Carptahian Journal of Electronic and Computer Engineering

4

Authors: C. Lung, S. Oniga, A. Buchman, A. Tisan

This paper presents an innovative implementation of a data acquisition, which is able to communicate with a chest belt in order to obtain the heart rate value and accelerometer data from a EZ Chronos watch. The main goal of the work presented is to implement an embedded system, which can be used in various life assisted or medical applications.

5

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

This paper describes overview and definitions about Multiple Input Multiple Output (MIMO) formats which can be used in hybrid Free Space Optics/Radio Frequency (FSO/RF) links. Free space optical links allow obtain high speed data transmission without optical fibers. This type of communication is dependent on weather properties and line of sight is needed. This fact has negative influence on infrared beams which are being use for transmission. Radio frequency links have different restrictions in compare with FSO links. Both links can complement each other. Availability can increase with using hybrid FSO/RF links as MIMO systems.

6

Authors: K. Lamár, G. Morva

This paper is dealing with the data acquisition instruments, which are necessary nowadays for the optimal operation of low voltage power distribution networks. It introduces the requirements of data acquisition instruments, the proper choice of data acquisition time step and the solutions for real-time placement of the acquired data. It describes the most common hardware architectures and the calculations that are fundamental for the usual software solutions of the data acquisition instruments. At last, it gives some practical advice to the application of data acquisition instruments.

6

Authors: D. Contraş, A. Pintescu

This paper presents the approach of building an ontology for automatic scene generation. Every scene contains various elements (backgrounds, characters, objects) which are spatially interrelated. The article focuses on these spatial and temporal relationships of the elements constituting a scene.

8

Authors: Z. Boudjema, A. Meroufel and Y. Djerriri

This paper deals with a variable speed device to produce electrical energy on a power network, based on a doubly-fed induction generator (DFIG) used in wind energy conversion systems. In the first place, we developed a model of the doubly fed induction machine. In order to control the power flowing between the stator of the DFIG and the power network, a control law is synthesized using two types of controllers : adaptive fuzzy logic and sliding mode. Their respective performances are compared in terms of power reference tracking, response to sudden speed variations, sensitivity to perturbations and robustness against machine parameters variations.

8

Authors: Á. Vas, Á. Fazekas, G. Nagy, L, Tóth

The prediction of weather generally means the solution of differential equations on the base of the measured initial conditions where the data of close and distant neighboring points are used for the calculations. It requires the maintenance of expensive weather stations and supercomputers. However, if weather stations are not only capable of measuring but can also communicate with each other, then these smart sensors can also be applied to run forecasting calculations. This applies the highest possible level of parallelization without the collection of measured data into one place. Furthermore, if more nodes are involved, the result becomes more accurate, but the computing power required from one node does not increase. Our Distributed Sensor Network for meteorological sensing and numerical weather Prediction Calculations (DSN-PC) can be applied in several different areas where sensing and numerical calculations, even the solution of differential equations, are needed.

3

Authors: F. Soha, I. Szabo, L. Harasztosi

This paper presents our results on the application of various inertial sensors for motion analysis. After the introduction of different sensor types (accelerometer, gyroscope, magnetic field sensor), we discuss the possible data collection and transfer techniques using embedded signal processing and wireless data communication methods [1,2]. Special consideration is given to the interpretation of accelerometer readings, which contains both the static and dynamic components, and is affected by the orientation and rotation of the sensor. We will demonstrate the possibility to decompose these components for quasiperiodic motions. Finally we will demonstrate the application of commercially available devices (Wii sensor, Kinect sensor, mobile phone) for motion analysis applications.

4

Authors: B. Almasi

The trouble - free moving of wireless clients b etween access points (i.e. “ roaming”) is a basic requirem ent in wireless sensor networks (e.g. when the sensor is attached to a moving object ) . The network layer roaming issues a problem to solve : t he IP address is changed during the roaming , so basically it would close all the runni ng communication se ssions. The Mobile IP specification offers a solution idea for this problem by keeping the old IP address , and establishing a tunnel between the “old” and the “new” network. In this solut ion the optimality of the communication is lost : T he path between the peer s must travel through the “old” network, so the triangle inequality holds. In this paper we introduce a new idea for wireless network layer roaming, which ensures the usage of the optimal path and also guarantees that the network co nnection will not be lost during the IP address changing.

4

Authors: O. Chiver, L. Neamt, E. Pop

The paper presents the way in which the electrical control and automation system of the 5 mc combined sewer and gully cleaning vehicle equipped by a local company was designed, using the intelligent relay of the easy 700 type of Moeller (Eaton) company. The control of all the equipments is performed locally from the control panel and some of them can also by remote controlled by means of the radio waves. The program required by the intelligent relay was created, tested and implemented with the help of the dedicated software easy-soft 6, developed by the manufacturing company.

4

Authors: C. Costea

Mobile devices are facing several challenges like frequent disconnections and limited resources like processor power, available memory, energy consumption. Mobile cloud computing can improve user experiences by executing applications on resource providers external to the mobile device. In this paper, we discuss recent mobile application models related to cloud computing technologies.

4

Authors: B. Muset, S. Emerich

Distance measurement is necessary in various areas and applications. This project is an alternative to GPS and is able to measure the distance traveled by a person inside a building. An algorithm was implemented for the purpose of distance measuring. The measuring is done by integrating twice the acceleration, but the results are not satisfactory because the errors are accumulating much faster than expected. The second method implemented was an algorithm that measures the distance traveled by counting the number of steps. The step distance determination was made by an algorithm that takes the angle between legs made by the accelerometer and gyroscope. To eliminate errors a complementary filter was used. The advantages in using this method are low cost and portability sensor circuit.

4

Authors: S. Sabou, C. Lung, I. Orha

This paper presents low cost Inertial Navigation Module, using MEMS sensor and an simple onboard microcontroller data processing (Kalman filters, basic interpretation for data). GPS navigation solutions are investigated, but they encounter big issues in indoor environment. The basic problem is the weak signal power received from satellite in indoor location and therefore the increased error for position. Using another technique and sensor add more precision. MEMS based techniques are promising ones. Using an accelerometer and a digital compass allows the determination of additional parameters that can lead to determine the position or improve existing location. The components used are the usual, available at any specialty store and precision obtained using a minimal data processing software is encouraging. Research direction to follow is to process the data obtained for growth and greater accuracy.

4

Authors: A. Vas, A. Fazekas, B. Lehotai, G. Nagy and L. Toth

Weather forecasting needs a lot of computing power. It is generally accomplished by using supercomputers which are expensive to rent and to maintain. In addition, weather services also have to maintain radars, balloons and pay for worldwide weather data measured by stations and satellites. Weather forecasting computations usually consist of solving differential equations based on the measured parameters. To do that, the computer uses the data of close and distant neighbor points. Accordingly, if small-sized weather stations, which are capable of making measurements, calculations and communication, are connected through the Internet, then they can be used to run weather forecasting calculations like a supercomputer does. It doesn’t need any central server to achieve this, because this network operates as a distributed system. We chose Microchip’s PIC18 microcontroller (μC) platform in the implementation of the hardware, and the embedded software uses the TCP/IP Stack v5.41 provided by Microchip.

5

Authors: L.T. Chira, J.M. Girault, C. Rusu

The resolution of ultrasound medical images is yet an important problem despite of the researchers efforts. In this paper we presents a nonlinear blind deconvolution to eliminate the blurring effect based on the measured radio-frequency signal envelope. This algorithm is executed in two steps. Firslty we make an estimation for Point Spread Function (PSF) and, secondly we use the estimated PSF to remove, iteratively their effect. The proposed algorithm is a greedy algorithm, called also matching pursuit or CLEAN. The use of this algorithm is motivated beacause theorically it avoid the so called inverse problem, which usually needs regularization to obtain an optimal solution. The results are presented using 1D simulated signals in term of visual evaluation and nMSE in comparison with the two most kwown regularisation solution methods for least square problem, Thikonov regularization or l2-norm and Total Variation or l1 norm.

5

Authors: T. Skopko

Gigabit per second and higher bandwidths imply greater challenge to perform lossless packet capturing on generic PC architectures. This is because of software based capture solutions, which did not improve as fast as network bandwidth and they still heavily rely on the OS's packet processing mechanism. There are hardware and operating system factors that primarily affect capture performance. This paper summarizes these parameters and shows how to predict packet loss ratio during the capture process.

6

Authors: T. Berczes, J. Sztrik, P. Orosz, P. Moyal, N. Limnios, S. Georgiadis

The main aim of the present paper is to draw the attention of the readers of this special issue to the modeling issues of sensor networks. The novelty of this investigation is the introduction of servers vacation combined with priority customers for finite-source retrial queues and its application to wireless sensor networks. In this paper we analyze a priority finite-source retrial queue with repeated vacations. Two types of priority customers are defined, customers with priority 1 (P1) go directly to an ordinary FIFO queue. However, if customers with priority 2 (P2) find the server in busy or unavailable state go to the orbit. These customers stay in the orbit and retry their request until find the server in idle and available state. We assume that P1 customers have non-preemptive priority over P2 customers. The server starts with a listening period and if no customer arrive during this period it will enter in the vacation mode. When the vacation period is terminated, then the node wakes up. If there is a P1 customer in the queue the server begin to serve it, and when there is no any P1 customer, the node will remain awake for exponentially distributed time period. If that period expires without arrivals the node will enter in the next sleeping period. All random variables involved in model construction are supposed to be independent and exponentially distributed ones. Our main interest is to give the main steady-state performance measures of the system computed by the help of the MOSEL tool. Several Figures illustrate the effect of input parameters on the mean response time.

6

Authors: C. Cernazanu-Glavan, M. Marcu

This paper describes the storage of electrical signals from a software framework that provides an automated diagnosis of household devices, based on power signature analysis. Storing power signatures of household devices into a database helps us in two ways: it meets the criteria for operation of the automatic diagnosis algorithm and ensures the possibility of performing future benchmarks tests to establish the performance of the algorithm. The initial electrical signal is stored into the database both in normal and in normalized format (according to amplitude). The results for each stage of signal processing and signal analysis are stored in different tables, together with the best results obtained and the methods that led to them. The article describes the creation and maintenance of this database and details the methods of data accessing. A series of stored procedures allows the user quick access to desired data whether he wants to access the full signal or only a part of it.

6

Authors: M. Marcu, D. Cuc and D. Tulvan

Nowadays smart mobile devices have enough processing power, memory, storage and always connected wireless communication bandwidth that makes them available for any type of application. Augmented reality (AR) proposes a new type of applications that tries to enhance the real world by superimposing or combining virtual objects or computer generated information with it. In this paper we present a camera based navigation system with augmented reality integration. The proposed system aims to the following: the user points the camera of the smartphone towards a point of interest, like a building or any other place, and the application searches for relevant information about that specific place and superimposes the data over the video feed on the display. When the user moves the camera away, changing its orientation, the data changes as well, in real-time, with the proper information about the place that is now in the camera view.

6

Authors: M. Popa, A. Marcu

Smart Cities is a domain of great interest in the modern society. The aim of a smart urban environment is to increase citizens’ comfort and quality of life with minimum resources and power consumption and without affecting the natural environment. Street lighting is one of the main interests in such a smart environment. This thesis focuses on implementing a lighting control system that makes street lighting to be an autonomous and efficient part of the urban environment. The performance of the proposed system is analyzed using an OMNET++ network simulation. The results lead to the conclusion that the smart control system improves some drawbacks of a classic street lighting system.

6

Authors: M. Tatarko, L. Ovsenik and J. Turan

This paper is focused on estimation availability and reliability of FSO systems. Shortcut FSO means Free Space Optics. It is a system which allows optical transmission between two steady points. We can say that it is a last mile communication system. It is an optical communication system, but the propagation media is air. This solution of last mile does not require expensive optical fiber and establishing of connection is very simple. But there are some drawbacks which have a bad influence of quality of services and availability of the link. Number of phenomena in the atmosphere such as scattering, absorption and turbulence cause a large variation of receiving optical power and laser beam attenuation. The influence of absorption and turbulence can be significantly reduced by an appropriate design of FSO link. But the visibility has the main influence on quality of the optical transmission channel. Thus, in typical continental area where rain, snow or fog occurs is important to know their values. This article gives a description of device for measuring weather conditions and information about estimation of availability and reliability of FSO links in Slovakia.

6

Authors: J. Turan, L. Ovsenik, J. Vasarhelyi

The paper presents development work related to create WWW based remote control laboratory for teaching Applied Photonics. In order to minimize the cost at the end-user domain, simple WWW browser with fundamental plug-in (Java applets, HTML Pages and LabWindows applets) to support the remote control and video transmission functionality of the remote control is proposed. As for telepresence and monitoring of device actions, a simple type zooming web-camera is connected to the hosting multimedia PC via the USB port. The web-camera assists in visual feedback of the system and presents the feeling of telepresence for the end-user (student). USB web-cameras are normally efficient and the presence of another video server is not necessary in this case, thanks to LabWindows.

8

Authors: A. Buchman, C. Lung

The main goal of this paper is to present some experimental results regarding power factor (PF) and current total harmonic distortions (THDi) of some very common loads on low voltage a.c. lines i.e. the power supply of computers, monitors and TV sets. The causes of some unexpected values are investigated and some physically meaningful explanations are delivered. The impact of the output current value on PF is emphasized thus proving that one single PF value cannot fully qualify a SMPS. It is also proven that harmonic analysis based THDi values may be very misleading if inter-harmonic components are neglected. Finally an old concept, of renewed interest, the dependency of THDi on PF is revisited.