ABSTRACT. In this paper a technique for inverting the lidar equation that does not require additional non-lidar data and can be used in the case of stratified atmosphere is proposed. A numerical experiment shows that the relative error of the inversion profile of the extinction coefficient is comparable to that due to noise fluctuations in the model profile of range-normalized lidar signal.

ABSTRACT. The paper is discussing problems connected with tools to non-intrusively evaluate VoIP quality by signal waveform analysis. The aim of this paper is to present new models for objective, nonintrusive, prediction of voice quality for IP networks and to illustrate their application to voice quality monitoring control in VoIP networks. The method detects impairments of quality of audio for human perception. It enables to see the quality of VoIP connection at a glance and warns when quality deteriorates. This gives the option to troubleshoot your VoIP network even before users are affected by VoIP specific connection problems (echo, noise or breaks in the conversation). The signal waveform envelope distortion is reviewed and practical questions of its numerical implementation are discussed. Several examples of how the criterion can be used are given.

ABSTRACT. In this paper a new comparative factor (CF) is developed and used to compare several classic downlink resource allocation algorithms (RAAs) in indoor wireless environments, simulated by means of the Realistic Indoor Environment Generator (RIEG). The CF components’ values are analysed for five different downlink RAAs studied across different numbers of users

ABSTRACT. Covariance based spectrum sensing methods of cognitive radio technology are known for their non-reliance property to signal and noise power. Using Tracy-Widom distribution of minimum eigenvalue, energy and one to minimum eigenvalue spectrum algorithm is proposed which is neither like energy detection which its performance highly rely on noise power and nor low performs like energy to minimum eigenvalue which is using asymptotic approach to minimum eigenvalue even though using the same ratio. Limiting distribution approach to minimum eigenvalue cause the detection algorithm perform much better in lower SNR ranges. Our proposed method performs better not only in low SNR range but also in low smoothing factors compared to very well known maximum to minimum eigenvalue method. The performance improvement is evaluated analytically and compared with other well known algorithms in a wide SNR range and different smoothing factors.

ABSTRACT. Spatio-temporal variation in traffic demand makes the cellular technologies suffer from load imbalance problem. The diversity of propositions handling this issue demonstrates their partial contribution to network performances. This paper presents Algorithm Suitability theory, which optimizes permanently system metrics. Based on software-defined networking and lexicographic optimality, it improves both energy and spectral efficiency.

ABSTRACT. This paper deals with contention resolution using signal tones for Wireless Sensor Networks (WSNs). We give an overview of existing contention resolution mechanisms, and describe briefly representative protocols by stating their essential behavior and emphasizing their strengths and weaknesses.

ABSTRACT. Due to the digital switchover, a new frequency band is available for mobile systems. This so-called digital dividend band 1 is advantageous for mobile systems, due to its good wave propagation parameters. However, even before the call has been sent out for frequency proposals, concerns raised about the potential disturbance of the various systemsas this band overlaps with the upper end of the band used by cable television broadcasting companies. Furthermore, the the possible consequences and the scale of disturbance for both actors has to be studied if the mobile service providers start using the above mentioned band. There may be cases where the disturbance limits are not satisfied, because the cables, connectors and couplers are damaged or the equipment built into the network is simply of poor quality. Another potential source of problems could be the age of the cable networks.

Nonetheless, by using various measurements it is essential to determine the ability of the various network elements to filter the external interference. The main objective of the study was to find out about the shielding effectiveness of various cables and taps. During the measurements we also investigated how the measured results change in the case of broken cables, damaged multitaps and not properly secured closings using the specifications and directions of the 50083-2 EMC standard as a guideline.

ABSTRACT. This paper deals with design of new CIC (Cascaded-Integrator-Comb) FIR (finite impulse response) filter functions. Closed-form expressions of new class of selective CIC filter functions by introducing spreading of the delays in the CIC filter comb stages are firstly presented here. Then, the authors are focused on the analysis of the proposed CIC filters in comparison with existing classical CIC structures and some recent results reported in the literature. The novel cascaded-filter architecture has valuable benefits: higher insertion loss in stopband, smaller impulse response coefficient values, and better characteristic in passband region compared with classical CIC filters.

ABSTRACT. This paper presents a modified Block Truncation Coding (BTC) algorithm and its application in wideband speech signal coding. Since the original BTC algorithm is designed for application in black and white image coding, it is modified to a great extent, while preserving the basic principles. The modified algorithm exploits the common characteristics of the speech signal and images, while the dominant modifications are implemented in the area of signal quantization. The algorithm is applied to real input speech signals and the results are very impressive, indicating a wide applicability of our proposal

ABSTRACT. In this paper is presented a general approach for the medical condition assessment of patients with disabilities. It is based on daily activity analysis using common accelerometer sensors carried by the monitored person while at home without medical personnel present. Six types of activities are being investigated using the k-NN classifier after initial pre-processing of the raw input data followed by additional reduction in dimension and thus recognition time. Promising results are obtained which could bring useful statistics for the progress of the medical state of the observed individual over prolonged time.

ABSTRACT. In this paper is examined the significance of tree classes of feature selection algorithms, extracted from 3D mesh data, generated from the Mars Orbiter Laser Altimeter (MOLA) for a classification task to automatically detect craters, while at the same time testing four classifiers. The key idea of this study is to study the discriminative power of the original values, hereafter called “pure” values, of a minimal curvature by only converting them to grey scale image. The experimental results with four different classifiers show that better accuracy results are ob-tained over the features selected from the grey scale image. It is employed technique from computer vision used for face detection in the task of crater detection.

ABSTRACT. The Wavelet transform is described as a tool for creating an image pseudo-hash in order to enable content-based image retrieval. The images are decomposed in few levels and the most important wavelet detail coefficients are selected to compose the pseudo-hash. When searching for digital images in large database, the pseudo-hashes of the images are considered instead of the images themselves.

ABSTRACT. An algorithm for digital watermarking of medical images using complex Hadamard transform is presented. The developed algorithm allow high detection of unauthorized access or attacks on the included watermark. The obtained experimental results for some attacks over the test medical images are made on the base of mean-squared error and signal to noise ratio of the reconstructed images.

ABSTRACT. This paper describes the development of low-cost and low-powered wireless sensor network, which can be used for improving the energy efficiency in buildings. This sensor network uses Low Energy Bluetooth technology for connecting the sensor nodes to the central device. As a central device and gateway is used Raspberry Pi 2, and as sensor nodes are used SimpleLink SensorTags CC2650 from Texas Instruments. The functionality of the WSN has been demonstrated by logging and comparing measured temperatures, collected from different locations of a building during various times of the day.

ABSTRACT. The scope of this paper is to determine what is the thermal impact over human head skin, created by a cell phone, while calling over UMTS network. The analysis is twofold: theoretical based on the human anatomy and physiology and the impact of EMF over biological structures and practical conducted via thermo-visual method with infrared camera. Thus the obtained data was from real people in equal conditions, not based on computer simulations. The distance between the infrared camera and observed participant was 1 meter which practically eliminates the interference between the object and the surrounding environment data. The results shows there is no critical heating of the human skin even after 40 minutes of calling This may be explained as a biological mechanism for adaptation in different conditions and biological processes related to it.

ABSTRACT. In this paper are presented the results from the measurements of the influence of the differences in the polarization between Tx and Rx antennas by DVB-T broadcasting. Considered are the cases of directional and omnidirectional antenna for Ricean and Rayleigh channels. Comparisons are made with the standard requirements of ETSI and the experimental results are presented through graphical interpretations.

ABSTRACT. In this paper a method for evaluating the outage probability of FSO system using optimal system parameters is provided. It is considered the presence of moderate to strong atmospheric turbulence and random jitter in the direction of laser beam propagation. Closed form expressions for calculating the outage probability are derived.

ABSTRACT. Abstract – In the quasi-static analysis of transmission lines, symmetry should be taken into account whenever possible, in order to reduce the number of unknowns and thus the calculation time. In this paper it is described how to include the symmetry in the calculation of quasi-static lines by using the strong FEM formulation.

ABSTRACT. An alternative approach to estimate the phase advance of the carrier signal in the ionosphere using artificial neural networks is presented. A neural model was developed based on multilayer perceptron network that, from information about the latitude of the observed receiving terminal and the current point in time during the day, determines the approximate value of the concentration of ions in the ionosphere. This value is then used to estimate a phase advance of the carrier signal, during its propagation through the ionosphere. Current model architecture enables the estimation of the ionospheric carrier phase advance for the spring and autumn periods of the Mediterranean areas.

ABSTRACT. This paper represents the linearization technique of RF power amplifier that exploits the second- and fourth-order nonlinear signals formed for linearization in a digital baseband domain. The combined second- and fourth-order linearization signals, adequately processed in amplitude and phase, modulate carrier second harmonic which is then injected at the input or output of the amplifier transistor. The effects of the proposed linearization method are evaluated on a single stage power amplifier for simulated QAM digitally modulated signal characterized with frequency spacing between spectral components up to 20 MHz for different input power levels.

ABSTRACT. In this paper a modification to extend the range of HB100 module is presented. As it is a typical example for doppler radar, consists of Dielectric Resonator Oscillator (DRO), microwave mixer and patch antennas. Disadvantage is the low gain stock antennas havel and thus become non-functional for use on larger distances. A method to increase the range is exposed in this article, allowing to extend the application of this radar - control flight of drones and other unmanned vehicles.

ABSTRACT. A coax-fed microstrip patch antenna of a circular geometry containing two arc-shaped slots within a radiated patch has been designed using the in-house solver based on the TLM method adjusted to the cylindrical grid. Its performances have been analysed with regards to the classic circular patch antenna. The antenna exhibits a dual-frequency operation, where the upper frequency can be easily controlled by adjustments of the arc–shaped slots dimensions.

ABSTRACT. The exponential function, since its introduction, was a subject of a lot of variotions, deformations and generalizations. The same happened with different classes of orthogonal polynomials. Here, we wish to empasize their appearance in some combinatorial problems. The Motzkin paths are a class of positive weighted paths with appearance in many contexts. We will connect them with the continued fractions, the moments of the functionals and generalizations ofthe exponential function. Such paths have their interpretations in the computer sciences to.

ABSTRACT. In this paper, we present the analysis of hybrid radio frequency (RF) / free-space optical (FSO) system. The switch-and-stay (SSC) diversity technique is employed at the receiver. The intensity fluctuations of the optical signal are modelled by Gamma-Gamma distribution, while the RF fink is affected by Rayleigh fading. Novel outage probability expression for hybrid RF/FSO system is derived. The effect of atmospheric turbulence strength and SSC implementation on the hybrid RF/FSO system performance is observed.

ABSTRACT. The multi-hop amplify-and-forward (AF) relay systems with larger number of mobile users is considered. In order to improve a signal transmission quality in environment with many obstacles, the multi-hop cooperative relays with maximum-ratio-combining (MRC) scheme are implemented. Opportunistic scheme for signal transmission to end users is applied. Outage probability expression for considered system is derived and numerical results are presented and analyzed.

ABSTRACT. In this paper, ergodic and outage capacity evaluation of wireless communication channel corrupted simultaneously by fading and shadowing phenomena, is given. Namely, capacity analysis over gamma shadowed Weibull fading channel is presented. In addition to ergodic capacity examination, the outage capacity appropriate as a metric of channel with slow signal intensity fluctuations is observed. The case of possible random blockage on the transmission path, taking into consideration both capacity metrics, is also analysed. On the basis of derived analytical expressions, numerical results are shown and influence of various performance parameters on ergodic and outage capacity is checked.

ABSTRACT. Critical infrastructures are attractive targets for attack by unauthorized persons with hostile intentions. Wireless sensor networks with modern communications and sensor technology can give the ability to detect unwanted effects. Proper design and structure of this network can provide a high level of protection of critical infrastructure, with a focus on early detection within the monitored zone. This paper will be presented elements of a wireless sensor network and how it can be optimally used in the control, monitoring and protection.

ABSTRACT. The increasing importance of wireless communications, involving electronic devices, has been widely recognized. Performance is a fundamental issue, leading to more reliable and efficient communications. Security is also critically important. Laboratory measurements were performed about several performance aspects of Wi-Fi IEEE 802.11a 54 Mbps Open links. Our study contributes to performance evaluation of this technology, using available equipments (HP V-M200 access points and Linksys WPC600N adapters). New detailed results are presented and discussed, namely at OSI level 4, from TCP and UDP experiments. TCP throughput is measured versus TCP packet length. Jitter and percentage datagram loss are measured versus UDP datagram size. Results are compared for both point-to-point and four-node point-to-multipoint links. Conclusions are drawn about performance of the links.

ABSTRACT. In this paper the relation between two different specialities as an interdisciplinary approach to solve a problem in engineering and medicine is shown. This study is a good example how to combine fluid dynamics with Power engineering and signal processing as a part of Telecommunications to produce a working model of a biological process. This method of approach leads to improved knowledge and practical use of theory by the lectures, as well an innovative approach to provoke the creative way of solving such tasks in the real working quarter. As a result it is shown that the biological data of a human cochlear and the simulation geometry, the internal sound wave signal, the provoked pressure as graphs, and the basilar membrane deflection. The successful creation of the geometry, simulation of the process with the biological parameters and the results interpreting are strongly related to the interdisciplinary understanding of the task.

ABSTRACT. In this work, the performance of the algorithm GMSAT protection of original video content in relation to the geometric malicious attacks are determined. The goal of geometric attacks on video is to disable the watermark extraction, thus endangering the copyrights. The paper analyses geometrical attacks realized by the addition of noise, filtering and cropping the parts of the video frames. The GMSAT algorithm showed good resistance to discussed geometric attacks so that it can be recommended for the protection of original video content before exposure on the Internet.

ABSTRACT. In this paper is described communication protocols for IoT devices (Embeded Systems ) and difference between them. Described the main features of each of them.

ABSTRACT. VANET is a network, which is used for wireless communication. Vehicular Ad Hoc Networks (VANET) is a subclass of Mobile ad hoc networks (MANET) which provides a distinguished approach for Intelligent Transport System (ITS). The research protocols in VANET are important and necessary for Intelligent Transport Systems (ITS). This paper describes a protocol that warns for dangerous weather. All of us know that when temperature falls down below zero degrees water freeze. If a road is wet after such a temperature fall, it will become icy and slippery. Finally the report concludes with an algorithm and block diagrams.

ABSTRACT. In this paper the software implementation of Online assisted Platform for Computer-aided design in communications (Online-CADCOM) in Cloud environment is described. The platform is presented as multi-tenant Cloud application. Platform and database architecture are discussed as well as platform availability and security. Application lifecycle in Cloud is also described. The role of each aspect is widely discussed and also each potential problem is explained and solutions, applicable for Online-CADCOM and similar cases are proposed

ABSTRACT. The exploding growth of unstructured data and overhead of ETL (Extract, Transform and Load) for storing data in RDBMS is the main reason to use schema on read. Schema on read refers to an innovative data analysis strategy in new data-handling tools like Hadoop. With schema on read, you just load your raw, source data into the data store and think about how to parse and interpret later. In the traffic field it is very important to provide an effective sharing of information of public importance. In this research, we apply schema on read modeling approach in order to provide various traffic authorities and other stakeholders with the ability to carry out their own specific Big Data analytics of the source traffic data, without the need to take the source data. The implementation was realized in a case study in road traffic, using Hadoop Distributed File System (HDFS), Apache Hive data warehouse and HiveQL query language.

ABSTRACT. The paper considers mining and analyzing geo-referenced data generated by Twitter social network in urban area of Barcelona, regarding time classification, language determination and spatial filtering. All of collected data is first being preprocessed, filtered and classified by given criteria, by using “Twitter search engine” (TSE) application, that has been upgraded in order to detect tweet language. This type of analysis can be used for determining popularity of city locations of interest and public spaces in general.

ABSTRACT. Macrodiversity (MACD) reception consisting of macrodiversity selection combining (SC) receiver and two microdiversity (MICD) maximal ratio combining (MRC) receivers is considered in this paper. Signal at multiple antennas at the first MRC receiver propagate in non line-of-sight shadowed multipath fading channel and signals at multiple antennas at the second MRC propagate in line-of-sight shadowed multipath fading channel. Signal envelopes of the first MRC receiver are described by using Nakagami-m distribution and signal envelopes at the second MRC receiver are described with Rician distribution. Long term fading is described by using Gamma distribution. Closed form expression for average level crossing rate (LCR) of MACD SC receiver output signal is calculated and the influence of Rician factor and Nakagami-m severity parameter on LCR is analysed and discussed.

ABSTRACT. Dual-hop system with simultaneous wireless information and power transfer and decode-and-forward (DF) relay is investigated. The outage probability performance in mixed Rician and shadowing fading channels is determined, for the scenario when relay harvests energy and time-switching (TS) scheme is applied. In addition, the closed-form tight asymptotic outage expression is derived. The impact of energy harvesting ratio, line-of-sight (LoS), shadowing components and fading parameters on outage probability is investigated and discussed.

ABSTRACT. The first part of this paper describes the experiment which is used for estimation of speech intelligibility depending on room reverberation and superimposed Babble noise. The estimation of the subjective intelligibility is done using MOS test of test sentence application from SMST base. The results are shown both in tables and graphically. The second part of this paper represents the comparative analysis of intelligibility. It also estimated degradation level of speech intelligibility with influence of Babble noise and relation to reverberation effect.

ABSTRACT. – First part of the paper describes the base Serbian Matrix Sentence Test – SMST, which composed of sentence on the Serbian language, with defined syntactically structure. Sentences from the SMST base were used to test the influence of various types of Industrial noise to the performance SMST for SNR = 15 ÷ 10dB, on the people with normal hearing. In the second part of paper are presents experimental results in tabular and graphical format and their analysis. Based on comparative analysis of the results with Babble and Gaussian noise and comparisons with the International Standard IEC 60268-16: 2011 it was shown the conclusion of the intelligibility of speech.

ABSTRACT. The densitometric analysis was performed by ImageJ in order to measure integrated optical density of the synaptophysin labeled parahippocampal region gray and white matter digital images. Obtained data were analyzed by linear regression analysis and revealed significant decrease of the synaptophysin immunoreactivity in the parahippocampal region of the human brain.

ABSTRACT. This Paper presents the methods for effective detection of the diseases for enhancing the product quality of plants. Recent studies have confirmed that average production crops in India is reducing because of disease occurred in fully developed plants. We have considered Chilli plants for our study. Producing Chilli is a daunting task as the plant is exposed to the attacks from various micro-organisms and bacterial diseases and pests. The symptoms of the attacks are usually distinguished through the leaves, stems or fruit inspection. Leaf features inspection methodology is used for early detection of chilli disease. Leaf image is captured and processed to determine the health status of each plant. Currently the chemicals are applied to the plants periodically without considering the requirement of each plant. This technique will ensure that the chemicals only applied when the plants are detected to be effected with the diseases. The image processing techniques are used to perform samples chilli disease images. The plant chilli disease detection through leaf image and data processing techniques is very useful and inexpensive system especially for assisting farmers in monitoring the big plantation area.

ABSTRACT. The analysis of the medical images is very important for the future diagnosis of the specialists, but is often not an easy task and is time-consuming. In this paper is proposed a semi-automated method for segmentation of abdominal organ and its pathological formation. The segmentation method that is used is based on the “Active Contours Without Edges” by Chan and Vese, that ignores edges completely [1]. The advantages of the algorithm are in the fast speed results and the ability to extract not only the organ, but also untypical formations, if there are some. After the segmentation it is easier to make some measurement of the organ and its pathology.