Telfor Journal Vol.8 No.1 (2016)

Content

Editorial HyperLink
Editor-in-Chief: Prof. Dr Đorđe Paunović

Maximum Entropy Whitening Algorithm with Adaptive Neuron Slope for Blind DFE

V. R. Krstić, B. R. Dimitrijević, and M. V. Banđur
Topic:
Communication Theory
Abstract
The addressed blind decision feedback equalizer (DFE) reverses the classical order of its feed-forward and feedback filters at the beginning of adaptation to achieve the best equalization of the minimum and maximum phase components of a channel transfer function. Although very effective, this blind equalization approach deals with the feedback filter mismatch at the time of its transformation from the front-end all-pole whitener of the received signal to the decision-directed feedback equalizer placed after the feed-forward filter. To eliminate this weakness, the adaptive neuron slope is introduced instead of the fixed one into the stochastic gradient whitening algorithm based on the joint entropy maximization cost. The performance of the innovated algorithm is verified by simulating m-QAM (quadrature amplitude modulation) signals transmission over multipath channels. The algorithm with the adaptive neuron slope achieves a better whitening of the received signal spectrum, and, hence, increases the equalization successfulness.
Keywords
Blind decision feedback equalization, joint entropy maximization cost, adaptive neuron slope.
Full Text
HyperLink Maximum Entropy Whitening Algorithm with Adaptive Neuron Slope for Blind DFE
Page(s)
2-7
Doi
10.5937/telfor1601002K

Extending the lifetime of wireless sensor network with partial SDN deployment

S. Tomovic and I. Radusinovic
Topic:
Telecommunications Networks
Abstract
Energy efficiency is one of the key requirements in Wireless Sensor Networks (WSNs). In order to optimize energy usage at sensor nodes, this paper proposes a new network architecture that relies on concepts of Software Defined Networking (SDN). Since SDN is a relatively new technology, originally envisioned for wired networks, it cannot be expected to get immediately and completely adopted in WSN domain, regardless of potential benefits. For this reason, we consider incremental SDN deployment where SDN nodes coexist with traditional sensor nodes, and propose a new routing algorithm for SDN controller that prolongs the WSN lifetime even when a small percentage of SDN nodes is deployed.
Keywords
energy efficiency, routing, SDN, WSN.
Full Text
HyperLink Extending the lifetime of wireless sensor network with partial SDN deployment
Page(s)
8-13
Doi
10.5937/telfor1601008T

Improving Security Incidents Detection for Networked Multilevel Intelligent Control Systems in Railway Transport

A. V. Chernov, M. A. Butakova, E. V. Karpenko, and O. O. Kartashov
Topic:
Intelligent Transport Systems
Abstract
Security monitoring and incident management systems have become the main research focus in the area of intelligent railway control systems. In this work, we discuss a system architecture of multilevel intelligent control system in Russian Railway transport and security incident classification and the handling of theprocess. We make a detailed explanation of problems and tasks of security information and event management system as an important part of a multilevel intelligent control system. We use a rough sets theory to detect an abnormal activity in the considered system. Our main result consists in the development of simple and fast detection techniques that are based on rough sets theory and allow investigating a new type of incidents.
Keywords
intelligent transport systems, railway control systems, rough set theory, security information and event management.
Full Text
HyperLink Improving Security Incidents Detection for Networked Multilevel Intelligent Control Systems in Railway Transport
Page(s)
14-19
Doi
10.5937/telfor1601014C

Inversion Algorithms and PS Detection in SAR Tomography, Case Study of Bucharest City

C. Dănişor, G. Fornaro, and M. Datcu
Topic:
Signal Processing
Abstract
Synthetic Aperture Radar (SAR) tomography can reconstruct the elevation profile of each pixel based on a set of co-registered complex images of a scene. Its main advantage over classical interferometric methods consists in the capability to improve the detection of single persistent scatterers as well as to enable the detection of multiple scatterers interfering within the same pixel. In this paper, three tomographic algorithms are compared and applied to a dataset of 32 images to generate the elevation map of dominant scatterers from a scene. Targets which present stable proprieties over time - Persistent Scatterers (PS) are then detected based on reflectivity functions reconstructed with Capon filtering.
Keywords
Beam-forming, Capon filtering, Least-Squares optimization, PS detection, SAR tomography.
Full Text
HyperLink Inversion Algorithms and PS Detection in SAR Tomography, Case Study of Bucharest City
Page(s)
20-25
Doi
10.5937/telfor1601020D

3D Point Cloud Reconstruction from Single Plenoptic Image

F. Murgia, Cristian Perra, and D. Giusto
Topic:
Signal Processing
Abstract
Novel plenoptic cameras sample the light field crossing the main camera lens. The information available in a plenoptic image must be processed, in order to create the depth map of the scene from a single camera shot. In this paper a novel algorithm, for the reconstruction of 3D point cloud of the scene from a single plenoptic image, taken with a consumer plenoptic camera, is proposed. Experimental analysis is conducted on several test images, and results are compared with state of the art methodologies. The results are very promising, as the quality of the 3D point cloud from plenoptic image, is comparable with the quality obtained with current non-plenoptic methodologies, that necessitate more than one image.
Keywords
Light field reconstruction, Plenoptic reconstruction, 3D reconstruction.
Full Text
HyperLink 3D Point Cloud Reconstruction from Single Plenoptic Image
Page(s)
26-31
Doi
10.5937/telfor1601026M

An Affine Combination of Adaptive Filters for Channels with Different Sparsity Levels

M. Butsenko and T. Trump
Topic:
Signal Processing
Abstract
In this paper we present an affine combination strategy for two adaptive filters. One filter is designed to handle sparse impulse responses and the other one performs better if impulse response is dispersive. Filter outputs are combined using an adaptive mixing parameter and the resulting output shows a better performance than each of the combining filters separately. We also demonstrate that affine combination results in faster convergence than a convex combination of two adaptive filters.
Keywords
Adaptive filters, combination filters, sparse impulse response.
Full Text
HyperLink An Affine Combination of Adaptive Filters for Channels with Different Sparsity Levels
Page(s)
32-37
Doi
10.5937/telfor1601032B

Layered AMI Architecture for Various Grid Topologies and Communication Technologies

I. Petruševski, A. Rakić, and I. Popović
Topic:
Applied Electronics
Abstract
Advanced metering infrastructure (AMI) system, proposed in this paper, is capable of fulfilling all smart metering functionalities in real-time. The novel Local Metering Concentrator (LMC) layer is introduced as the set of independent embedded system components, allowing distributed architecture implementation. Two main data flows can be defined as command request processing and meter data acquisition. A command request, initiated by some of the top layer applications, is processed and forwarded through the system to the LMC layer, where the request is executed and the status is sent as a reply. The data and event acquisition is performed as an automatic function of the LMC layer. The collected data is forwarded to the system as soon as it is downloaded from the meters. The results of more than one-year exploitation of the installed pilot system are presented, emphasizing the real-time load profile data acquisition, allowing the distribution system operators (DSO) and the end consumer to be actively involved in energy saving. The introduced architecture enables load profiling, energy diagnostic and easy integration with any meter data management system.
Keywords
Advanced metering infrastructure, power line communication, smart grid, smart meters.
Full Text
HyperLink Layered AMI Architecture for Various Grid Topologies and Communication Technologies
Page(s)
38-43
Doi
10.5937/telfor1601038P

Microcontroller Power Consumption Measurement Based on PSoC

S. P. Janković and V. R. Drndarević
Topic:
Applied Electronics
Abstract
Microcontrollers are often used as central processing elements in embedded systems. Because of different sleep and performance modes that microcontrollers support, their power consumption may have a high dynamic range, over 100 dB. In this paper, a data acquisition (DAQ) system for measuring and analyzing the power consumption of microcontrollers is presented. DAQ system consists of a current measurement circuit using potentiostat technique, a DAQ device based on system on chip PSoC 5LP and Python PC program for the analysis, storage and visualization of measured data. Both Successive Approximation Register (SAR) and Delta-Sigma (DS) ADCs contained in the PSoC 5LP are used for measuring voltage drop across the shunt resistor. SAR ADC samples data at a 10 times higher rate than DS ADC, so the input range of DS ADC can be adjusted based on data measured by SAR ADC, thus enabling the extension of current measuring range by 28%. Implemented DAQ device is connected with a computer through a USB port and tested with developed Python PC program.
Keywords
DAQ, Microcontrollers, Power consumption, PSoC.
Full Text
HyperLink Microcontroller Power Consumption Measurement Based on PSoC
Page(s)
44-49
Doi
10.5937/telfor1601044J

Breast Region Segmentation and Pectoral Muscle Removal in Mammograms

M. Slavković-Ilić, .A. Gavrovska, M. Milivojević, I. Reljin, and B. Reljin
Topic:
Multimedia
Abstract
The first step in most computer aided diagnosis systems is an accurate segmentation of breast region, which affects not only the accuracy but also the speed of the analysis because it significantly reduces the area of the image to be examined. The second step usually includes removal of pectoral muscle region, which is seen in mediolateral oblique view mammograms. This is primarily done to reduce the number of false positive breast cancer detections. In this paper, a method for the segmentation of breast region based on contrast enhancement and k-means algorithm is proposed. To extract pectoral muscle, a region of interest is found, its contrast is enhanced and the pectoral muscle is identified using k-means algorithm. Cubic polynomial fitting is used for the estimation of muscle's boundary. The method is validated with mammograms from miniMIAS database.
Keywords
Breast segmentation, computer aided detection, MIAS database, pectoral muscle.
Full Text
HyperLink Breast Region Segmentation and Pectoral Muscle Removal in Mammograms
Page(s)
50-55
Doi
10.5937/telfor1601050S

Soil data clustering by using K-means and fuzzy K-means algorithm

E. Hot and V. Popović-Bugarin
Topic:
Software Tools and Applications
Abstract
A problem of soil clustering based on the chemical characteristics of soil, and proper visual representation of the obtained results, is analysed in the paper. To that aim, K-means and fuzzy K-means algorithms are adapted for soil data clustering. A database of soil characteristics sampled in Montenegro is used for a comparative analysis of implemented algorithms. The procedure of setting proper values for control parameters of fuzzy K-means is illustrated on the used database. In addition, validation of clustering is made through visualisation. Classified soil data are presented on the static Google map and dynamic Open Street Map.
Keywords
clustering, data mining, K-means, fuzzy K-means, pedologic map.
Full Text
HyperLink Soil data clustering by using K-means and fuzzy K-means algorithm
Page(s)
56-61
Doi
10.5937/telfor1601056H

A Comparative Study of Voltage, Peak Current and Dual Current Mode Control Methods for Noninverting Buck-Boost Converter

M. Č. Bošković
Topic:
Applied Electronics (Student Paper)
Abstract
This paper presents a comparison of voltage mode control (VMC) and two current mode control (CMC) methods of noninverting buck-boost converter. The converter control-to-output transfer function, line-to-output transfer function and the output impedance are obtained for all methods by averaging converter equations over one switching period and applying small-signal linearization. The obtained results are required for the design procedure of feedback compensator to keep a system stable and robust. A comparative study of VMC, peak current mode control (PCMC) and dual-current mode control (DCMC) is performed. Performance evaluation of the closed-loop system with obtained compensator between these methods is performed via numerical simulations.
Keywords
Noninverting buck-boost converter, Voltage mode control, Current mode control, Performance.
Full Text
HyperLink A Comparative Study of Voltage, Peak Current and Dual Current Mode Control Methods for Noninverting Buck-Boost Converter
Page(s)
62-67
Doi
10.5937/telfor1601062B