Nedjeljko Lekic

An Implementation of the L-Estimate Distributions for Analysis of Signals in Heavy-Tailed Noise

An analog-digital system for implementation of the robust time-frequency distributions is proposed. It provides an efficient real-time analysis of nonstationary signals corrupted by heavy-tailed noise. The most important part of this system is the realization of the L-estimate short-time Fourier transform that requires sorting operation. The proposed solution is designed to execute sorting operation within a single clock cycle, regardless of the number of inputs. The performance of the proposed hardware is tested on a real signal example.

A strategy for deploying diverse sensor-based networks as an evolution towards integrated Internet of Things and Future Internet

Buying an off-the-shelf sensor or actuator device has become a common practice with individual developers or universities that are keen on exploring ways of flexibly building networks for increasing possibilities of use. Their objective might not be on a targeted single application or an integrated product, but by conducing trials, suitable development and research, they explore novel networking opportunities and fit them to suitable applications. Internet of Things is a concept that promises a world of interconnected IP entities to be facilitated by new underlying capabilities in the Internet. This new initiative meets the vast population of Wireless Sensor (and actuator) Networks that have been deployed in an ever-increasing ranges of applications. The paper shows an understanding of how topics can be coherently combined behind a target for developing a regional and multi-application system and grouping the research topics that would foster its further development.

The simple RS232 hub to interface microcontroller peripheral devices with the central processor

A simple interface, which can link up to 32 peripheral devices with the central processor, has been presented in this paper. Peripheral devices can be extremely simple even without a quartz-stable clock. The interface was named RS232 hub. Hub enables that the peripheral devices linked to it simultaneously send and receive data. The peripheral devices are linked to hub with a two-wire line, over which gets power supply and communicates.

The simple multiprocessor communication system

A very simple multiprocessor communication protocol has been presented in this paper. This protocol links a large number of peripheral processors with the central processor. Peripheral processors asynchronously transmit data packages at slightly varied speeds. This is of a particular interest when peripherals are utterly simplified and have no quartz-stable clock. The central processor accepts the data by means of multiplexer. The proposed protocol accepts data of varied speeds with the minimum number of samples per bit. For an undistorted signal, the number of samples per bit is very close to the theoretical minimum.

An Analog---Digital Hardware for L-Estimate Space-Varying Image Filtering

An analog–digital hardware solution for implementation of the L-estimate space-varying filtering has been proposed. The considered filter form is based on the robust space/spatial-frequency representation and provides efficient denoising of two-dimensional signals/images corrupted by heavy-tailed noise. Moreover, for images with fast-varying details and textures, the L-estimate filtering outperforms the commonly used filters. However, it requires significant processing time, since the space/spatial-frequency representation is calculated for each pixel, on a window by window basis. Therefore, in order to make it feasible for practical applications, a fast implementation of L-estimate space-varying filtering is proposed using a combined analog–digital approach. It provides efficient real-time processing of images corrupted by strong mixed Gaussian and impulse noise.

A bioinformatic system for collecting and processing environmental data

The paper presents a system for collecting, transferring and processing environmental data, implemented within the Centre of Excellence in Bioinformatics (BIO-ICT). Environmental data, collected by three weather stations, are transferred to a remote server via a specially designed and developed GPRS communication device. At the server side, the received data are stored into a database and further processed. The proposed system is scalable in a sense that it provides very simple inclusion of additional weather stations. The system envisions the use of collected data in a decision-making process supported by a model specially developed for the corresponding climate and weather conditions.

Architecture for single iteration reconstruction algorithm

A hardware architecture for the single iteration algorithm is proposed in this paper. Single iteration algorithm enables reconstruction of the full signal when small number of signal samples is available. The algorithm is based on the threshold calculation, and allows distinguishing between signal components and noise that appears as a consequence of missing samples. The proposed system for hardware realization is divided into three parts, each part with different functionality. The system is suitable for the FPGA realization. Realization of the blocks for which there are no standard components in FPGA, is discussed as well.

Performance analysis of variable packet size crosspoint-queued switch

The performance analysis of the variable packet size crosspoint queued switch is presented in this paper. Packet switch throughput and average latency are evaluated under Interrupted Bernoulli Process incoming traffic pattern. It is shown that among the observed algorithms, the longest queue first algorithm has the highest throughput with short crosspoint buffers, but the highest average latency. Also, we establish that the choice of the scheduling algorithm does not play a significant role in the switch performance if the buffers are long enough. Therefore, the round robin algorithm becomes the best choice for implementation due to its simplicity.

Gepsus: simulation-based decision making system for air pollution accidents

We describe a GIS-based real-time system for emergency response and management of air pollution accidents in an urban area. The system architecture emphasises the integration of meteorological, chemical and GIS data, dispersion modeling, decision-making and geo-spatial visualization. The threat zones, unsafe areas and safe traffic routes are obtained using an improved Gaussian plume model with a decision-making module and then exported to the Google Earth browser via “kml” file format. Several simulation scenarios were conducted and verified for notable industrial sites in Montenegro using recorded meteorological data. The results demonstrate that emergency response authorities can use the proposed methodology and system as a cost effective and accurate support tool in case of industrial or deliberate air pollution incidents.

The identification system for monitoring of teaching activities

The identification system for monitoring of teaching activities has been described in this paper. The system is being used at Faculty of Economics, University of Montenegro. It is RFID based using Mifare contactless cards as identifiers. RF readers are connected to the Ethernet network and all card readings events are stored to central database. The system has no local data buffering. The real time functions and other system functions are clearly separated. Without major changes, the system can be adapted for many other applications.