Aljo Mujcic

Frequency Characteristics Measurement of Overhead High-Voltage Power-Line in Low Radio-Frequency Range

This paper presents measurement results of frequency characteristics of the high-voltage power line in low radio-frequency range: amplitude and phase characteristic, group delay, and input impedance. Measurement results for the 400-kV overhead power-line under operation are presented together with the developed measurement methodology. The methodology provides a method to measure amplitude and phase characteristics, group delay and the return loss of the HV power line for a geographically distributed system utilizing an optical link as a return path. The measurement results confirm very low attenuation with a linear phase, but with oscillations present in all characteristics caused by reflection of the signal on the power line. The complete knowledge of frequency characteristics of the HV power line and noise description is crucial for the design of digital power-line carrier (PLC) systems.

Computation of high-frequency and time characteristics of corona noise on HV power line

This work presents an algorithm for the computation of frequency and time characteristics of the corona noise in power-line carrier communications. In the frequency domain, the corona noise is represented with a power spectral density and with a Gaussian noise voltage with variable root mean square value in the time domain. Simulations results are compared with measurements on an actual 400-kV power line.

Dynamic Languages Integration Path for Telecom Applications

The paper presents an approach to integrate dynamic programming languages with IMS application servers. Existing Java-based platforms for telecom applications are surveyed. Specific steps of integration of Ruby and JEE server are given. A proof of concept application is developed and deployed on an open-source Java Enterprise server.

The Usage of Smartphones in Remote ECG Monitoring Scenarios

The rapid development of smartphones and their widespread integration in everyday living has prompted their usage in healthcare and medical applications. With the emergence of wireless communications and biomedical sensors, remote patient monitoring (RPM) systems are allowing for patient-centered healthcare services while improving quality of life and reducing hospitalization costs. Energy-efficiency of wireless sensor nodes and mobile devices is of high importance in RPM systems in order to ensure unobtrusive sensing and long-term monitoring, without interfering with patients daily activities. In this paper we tested the reliability of Android smartphone in terms of long-term monitoring, by measuring its power consumption. This study shows the trade-off between smartphone’s streaming of ECG signals and local processing operations. If basic ECG signals processing operations are moved to wireless sensor node, our results show that smartphone can be utilized for more advanced analysis without excessive resource consumption. In order to further lower the number of samples for transmission, Android smartphone was tested in real-time compressed sensing recovery scenario as well.

An application of the broadband PLC for smart homes in Turkey

This paper describes the PLC broadband channel application for home automation in Turkey. Firstly, the necessity of information and communication technologies (ICT) for smart grid is discussed and channel models for LV power lines-especially transmission line based models are explained. For application step, a typical house which has five rooms is selected. Then, the potential loads are located. In addition, all cable types and cable lengths are selected according to the real home wiring application in Turkey. Then, the PLC channel behavior is observed with the help of FTW simulator in fixed and random mode.

Requirements for communication infrastructure in smart grids

The paper provides an overview of the requirements for the communication infrastructure in the smart grid. Communication traffic is classified as the time critical and non-critical and correlated with the power system phenomena. Required values of quality of service parameters are given for particular applications: wide area measurement system, distribution automation and advanced metering infrastructure. Since available standards describing communications in the smart grid define Internet Protocol (IP) and Ethernet as the most appropriate communication protocols for the broad deployment of the smart grid applications, mechanisms for traffic prioritization at the MAC layer are reviewed in the paper.

Influence of data frame duration on performance of BITCM system over HV power line

The impulse noise in the HV power line channel is mainly caused by high voltage existing on conductors and station apparatus. Such impulse noise has repetition rate of SO or 150 Hz and is synchronous to power frequency period. In this paper, we have shown that the digital transmission via HV PLC channel have better performance if it is realized through the transmission of interleaved data blocks. The data frame duration must be adjusted to the periodicity of impulse noise or the power frequency period.

Mental workload vs. stress differentiation using single-channel EEG

The emergence of wearable low-cost wireless devices has allowed for continuous acquisition of physiological signals. Recently number of studies have applied these acquisition systems in different types of health monitoring. Since continuous elevation of stress hormones can have negative impact on individuals’ health, it is important to recognize and possibly prevent stress episodes in working environments. In this paper, we have tested if single-channel electroencephalography (EEG) signals can be utilized in assessment of different levels of mental workload and stress. Experimental study was conducted in laboratory settings with nine participants. In addition to EEG signals, we have acquired electrocardiogram (ECG) and electrodermal activity (EDA) recordings during all stages. Two scenarios are tested: first group of participants was introduced to only mental workload assignments, while second group was tested with mental workload and public speaking task as an stress inducing assignment. The experimental results show that EEG features have an acceptable separation ability between investigated states, where best classification accuracy, obtained between relaxed and high mental workload states, was 86.66%. Compared to only ECG or EDA features, EEG-based classification accuracy is higher in both scenarios, but lower in comparison with combined features from all three physiological signals.

Blood pressure estimation using video plethysmography

Remote sensing of vital physiological signs allows for unobtrusive, nonrestrictive and non-contact assessment of individuals health. By using video plethysmogram obtained by digital camera recordings of patients face or hands, health parameters such as heart rate, respiratory rate and heart rate variability have already been investigated. In this paper, time-domain video plethysmogram from forehead was used for calculation of pulse transit time, which is related to blood pressure. Synchronous measurements of non-contact video plethysmogram, 12-channel electrocardiogram and invasive blood pressure were performed on three subjects. Our results demonstrate that pulse transit time method can be equally efficient with non-contact VPG signal, with error mean and standard deviation of 9.48 ± 7.13 mmHg and 4.48 ± 3.29 mmHg, for systolic and mean arterial pressure, respectively. Additionally our findings show that delay in pulse transit time, calculated from two different VPG signals from forehead and palm, could provide clinically useful measure of changes in systolic blood pressure.

A cost effective topology in fiber to the home point to point networks based on single wavelength bi-directional multiplex

The study about a cost effective topology based on the single wavelength bi-directional multiplex is conducted. In this study the Capital Expenditure (CAPEX) from point of view of payback period is analyzed, and a cost-effective novel FTTH (Fiber to the Home) scheme based on the single wavelength bidirectional multiplex is proposed. By using the proposed schema it is possible to reduce initial CAPEX and at the same time to reduce a payback period for new FTTH networks. The proposed schema allows achieving an increase in capacity of 50% in existing FTTH P2P (Point to Point) network.