-dimensional (3D)
structures comprising of Cu, DMLGNR, and NMLGNR have maximum transmission loss values of -15.93 dB, -22.03 dB, and -
13.73 dB at frequencies of 643 GHz, 402 GHz, and 643 GHz, respectively whereas three-line bus structure exhibit maximum
victim-line transmission loss values of -15.28 dB, -17.47 dB, and -15.98 dB at frequencies of 247 GHz, 829 GHz, and 377 GHz,
respectively. Further, the crosstalk results have demonstrated that as frequency increases significant crosstalk is observed
between nearby lines due to electromagnetic interference and coupling (EMI/EMC) issues
HAAR WAVELET TRANSFORM FOR SOLUTION OF IMAGE RETRIEVAL
Get PDFABSTRACT: An efficient algorithm based Haar Wavelet approach for image retrieval solution, is proposed. This method is applicable for different kinds of image extraction features. Wavelet Transformation is a powerful tool for many problems. It can be used in numerical techniques. Here we proposed a new technique of wavelet transformation trough which a feature vector of size ten, characterizing texture feature of image is constructed from only three iterations of Wavelet transform. Mask technique is used to group images based on feature vector of images by considering the minimum Euclidean distance. Experiments are performed on texture images, and successful matching results are found
