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Objective: In this research we explored the (homeo)dynamic character of cardiorespiratory coupling (CRC) under the influence of different body posture and breathing regimes. Our tool for it was the pulse respiration quotient (PRQ), representing the number of heartbeat intervals per breathing cycle. We obtained non-integer PRQ values using our advanced Matlab® algorithm and applied it on the signals of 20 healthy subjects in four conditions: supine position with spontaneous breathing (Supin), standing with spontaneous breathing (Stand), supine position with slow (0.1 Hz) breathing (Supin01) and standing with slow (0.1 Hz) breathing (Stand01).Main results: Linear features of CRC (in PRQ signals) were dynamically very sensitive to posture and breathing rhythm perturbations. There are obvious increases in PRQ mean level and variability under the separated and joined influence of orthostasis and slow (0.1 Hz) breathing. This increase was most pronounced in Stand01 as the state of joint influences. Importantly, PRQ dynamic modification showed greater sensitivity to body posture and breathing regime changes than mean value and standard deviation of heart rhythm and breathing rhythm. In addition, as a consequence of prolonged supine position, we noticed the tendency to integer quantization of PRQ (especially after 14 min), in which the most common quantization number was 4:1 (demonstrated in other research reports as well). In orthostasis and slow breathing, quantization can also be observed, but shifted to other values. We postulate that these results manifest resonance effects induced by coupling patterns from sympathetic and parasympathetic adjustments (with the second as dominant factor).Significance: Our research confirms that cardiorespiratory coupling adaptability could be profoundly explored by precisely calculated PRQ parameter since cardiorespiratory regulation in healthy subjects is characterized by a high level of autonomic adaptability (responsiveness) to posture and breathing regime, although comparisons with pathological states has yet to be performed. We found Stand01 to be the most provoking state for the dynamic modification of PRQ (cardiorespiratory inducement). As such, Stand01 has the potential of using for PRQ tuning by conditioning the cardiorespiratory autonomic neural networks, e.g., in the cases where PRQ is disturbed by environmental (i.e., microgravity) or pathologic conditions.

Сажетак: Промена положаја тела и режима дисања су пертурбације које у људском организму доводе до различитих физичких и физиолошких услова функционисања. На ове пертурбације људски организам се прилагодио кроз врло суптилна подешавања карактеристика унутрашњих биолошких ритмова, највише уз регулационо посредовање аутономног нервног система (АНС). Испитивања утицаја положаја тела и нарочито успореног дисања на регулациону функционалност АНС-а последњих година су постала веома актуелна, како у домену фундаменталних биомедицинских истраживања, тако и на пољу клинички примењивих испитивања. Из тога је утврђено и уопштено да при лежећем положају парасимпатички (вагусни) део АНС има предоминантан утицај на срчани ритам и дисање. Насупрот томе, у стојећем положају, испољава се симпатичка предоминација. Успорено дисање са темпом од 0.1 Hz показало се да врши известан резонантан утицај на биоритмику организма (мождану активност, менталне функције, срчани ритам, крвни притисак итд). Основна замисао ове тезе своди се на испитивање одвојеног и заједничког (синергетског) утицаја промене положаја тела (лежање - стајање) и режима дисања (спонтано - успорено-контролисано) на временску променљивост (впр), сложеност (слож) и спрезање (спрез) срчаног ритма и дисања. Впр, слож и спр су примарне одлике биолошких осцилација за које су одговорне регулационе повратне спреге АНС. Увид у впр добили смо кроз линеарне статистичке параметре, у слож кроз корелационе нелинеарне параметре и мултискалирајућу анализу (детрендована флуктуациона анализа (DFA), мултискаслирајућа ентропија (MSE)), а у спрез помоћу линеарних (пулс-респираторни количник (PRQ), спектрална кохеренција (CohRRI-Resp)) мера и нелинеарних корелационих параметара (унакрсна DFA, унакрсна MSE). Сажето, извршили смо мултипараметарско карактерисање споменутих одлика биолошких осцилација. Циљ нам је био да из добијених резултата извучемо информације о стању одзивљивости и прилагодљивости АНС. Зарад тога, осмишљен је посебан протокол експерименталног испитивања и анализирања који подразумева детаљно дефинисање услова и процедура (маневара) у којима се врши снимање сигнала, примењивање наменских алгоритама за рачунање линеарних и нелинеарних карактеризационих параметара, статистичких тестова којима се врши поређење резултата и систематска физичко-физиолошка интерпретација резултата. Овај протокол примењен је на 20 здравих испитаника у четири физиолошка стања: лежање са спонтаним дисањем (Леж), стајање са спонтаним дисањем (Ст), лежање са успореним (0.1 Hz) дисањем (Леж01) и стајање са успореним (0.1 Hz) дисањем. За Ст карактеристичне су биле промене RRI параметара и смањење CohRRI-Resp и неосетљивост на промене параметара дисања. У Леж01 дошло је до промене и линеарних и нелинеарних параметара оба сигнала, што одражава доминантну вагусну регулацију RRI и утицај успореног (0.1 Hz) дисањa на параметре дисања, уз пораст унакрсне DFA на кратким скалама, а без утицаја на CohRRI-Resp. Сва истражена стања произвела су промену односа нагиба α1 наспрам α2 на DFA дијаграмима, што се знатно прецизније може изразити новом мером сложености - међуфракталним углом θ коју кроз нашу анализу предочавамо као нелинеарни пандан концепта симпато-вагалног баланса... Abstract: Changes in body posture and respiratory regime are perturbations that lead to different physical and physiological conditions of functioning in the human body. The human organism has adapted to these perturbations through very subtle adjustments of the characteristics of internal biological rhythms, mostly with the regulatory mediation of the autonomic nervous system (ANS). Studies of the influence of body posture and especially slow breathing on the regulation functionality of ANS have become very relevant in recent years, both in the domain of fundamental biomedical research and in the field of clinically applicable testing. From that, it was determined and generalized that in the supine position, the parasympathetic (vagal) part of ANS has a predominant influence on heart rhythm and respiration. In contrast, in the standing position, sympathetic predominance is manifested. Slow breathing at a rate of 0.1 Hz has been shown to exert a certain resonant effect on the biorhymicity of the organism (brain activity, mental functions, heart rate, blood pressure, etc.). The basic idea of this thesis was to examine the separate and joint (synergetic) influence of changes in body position (supination - standing) and breathing regime (spontaneous - slow-controlled) on the temporal variability (var), complexity (comp) and coupling (coup) of heart rhythm and respiration. Var, comp and coup are the primary features of biological oscillations for which ANS regulatory feedback is responsible. Insight into var was obtained through linear statistical parameters, into comp through correlation nonlinear parameters and multiscaling analysis (detrended fluctuation analysis (DFA), multiscalating entropy (MSE)), and into coup using linear (pulse-respiratory quotient (PRQ) and spectral coherence (CohRRI-Resp)) measures and nonlinear correlation parameters (cross DFA, cross MSE). In general, we performed a multiparameter characterization of the mentioned features of biological oscillations. Our goal was to extract information on the state of responsiveness and adaptability of ANS from the obtained results. Therefore, a special protocol for experimental testing and analysis has been developed, which includes detailed definition of conditions and procedures (maneuvers) in which signal acquisition was performed, application of advanced algorithms for calculating linear and nonlinear characterizing parameters, batery for statistical comparing results and systematic physical and physiological interpretation of results. This protocol was applied to 20 healthy subjects in four physiological states: supination with spontaneous breathing (Supin), standing with spontaneous breathing (Stand), supination with slow (0.1 Hz) breathing (Supin01), and standing with slow (0.1 Hz) breathing (Stand01). Changes in RRI parameters, a decrease in CohRRI-Resp and insensitivity to changes in respiratory parameters were characteristic of Stand. In Supin01 there was a significant change in both linear and nonlinear parameters of both signals, which reflects the dominant vagal regulation of RRI and the influence of slow (0.1 Hz) breathing on respiratory parameters, with an increase in cross-DFA on short scales, without affecting CohRRI-Resp. All investigated states produced a change in the slope ratio α1 versus α2 on DFA diagrams, which can be expressed much more profound with a new measure of complexity - interfractal angle θ, which we present in our analysis as a nonlinear counterpart of the sympatho-vagal balance concept. Measures of complexity on short scales (α1 versus MSE1-4) and long scales (α2 versus MSE5-10) had a reciprocal relationship in Stand01, with a specific pattern of cardiorespiratory coupling (ρ1 versus XMSE1-4)...

Naziv ovog završnog rada je “TS 110/35 kV Zadar – relejna zaštita vodova 110 kV“. U radu su izvršeni proračuni podešenja relejne zaštite vodova 110 kV u TS 110/35 kV Zadar. Ivršen je izbor funkcija zaštite koje će se koristiti u slučaju nastupa međufaznog kratkog spoja te zemljospoja, kao i konkretna podešenja korištenih funkcija zaštite. Pri proračunima su uvaženi svi osnovni kriteriji za kvalitetan rada relejne zaštite. Kvalitetan rad sustava relejne zaštite doprinosi kvalitetnom funkcioniranju EES-a u cjelini., The title of this final work is "TS 110/35 kV Zadar - relay protection of 110 kV lines". The paper presents the calculations of relay protection settings for 110 kV lines in TS 110/35 kV Zadar. The selection choice of protection functions that will be used in case of interphase short circuit and earth fault, as well as the specific settings used functions of protection. All the basic criteria for quality relay protection work are respected in the calculations. The quality operation of the relay protection system contributes to the smooth functioning of the power system as a whole.

Glavna tema ovog završnog rada je Internet protokol verzija 6 (engl. IPv6 – Internet Protocol version 6) – kako i zbog kakvih potreba je nastao, koji su principi njegova funkcioniranja, te koje nam nove mogućnosti pruža. Naravno, da bi se moglo govoriti o IPv6 protokolu, svakako se mora spomenuti i njegov prethodnik, IPv4 protokol. Kroz kratku usporedbu tih dvaju protokola navest ćemo prednosti verzije 6, ali i spomenuti probleme oko njegove implementacije u sustave, koja traje već petnaestak godina. Budući je implementacija spora i ne odvija se istom brzinom u svim zemljama svijeta, dotaknut ćemo se i situacije koja se zbiva u našoj zemlji u odnosu na države koje nas okružuju. Main subject of this final paper is the Internet Protocol version 6 – how and due to what needs is was designed and created, what are the principles of its functioning and what new possibilities is it offering. To be able to talk about IPv6, we certainly have to mention its forerunner: the Internet Protocol version 4. Through short comparison of these two protocols we will explain the advantages of the version 6, but also mention the problems, which turned up during its implementation into the systems for the past 15 years. Because of its slow implementation the situation and progress is not in the same in every country, and we will compare the process in our country with neighbouring countries.

The use of compensators in order to achieve desired dose distribution had a long history and is well-established technique in radiation therapy planning. There are several different methods of calculation for compensator’ s shape discussed in literature. An alternative method is presented. The method is based on Cunningham's modification of Clarkson's method to calculate scattered radiation in beams with inhomogeneous cross-sectional dose distribution. The algorithm is rather general and could be applied to different required dose distributions in various clinical situations, different photon beams, and various compensating materials. The algorithm is feasible, quickly computable and versatile. The method is verified using film dosimetry in several practical situations manufacturing compensators out of steel granules and low melting alloy. Additional measurements were made using electronic portal imaging developed in our hospital. The results are compared with effective attenuation method.

Preliminary research of the sound monitoring during gas metal arc welding (GMAW) process did not give satisfactory quantitative results. One reason of the significant deviation to the expectation was insufficient precise motion of the electrode (for the research phase). To eliminate this problem it was adopted to involve the subsystem for the 3D/PC (three dimensions/personal computer) motion control in the laboratory GMAW process research system. The subsystemwas made and tested (with partial developed software) with the electric motor and milling cutter. The introduction of this paper shortly describes the main results of the preliminary research of sound monitoring. The second part presents the block diagram of the developed laboratory GMAW process research system. Third part of the paper is devoted to the detailed descriptions of the finished subsystem for the 3D/PC motion control.