Telfor Journal Vol.7 No.2 (2015)
Content
Editorial
Editor-in-Chief:
Prof. Dr Đorđe Paunović
Collaborative Beamforming Techniques for Data Transmission in Wireless Sensor Networks
L. Berbakov and M. Beko
- Topic:
- Radio Communications
- Abstract
- Collaborative beamforming is a technique for improving energy efficiency of uplink communications in wireless sensor networks. It is done by synchronizing carrier phases of individual sensor nodes precisely enough, so that they jointly form a beampattern with a stable mainlobe. In this paper, we analyze the impact of additive noise in the received signal on the behavior of an iterative phase synchronization scheme. Besides, we analyze the bit error rate performance of such collaborative transmission. In particular, we consider a decentralized antenna array where sensors are allowed to perform distributed carrier synchronization and collaborative data transmission simultaneously. We evaluate the system performance by using numerical simulations and provide a semi-analytical solution for the algorithm convergence characteristics and the overall bit error rate as a function of the algorithm’s iteration index.
- Keywords
- Collaborative Beamforming, Wireless Sensor Networks.
- Full Text
- Collaborative Beamforming Techniques for Data Transmission in Wireless Sensor Networks
- Page(s)
- 62-67
- Doi
- 10.5937/telfor1502062B
Cost-effectiveness Assessment of 5G Systems with Cooperative Radio Resource Sharing
V. Nikolikj and T. Janevski
- Topic:
- Radio Communications
- Abstract
- By use of techno-economic analysis of heterogeneous hierarchical cell structures and spectral efficiencies of the forthcoming advanced radio access technologies, this paper proposes various cost-efficient capacity enlargement strategies evaluated through the level of the production cost per transferred data unit and achievable profit margins. For the purpose of maximizing the aggregate performance (capacity or profit), we also assess the cooperative manners of radio resource sharing between mobile network operators, especially in the cases of capacity over-provisioning, when we also determine the principles to provide guaranteed data rates to a particular number of users. The results show that, for heavily loaded office environments, the future 5G pico base stations could be a preferable deployment solution. Also, we confirm that the radio resource management method with dynamic resource allocation can significantly improve the capacity of two comparably loaded operators which share the resources and aim to increase their cost effectiveness.
- Keywords
- 5G millimeter wave, Cost-effectiveness, EBIT margin, Guaranteed QoS, IEEE 802.11ad, LTE-Advanced, Radio Resource Management, Radio Resource Sharing.
- Full Text
- Cost-effectiveness Assessment of 5G Systems with Cooperative Radio Resource Sharing
- Page(s)
- 68-73
- Doi
- 10.5937/telfor1502068N
Performance of Fractionally Spaced MLSE in OOK and PAM4 Bandwidth Limited Optical Systems
C. Prodaniuc, N. Stojanovic, and Z. Qiang
- Topic:
- Optical Communications
- Abstract
- We analyze the performance of fractionally spaced maximum likelihood sequence estimation (MLSE) equalizers in OOK and PAM4 optical systems using optical and electrical components with cut-off frequencies less than the baud rate. It has been demonstrated that signals suffering from optical and electrical impairments can be efficiently equalized in cheap direct-detection optical receivers using MLSE equalizers with one or two samples, depending on the extent of bandwidth limitations.
- Keywords
- Maximum likelihood sequence estimation, chromatic dispersion, bandlimited systems, direct detection, digital receiver.
- Full Text
- Performance of Fractionally Spaced MLSE in OOK and PAM4 Bandwidth Limited Optical Systems
- Page(s)
- 74-79
- Doi
- 10.5937/telfor1502074P
Analysis of RF MEMS Capacitive Switches by Using Switch EM ANN Models
Z. Marinković, A. Aleksić, O. Pronić-Rančić, and L. Vietzorreck
- Topic:
- Applied Electronics
- Abstract
- Artificial neural networks (ANNs) have appeared to be an alternative to the conventional models of RF MEMS switches. In this paper, neural models of an RF MEMS capacitive switch are developed and used for the electrical design of the switch. Namely, an ANN model relating the switch resonant frequency and the bridge dimensions is used to analyze efficiently the switch behavior with changes of bridge dimensions. Furthermore, it is illustrated how the developed model can be used for the determination of bridge dimensions in order to achieve the desired switch resonant frequency. In addition, application of a switch inverse ANN model for the determination of bridge dimensions is analyzed as well.
- Keywords
- Artificial neural networks, resonant frequency, RF MEMS switch, design.
- Full Text
- Analysis of RF MEMS Capacitive Switches by Using Switch EM ANN Models
- Page(s)
- 80-85
- Doi
- 10.5937/telfor1502080M
DVB-T2: An Outline of HDTV and UHDTV Programmes Broadcasting
M. Milivojević, B. Mišković, and I. Reljin
- Topic:
- Multimedia
- Abstract
- Increasing of video resolution of the HD programmes requires a higher bit rate. On the other hand, a continuous enhancement of existing and introduction of new source coding techniques are evident. Technical evolution of the Digital Terrestrial Television platform improves channel coding and RF channel utilization. Some optional solutions have also been proposed. This paper discusses the possibilities of allocating HD programmes in formats expected in the near future. Performed calculations are guidance to accurate examination of the efficiency of allocating high definition programmes in the DVB-T2 multiplex, in line with existing and expected enhancements.
- Keywords
- High definition television; ultra high definition television; high efficiency video coding; terrestrial digital video broadcasting; utilization; broadband statistical multiplexing; time frequency slicing; channel efficiency; statistical gain; network planning gain.
- Full Text
- DVB-T2: An Outline of HDTV and UHDTV Programmes Broadcasting
- Page(s)
- 86-90
- Doi
- 10.5937/telfor1502086M
Aggregated Color Descriptors for Land Use Classification
V. Jovanović and V. Risojević
- Topic:
- Multimedia
- Abstract
- In this paper we propose and evaluate aggregated color descriptors for land use classification in aerial images. First, global and local Bag-of-Colors (BoC) descriptors are evaluated for land use classification. Influence of different parameters on the performance and efficiency of classification were tested. A small modification in the process of computing of BoC is introduced, which improves the overall classification performance. We also present a new, very simple color descriptor, termed Vector of Locally Aggregated Colors (VLAC) which has as good classification results as the modified BoC, but using linear support vector machines.
- Keywords
- BoC descriptor, VLAC descriptor, color descriptors, Land Use Classification.
- Full Text
- Aggregated Color Descriptors for Land Use Classification
- Page(s)
- 91-96
- Doi
- 10.5937/telfor1502091J
Interactive Multimedia System Using Serious Game for Users with Motor Disabilities
A. Jaume-i-Capó and A. Samčović
- Topic:
- Multimedia
- Abstract
- User demotivation is habitual in a long-term rehabilitation process, because this process usually consists in repetitive and intensive activities which become boring after hundreds of sessions. Research studies have shown that serious games help to motivate users in a rehabilitation process. Motor rehabilitation consists of body movements that can be captured and patients can have difficulties in holding physical devices. For this reason, therapy studies include vision input devices and propose what features are desirable for rehabilitation serious games. In this paper, we present a case of success, an interactive multimedia system using a serious game to improve abilities of patients with cerebral palsy.
- Keywords
- health care, kinect, motor rehabilitation, multimedia, serious game, vision-based interaction.
- Full Text
- Interactive Multimedia System Using Serious Game for Users with Motor Disabilities
- Page(s)
- 97-102
- Doi
- 10.5937/telfor1502097J
A Matlab Tool for Tumor Localization in Parathyroid Sestamibi Scintigraphy
M. Đurović, M. M. Jankovic, and A. Koljević Marković
- Topic:
- Multimedia
- Abstract
- Submarine method for localization of parathyroid tumors (PT) has proved to be effective in case of typical pitfalls of conventional scintigraphic methods (combined subtraction and double phase methods). It uses images obtained by standard dynamic parathyroid sestamibi scintigraphy suggested by European Association of Nuclear Medicine. This paper presents: 1) the developed Matlab interface that enables the implementation and evaluation of algorithms for the automatic application of Submarine method; 2) the algorithm for automatic extraction of the entire thyroid region from the background radioactivity using operations from mathematical morphology applied on dynamic scintigrams; 3) the results obtained by algorithm for localization and visualization of PTs based on estimation of exponential decreasing trend of time-activity curves. The algorithm was tested on a group of 20 patients with histopathologically proven PTs using developed Matlab interface.
- Keywords
- image segmentation, Matlab, parathyroid scintigraphy, Submarine method.
- Full Text
- A Matlab Tool for Tumor Localization in Parathyroid Sestamibi Scintigraphy
- Page(s)
- 103-107
- Doi
- 10.5937/telfor1502103D
Potential of knowledge discovery in automated test assembly
M. Ignjatović, D. Bojić, B. Furlan, and I. Tartalja
- Topic:
- Software Tools and Applications
- Abstract
- In the academic environment, acquired student's knowledge is usually assessed through paper-pencil or computer based tests. Testing is usually done several times during the academic year. Assembling a test that estimates students' knowledge requires significant examiner’s effort and time invested. While assembling a test, examiner has to be objective, to provide consistent and reliable tests during the whole year. Automating the procedure can facilitate the process to the examiner and improve objectivity, consistency and reliability of student's knowledge assessment. This paper presents the results of development of a test assembly method based on the discovery of test assembly knowledge implicitly embedded in a bank of representative already administered tests. The method uses the nearest neighbour algorithm and it does not depend on a method of creation of existing tests in the test-bank. Results of the conducted experiments are promising and encourage further research in the same direction.
- Keywords
- automated test assembly, knowledge discovery, knowledge test, nearest neighbour.
- Full Text
- Potential of knowledge discovery in automated test assembly
- Page(s)
- 108-112
- Doi
- 10.5937/telfor1502108I
The TELFOR Journal appreciates the support received from the reviewers. The following is the alphabetic list of the reviewers who have submitted one or more reviews for the current volume of the TELFOR Journal.
Slobodanka Beatović, Nenad Cakić, Jasna Crnjanski, Milan Čabarkapa, Zoran Čiča, Jelena Ćertić, Goran Dimić,
Bojan Dimitrijević, Radivoje Djurić, Dejan Drajić, Dušan Drajić, Miljko Erić, Octavian Fratu, Ana Gavrovska,
Nataša Gospić, Dejan Gvozdić, Predrag Ivaniš, Toni Janevski, Milica Janković, Enis Kočan, Miroslav Lutovac,
Marija Malnar, Goran Marković, Ivan Milentijević, Ljiljana Milić, Aleksandar Nešković, Boško Nikolić, Milorad Paskaš, Milica Pejanović-Djurišić, Lucian Andrei Perisoara, Ana Petrović, Grozdan Petrović, Mirjana Popović, Siniša Ranđić, Siniša Ranđić, Branimir Reljin, Irini Reljin, Nataša Reljin, Lazar Saranovac, Igor Simić, Dušan Starčević,
Mirjana Stojanović, Aleksandar Sugaris, Milo Tomašević, Zoran Veljović, Goran Zajić, Miloš Živanov.