Carptahian Journal of Electronic and Computer Engineering

4

Authors: I. Orha, S. Oniga

The aim of this paper is to present the implementation of an activity recognition system based on a data acquisition system with inertial sensors. One of the requirement of data acquisition systems used in human activity recognition is their level of acceptability or their level of obstruction [2, 4]. Starting from this important requirement, we designed a few wearable data acquisition systems using inertial sensors. The idea from which we started, takes into account the need to obtain more complete information about the studied human subject, in complex activities recognition systems. In our experiment we used inertial sensor built into so called “9DOF inertial module”. Our systems contain, on the wearable side, a maximum of three inertial sensors, a microcontroller module, and a communication module which can be one of the three solutions. For data reception, on the fixed part of the system, we have a communication module corresponding to the one on wearable parts and a microcontroller module connected to a PC through a serial port. For activity recognition, data files are transferred to a PC, and data is processed in Matlab using artificial neural networks as classifier. The networks have been configured according to the number of sensors that acquired data and the number of activities that we want to recognize.

4

Authors: Mihaela Osaci, Adela Berdie, Iulia Andrea, Iohana Varadi

The paper presents a monitoring solution for flow measurement through Web Dynpro ABAP interface. The use of integrated software systems in companies currently represents an essential condition for providing higher and more reliable access to information resources. The SAP Netweaver, a multilingual & multitasking system based on the three-tier client-server technology, is one of the mostly used integrated platforms implemented in companies.

4

Authors: Ján Tóth, Ľuboš Ovseník, Ján Turán

This paper deals with advanced Free Space Optics communication technology. Two FSO nodes are needed in order to make a connection. Laser diodes are used as light sources. Simple OOK modulation is involved in this technology. FSO system offers multiple advantages indeed. However, a direct visibility is required in order to set up a communication link. This fact yields perhaps the most significant weakness of this technology. Obviously, there is no a chance to fight the weather phenomena like fog, heavy rain, dust and many other particles which are naturally present in the atmosphere. That’s why there is a key task to find a suitable solution to keep FSO link working with high reliability and availability. It turns out that it’s necessary to have knowledge about weather situation when FSO link operates (liquid water content - LWC, geographical location, particle size distribution, average particle diameter, temperature, humidity, wind conditions, pressure and many other variable weather parameters. It’s obvious that having most of mentioned parameter’s values stored in database (implicitly in charts) would be really beneficial. This paper presents some of mentioned indicators continuously gathered from several sensors located close to one of FSO nodes.

6

Authors: Moloud Abdar

Statistics from the World Health Organization (WHO) shows that heart disease is one of the leading causes of mortality all over the world. Because of the importance of heart disease, in recent years, many studies have been conducted on this disease using data mining. The main objective of this study is to find a better decision tree algorithm and then use the algorithm for extracting rules in predicting heart disease. Cleveland data, including 303 records are used for this study. These data include 13 features and we have categorized them into five classes. In this paper, C5.0 algorithm with a accuracy value of 85.33% has a better performance compared to the rest of the algorithms used in this study. Considering the rules created by this algorithm, the attributes of Trestbps, Restecg, Thalach, Slope, Oldpeak, and CP were extracted as the most influential causes in predicting heart disease.

4

Authors: P. Molnár, A. Kicsák, J. Végh

The todays computing technology provokes serious debates whether the operating system functions are implemented in the best possible way. The suggestions range from accelerating only certain functions through providing complete real-time operating systems as coprocessors to using simultaneously hardware and software implemented threads in the operating system. The performance gain in such systems depends on many factors, so its quantification is not a simple task at all. In addition to the subtleties of operating systems, the hardware accelerators in modern processors may considerably affect the results of such measurements. The reconfigurable systems offer a platform, where even end users can carry out reliable and accurate measurements. The paper presents a hardware acceleration idea for speeding up a simple OS service, its verification setup and the measurement results.

4

Authors: N. Crișan, L. C. Cremene

A rewriting of the MIMO channel capacity formula is proposed, in order to capture the direct influence of the array matrix (array configuration plus AoA information). The proposed theoretical framework will eventually allow direct comparison between antenna geometries in terms of channel capacity. Simulations indicate that, for small size arrays (up to 8x8), the configuration has a significant influence on the channel capacity, which is no longer the case for larger arrays.

5

Authors: Z. Boudjema, R. Taleb, A. Yahdou, H. Kahal

Traditional vector control structures which include proportional-integral (PI) regulator for the speed of a doubly fed induction motor (DFIM) driven have some disadvantages such as parameter tuning complications, mediocre dynamic performances and reduced robustness. Thus, based on the analysis of the mathematical model of a DFIM supplied by two indirect inverters, this paper addresses a nonlinear control algorithm based on high order sliding mode. The conventional sliding mode control has large chattering on the electromagnetic torque developed by the DFIM. In order to solve this problem, the second order sliding mode technique is used. The simulation results show the effectiveness of the proposed method especially in chattering-free behavior, response to sudden load torque variations and robustness against machine parameters variations.

6

Authors: T. Ivaniga, L. Ovseník, J. Turán

This article is focused SPM (Self-Phase Modulation), whic affects the signal transmision in fully optical communication systems. With the advent of WDM (Wavelength Division Multiplexing) the optical power in optical fiber. For WDM are used weak lasers with 16 or 32 channels. A power of these channels are summed and then we work with the power in fiber about 0.5W which is dangerous for eyes. Therefore for design of the optical network over 10Gbit/s per 1 channel WDM, it is obligation to solve this nonlinear phenomenon. In program package OptSim was created topology 8 and 16- channel DWDM (Dense Wavelenght Division Multiplexing) system according to standard ITU-T (International Telecommunication Union-Telecommunication) G.694.1 with channel spacing of 25GHz, transmission power of 1 and 15 dBm, with transmision speed of 10Gbit/s and two coding types to see the SPM.

4

Authors: T. Krausz, J. Sztrik

We can use variety of encryption standards to encrypt data traffic to ensure the safety of wireless networks. The question is to what extent the security of the network affects network performance. For answering this question, experiments were performed without data encryption, and the use of various encryption standards.

4

Authors: M. Tatarko, L. Ovseník, J. Turán

The paper describe a new method for switching in hybrid Free Space Optics/ Radio Frequency (FSO/RF) link based on use of simple Fog Sensor. Fog Sensor operation principle is described with experimental method of how to do switching between FSO and RF link in hybrid transmission system. Results of experimental verification of the proposed switching method are discussed.

5

Authors: J. Tóth, M. Tatarko, L. Ovseník, J. Turán, J. Ružbarský

Free Space Optics technology is a new progressive communication form. The basic FSO link is made of two FSO heads which communicate through a laser beam on a specific wavelength. FSO link requires a direct visibility between its nodes. It is a very efficient form for data transmission for short distance communication links. This paper describes basic FSO features with consideration on negative weather factors which have the negative influence on signal transmission. The unique fog sensor will be presented in this paper. This device gathers some specific data about weather conditions. Measured data is processed mathematically and results can be used in further FSO link evaluation as well as in process of switching FSO link with some form of back up radio link.

4

Authors: A. Abdullaev, Ján Turán

Optical networks evolve fast. Nowadays many technologies of optical networks are using. But there are some restrictions which make limited of the possibilities of the optical networks. Contention Resolution is one of them. There are several technologies of reducing of Contention Resolution. They will be analyzed in this paper. The advantages and disadvantages of these technologies will be described and discussed at the end of the paper.

5

Authors: I. Orha, S. Oniga

In this paper we have proposed to present a wearable system for automatic recording of the main physiological parameters of the human body: body temperature, galvanic skin response, respiration rate, blood pressure, pulse, blood oxygen content, blood glucose content, electrocardiogram (ECG), electromyography(EMG), and patient position. To realize this system, we have developed a program that can read and automatically save in a file, the data from specialized sensors. The results can be later interpreted, by comparing them with known normal values and thus offering the possibility for a primary health status diagnosis by specialized personnel. The data received from the wearable sensors is taken by an interface circuit, provided with signal conditioning (filtering, amplification, etc). A microcontroller controls the data acquisition. In this applications we used an Arduino Uno standard development platform. The data are transferred to a PC, using serial communication port of Arduino platform and a communications shield. The whole process of health assessment is commissioned by a program developed by us in the Python programming language. The program provides automatic recording of the aforementioned parameters in a predetermined sequence, or only certain parameters are registered.

6

Authors: S. Oudjemia, Z. Ameur, A. Ouahabi

In this paper we present a method for segmentation of documents image with complex structure. This technique based on GLCM (Grey Level Co-occurrence Matrix) used to segment this type of document in three regions namely, 'graphics', 'background' and 'text'. Very briefly, this method is to divide the document image, in block size chosen after a series of tests and then applying the co-occurrence matrix to each block in order to extract five textural parameters which are energy, entropy, the sum entropy, difference entropy and standard deviation. These parameters are then used to classify the image into three regions using the k-means algorithm; the last step of segmentation is obtained by grouping connected pixels. Two performance measurements are performed for both graphics and text zones; we have obtained a classification rate of 98.3% and a Misclassification rate of 1.79%.

4

Authors: J. Sütő, S. Oniga

This paper presents the implementation of a simulator application for feed forward neural networks which was made in Qt application framework. The paper demonstrates the object oriented design and the performance of the software. The main topics cover the class organization and some test results where the Matlab neural network toolbox was used as reference.

4

Authors: J. Tóth, Ľ. Ovseník, J. Turán

FSO technology is a progressive implementation of smart network solutions these days. The link speed, low cost, a fast implementation are just a few advantages of many other. Despite all those strengths there is at least one limitation. It is called weather. The wavelengths values on which FSO operates are quite similar to fog, smoke, snow and dust particles. It is obvious that if those proportions are comparable, it’s not surprising that there will be some interactions among beams and particles. That’s why we decided to investigate the weather influence to a link availability of FSO at our location in Kosice, Slovakia. To accomplish this we used fog sensor and wrote a simulating program for data processing. The industries as well as universities are already trying to solve the problems when FSO link is not working out because of low visibility. There is already the hybrid equipment on the market which serves as an additional component (an enhancement) by using RF (Radio Frequency) waves.

5

Authors: T. Harasthy, Ľ. Ovseník, J. Turán

Paper describes design of color filter for preprocessing of input plane for Traffic Sign Recognition System. Driver Assistance Systems (DAS) are nowadays very popular topic of info-electronic. One of the most often cited topic of DAS is Traffic Sign Recognition System. This system is usually based on edge detection, neural networks or invariant transform e.g. Trace Transform. In this article is color filter designed for traffic sign recognition system based on optical correlator. Optical correlator compares two images or two-dimensional data sets in very high speed. Usage of optical correlator request specific preprocessing of input scene, which is described in this paper. Color filtering is one of basic steps of preprocessing of input data (video) for Traffic Sign Recognition with usage Optical Correlator.

6

Authors: A. Buchman, C. Lung

Every WiFi, ZigBee or Bluetooth compatible radio chip provides a byte of information related to the received signal strength (RSS), the so called received signal strength index (RSSI). In a given point in space, on a specific radio channel, the RSS has a unique value at a given moment in time. Still, radio chips produced by different manufacturers will report different RSSI numbers. So RSSI is only related to, but not identical to RSS. In this paper, a formula that relates RSS and RSSI is derived. The validity of this theoretical assumption is tested on various vendors’ data. For Microchip’s MRF24WB radio chip the testing is done experimentally.

6

Authors: K. Lamár, A. G. Kocsis

The paper introduces the fundamentals of motor control. It explains the basic equations and introduces the control diagram of the brushed DC motor. It introduces the four quadrant DC chopper circuit and the basic methods to operate it. After that, it explains the fundamentals of the current control of DC motors and its two basic methods: the pulse width modulation and the hysteresis current control. Finally it gives a short example of the practical implementation of the hysteresis current controller for the four quadrant DC chopper in LabVIEW FPGA.