579 research outputs found
Aritmetičke funkcije teorije brojeva
U ovom radu opisujemo aritmetičke funkcije teorije brojeva. Rad je podijeljen na četiri poglavlja. U prvom poglavlju donosimo definicije i pregled multiplikativnih funkcija, te aditivnih funkcija uz neka njihova svojstva. Funkcije koje obrađujemo su: Eulerova funkcija, zbroj djelitelja, broj djelitelja, Liouvilleova funkcija, Möbiusova funkcija, broj različitih prostih faktora, von Mangoldtova funkcija. U drugom poglavlju donosimo definiciju i tvrdnje vezane za Dirichletov produkt aritmetičkih funkcija, dok se u trećem poglavlju bavimo generalizacijom konvolucije. U posljednjem poglavlju definiramo derivaciju aritmetičke funkcije te opisujemo njezina svojstava i dokazujemo Selbergov identitet.In this thesis, we describe some arithmetic functions of the theory of numbers. Thesis is divided into four chapters. In the first chapter, we provide basic definitions and properties of multiplicative functions and additive functions. We also describe particular functions such as: Euler function, sum of divisor function, divisor function, Liouville function, Möbius function, the number of distinct prime factors and the von Mangoldt function. In the second chapter, we provide an overview of basic definition and claims related to the Dirichlet product of arithmetic functions, while in the third chapter we define the generalized convolutions. In the last chapter, we define the derivation of arithmetic functions, describe its properties, and prove the Selberg identity
Evolution of Communication Skills in Virtual Product Development Process: Experience From EGPR
More than a decade of continuous international collaboration of several European universities in teaching new product development in virtual environment gives unique opportunity to investigate evolution and development of communication techniques for NPD collaboration in virtual environment. This chapter provides theoretical and practical view on different aspects: technical evolution of ICT tools, development and fostering of communication flow, personal aspects of IT communication, with important emphasis on building of trust within virtual teams. The reader can extract from this chapter guidelines for work in collaborative virtual environment, to run effectively either small projects, meetings and lectures or even more complex projects, distributed among several dislocated teams. The chronological overview of the continuous virtual communication in the last 15 years gives also fair suggestions about future evolution for the next decade
The influence of product complexity on team performance within NPD
This paper explores the influence of product complexity on team performance. A longitudinal case study of a Masters course European Global Product Realisation, where 4 universities collaborate on product development projects is used to study the phenomenon. 4 different projects are explored, where in 2 of them teams worked on the full product development process for a particular product and 2 projects where several teams worked on a single product, thus the focus was on developing specific modules of the same product, due to its complexity
PREMISE OF ENCOURAGING AUTONOMY IN CHILDREN\u27S WORK AND OPINION
Cilj ovoga rada je uočavanje određenih metoda koje bi dovele do autonomije djece u njihovim aktivnostima, a samim time i do razvoja kritičkog mišljenja. Pripremajući poticajno prostorno-materijalno okruženje, nastoji se imati na umu individualne sposobnosti djece i individualne interese prema pojedinim područjima. Podjelom prostora na mnoštvo različitih centara djeca samostalno biraju individualni pristup ili rad u manjim grupama. Podržavanjem samoiniciranih aktivnosti djece proizašlih iz poticajnog okruženja djeci se omogućava stjecanje znanja, konstruiranje znanja, samostalno donošenje odluka, smjer razvoja aktivnosti te preuzimanje odgovornosti za realizaciju iste. Postavljajući pitanja, nastoji se djetetu ukazati na zanimanje za ono što radi naglašavanjem važnosti djetetove aktivnosti i davanje podrške za daljnji nivo djetetova razmišljanja. Na taj se način potiče djetetovo samopouzdanje i samostalnost. Osim osiguravanja prostorno-materijalnog okruženja i podržavanjem samoiniciranih dječjih aktivnosti, odgojitelj podržava i prepoznaje rad djece na projektima proizašlih iz njihovih interesa. Rad djece na projektu, kao metoda apsolutne autonomije, omogućava atmosferu koja će rezultirati opuštenom realizacijom projekta, uvažavajući dječje mišljenje o daljnjem razvoju projekta. Rezultati praćenja kroz određeni vremenski period pokazali su da se ovakvim pristupom radu djeca osjećaju prihvaćena, jačaju samopouzdanje, konstruiraju vlastito razumijevanje, uče se dijalogu, neometano iznose mišljenja i stavove te postavljaju nove hipoteze i sve više ulaze u druge nivoe nadogradnje cjelokupnog razvoja
Zavisnost efikasnosti germanijumskih detektora od gustine uzoraka u spektrometriji gama zračenja
The effect of the density of environmental samples on the counting efficiency of Ge detectors used in gamma-spectrometry was studied. The dependence εff(ρ) was determined for two HPGe detectors (relative efficiencies 18% and 20%) using five radioactive standard reference materials (silicone resins, epoxy resin, milk powder, soil) with different matrix densities (0.45-1.22 g/cm3) in Marinelli beakers (V = 500 cm3). The dependence of efficiency vs. density was found to be linear and the regression parameters for energies in the range of 60-2000 keV were determined, too. The effect of variation in density on the counting efficiency of Ge detectors is dominant in the range of lower energies (60-600 keV) and de creases with energies in the higher energy range.Ispitivan je uticaj gustine uzoraka iz životne sredine na efikasnost brojanja germanijumskih detektora u spektrometriji gama zračenja. Zavisnost εff(ρ) određena je za dva HPGe detektora (relativnih efikasnosti 18% i 20%) za različite radioaktivne standardne referentne materijale (silikonske smole epoksi smolu, mleko u prahu, zemlju) različitih gustina (0,45-1,22 g/cm3) u Marineli posudama zapremine V = 500 cm3. Utvrđena je linearna zavisnost efikasnosti brojanja od gustine uzoraka pri čemu su određeni parametri linearne regresije za niz energija iz intervala od 60-2000 keV. Efekt promene gustina na efikasnost brojanja germanijumskih detektora dominantan je u intervalu nižih energija (60-600 keV) i smanjuje se sa porastom energije u intervalu viših energija
Exploring the KEER knowledge landscape over the past decade
The aim of this paper was to systematically explore the knowledge landscape of papers presented at KEER conferences over the last decade. We collected all papers published in conference proceedings between 2010 and 2020. We (i) used a text mining pipeline to extract, clean, and normalize keywords from the Title and Abstract fields, and (ii) created a co-occurrence network reflecting the relationships between keywords. The network was then characterized at different levels of granularity (static analysis vs. time slice analysis and whole network vs. node-level analysis). The exploratory analysis showed a stable expansion of the network over time. The cluster structure revealed several groups of keywords that did not change over time and reflected both domain-specific and method-specific topics of research in Kansei engineering
Selected Metal Concentrations in Some Medical Herbs from Localities Around Mount Bjelasica
The use of wild herbs to relieve and treat many human diseases is increasing worldwide, due to their medicinal features and limited side effects. The content of metals in them is of great interest. Our objective was to determine the levels of Cu, Fe, Mn, Ni, and Zn in individual parts of four medicinal plant species (Achillea millefolium L., Origanum vulgare L., Thymus serpyllum L., and Hypericum perforatum L.) and their native soil. For the study, we selected four sites located at the foot of Mount Bjelasica in Montenegro. Microwave-assisted digestion was applied for the dissolution of the samples and the metal concentrations were determined using atomic absorption spectrometry (AAS). All the investigated metals are most concentrated in the roots of the tested herbs. The translocation of metal from the root to the aboveground parts is different and depends on the metal and the plant. All the tested plants contain the most Fe (except oregano) and the least Ni. The most significant levels of Zn (44.6–116 mg kg–1), Ni (0.10–26.3 mg kg–1) and Mn (28.4–329 mg kg–1) were found in O. vulgare, the largest concentration of Cu (20.6–85.4 mg kg–1) in H. perforatum and Fe (108–1324 mg kg–1) showed its largest value in T. serpyllum.
This work is licensed under a Creative Commons Attribution 4.0 International License
The Decameron by Giovanni Boccaccio according to the medieval exemplum
Cilj ovog završnoga rada usporedba je Boccacciove zbirke novela Dekameron sa srednjovjekovnim exemplumom koji svoje ishodište ima u grčko-rimskoj kulturi. Srednjovjekovni je exemplum obrnuti Boccacciov Dekameron u ozračju antičkog utjecaja. Iščitavajući zadane predloške, detektirali smo karakteristike značajne za razdoblje renesanse, a ujedno i Boccacciove zbirke novela koja pripada navedenome razdoblju. Govoreći o Dekameronu, važno je spomenuti i osnovne značajke srednjovjekovnog exempluma koji prethodi Dekameronu
Analysis of lipids and fatty acids of non-diapausing and diapausing larvae of European corn borer (Ostrinia nubilalis, Hbn.) (Insecta: Lepidoptera)
Kukuruzni plamenca (Ostrinia nubilalis, Hbn.) je vrsta umerenog klimatskog područja koja niske zimske temperature preživljava ulaskom u dijapauzu u stadijumu gusenice. Dijapauza i otpornost na hladnoću (cold hardiness, eng.), kod mnogih insekatskih vrsta često predstavljaju esencijalne, tesno povezane komponente strategije preživljavanja delovanja niske temperature, kao što je to slučaj i kod kukuruznog plamenca Ostrinia nubilalis, Hbn. U okviru grupe insekata otpornih na hladnoću, svrstava se u insekte otporne na zamrzavanje (freeze tolerant, eng.) jer su sposobne da prežive ekstracelularno zamrzavanje telesnih tečnosti. Iako se o osnovnim strukturnim i metaboličkim dešavanjima u dijapauzi insekata već dosta zna, još uvek postoje brojne dileme o ovom vidu preživljavanja insekata u nepovoljnim uslovima sredine, posebno sa aspekta izloženosti niskim zimskim temperaturama i mehanizmima krioprotekcije. Zbog toga je cilj ove doktorske disertacije bio da se sa aspekta biofizičkih osobina lipida i sastava masnih kiselina: odrede biofizičke osobine (temperature faznog prelaza) ukupnih lipida nedijapauzirajućih i dijapauzirajućih gusenica tokom dijapauze (početak, sredina i kraj), kao i u kontrolisanim uslovima hlađenja dijapauzirajućih gusenica; zatim da se odredi zastupljenost pojedinih klasa lipida u hemolimfi i masnom telu nedijapauzirajućih i dijapauzirajućih gusenica; da se utvrde promene sastava masnih kiselina strukturne (polarne) i rezervne (nepolarne) frakcije lipida celih gusenica tokom dijapauze i pod uticajem različitih temperatura u eksperimentalnim uslovima; kao i da se odredi tkivna specifičnost, hemolimfe i masnog tela, masnih kiselina ukupnih lipida i biofizičke osobine ukupnih lipida masnog tela nedijapauzirajućih i dijapauzirajućih gusenica tokom dijapauze, kao i u kontrolisanim uslovima hlađenja dijapauzirajućih gusenica. U analizi lipida kukuruznog plamenca Ostrinia nubilalis, Hbn. korišćene su sledeće tehnike: tankoslojna hromatografija (TLC) sa skenirajućom denzitometrijom, za razdvajanje i analizu klasa lipida; zatim gasno-masena hromatografija (GC-MS), za analizu masnih kiselina kao i diferencijalna skenirajuća kalorimetrija (DSC – differential scanning calorimetry, eng.), za termalnu analizu ekstrahovanih lipida. Kod gusenica Ostrinia nubilalis sastav masnih kiselina ukupnih lipida analiziranih tkiva i lipidnih frakcija značajno se razlikuje između ova dva fiziološka stanja, stanja dijapauze i nedijapauze. Dijapauza indukuje značajno povećanje sadržaja mononezasićenih masnih kiselina, pre svega palmitoleinske (16:1n-7) i oleinske masne kiseline (18:1n-9) uz istovremeno smanjenje sadržaja zasićenih i polinezasićenih masnih kiselina, pre svega palmitinske (16:0) i linolne masne kiseline (18:2n-6). Temperature faznog prelaza ukupnih lipida celih gusenica i masnog tela značajno su niže kod dijapauzirajućih gusenica O. nubilalis, usled značajnog povećanja stepena nezasićenosti masnih kiselina u njihovom sastavu. Značajno niže temperature faznog prelaza lipida dijapauzirajućih gusenica O. nubilalis rezultat su povećanja stepena nezasićenosti njihovih masnih kiselina. Možemo zaključiti da su promene u sastavu masnih kiselina lipida indukovane dijapauzom važna komponenta preživljavanja niskih temperatura kod O. nubilalis Hbn. jer se veliki deo lipida održava u tečnom stanju čak i na temperaturama daleko ispod 0°C, što je neophodno za održavanje njihove fluidnosti odnosno funkcionalnosti.European corn borer (Ostrinia nubilalis, Hbn.) inhabiting temperate regions that survive low winter temperatures as a diapausing fifth instar larva. Diapausing larvae are cold hardy and freeze tolerant as they are able to survive the extracellular formation of ice crystals. Winter survival for many insect species living in seasonally cold environments includes a radical remodeling of metabolism. This implies entry into a developmentally arrested, hypometabolic state of winter diapause, which in O. nubilalis and many other insect species of these habitats is closely related to their cold hardiness. Although the basic structural and metabolic events consider insect diapause is already known, there are still many doubts about the survival of insects in an unfavorable environment, particularly in terms of exposure to low winter temperatures and mechanisms of cryoprotection. Therefore, the aim of this thesis in terms of biophysical properties of lipids and fatty acid compositions, was to: i) to determine the biophysical properties (phase transition temperatures) of the total lipids of non-diapausing larvae and diapausing larvae during diapause (early diapause, mid diapause and termination of diapause), as well as under controlled cooling conditions during different phases of diapause; ii) to determine the fatty acid compositions of structural (polar) and storage (non-polar) total lipid fractions of non-diapausing larvae and diapausing larvae, as well as under the influence of different temperatures during diapause in the controled experimental conditions; iii) to determine the lipid classes composition of total lipids extracted from the haemolymph and fat body of non-diapausing and diapausing larvae; iiii) to determine the haemolymph and fat body total lipid fatty acid compositions as well as the biophysical properties of the fat body total lipids of non-diapausing larvae and diapausing larvae during diapause as well as in terms of controlled cooling conditions. Thus, our research was focused on the non-diapausing (ND) as well as the diapausing larvae (D) that were exposed to low temperatures during different phases of diapause. During analysis of European corn borer O. nubilalis lipids, the following techniques was used: thin layer chromatography (TLC) with scanning densitometry, for the separation and quantification of lipid classes; gas-mass chromatography (GC-MS ) for the analysis of the fatty acid composition of lipids and the differential scanning calorimetry (DSC), for the thermal analysis of the extracted lipids. The fatty acid compositions and biophysical properties of lipids differed markedly between non-diapausing and diapausing larvae of O. nubilalis. Diapause was associated with a dramatic increase mainly the proportions of palmitoleic acid (16:1n-7) and oleic acid (18:1n-9), with concurrent reductions in palmitic acid (16:0) and linoleic acid (18:2n-6). The increase in the level of unsaturation of lipids, which caused a marked shift in their phase transitions to lower temperatures, was triggered by diapause rather than low temperatures. Adjustments of fatty acid compositions are likely to be an important component of winter diapause mechaisms, possibly maintaining the fluidity of cell membranes, and the functionality of the organism during lower winter temperatures. We conclude that O. nubilalis undergoes remodeling of fatty acid profiles of lipids as an element of its overwintering physiology which may improve the ability to harden during diapause
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