Multivariate and multi-scale generator based on non-parametric stochastic algorithms

A method for generating combined multivariate time series at multiple locations and at different time scales is presented. The procedure is based on three steps: first, the Monte Carlo method generation of data with statistical properties as close as possible to the observed series; second, the rearrangement of the order of simulated data in the series to achieve target correlations; and third, the permutation of series for correlation adjustment between consecutive years. The method is non-parametric and retains, to a satisfactory degree, the properties of the observed time series at the selected simulation time scale and at coarser time scales. The new approach is tested on two case studies, where it is applied to the log-transformed streamflow and precipitation at weekly and monthly time scales. Special attention is given to the extrapolation of non-parametric cumulative frequency distributions in their tail zones. The results show a good agreement of stochastic properties between the simulated and observed data. For example, for one of the case studies, the average relative errors of the observed and simulated weekly precipitation and streamflow statistics (up to skewness coefficient) are in the range of 0.1–9.2% and 0–5.4%, respectively.This is the submitted version of the article: Đ. Marković, S. Ilić, D. Pavlović, J. Plavšić, and N. Ilich, ‘Multivariate and multi-scale generator based on non-parametric stochastic algorithms’, Journal of Hydroinformatics, vol. 21, no. 6, pp. 1102–1117, Nov. 2019, [https://doi.org/10.2166/hydro.2019.071

Analiza okluzalnih karakteristika jednojajčanih blizanaca

Background/Aim. Functionally stable occlusion is characterized by optimal and orthopedic stable position of the condyle, harmonious contact ratio of upper and lower teeth in the final occlusal position of the mandible, optimal relationship of dental arches at the eccentric movement of the lower jaw and stable interocclusal space in physiological position. As there are no ideal order of teeth and absolute intermaxilar harmony nor individually acceptable standards or prototype of functionally optimal occlusion, the aim of this study was to analyze occlusal characteristics of identical twins. Methods. This clinical-epidemiological and functional study involved 30 pairs of identical twins, both males and females, aged 20 to 40 years. The main criterion for the selection of participants was preserved function of orofacial system, as a precondition for application of the Peer Assessment Rating (PAR) index, which is the most reliable tool for diagnosing malocclusion and evaluating occlusal parameters: the distance between the contact points of agonists of front segments of the dental arches, side occlusion of the sagittal, vertical and transversal position, overjet, anterior crossbite, deep and open bite, overbite of incisors and relationship of middle dental arches. Results. Using t-test for independent samples, no significant difference in the values of PAR index, according to gender, was established. The average difference of 0.833 between the twin groups (for male twins: ẍ = 7.97, SD = 6.625; for female twins: ẍ = 7.13, SD = 5.606) was not statistically significant [t (58) = 0.526; p = 0.601; 95% confidence interval: -2.339-4.005]. Conclusion. The lack of significant differences in occlusal PAR index analysis in both the same and different twin groups, implies the dominance of hereditary factors.Uvod/Cilj. Funkcionalno stabilnu okluziju karakterišu optimalan i ortopedski stabilan položaj kondila, harmoničan kontaktni odnos gornjih i donjih zuba u završnom okluzionom položaju mandibule, optimalna relacija pri ekscentričnim kretnjama donje vilice i stabilan interokluzioni prostor u po- ložaju fiziološkog mirovanja. Pošto ne postoje idealni poredak zuba i apsolutni međuvilični sklad, kao ni individualno prihvatljivi standardi optimalne okluzije, cilj rada bio je analiza okluzalnih obeležja jednojajčanih blizanaca. Metode. Kliničko-epidemiološkim i funkcionalnim ispitivanjem obuhvaćeno je 30 parova jednojajčanih blizanaca, podjednake polne zastupljenosti, starosti od 20 do 40 godina. Osnovni kriterijum za izbor ispitanika bila je očuvana funkcija orofacijalnog sistema, kao preduslov primene Peer Assessment Rating (PAR) indeksa kojim se najpouzdanije dijagnostikuju malokluzije i ocenjuju okluzalni parametri: rastojanje između kontaktnih tačaka agonista prednjih segmenata zubnih nizova, bočna okluzija u sagitalnom, vertikalnom i transverzalnom položaju, incizalni stepenik, prednji ukršten zagrižaj, dubok i otvoren zagrižaj, vertikalni preklop sekutića i odnos sredina zubnih nizova. Rezultati. Primenom t-testa za nezavisne uzorke nije utvrđena statistički značajna razlika u vrednostima PAR indeksa u zavisnosti od pola. Prosečna razlika od 0,833 između blizanačkih grupa (za blizance muškog pola: ẍ = 7,97, SD = 6,625; za blizance ženskog pola: ẍ = 7,13, SD = 5,606) nije bila statistički značajna [t (58) = 0,526, p = 0,601; 95% interval poverenja -2,339-4,005]. Zaključak. Izostanak značajnih razlika pri okluzalnoj analizi PAR indeksa, kod istih i različitih blizanačkih grupa, tumači se dominacijom naslednih faktora

Nature based solutions as the sustainable measures for hydrometeorological risk reduction – the Tamnava river case study

У раду се даје кратак приказ холистичког приступа смањењу ризика од поплава помоћу природи блиских решења. Овакав приступ узима у обзир не само смањење ризика као основни циљ мера заштите од поплава, већ и друге циљеве заједнице као што су заштита животне средине, добробит и здравље људи и друштвено-економски развој. На примеру слива реке Тамнаве, а као резултат истраживачког рада у међународном пројекту RECONECT у оквиру H2020 програма ЕУ, приказују се прелиминарни резултати примене овог концепта уз разматрање неколико сценарија могућих мера заштите и користи које оне могу донети у погледу смањења ризика од поплава и унапређења екосистемских услуга на сливу. Приказана методологија укључује новчано вредновање ефеката мера са гледишта смањења ризика (избегнутих штета), као секундарних ефеката од смањења ерозије додатним пошумљавањем. Ово друго вредновање је такође искоришћено за прелиминарну процену свих релевантних екосистемских услуга на сливу, што указује на вредност природног капитала овог слива. Овакве процене су важне за процес доношења одлука о мерама заштите од поплава.This paper presents briefly a holistic approach to reducing flood risks using the nature-based solutions. This approach takes into account not only the reduced risk as the primary goal of flood mitigation, but also involves other goals such as the protection of the environment, human well-being, socio-economic goals etc. The Tamnava River basin is used as a pilot case to demonstrate the methodology of such an approach, resulting from the work within the RECONECT project from the EU Horizon 2020 programme. The paper presents preliminary results for the Tamnava River basin by considering several scenarios for flood mitigation measures and potential benefits from these measures in flood risk reduction and in improved ecosystem services in the basin. The methodology includes monetary valuation of the effects of the proposed flood mitigation measures in terms of the avoided damages, as well as of the secondary benefits from the erosion control by additional afforestation. The latter also provides basis for preliminary valuation of all relevant ecosystem services in the basin, thus indicating the value of the basin’s natural capital. Such an evaluation is important for the decision-making process on possible flood mitigation strategies.Рад је добио Награду за најбољи научни рад са Прве меморијалне научно-стручне конференције ,,Предраг Марић". Конференција је одржана 11.2.2022. године. у просторијама Института за међународну политику и привреду, Македонска 25, у Београду. Годишњак Факултета безбедности 2022 (Faculty of Security Studies Annual), издавач Факултет безбедности Универзитета у Београду; адреса - Господара Вучића 50, Београд; обим 434 стране, штампани тираж 100 примерака, припрема и штампа ,,Чигоја штампа". Категорија часописа - M52. UDK 556.166(282)(497.11) COBISS.SR-ID 112460809 https://aseestant.ceon.rs/index.php/fb_godisnjak/article/view/37341/2267

Neizvesnosti u krivama protoka

The stage-discharge relayionships are the basic tool for transformation of observed water stages to streamflow discharges. As such, they have a key role in subsequent hydrological, hydraulic and water resources analyses. Uncertainties inherent in the stage-discharge relationships are the result of multiple causes; the complexity of the nature of catchment runoff, physics of water flow, its determination and interpretation. Тhe contemporary approach to the uncertainty definition is given, through definitions of the terms and calculation formulas. The method for stagedischarge curve uncertainty assesment, based on the ISO standard is presented. Used data are from the gauging station Bajina Bašta (the Drina river).Zbornik radova Građevinskog fakultet

Neizvesnosti u rezultatima hidrometrijskih merenja protoka

Zbornik radova Građevinskog fakultet

Učestalost hipodoncije i atipičnih lateralnih sekutića udruženih sa impaktiranim maksilarnim očnjacima

Background/Aim. Many authors find that impacted maxillary canines is associated with missing and peg-shaped lateral incisor. The aim of this study was to examine the prevalence of peg-shaped and missing lateral incisor in subjects with impacted maxillary canines, and compare the size of maxillary lateral incisor on the side with palatally impacted canines and on the opposite side of the jaw where there is no impaction. Methods. The study included 64 patients with 80 impacted maxillary canines (23 males and 41 females, mean age 16.3). For each maxillary unerupted canine, precisely correct localization and classification into groups was done. We analyzed the morphology of the lateral incisor (normal, atypical) and frequency of missing of lateral maxillary incisors with canine impaction. Then, from the mentioned examinees sample with the maxillary canine teeth, a subgroup was formed. The criteria for selection were those with unilateral palatally impacted canines (33 subjects, 22 females and 11 males, mean age 17.8 years). The linear variables of the maxillary lateral incisor were measured by using digital measurements tools. The t-test was used to test the differences between the groups. Results. Normal morphology of the lateral incisors was found in 72% of the subjects with the impacted canines, 11.2% of the subjects had the peg-shaped lateral incisors, 6% had a bilateral and 4% had unilateral deficiency of lateral incisors. In the subgroup of the patients with unilateral palatal impaction, the middle value of the length of the lateral incisors was 1.9 mm shorter and the middle value of the width of the lateral incisors was smaller by 0.9 mm when comparing to the control group. Conclusion. The frequency of the deficiency of lateral incisors was statistically significantly higher in the group with palatal canine impaction. The maxillary lateral incisors on the side with palatally impacted canines were smaller than those on the side where there was no impaction.Uvod/Cilj. Mnogi autori pronalazili su da su atipični lateralni sekutići, kao i njihov nedostatak, udruženi sa impakcijama maksilarnih očnjaka. Cilj ovog rada bio je da se ispita učestalost atipičnih lateralnih sekutića i njihov nedostatak kod pacijenata sa impaktiranim maksilarnim očnjacima kao i da se uporede veličine maksilarnih lateralnih sekutića na strani gde postoji palatinalno impaktiran očnjak i na suprotnoj strani vilice, gde ne postoji impakcija. Dužina i širina lateralnih sekutića merene su na trodimentzionalnim snimcima. Metode. Istraživanjem je bilo obuhvaćeno 64 ispitanika (23 muškog pola i 41 ženskog pola, prosečne starosti 16,3 godine) sa 80 impaktiranih maksilarnih očnjaka. Za svaki impaktirani očnjak precizno je određena njegova lokalizacija (bukalan, palatinalan ili sredina alveole) pomoću trodimenzionalnog snimka maksile na osnovu čega su podeljeni u grupe po mestu impakcije. Analizirana je morfologija lateralnih sekutića (normalni, atipični) i učestalost nedostatka lateralnih sekutića u grupi sa bukalnim i palatinalnim impakcijama, a zatim je iz te grupe ispitanika izdvojena podgrupa. Kriterijum za odabir bile su unilateralne palatinalne impakcije očnjaka (33 ispitanika, 22 ženskog pola i 11 muškog pola, prosečne starosti 17,8 godina). T-test je korišćen za testiranje razlika između grupa. Rezultati. Ukupno 72% ispitanika sa impaktiranim očnjacima imalo je lateralne sekutiće normalne morfologije, 11,2% konične lateralne sekutiće, 6% ispitanika imalo je bilateralni nedostatak lateralnih sekutića i 4% unilateralni nedostatak lateralnog sekutića. U podgrupi ispitanika sa unilateralnim palatinalnim impakcijama srednja vrednost dužine lateralnih sekutića bila je za 0,9 mm kraća, u poređenju sa kontrolnom grupom. Zaključak. Učestalost nedostatka lateranih sekutića bila je statistički značajno veća u grupi ispitanika sa palatinalnim impakcijama očnjaka nego u grupi sa bukalnim impakcijama očnjaka. Lateralni sekutići na strani palatinalno impaktiranih očnjaka bili su manji od onih na strani na kojoj nije bilo impakcije

Indexing of fatty acids in raw turkey meat and products for their characterization in a healthy diet

The aim of this work was to determine the fatty acid profile and health lipid indices of fresh turkey meat, as well as products obtained from turkey meat, i.e. turkey sausage and pate. Turkey breast muscles were cut from the side of the carcass, separately vacuum packed and stored in a refrigerator before analysis. Sausages and pate were produced from turkey meat using a technological process. The fatty acid profile of the samples was determined by gas chromatography with a flame ionization detector (GC/FID), and lipid indices were calculated based on the composition. Turkey muscle had a higher percentage of C16:0 and C18:0 than turkey sausage and pate. A significantly higher proportion of saturated fatty acids (47.9%) than in sausage and pate, 27.2 and 8.9%, respectively, characterized turkey muscle. The lowest determined proportion of polyunsaturated fatty acids for turkey muscle was 12.0%. The atherogenicity index was satisfactory for all three tested products, while the thrombogenicity index was satisfactory only for the tested raw turkey muscle meat (1.656)

Uticaj klimatskih promena na velike vode na dva sliva u Srbiji

Hydraulic structures are designed according to flows of a given return period. The design flows, estimated by means of statistical analysis, depend on the observations, while climate change impact is not explicitlytaken into account. As operating life of most hydraulic structures spreads over several decades, climate change impact should not be neglected. In this paper an analysis of climate change impact on flood flows is conducted for the Kolubara River at Slovac and for the Toplica River at Doljevac. The analysis is performed on the outputs of hydrologic modelling with the precipitation and temperature projections as the input. The Peaks over Threshold (POT) method is applied for frequency analysis of floods extracted from the flow projections. Characteristic quantiles are calculated for two future periods and compared to those estimated over the baseline period. The results suggest an increase in flood flows, particularly in the mid-21stcentury. Regardless of considerable uncertainty, these results can be used as indication of increase in design flows, and should be therefore taken into consideration within the hydraulic structure design.Zbornik radova Građevinskog fakultet

Metoda pikova - jedan stohastički model zapremina prekoračenja

Peaks-over-threshold method (POT) is the way for analysis of the stochastic structure of extreme hydrological events. For a chosen base flow and for characteristic value obtained form partial hydrographs, the POT method encompasses detection of discrete probability distribution of number of events in chosen time interval and continuous distribution of the exceedance values (peaks). This article presents a stochastic model for the analysis of the base flow exceedance volumes and accompanied cycle times between the ends of the successive exceedaence events. The model is based on the Markov's discreteds model principles and the assumptions about the form of the process intensity functions. The number of occurrence discrete distributions are discussed according to chosen forms of the time and volume intensity functions. The continuous distributions of the base flow exceedance characteristic values are modelled for the base series of values and their aggregation. The distribution of the maximum exceedance volume over the base flow in chosen time interval is formulated. The article presents an application of the suggested procedures on the mean daily flows hydrographs from the Bezdan gauging station on the Danube river.Metoda pikova je način analize ekstremnih hidroloških vrednosti kojim se iz rapoloživih podataka-hidrograma dolazi do osobina stohastičke strukture pojave. Analizira se diskretna raspodela broja javljanja veličine u zadatom intervalu vremena t i kontinualna raspodela vrednosti veličine prekoračenja baznog protoka. U ovom radu koristi se stohastički model za analizu zapremine prekoračenja baznog protoka i odgovarajućih trajanja ciklusa između prekoračenja. Model je zasnovan na principima prekidnih procesa Markova i pretpostavkama o prirodi funkcija intenziteta procesa. Analiziraju se moguće diskretne raspodele broja javljanja kao posledice izabranih oblika funkcija vremenskog i zapreminskog intenziteta procesa. Modelira se neprekidna raspodela veličina prekoračenja, za osnovne nizove i agregacije (udruživanja) njihovih članova. Data je formulacija ovih raspodela u funkciji raspodele broja javljanja. Navodi se izraz za funkciju raspodele maksimalne vrednosti zapremine prekoračenja baznog protoka u intervalu vremena t. Uz tekst su dati primeri analize podataka sa hidrometrijske stanice Bezdan na Dunavu

Formation of conductive pathways in electrolytic copper filled lignocellulose composites

Ispitivana je električna provodljivost sistema baziranog na lignoceluloznom (LC) biopolimernom matriksu ispunjenog elektrohemijski dobijenim bakarnim prahom. Galvanostatski dobijen bakarni prah sa veoma poroznim, veoma dendritičnim i česticama sa velikom specifičnom površinom je korišćen kao punilac. Zapreminski udeo elektrohemijski dobijenog bakarnog praha je iznosio od 2.0 - 29.8 vol%. Analiza najznačajnijih osobina pripremljenih kompozita je obuhvatala merenja električne provodnosti, impedansnu spektroskopiju (IS) i strukturnu analizu. Značajan porast električne provodnosti se javlja kada udeo bakarnog praha dostigne vrednost perkolacionog praga (PP). Pokazano je da PP zavisi od oblika čestica i spatijalne distribucije. SEM analiza uzoraka je pokazala da čestice sa izraženim granicama zrna igraju veliku ulogu u pojavljivanju provodnih puteva i na elektroprovodljivost kompozita. Efekat pakovanja i izraženi međučestični kontantakti između čestica bakarnog praha sa velikom specifičnom površinom su doveli do pomeranja perkolacionog praga, koji za čestice 45 μm i pritisak od 27 MPa iznosi 7.2% v/v.The electrical conductivity of the composite system based on lignocellulose (LC) biopolymer matrix electrodeposited copper powder filler has been studied. Highly porous, highly dendritic galvanostatically produced copper powder was used as filler since these particles have high values of specific area. Volume fraction of the electrodeposited copper powder was varied from 1.9 - 29.4 vol%. Analysis of the most significant properties of prepared composites and its components included impedance spectroscopy (IS) behavior, measurements of electrical conductivity, scanning electron microscopy (SEM) and structural analysis. The significant increase of the electrical conductivity could be observed as the copper powder content reaches the percolation threshold (PT). It was shown that PT depends on both particle shape and type of spatial distribution. IS measurements and SEM analysis have shown that particles having pronounced grain boundaries have great effect on appearance of electric conductive pathways thus on the composite conductivity. The packaging effect and more pronounced interpartical contact with copper powder particles lead to “movement” of PT, which for the particles <45 μm and highest processing pressure of 27 MPa was 7.2% (v/v). IS response of the composites showed existence of electrical conductive layers, each having different resistivity which increases towards interior of the composite