تبدیل موجک

List of Articles تبدیل موجک

Open Access Article
- Abstract Page
- Full-Text
1 - A Multi-Resolution Learning Based Method for Multimodal Medical Image Registration
S. S. Alehojat Khasmakhi M. R. Keyvanpour
20.1001.1.16823745.1393.12.4.2.6

The main purpose in various methods of image registration is to find the transformation parameters for accurate mapping an image onto another image coordinates. In medical sciences creating a precise mapping between medical images data is very important in application More

The main purpose in various methods of image registration is to find the transformation parameters for accurate mapping an image onto another image coordinates. In medical sciences creating a precise mapping between medical images data is very important in application such as diagnosis and treatment. Accordingly, several approaches have been proposed for image registration. The compression of results and performance between different image registration algorithms was the main motivation for this research to design and implement a new hybrid algorithm so that provide high accuracy in multimodal image registration. Automating the image registration process by using machine learning approach is the innovation of this method compared to previous ones. To this end, the proposed method which is named multi resolution learning is composed of multi resolution decomposition and a hierarchical neural network which it learn the transformation parameters by using global properties of the image and uses learned transformation parameter for image registration. The proposed method is implemented and tested on the medical images of Vanderbilt university database. Experiment result show acceptable accuracy for the proposed method compared with other methods. Manuscript profile
Open Access Article
- Abstract Page
- Full-Text
2 - Detection and Analysis of Acoustic Signals of Power Transformers On-Load Tap Changers for Assessment of Their Faults
adel younesi Abbas Ghayebloo Hasanreza Mirzaei

On load tap changers are very important equipment of the power transfor More

On load tap changers are very important equipment of the power transformers. Due to the strongly mechanical movements and high-energy arcs, this equipment has a much higher failure rate with respect to other internal transformer equipment. Online and accurate evaluation of well operation of these equipment by indicators with no interfere on the normal operation of the transformer, is very important issue. In this paper, various faults detecting methods in the tap changer have been discussed an investigated by some extracted features of acoustic signals. These signals have been captured experimentally in various tap changing periods by an accelerometer sensor mounted on a power transformer body. In this paper, in addition to common features, two new feathers entitled time and frequency indicators have been introduced. Finally, for selecting the proper features to faults detection and proposing an effective classification method, some available experimental data were randomly defected by results in the references, and classified successfully as healthy and defective data by support vector machine (SVM) method. Manuscript profile
Open Access Article
- Abstract Page
- Full-Text
3 - Fault Detection and Localization in Hybrid Shipboard Electrical Power Grids Using Wavelet Transform
Mohsen Aliyani Arash Dehestani Kolagar Mohammad Reza Alizadeh Pahlavani

In the hybrid shipboard power networks, the possibility of occurrence of various types of faults is very high. According to the studies conducted in the field of fault detection and localization in hybrid microgrids, the lack of comprehensive fault management techniq More

In the hybrid shipboard power networks, the possibility of occurrence of various types of faults is very high. According to the studies conducted in the field of fault detection and localization in hybrid microgrids, the lack of comprehensive fault management techniques to protect the microgrid against short-circuit faults is the main obstacle to the use of hybrid microgrids in vessels for vital marine missions. Considering the restrictions and limitations in marine vessels, the design of an electrical protection system for hybrid microgrids requires high attention to special requirements. In this paper, an appropriate protection scheme for fault detection and localization in hybrid shipboard microgrids is presented. In this regard, fault detection, classification and localization in a period of 0.034 to 0.54 seconds are performed using an algorithm based on Daubechies order 4 wavelet transform (db4). Observing the results and analyzing them shows that the proposed algorithm can detect, classify and localize all types of faults both in the AC and DC parts of the shipboard microgrids. Manuscript profile

Current Issue

Published Issues

Menu

Browse

List of Articles تبدیل موجک