COEFFICIENT QUANTIZATION EFFECTS ON NEW FILTERS BASED ON CHEBYSHEV FOURTH-KIND POLYNOMIALS

The aim of this paper is to construct non-recursive filters, extensively used type of digital filters in digital signal processing applications, based on Chebyshev orthogonal polynomials. The paper proposes the use of the fourth-kind Chebyshev polynomials as functions in generating new filters. In this kind, low-pass filters with linear phase responses are obtained. Comprenhansive study of the frequency response characteristics of the generated filter functions is presented. The effects of coefficient quantization as one type of quantization that influences a filter characteristic are investigated here also. The quantized-coefficient errors are considered based on the number of bits and the implementation algorithm

WAVE DIGITAL MODELS OF IDEAL AND REAL TRANSFORMERS

In this paper, a generalization of the wave digital models of ideal transformer is done, aiming to increase a number of types of structures that can be modeled by using wave digital filter theory. Wave digital networks are described in details and developed here based on scattering parameter formalism and two-port networks of parallel or series adaptors

Аnalysis of Composite Construction of the Access Bridge Parts over the Danube by Beska, Serbia

In the conception design of the bridge over the Danube by Beska, which presents the purchased work at the international competition, besides the main bridge part over the river, the access bridge parts over the river inundation should be designed. The spans between columns for the access bridge parts, according to the conditions of the competition, were defined in advance. These spans are 45.0m. The length of the right side of the access bridge part is 180.0m and the length of the left side is 1492.55m. Since these lengths are too long, especially on the left side, the authors suggested that the access bridge parts should be designed of more composite continuous girders. The analysis of this composite construction is presented in the paper

ANESTHETIC MANAGEMENT FOR A PATIENT WITH ACUTE INTERMITTENT PORPHYRIA

Acute intermittent porphyria is a rare metabolic disorder resulting from a partial deficiency of porphobilinogen deaminase, enzyme in the heme biosynthetic pathway. Its inheritance is autosomal dominant. A deficiency of porphobilinogen deaminase is not sufficient by its self to produce acute intermittent porphyria, and other activating factors must also be present. These include some drugs, hormones, infection, injury and alcohol. Besides others, anesthetics have been implicated in the triggering of a number of severe porphyric reactions. Although there is no clinical evidence, the fear of hypothesized porphyrinogenicity of repetitive anesthetics exposures still remains. Despite these doubts, we report here the case of uneventful repeated exposure to anesthetics in a patient suffering from acute intermittent porphyria, within a fifteen- month period. On both occasions, the patient was safely exposed to certain anesthetics included: propofol, sevoflurane, rocuronium, midazolam and fentanyl

The Stiffness Matrix of the Fixed-End Composite Frame Element

The displacement method of frame analysis involves determination of the element stiffness matrix. In the paper, the stiffness matrix of the fixed-end composite frame element (type “k”) is derived. In general, the composite section consists of concrete part, steel section, reinforcing and prestressing steel. Concrete is considered as an aging, linear viscoelastic material. The relaxation of the prestressing steel is taken into account. The derived expressions can be used with any creep function and, also, for elements with variable cross-sections. The derivation of the element stiffness matrix follows two different approaches. The first approach is based on the integral stress-strain relation for concrete. The linear integral operators are used. In the second approach, the element flexibility matrix and the resisting force vector are determined through the numerical integration of the cross- section deformations. The class of cross-sections which accounts for viscous effects of a composite section is developed. The results of the two approaches are compared in the numerical example

Effects of Creep and Shrinkage on Deflections of Continuous Composite Beams

Creep and shrinkage of concrete affect the behavior of steel-concrete composite beams and should be taken into account in the analysis of these structures. A number of methods which have different level of accuracy are available for the time analysis of composite structures. Eurocode 4, the contemporary European code for design of steel- concrete composite structures, recommends simple methods for calculation of creep and shrinkage effects. In this paper, the deflections of continuous composite beams calculated with method proposed by Eurocode 4 and the more accurate Age Adjusted Effective Modulus Method (AAEM) are compared. Cracking of concrete is also considered. Through a set of numerical examples, accuracy of methods proposed by Eurocode 4 is discusse

Accuracy Evaluation of Creep and Shrinkage Calculation Methods According to EC4

In the paper, the creep and shrinkage calculation methods for composite steel-concrete beams are presented. The approximate methods AAEM, EM and methods according to Eurocode 4, as well as, the exact method based on the integral relation between stress and strain for concrete are used. For doubly-clamped composite beam, stresses at characteristic points of the cross-section for permanent loading and shrinkage effects are determined. Using the creep limit functions for concrete, the upper and lower limits for stresses are determined. According to these limits, the accuracy of the methods for creep and shrinkage calculation given in EC4 is evaluated

Medijska i informacijska pismenost – osnova za primjenu digitalnih tehnologija u nastavi iz diskursa obrazovnih potreba nastavnika

The expansion of new digital media and the development of information technology give even bigger importance to media and information literacy, which is recognized as one of the key skills in the educational system almost everywhere in the world. The concept of media and information literacy in this paper is considered from the pedagogical aspect, i.e., the aspect of the educational needs of the teacher in learning and applying digital technologies in the teaching process. The aim of this paper is to determine the level of the teachers’ interest in the application of certain digital technologies in the teaching process on the one hand, and to determine similarities and differences in their needs for learning and applying digital technologies in the teaching process according to their gender and work experience, on the other hand. The conclusion is that teachers who participated in the survey showed high interest in learning and applying digital technologies in the teaching process. The use of the computer and the Internet appeared to be the biggest need teachers have.Ekspanzija novih digitalnih medija i napredak informacijske tehnologije uvjetuju sve veću važnost medijske i informacijske pismenosti, koja se priznaje kao jedna od ključnih vještina u obrazovnom sustavu gotovo u cijelom svijetu. Koncept medijske i informacijske pismenosti u ovom se radu promatra s pedagoškog aspekta, odnosno s aspekta obrazovnih potreba nastavnika za poznavanjem i primjenom digitalnih tehnologija u nastavnom procesu. Cilj rada jest utvrditi kolika je zainteresiranost nastavnika za primjenu pojedinih digitalnih tehnologija u nastavi, kao i utvrditi sličnosti i razlike u njihovim potrebama za upoznavanjem i primjenom digitalnih tehnologija u nastavi u odnosu na spol i radno iskustvo nastavnika. Zaključak je da su nastavnici očitovali visoku zainteresiranost za upoznavanje i primjenu digitalnih tehnologija u nastavi. Kao najveća potreba nastavnika pokazala se primjena računala i interneta

Polymorphisms of the GSTT1 and GSTM1 genes in women of central Serbia: Absence of association with uterine myoma

Since glutathione S-transferase (GST) enzymes are involved in cellular protection, we aimed to determine the distribution of GSTT1 and GSTM1 null genotypes in women in central Serbia in order to assess the risk of development of uterine myoma. The study consisted of 34 clinically diagnosed uterine myoma patients and 35 healthy control women. Analyses of GST polymorphism were carried out by multiplex PCR. Our results showed no significant differences in the GSTT1 and GSTM1 null genotypes between the patients and controls. Using the GSTT1 positive/GSTM1 positive combination as reference, there was no statistically significant risk of uterine myoma with the combination of GSTT1 null and GSTM1 null genotypes. We conclude that polymorphism of both GSTT1 and GSTM1 genes, alone or in combination, did not present the main risk for uterine myoma in women from central Serbia.[Projekat Ministarstva nauke Republike Srbije, br. III41010 i br. ON 175103

Resistance of Composite Column to Compression and Bending

Design of the composite steel-concrete columns subjected to compression and bending, according to Eurocode 4, is shown in the paper. The effects of imperfections in the axial compression are taken into account indirectly by using the relevant European buckling curves. When a composite column is subjected to combined axial compression and bending, the analysis includes an increase in bending moment due to second order effects. The verification of the column resistance to compression and bending is based on the use of interaction curve. For the cross sections of fully encased columns with the I steel sections, very practical sets of continuous interaction curves are given. The curves are constructed for different composite column dimensions, steel sections and concrete classes