bluuebunny/crossref_metadata_2025 huggingface dataset:
Design, synthesis, and characterization of novel nanowire structures for photovoltaics and intracellular probes
Authors: Tian Bozhi , Lieber Charles M.
Published: October 2011

Semiconductor nanowires (NWs) represent a unique system for exploring phenomena at the nanoscale and are expected to play a critical role in future electronic, optoelectronic, and miniaturized biomedical devices. Modulation of the composition and geometry of nanostructures during growth could encode information or function, and realize novel applications beyond the conventional lithographical limits. This review focuses on the fundamental science aspects of the bottom-up paradigm, which are synthesis and physical property characterization of semiconductor NWs and NW heterostructures, as well as proof-of-concept device concept demonstrations, including solar energy conversion and intracellular probes. A new NW materials synthesis is discussed and, in particular, a new “nano-tectonic” approach is introduced that provides iterative control over the NW nucleation and growth for constructing 2D kinked NW superstructures. The use of radial and axial p-type/intrinsic/n-type (p-i-n) silicon NW (Si-NW) building blocks for solar cells and nanoscale power source applications is then discussed. The critical benefits of such structures and recent results are described and critically analyzed, together with some of the diverse challenges and opportunities in the near future. Finally, results are presented on several new directions, which have recently been exploited in interfacing biological systems with NW devices.
Association between Socioeconomic Position in Earlier and Later Life and Age at Natural Menopause: Estudo Pró-SaúDe, Brazil
Authors: Otero Ubirani Barros , Chor Dóra , Carvalho Marília Sá , Faerstein Eduardo , de Souza Lopes Cláudia , Werneck Guilherme Loureiro
Published: October 2011

This study was based on a prospective cohort of university staff in Rio de Janeiro, Brazil (the Estudo Pró-Saúde). In this article the association between socioeconomic position (SEP) earlier and later in life and age at menopause is investigated. The main indicators investigated were for earlier SEP: mother's and father's schooling; stature; leg and trunk length. For later SEP they were: schooling; home and/or car ownership. Median age at menopause was estimated and survival curves were generated by the Kaplan–Meier method, while the association between indicators of SEP and age at menopause was explored by means of Cox semiparametric models. Associations were found between earlier SEP – represented by trunk length – and earlier menopause and between later SEP – represented by the indicator ‘present schooling’ – and earlier menopause. The association between earlier and later SEP was confirmed. Adverse situations over the life course can impact age at menopause and related health outcomes.
Preservation of Ovarian Function and Minimizing Premature Ovarian Failure during Chemotherapy Using Gonadotropin-Releasing Hormone Analogs
Authors: Blumenfeld Zeev
Published: October 2011

Evaluation of: Del Mastro L, Boni L, Michelotti A et al. Effect of the gonadotropin-releasing hormone analogue triptorelin on the occurrence of chemotherapy-induced early menopause in premenopausal women with breast cancer: a randomized trial. JAMA 306(3), 269–276 (2011). This study is a randomized, open-label, Phase III trial, conducted in 16 Italian centers that enrolled 281 patients between 2003 and 2008. The recruited patients were prospectively and randomly allocated to either chemotherapy alone or combined with monthly triptorelin gonadotropin-releasing hormone analog, started before chemotherapy and repeated every month throughout chemotherapy. The clinical and tumor characteristics of the patients in the control or treatment groups were similar. A total of 12 months after ending chemotherapy, the premature ovarian failure rate was 25.9% in the chemotherapy-alone group versus 8.9% in the chemotherapy and gonadotropin-releasing hormone analog group, an absolute difference of −17% (95% CI: −26 to −7.9%; p < 0.001). The odds ratio for treatment-induced premature ovarian failure was 0.28 (95% CI: 0.14–0.59; p < 0,001). The authors concluded that use of gonadotropin-releasing hormone analog chemotherapy in premenopausal breast cancer patients can significantly reduce the occurrence of chemotherapy-induced early menopause.
Use of Bone Turnover Markers in Clinical Osteoporosis Assessment in Women: Current Issues and Future Options
Authors: Henriksen K , Leeming DJ , Christiansen C , Karsdal MA
Published: October 2011

Monitoring bone turnover of the adult and aging skeleton is essential for optimal treatment of bone metabolic diseases, such as postmenopausal osteoporosis. Diagnosis of osteoporosis is based solely on dual-emission x-ray absorptiometry-based measurements of bone mineral density. However, within the last 20 years, biochemical markers of bone turnover have been implemented to a larger degree, and especially within the field of drug development. Numerous clinical studies have underscored that the markers have promise in terms of predicting patients at high risk of losing bone, future fracture events and importantly also the fracture efficacy of drugs in development. Furthermore, while classical methods often require years to monitor the changes, the bone turnover markers do so within a shorter time span. The aims of this article are to provide an update on the different biochemical markers of bone turnover, and to give an overview of their applications in epidemiological and clinical research especially in women. The main emphasis will be on their utility in clinical trials testing the efficacy of drugs for the treatment of osteoporosis, and their ability to supplement bone mass measurements. Finally, recent evidence suggests that biochemical markers may provide information on bone age that may indirectly relate to bone quality, and this is discussed together with future possibilities for measuring bone quality using bone turnover markers. In summary, a more targeted use of biomarkers could assist in the identification of high-risk patients, the process of drug discovery and monitoring of the efficacy of osteoporosis treatment in clinical settings.
Environmental risk assessment of low density polyethylene unit using the method of failure mode and effect analysis
Authors: Salati Parinaz , Jozi Seyed
Published: October 2011

The ninth olefin plan of Arya Sasol Petrochemical Company (A.S.P.C.) is
regarded the largest gas Olefin Unit located on Pars Special Economic Energy
Zone (P.S.E.E.Z). Considering the importance of the petrochemical unit, its
environmental assessment seems necessary to identify and reduce potential
hazards. For this purpose, after determining the scope of the study area,
identification and measurement of the environmental parameters, environmental
risk assessment of the unit was carried out using Environment Failure Mode
and Effect Analysis (EFMEA). Using the noted method, sources causing
environmental risks were identified, rated and prioritized. Beside, the
impacts of the environmental aspects derived from the unit activities as well
as their consequences were also analyzed. Furthermore, the identified impacts
were prioritized based on Risk Priority Number (RPN) and severity level of
the consequences imposed on the affected environment. After performing
statistical calculations, it was found that the environmental aspects owing
the risk priority number higher than 15 have a high level of risk. Results
obtained from Low Density Polyethylene Unit revealed that the highest risk
belongs to the emergency vent system with risk priority number equal to 48.
It is occurred due to imperfect performance of the reactor safety system
leading to the emissions of ethylene gas, particles, and radioactive steam as
well as air and noise pollutions. Results derived from secondary assessment
of the environmental aspects, through difference in calculated RPN and
activities risk levels showed that employing modern methods and risk
assessment are have remarkably reduced the severity of risk and consequently
detracted the damages and losses incurred on the environment.
The electromagnetic field around a high voltage 400 KV electrical overhead lines and the influence on the biological systems
Authors: Marincu Adrian , Greconici Marian , Musuroi Sorin
Published: October 2011

In this paper the analytical calculus and the experimental measurements of the electric and magnetic field around a high voltage 400KV electrical overhead lines has been analyzed. There have been analyzed the possible influences of the electromagnetic field on the health of the human beings. The calculus has been done using the Mat Lab medium, the experimental measurements of the electric strength have been done using a spherical dipole.
Teaching tools for parallel processing
Authors: Milovanovic Emina , Stojanovic Natalija
Published: October 2011

Because many universities lack the funds to purchase expensive parallel computers, cost effective alternatives are needed to teach students about parallel processing. Free software is available to support the three major paradigms of parallel computing. Parallaxis is a sophisticated SIMD simulator which runs on a variety of platforms.jBACI shared memory simulator supports the MIMD model of computing with a common shared memory. PVM and MPI allow students to treat a network of workstations as a message passing MIMD multicomputer with distributed memory. Each of this software tools can be used in a variety of courses to give students experience with parallel algorithms.
Simulators for courses in advance computer architecture
Authors: Misev Anastas , Gusev Marjan
Published: October 2011

The usage of simulator in teaching computer architecture courses has proven to be the most acceptable way, especially when the simulators offer rich graphical and visual representation of the architecture. In this paper we present several simulators used to teach ILP (Instruction Level of Parallelism) courses. The simulators cover wide area of concepts such as internal logic organization, datapath, control, memory behavior, register renaming, branch prediction, and overall out of order execution. Special dedicated simulators cover details in internal organization like Tomasulo approach and scoreboard for organization of reservation stations. This innovative approach in laboratory exercises is used for advanced ILP course.
Improved learning methodology system
Authors: Gusev Marjan
Published: October 2011

Education is one of the systems that have been always upgrading. During past years the teaching process has been always modified and upgraded in order to enable more efficient learning. The use of new ICT technologies enables innovative ideas to make the learning process more efficient. The students gain with better skills and obtained knowledge by these innovations. We established an e-learning system that supports the education process. This system offers not just content available on-line by using web technologies, but also a wide variety of simulators, animations and films as multimedia approach to the system. In addition to this system we use a system of interactive quizzes and questionnaires as part of the self testing tool that help students understand basic concepts and acquire skills. The system of e-testing helps the professor to assess the knowledge and grade the students. The on-line learning tool is the interactive system that supports the homework assignment and grading tool and helps both the students to learn and the professors to check the knowledge obtained. In this paper we report the results from using these innovations as improved learning methodology, and how it affects the level and degree of obtained knowledge and skills, students? interest and average score in total knowledge. We present indicators to measure the results gained by introducing new methodology. These indicators concern quantity and quality measures, obtained by analyzing the pass rate and average scores in the class.
Control solutions in mechatronics systems
Authors: Precup Radu-Emil , Preitl Stefan
Published: October 2011

This paper presents control solutions dedicated to a class of controlled plants widely used in mechatronics systems, characterized by simplified mathematical models of second-order and third-order plus integral type. The conventional control solution is focused on the Extended Symmetrical Optimum method proposed by the authors in 1996. There are proposed six fuzzy control solutions employing PI-fuzzy controllers. These solutions are based on the approximate equivalence in certain conditions between fuzzy control systems and linear ones, on the application of the modal equivalence principle, and on the transfer of results from the continuous-time conventional solution to the fuzzy solutions via a discrete-time expression of the controller where Prof. Milic R. Stojic's book [1] is used. There is performed the sensitivity analysis of the fuzzy control systems with respect to the parametric variations of the controlled plant, which enables the development of the fuzzy controllers. In addition, the paper presents aspects concerning Iterative Feedback Tuning and Iterative Learning Control in the framework of fuzzy control systems. The theoretical results are validated by considering a real-world application.
Peak power optimization based on nonlinear prediction and fuzzy logic
Authors: Dankovic Bratislav , Jovanovic Zoran , Antic Dragan
Published: October 2011

A new peak power optimization algorithm of the electric energy consumption with nonlinear prediction is presented in this paper. The system parameters for optimization are adjusted using fuzzy logic.
Comparative study of zero effects in pole-placement control system design via the shift and delta transforms
Authors: Naumovic Milica
Published: October 2011

This paper deals with the special replacement of the shift operator and its associated z transform by delta operator and ? transform, respectively. The aim of the paper is to clarify the role of zeros of discretized linear single input single output continuous-time systems modeled by shift and delta operators. In particular, the effect of zero dynamics on the control system design based on classical pole-zero assignment in the case of both operators is considered. The analysis is illustrated by simulation results.
A predictive-adaptive hierarchical control system of bucket-wheel excavator: Theory and experimental results
Authors: Jevtovic Branislav , Matausek Miroslav
Published: October 2011

Development of a new two-level hierarchical control system, which significantly increases excavating capacity, as well as availability, and reliability of the bucket wheel excavator, is presented in this paper. On the first ? basic level functions of local regulators and sensors are executed and the second ? higher level is performing adaptation based on prediction of cutting resistance of materials to be excavated. Development of basic control system consists of design and tuning of local regulators, as well as design of highly precise and reliable sensors of basic movements. The predictive?adaptive higher-level control system is a neuro-fuzzy controller. By predicting cutting resistance of materials to be excavated reference of slewing speed and controller parameters are adapted. The structure of the new control system is based on expert knowledge, gained through numerous simulations of developed non-linear model in state space, where the disturbances are precisely modeled, and numerous experiments.
Practical realizations of optimized adaptive digital signal processing solutions implemented in preset time count rate meters
Authors: Zigic Aleksandar , Arandjelovic Vojislav , Saponjic Ðordje , Veselinovic Ivana
Published: October 2011

Two optimized adaptive digital signal processors were implemented to the preset time count rate meters. Three mean count rate meters, based on the developed adaptive digital signal processors, were realized and were used for experimental validation of proposed adaptive digital signal processors. The experimental results, conducted without and with radioisotope for the specified errors of 10% and 5%, showed to agree well with theoretical predictions.
Application of the α-approximation for discretization of analogue systems
Authors: Sekara Tomislav , Stojic Milic
Published: October 2011

The method for discretization of analogue systems using the ?-approximation is presented. A generalization of some of the existing transformation methods is also done. A comparative analysis, through the corresponding examples involving several known discretization methods, is carried out. It is demonstrated that the application of this ?-approximation allows the reduction of discretization error compared to other approximation methods. The frequency characteristics of the discrete system obtained by these transformations are approximately equal to these of the original analogue system in the basic frequency range.
Bit error probability of PSK systems in the presence of impulse noise
Authors: Petrovic Mile , Martinovic Dragoljub , Krstic Dragana
Published: October 2011

In this paper the phase error probability density function in the digital systems for the digital phase modulated signals transmission is derived. The circuit for the referent carrier extraction consists of phase locked loop. The referent carrier extraction is not ideal. The pulse interferences narrow-band Gaussian noise and different interferences are present with useful signal at the input of the receiver. The error probability of the digital system for the phase modulated signal demodulation is also calculated in the paper.
Wind energy potential in the world and in Serbia and Montenegro
Authors: Mikicic Dusan , Radicevic Branko , Djurisic Zeljko
Published: October 2011

Today, wind energy participates by not more than 0,5 % in the gross world production of electric energy. However, according to the presently existing world trends and due to the fact that the world?s wind energy potential is immense, it can be predicted that in the following decades this low percentage might become thirty times larger. Unfortunately, not one modern wind generator has yet been installed in our country, although conditions are favourable in this respect. Experiences the world has had so far impose the necessity of analyzing technical possibilities for the construction of wind generators and the necessity to incorporate wind energy into the strategic model of the development of energetics in Serbia and Montenegro (SM). In this paper we analyze the availability of wind energy on the global scale, in Europe and in SM. We show in this paper that in SM wind is the energy resource about 10 000 MW (20 TWh/year) whose activation would greatly enlarge already installed capacities, increase the diversity of types of energy sources and reduce the dependence on the importation of raw energy sources.
Reduction factor of aerial bundled cable
Authors: Tasic Dragan , Stojanovic Miodrag
Published: October 2011

This paper presents mathematical model for determination of reduction factor of aerial bundled cables. Knowledge of reduction factor of aerial bundled cables, that supplies a substation, is important for substation grounding design as well as for right estimation of safety conditions. Reduction factors of frequently used aerial bundled cables are determined by presented mathematical model. Influence of metal screen temperature as well as influence of supporting wire characteristics on reduction factor value are shown.
Efficient implementation of the third order RLS adaptive Volterra filter
Authors: Budura Georgeta , Botoca C.
Published: October 2011

Nonlinear adaptive filtering techniques are widely used for the nonlinearities identification in many applications. This paper proposes a new implementation of the third order RLS Volterra filter based on the decomposition of the input vector. Its performances are evaluated in a typical nonlinear system identification application. Different degrees of nonlinearity for the nonlinear system are considered. Comparations, based on the adaptive filter error, are made in all cases with a linear identifier. The experimental results show that the proposed nonlinear identifier has better performances than the linear one.
Distribution of earth atmospheric electric field in the vicinity of the vehicles for transport petroleum derivates
Authors: Milovanovic Alenka
Published: October 2011

In this paper using Equivalent Electrode Method (EEM) Atmospheric Electric Field (AEF) distribution in the vicinity of the cargo vehicle is approximately numerically determined, when the vehicles are situated on petrol station near by petrol pump and people. The petrol pump is always grounded, but human body and vehicle are treated as grounded or 'floating' electrodes. Several results of electric field enhancement factor for the vehicle including maps of equienergetic curves are presented.
Study of the weak to heavy-current transition in high-frequency discharge in nitrogen
Authors: Iliev Iliycho , Gocheva-Ilieva Snezhana
Published: October 2011

Variety of electron, ion and plasma technologies as well as gas discharge devices operate in fixed form of the discharge. The transition from weak to heavy current in radio-frequency low-current discharge leads to instabilities in physical processes and it is very critical for the normal functionality of the technology or device. In this paper by means of Townsend criterion the influence of the incoming electric power and voltage on this transition in a cross-section of the discharge is numerically simulated. The calculations show a possible change of applied designed power up to 32% without weak to heavy-current transition. It is also obtained that the rise in 40% of the pressure can change the critical breakdown power only up to 12%. These results are in agreement with the simple analytical one-dimensional models and experimental data.
A new averaged switch model including conduction losses for PWM converters operating in discontinuous inductor current mode
Authors: Corina Mirela , Lascu Dan , Popescu Viorel
Published: October 2011

In this paper a new PWM switch model including conduction losses, for Discontinuous Inductor Current Mode (DICM) dc-dc converters is developed. Compared to other models for DICM, the proposed model is more accurate, its derivation considering the correct, exponential waveforms for the currents and voltages. The proposed model is verified through PSpice simulation. A possibility of simplifying the model is also presented and verified through PSpice simulation.
Interval criterion for stability analysis of discrete-time nonlinear systems with partial state saturation nonlinearities
Authors: Kolev Lubomir , Filipova-Petrakieva Simona , Mladenov Valeri
Published: October 2011

A generalization of sufficient conditions for global asymptotic stability of the equilibrium of discrete-time nonlinear systems with saturation non linearity's on part of the states in the case of interval uncertainties is considered. When using quadratic form Lyapunov functions, sufficient conditions based on the positive definite interval matrices are presented. In order to check this, a recently proposed method for determining the outer bounds of eigenvalues ranges is used. A numerical example illustrating the applicability of the method suggested is solved in the end of the paper.
Kanalkapazität vielpaariger symmetrischer Kupferkabel, Teil I: Nebensprechen als Störung
Authors: Lange Christoph , Ahrens Andreas
Published: October 2011

(nemacki) Durch elektromagnetische Kopplungen zwischen den Aderpaaren eines Kupferkabels wird Nebensprechen verursacht, wobei das Nah- und das Fernnebensprechen unterschieden werden. Ausgehend von der Kanalkapazit?t eines frequenzabh ?ngigen Kanals bei Rauschst?rung (z.B. perfekt geschirmtes Einzelpaar) wird die Kanalkapazit?t von Aderpaaren innerhalb eines vielpaarigen Kabels als informationstheoretische Grenze f?r die ?bertragbare Datenrate berechnet, wenn Nah- und Fernnebensprechst?rungen auftreten. Die Kapazit?t symmetrischer Aderpaare in bidirektional betriebenen Kabeln wird insbesondere durch das gegen?ber dem Fernnebensprechen weitaus st?rkere Nahnebensprechen reduziert. In unidirektional genutzten Kabeln hingegen tritt kein Nahnebensprechen auf und der begrenzende Einfluss der verbleibenden Fernnebensprechst?rung auf die Kapazit?t nimmt mit steigender Kabell?nge ab. Mit zunehmender Anzahls st?render Aderpaare steigt der durch das Nebensprechen verursachte Kapazit?tsverlust. In einem zweiten Teil dieses Beitrages wird die Kanalkapazit?t unidirektional betriebener Kabel berechnet, wenn die Fernnebensprechpfade als zus?tzliche Nutzsignalpfade aufgefasst werden.
An overview of on-chip buses
Authors: Mitic Milica , Stojcev Mile
Published: October 2011

The electronics industry has entered the era of multi-million-gate chips, and there Xs no turning back. This technology promises new levels of integration on a single chip, called the System-on-a-Chip (SoC) design, but also presents significant challenges to the chip designer. Processing cores on a single chip, may number well into the high tens within the next decade, given the current rate of advancements, [1]. Interconnection networks in such an environment are, therefore, becoming more and more important [2]. Currently on-chip interconnection networks are mostly implemented using buses. For SoC applications, design reuse becomes easier if standard internal connection buses are used for interconnecting components of the design. Design teams developing modules intended for future reuse can design interfaces for the standard bus around their particular modules. This allows future designers to slot the reuse module into their new design simply, which is also based around the same standard bus [3]. In this paper we give an overview of the more popular on-chip bus-based interconnection networks such as AMBA, Avalon CoreConnect, STBus, Wishbone, etc. The main characteristics of the considered buses in respect to topology, arbitration method, bus-width, and types of data transfers are discussed.
Text classification: Forming candidate key-phrases from existing shorter ones
Authors: Karanikolas Nikitas , Skourlas Christos
Published: October 2011

The hard problem of the Text Classification usually has various aspects and potential solutions. In this paper, two main research directions for narrative documents? classification are considered. The first one is based on data mining and rule induction techniques, while the second combines the traditional Text Retrieval techniques (use of the vector space model, index terms, and similarity measures), Natural Language Processing and Instance based Learning techniques. Key-phrases can be used as attributes for mining rules or as a basis for measuring the similarity of new (unclassified) documents with existing (classified) ones. Hence, we eventually focus on the problem of extracting key-phrases from text?s collection in order to use them as attributes for text classification. A new algorithm for the discovery of key-phrases is described. Candidate key-phrases are built using frequent smaller ones and special emphasis is given to the reduction of the complexity of the algorithm.
Using XML Web services as a platform for remote access and control of embedded systems
Authors: Oklobdzija Danilo , Jevtovic Branislav
Published: October 2011

This paper has pointed out the need for new technologies for integrating embedded devices in heterogeneous distributed networks, and outlines the perspectives opened by applying service-oriented paradigm for realizing interaction with embedded devices. As a foundation for interaction with embedded devices, XML and Web services have been used. Strong integration power of XML and Web services make presented framework appropriate for unique approach to all resources of embedded device regardless of applied technology. Developed Web services based middleware, provides application designers with a high level of semantic abstraction, hiding the complexity of the applied technologies. This makes presented framework suitable for use in many domains, independent of embedded devices physical realization or network characteristics. Two ways to achieve such integration have been presented in this paper: device level for modern embedded devices, and using service oriented gateway for "legacy" embedded systems. .
Statistical dynamics of dual-power law optical soliton
Authors: Biswas Anjan
Published: October 2011

The dynamics of optical solitons with dual-power law nonlinearity, in presence of a stochastic perturbation term, is studied in this paper. The soliton perturbation theory is exploited to obtain the Langevin equation by virtue of which one can conclude that solitons travel down the optical fiber with a fixed mean free velocity. .
Analysis of feed waveguide length influence on EM field in microwave applicator using TLM method
Authors: Milovanovic Bratislav , Jokovic Jugoslav , Dimitrijevic Tijana
Published: October 2011

A microwave applicator based on metallic cavity with a waveguide used to launch the energy from the source into the cavity is modelled using time-domain 3-D TLM method enhanced with model for modelling of wire and boundaries. An influence of waveguide length on EM field distribution inside the cavity is analyzed, in terms of modes presence and corresponding EM field levels. .
An accurate determination of current distribution within the Earth
Authors: Prsa Miroslav , Kasas-Lazetic Karolina
Published: October 2011

In electrical engineering the Earth appears frequently as a media of conducting currents. In order to protect humans of electrocuting, the utilities chassis are usually grounded, the lightning rods are grounded as well and sometime the Earth is applied as a return conductor. For that reason, it is necessary to investigate the Earth's behavior when it is used as a conducting media. The best way to do this investigation is to determine the current distribution within the Earth. .
A hybrid approach to bilingual text-to-phoneme mapping
Authors: Bilcu Beatrice , Astola Jaakko
Published: October 2011

In this paper, we address the problem of bilingual text-to-phoneme (TTP) mapping in which the phonetic transcription of isolated written words must be found. In general, in the bilingual/multilingual TTP mapping for isolated words, two processing steps are applied to each input word. The language of each word is first identified and then the letters of the word are translated into their phonetic transcriptions according to the recognized language. We use the multilayer perceptron (MLP) neural network for the letter to phoneme conversion task and a hybrid approach composed of a MLP and a decision rule system for the language recognition task. We introduce a new bilingual TTP mapping system and we provide an analysis of the influence of several different factors on its phoneme accuracy. .
An approach to selective intra coding and early inter skip prediction in H.264/AVC standard
Authors: Milicevic Zoran , Bojkovic Zoran
Published: October 2011

This paper presents selective intra coding and early inter skip fast mode decision algorithm for H.264/AVC and compares performance of H.264/AVC with prior standards. Video coding standard H.264/AVC provides gains in compression efficiency of up to 50% over a wide range of bit rates and video resolutions compared to previous standards. In order to achieve this, a robust rate-distortion optimization (RDO) technique is employed to select best coding mode and reference frame for each macroblock. Also, the original and modification test models are compared for combined skip and intra prediction method in H.264/AVC encoder, when ? pictures are analyzed. Experimental results show that the coding time is reduced by 35-42% through early identification of macroblocks that are likely to be skipped during the coding process and through reducing the number of candidate modes. .
Modelling and performance evaluation of optical burst switched node with deflection routing and dynamic wavelength allocation
Authors: Pevac Danka , Bojovic Risto , Petrovic Ivana
Published: October 2011

In this paper the effect of dynamic wavelength allocation (DWA) scheme implementation to the OBS node performance is investigated. We have developed the mathematical model of an OBS node in order to evaluate the burst blocking probability. It is proposed to allocate a part of total wavelength capacity to be used by deflected bursts only. The results obtained from the model show that if the number of allocated wavelengths is dynamically adapted to the deflected burst traffic intensity, the total blocking probability and deflected burst blocking probability significantly decrease. Concerning to the hardware requirements the implementation of deflection routing needs the limited optical FDL buffer incorporation, to provide the deflected burst with the extra offset time. Also, control logic for burst scheduler needs to be upgraded to perform the dynamic wavelength allocation for deflected bursts. .
Convergence and divergence of Fejér means of Fourier series on one and two-dimensional Walsh and Vilenkin groups
Authors: Gát György
Published: October 2011

It is a highly celebrated issue in dyadic harmonic analysis the pointwise convergence of the Fej?r (or (C, 1)) means of functions on the Walsh and Vilenkin groups both in the point of view of one and two dimensional cases. We give a resume of the very recent developments concerning this matter, propose unsolved problems and throw a glance at the investigation of Vilenkin-like systems too. .
p-adic calculus and its applications to fractal analysis and medical science
Authors: Su Weiyi , Qiu Hua
Published: October 2011

Recently, we reconsider continuously definitions and properties of Gibbs derivatives on p adic field Qp, by using so called pseudo-differential operators T?, we find the kernel k? of T?, as well as the spectra of it. Moreover, we show some applications of T? to fractal analysis and medical science. .
On a large class of non-linear coding methods based on Boolean invertible matrices
Authors: Karanikas Costas , Atreas Nikolaos
Published: October 2011

The main target of this work is to construct a large enumerated class of non- linear coding methods, based on a discrete invertible transform called Riesz Product, which is associated to a class of Boolean invertible matrices of order m ? m. The particular class of matrices is uniquely determined by a couple of permutations of the first m natural numbers {1, 2, ..., m}, so for any m = 1, 2, 3, ..., we get at least (m!)2 different non-linear coding methods. The resulting encoding/decoding method is very fast and requires low memory. It can be used both as a new encryption tool or as a Boolean random generator. .
Counting addressing method: False triggering problem
Authors: Ristic Jovan , Lekic Julijana
Published: October 2011

The specific requirements that appear in addressable fire detection and alarm systems and the shortcomings of the existing addressing methods were discussed. A new method of addressing of detectors was proposed. The basic principles of addressing and responding of a called element are stated. The sensitivity to electromagnetic disturbances is one of the greatest problems of the proposed addressing method - counting type of addressing. The proposed solutions of this problem were verified experimentally. The paper also gives the conditions and results of the experiment. The counting addressing method was developed for specific requirements in fire detection and alarm systems, yet its speed and reliability justifies its use in the acquisition of data on slowly variable parameters under industrial conditions. .
Automatic cross-border transmission capacity calculation in electric power interconnections
Authors: Popovic Dragan
Published: October 2011

The paper deals with relevant methodological and practical aspects of automatic cross-border transmission capacity assessment in electric power interconnections. It is based on advanced methodology for steady-state security analyses, using all its favourable properties, respecting the latest criterions, standards and practice of European Transmission System Operators (ETSO). The practical presentation of developed computer program is made on example of transmission capacity calculation in condition of ex Second UCTE synchronous zone. This presentation gives an overview of the characteristics and possibilities of this computer program, regarding the real necessities of operational practice in new conditions of liberalized electricity markets. .
Dynamic load modeling of some low voltage devices
Authors: Korunovic Lidija , Stojanovic Dobrivoje
Published: October 2011

This paper presents the results of dynamic load modeling for some frequently used low voltage devices. The modeling of long-term dynamics is performed on the basis of step changes of supply voltage of the heater, incandescent lamp, mercury lamp, fluorescent lamps, refrigerator, TV set and induction motor. Parameters of dynamic exponential load model of these load devices are identified, analyzed and mutually compared.
An effective and robust fingerprint enhancement by adaptive filtering in frequency domain
Authors: Raicevic Andjelija , Popovic Brankica
Published: October 2011

Extensive research of automatic fingerprint identification system (AFIS), although started in the early 1960s, has not yet give the answer to reliable fingerprint recognition problem. A critical step for AFIS accuracy is reliable extraction of features (mostly minutiae) from the input fingerprint image. However, the effectiveness of a feature extraction relies heavily on the quality of the input fingerprint images. This leads to the incorporation of a fingerprint enhancement module in fingerprint recognition system to make the system robust with respect to the quality of input fingerprint images. In this paper we propose an adaptive filtering in frequency domain in order to enhance fingerprint image. Two different directional filters are proposed and results are compared. .
A systematic approach to the concept of surface impedance boundary conditions
Authors: Nathan Ida , Yuferev Sergey , Di Rienzo
Published: October 2011

This paper discusses the general issues, derivation, implementation and applications of Surface Impedance Boundary Conditions (SIBCs) in the time- and frequency-domains. A comprehensive approach based on perturbation methods leads to SIBCs of desired order of approximation as well as systematic implementation within existing formulations for linear and nonlinear media. The approach described here also allows evaluation of errors and appropriateness of SIBCs for specific applications. A suite of SIBCs is proposed, suitable for use in a wide range of practical applications and formulations including FEM, FDTD, FIT and BEM. A general toolbox that can be used for derivation of SIBCs for the users specific formulation and application has been developed and is described here as well. .
Forced dynamics control of an actuator with linear PMSM
Authors: Vittek Ján , Vavrús Vladimir , Buday Jozef , Kuchta Jozef
Published: October 2011

The paper presents design and verification of Forced Dynamics Control of an actuator with linear permanent magnet synchronous motor. This control method is a relatively new one and offers an accurate realization of a dynamic speed response, which can be selected for given application by the user. In addition to this, the angle between stator current vector and moving part flux vector is maintained mutually perpendicular as it is under conventional vector control. To achieve prescribed speed response derived control law requires estimation of an external force, which is obtained from the set of observers. The first observer works in pseudo-sliding mode and observes speed of moving part while the second one has filtering effect for elimination of the previous one chattering. The overall control system is verified by simulations and experimentally. Preliminary experiments confirmed that the moving part speed response follows the prescribed one fairly closely.
Electromagnetic field in biological tissue objects
Authors: Marinova Iliana , Mateev Valentin
Published: October 2011

In this paper a method for automatic 3D model building is presented. These models are suitable for investigations of electromagnetic field distribution with Finite Element Method (FEM). Models are made by meshed structures and specific electromagnetic material properties for each tissue type. Mesh is built according to specific FEM criteria for achieving good solution accuracy. Bioimpedance measurement system is developed and electromagnetic properties, acquired by the system, are used in 3D FEM model. Achieved models are applied for electromagnetic field distribution investigation. .
Electrode configurations and non-uniform dielectric barrier discharge properties
Authors: Dineff Peter , Gospodinova Dilyana
Published: October 2011

Interesting types of AC discharges in ambient air at atmospheric pressure for the generation of non-thermal plasma at/on dielectric surfaces were investigated. Pin-to-plane dielectric barrier discharge (PTP-DBD) was sustained in the electrode configurations combining electrode components of both corona and DBD - metallic pins, or triangle spikes electrode, situated single- or double-in-line and metallic plate electrode covered with a dielectric barrier. It was investigated experimentally and theoretically the burning mode of a PTP-DBD in ambient air at atmospheric pressure. The PTP-DBD behavior with single- or double-in-line spikes high voltage electrode was discussed. The PTP-DBD is a new DBD-based discharge. .
Investigation of three-phase to single-phase matrix converter
Authors: Antchev Mihail , Kunov Georgi
Published: October 2011

A three-phase to single-phase matrix converter is investigated in the present paper. Based on the state matrix vector, a mathematical analysis of the converter is performed giving the relation between the sinusoidal line voltage (current) and the output voltage (current). The results of the investigation are confirmed using computer simulation of the converter by the program product Cadence PSpice. .
A point source in the presence of spherical material inhomogenity: Analysis of two approximate closed form solutions for electrical scalar potential
Authors: Rancic Predrag , Stojanovic Miodrag , Rancic Milica , Cvetkovic Nenad
Published: October 2011

A brief review of derivation of two groups of approximate closed form expressions for the electrical scalar potential (ESP) Green functions that originates from the current of the point ground electrode (PGE) in the presence of a spherical ground inhomogenity, are presented in this paper. The PGE is fed by a very low frequency periodic current through a thin isolated conductor. One of approximate solutions is proposed in this paper. Known exact solutions that have parts in a form of infinite series sums are also given in this paper. Here, the exact solution is solely reorganized in order to facilitate comparison to the closed form solutions, and to estimate the error introduced by the approximate solutions. Finally, error estimation is performed comparing the results for the electrical scalar potential obtained applying the approximate expressions and accurate calculations. This is illustrated by numerous numerical experiments. .
Voltage-reactive states on interconnected lines according to the generator voltages control in real-time
Authors: Popovic Dragan , Stojkovic Milos
Published: October 2011

This papers presents the possibility effects of application in real-time an advanced method for fast and sufficiently accurate definition of generator voltages to realize the favorable voltage-reactive states of electric power interconnection. The application in real-time will be realized by use the results of state estimation, which is the part of the new SCADA/EMS system in NDC Elektromreza Srbije. The special part of method developed is the possibility to make the direct connection between the values of generator voltages and voltage-reactive states on interconnected lines. The verification of method proposed is made, on the examples of perspective states of Serbian transmission network, in own wide environment. .
An example of superstable quadratic mapping of the space
Authors: Elhadj Zeraoulia
Published: October 2011

It is shown rigorously in this paper that an elementary 3-D quadratic mapping is superstable, i.e. it is superstable for some ranges of its bifurcation parameters. Numerical results that confirm the theory are also given and discussed. These numerical results give a new route to chaos which we call: the superstable quasi-periodic route to chaos.
New finite-difference formulas for dielectric interfaces
Authors: Djurdjevic Dusan
Published: October 2011

The finite difference method is often-used numerical simulation method in electromagnetics. In this paper a new methodology is presented that allows the derivation of finite difference formulas near dielectric interfaces with high accuracy. Derived finite difference formulas have been used in the electric field computations in electrostatics (the two-dimensional Laplace's equation is employed) and in full-vectorial waveguide simulations in photonics (the three-dimensional Helmholtz's equation and the beam propagation simulation technique in frequency domain are employed). The finite difference formulas derivation is made under a power series expansion of the transverse field components in the case for uniform rectangular discretization mesh. The resulting finite difference formulas provide highly accurate solutions, both for electrostatic and waveguide propagation problems even on coarse grids and thus enable a very cost-effective and rapid numerical field simulations. Reported methodology and derived formulas have not been used in finite difference method formulations in literature. Some results for the electric field computation and dielectric waveguide eigenmode and propagation analysis are presented. .
Probabilistic approach for deriving immunity levels against electromagnetic disturbances
Authors: Jaekel Bernd , Carpenter Darren
Published: October 2011

Knowledge of electromagnetic environments existing at locations where equipment is intended to be operated is an essential prerequisite for achievement of electromagnetic compatibility. The necessity of such a knowledge results from the fact that suitable immunity requirements can be concluded from corresponding data regarding the electromagnetic environment. This information should include the type as well as the characteristics of electromagnetic phenomena occurring at those locations. Appropriate information can be obtained by various approaches, such as site surveys or technical assessments accompanied by evaluations of technical literature. It is obvious that the description of a general electromagnetic environment should consider a multitude of phenomena having a broad spectrum of parameters. However, in many cases such a general description is not helpful because it would imply that immunity against all such phenomena has to be taken into consideration. A more practical approach consists in introducing a classification scheme which gives a correlation between locations and the electromagnetic phenomena existing there. This concept forms the basis of the EMC publication IEC 61000-2-5. Because of continuous change of existing technologies and introduction of new ones, electromagnetic environments in a certain respect change fundamentally. This is very obvious in case of all the recently introduced radio and communication services with the generation of electromagnetic fields in the frequency range above 1 GHz. Hence the need arises to monitor continuously the electromagnetic environment and to adapt its description. Such adaptation is currently being done by a working group of IEC TC 77. The results of its work is object of the next edition of IEC 61000-2-5. The present status as well as expected changes are discussed in this paper. .
Information system development with the enhancement of CASE tools functionality
Authors: Novakovic Igor , Deletic Velimir , Deletic Milan
Published: October 2011

This paper presents how functionality of certain CASE tools can be extended in order to facilitate requirements engineering. It describes the technique for information flows analysis, which can be used in conceptual modeling and further development of the system. .