| Judul | Abstract | Halaman |
|---|
| A 2.3/3.3 GHz Dual Band Antenna Design for WiMax Applications | A triangular-slot antenna with rectangular patch for 2.3/3.3 GHz WiMax applications has been implemented on DICLAD 527 substrate (relative permittivity εr = 2.5) with 1.524 mm of substrate thickness. A rectangular patch printed on one side of the substrate is fed by a 50 Ω microstrip line and acts as the frequency tuning stub, while the triangular slot is positioned on the opposite side of the substrate, center lined to the rectangular stub. From the measurement results based on VSWR = 2 or equal to the return loss of 9.53 dB, at the lower band of 2.3 GHz the resulting impedance bandwidth is 290 MHz (from 2.16 to 2.45 GHZ) and at the upper band of 3.3 GHz is 370 MHz (from 3.31 to 3.68GHz), providing services for 2.3 GHz and 3.3 GHz frequency bands allocated for WiMax applications. The antenna gain measurement at 2.3 GHz frequency band is almost agrees with the simulation result of 3.2 dBi. While at 3.3 GHz the gain is approximately 4.4 dBi and continues to decrease with increasing frequency. The antenna gain measurement achieves maximum of 4.8 dBi (6 dBi from simulation) at about 3 GHz. The simulation and measurement results are evaluated and discussed. | 67-78 |
| Ultrafuzziness Optimization Based on Type II Fuzzy Sets for Image Thresholding | Image thresholding is one of the processing techniques to provide high quality preprocessed image. Image vagueness and bad illumination are common obstacles yielding in a poor image thresholding output. By assuming image as fuzzy sets, several different fuzzy thresholding techniques have been proposed to remove these obstacles during threshold selection. In this paper, we proposed an algorithm for thresholding image using ultrafuzziness optimization to decrease uncertainty in fuzzy system by common fuzzy sets like type II fuzzy sets. Optimization was conducted by involving ultrafuzziness measurement for background and object fuzzy sets separately. Experimental results demonstrated that the proposed image thresholding method had good performances for images with high vagueness, low level contrast, and grayscale ambiguity. | 79-94 |
| Robust Reed Solomon Coded MPSK Modulation | In this paper, construction of partitioned Reed Solomon coded modulation (RSCM), which is robust for the additive white Gaussian noise channel and a Rayleigh fading channel, is investigated. By matching configuration of component codes with the channel characteristics, it is shown that this system is robust for the Gaussian and a Rayleigh fading channel. This approach is compared with non-partitioned RSCM, a Reed Solomon code combined with an MPSK signal set using Gray mapping; and block coded MPSK modulation using binary codes, Reed Muller codes. All codes use hard decision decoding algorithm. Simulation results for these schemes show that RSCM based on set partitioning performs better than those that are not based on set partitioning and Reed Muller Coded Modulation across a wide range of conditions. The novel idea here is that in the receiver, we use a rotated 2^(m+1)-PSK detector if the transmitter uses a 2^m-PSK modulator. | 95-114 |
| Determining the Standard Value of Acquisition Distortion of Fingerprint Images Based on Image Quality | This paper describes a novel procedure for determining the standard value of acquisition distortion of fingerprint images. Knowledge about the standard value of acquisition distortion of the fingerprint images is very important in determining the method for improving image quality. In this paper, we propose a model to determine the standard value that can be used in classifying the type of distortion of the fingerprint images based on the image quality. The results show that the standard value of acquisition distortion of the fingerprint images based on the image quality have values of the local clarity scores (LCS) follows: dry parameter values are in the range of 0.0127-0.0149, neutral parameter values are less than 0.0127, and oily parameter values are greater than 0.0149. Meanwhile, the global clarity scores (GCS) are as follows: dry parameter values are in the range of 0.0117-0.0120, neutral parameter values are less than 0.0117, and oily parameter values are greater than 0.0120; and ridge-valley thickness ratios (RVTR) are as follows: dry parameter values are less than 7.75E-05, neutral parameter values are 7.75E-05-5.94E-05, and oily parameter values are greater than 5.94E-05. | 115-132 |
