Sirindhorn International Institute of Technology

About: Sirindhorn International Institute of Technology is a based out in . It is known for research contribution in the topics: Supply chain & Combustion. The organization has 1048 authors who have published 1678 publications receiving 30067 citations.

All-pass based IIR multiple notch filter design using Gröbner Basis

Abstract: In this paper, the digital IIR multiple notch filter based on an all-pass filter design of order 2N is considered. The most important step is about the calculation of the exact notch frequencies. The previous method requires solving of non-linear polynomial equation system which can be difficult to tackle especially for the case with higher number of notch frequencies. The analytical result was derived only for the case of N = 2 not for N = 3 and higher, then the main idea proposed in this paper is focused on solving of the non-linear systems for the cases of higher number of notch frequencies, e.g. N ≥ 3, by employing “Grobner Basis” theory which has ability to solve multi-variance polynomial equation systems by using the benefit of “lexicographical orderings” in the polynomial rings to make those systems to be “triangular systems” which can be solved by backward substitution. Although the proposed filter design is a one dimensional but the proposed technique involved multi-variance polynomials. Another advantage is that the Grobner Basis provides symbolic solutions which allow further optimization to satisfy additional constraints such as having minimum group delay.

Vessel extraction in retinal images using multilevel line detection

Abstract: This paper presents an algorithm to segment the blood vessels in retinal images. The contribution of this work is that we exhibit how a line detection can be applied in a multi-scale framework to fulfill the sophisticated task of vessel segmentation. The key idea of our algorithm is to systematically combine the outputs of Gaussian based line detection that is applied sequentially to the input image at several scales from coarse to fine levels. This brings down to the strategy that the evidences of larger size vessels are used to steer the process of addition of smaller vessels. Our proposed method is evaluated on the public DRIVE database and shows results with false positive rate.