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.