Performance simulation methodologies for hardware/software co-designed processors

Recently the community started looking into Hardware/Software (HW/SW) co-designed processors as potential solutions to move towards the less power consuming and the less complex designs. Unlike other solutions, they reduce the power and the complexity doing so called dynamic binary translation and optimization from a guest ISA to an internal host custom ISA. This thesis tries to answer the question on how to simulate this kind of architectures. For any kind of processor's architecture, the simulation is the common practice, because it is impossible to build several versions of hardware in order to try all alternatives. The simulation of HW/SW co-designed processors has a big issue in comparison with the simulation of traditional HW-only architectures. First of all, open source tools do not exist. Therefore researches many times assume that the software layer overhead, which is in charge for dynamic binary translation and optimization, is constant or ignored. In this thesis we show that such an assumption is not valid and that can lead to very inaccurate results. Therefore including the software layer in the simulation is a must. On the other side, the simulation is very slow in comparison to native execution, so the community spent a big effort on delivering accurate results in a reasonable amount of time. Therefore it is the common practice for HW-only processors that only parts of application stream, which are called samples, are simulated. Samples usually correspond to different phases in the application stream and usually they are no longer than a few million of instructions. In order to archive accurate starting state of each sample, microarchitectural structures are warmed-up for a few million instructions prior to samples instructions. Unfortunately, such a methodology cannot be directly applied for HW/SW co-designed processors. The warm-up for HW/SW co-designed processors needs to be 3-4 orders of magnitude longer than the warm-up needed for traditional HW-only processor, because the warm-up of software layer needs to be longer than the warm-up of hardware structures. To overcome such a problem, in this thesis we propose a novel warm-up technique specialized for HW/SW co-designed processors. Our solution reduces the simulation time by at least 65X with an average error of just 0.75\%. Such a trend is visible for different software and hardware configurations. The process used to determine simulation samples cannot be applied to HW/SW co-designed processors as well, because due to the software layer, samples show more dissimilarities than in the case of HW-only processors. Therefore we propose a novel algorithm that needs 3X less number of samples to achieve similar error like the state of the art algorithms. Again, such a trend is visible for different software and hardware configurations.Els processadors co-dissenyats Hardware/Software (HW/SW co-designed processors) han estat proposats per l'acadèmia i la indústria com a solucions potencials per a fabricar processadors menys complexos i que consumeixen menys energia. A diferència d'altres alternatives, aquest tipus de processadors redueixen la complexitat i el consum d'energia aplicant traducció y optimització dinàmica de binaris des d'un repertori d'instruccions (instruction set architecture) extern cap a un repertori d'instruccions intern adaptat. Aquesta tesi intenta resoldre els reptes relacionats a la simulació d'aquest tipus d'arquitectures. La simulació és un procés comú en el disseny i desenvolupament de processadors ja que permet explorar diverses alternatives sense haver de fabricar el hardware per a cadascuna d'elles. La simulació de processadors co-dissenyats Hardware/Software és un procés més complex que la simulació de processadores tradicionals, purament hardware. Per exemple, no existeixen eines de simulació disponibles per a la comunitat. Per tant, els investigadors acostumen a assumir que la capa de software, que s'encarrega de la traducció i optimització de les aplicacions, no té un pes específic i, per tant, uns costos computacionals baixos o constants en el millor dels casos. En aquesta tesis demostrem que aquestes premisses són incorrectes i que els resultats amb aquestes acostumen a ser molt imprecisos. Una primera conclusió d'aquesta tesi doncs és que la simulació de la capa software és totalment necessària. A més a més, degut a que els processos de simulació són lents, s'han proposat tècniques de simulació que intenten obtenir resultats precisos en el menor temps possible. Una pràctica habitual és la simulació només de parts de les aplicacions, anomenades mostres, en el disseny de processadors convencionals, purament hardware. Aquestes mostres corresponen a diferents fases de les aplicacions i acostumen a ser de pocs milions d'instruccions. Per tal d'aconseguir un estat microarquitectònic acurat per a cadascuna de les mostres, s'acostumen a estressar aquestes estructures microarquitectòniques del simulador abans de començar a extreure resultats, procés anomenat "escalfament" (warm-up). Desafortunadament, aquesta metodologia no pot ser aplicada a processadors co-dissenyats Hardware/Software. L'"escalfament" de les estructures internes del simulador en el disseny de processadores co-dissenyats Hardware/Software són 3-4 ordres de magnitud més gran que el mateix procés d' "escalfament" en simulacions de processadors convencionals, ja que en els primers cal "escalfar" també les estructures i l'estat de la capa software. En aquesta tesi proposem tècniques de simulació basades en l' "escalfament" de les estructures que redueixen el temps de simulació en 65X amb un error mig del 0,75%. Aquests resultats són extrapolables a diferents configuracions del hardware i de la capa software. Finalment, les tècniques convencionals de selecció de mostres d'aplicacions a simular no són aplicables tampoc a la simulació de processadors co-dissenyats Hardware/Software degut a que les mostres es comporten de manera molt diferent quan es té en compte la capa software. En aquesta tesi, proposem un nou algorisme que redueix 3X el nombre de mostres a simular comparat amb els algorismes tradicionals per a processadors convencionals per a obtenir un error similar. Aquests resultats també són extrapolables a diferents configuracions de hardware i de software. En conclusió, en aquesta tesi es respon al repte de com simular processadors co-dissenyats Hardware/Software, que són una alternativa al disseny tradicional de processadors. Hem demostrat que cal simular la capa software i s'han proposat noves tècniques i algorismes eficients d' "escalfament" i selecció de mostres que són tolerants a diferents configuracion

Influence of ZnO nanoparticles on slow release of essential oil from polimeric matrix

Biopolymer emulsions were processed in the form of thin films for application in active food packaging. Active packaging is defined as material designed to release active components into food or absorb them from food in order to extend durability or to maintain/improve packaging conditions and extend shelf-life of food. We synthesized emulsion based on biodegradable polymers (pectin, gelatin, chitosan) with addition of active components -essential oils and ZnO nanoparticles (NPs). By introducing essential oils in the polymer matrix, with the addition of certain emulsifiers, it comes to encapsulation of oil droplets and the formation of a homogeneous emulsion. Thin films were fabricated by mold casting or spraying of the emulsions on a substrate. The slow release of an essential oil from the polymeric matrix was determined by UV-vis spectrophotometry. It was shown that polymers with addition of nanoparticles provided a prolonged action of active components. Surface morphology of the films was characterized by atomic force microscopy (AFM), and it was noticed that nanoparticles were mainly accumulated around oil droplets, which additionally contributed to a slow release of the active components

Visible-light photocatalytic degradation of mordant blue 9 by BiVO4 nanopowder

The photocatalytic degradation of highly toxic azo dye Mordant Blue 9 (MB 9) was investigated using single-phase monoclinic BiVO4 nanopowder as a photocatalyst under the simulated solar irradiation. The photodegradation process as a function of different pH values of aqueous dye solution (pH = 1 – 13) and irradiation time was investigated, and the complete degradation mechanism was proposed. MB 9 was resistant to direct photolysis and the BiVO4 nanoparticles exhibited higher photocatalytic activity in a basic medium than in neutral and acid media. Photodegradation of the dye molecules occurred primarily due to a reaction with the photo-generated holes and OH– anions forming ∙OH radicals. The alkaline pH range favors the formation of more ∙OH radicals through the oxidation of hydroxide ions existing at the BiVO4 surface, thus the effectiveness of the photocatalytic process significantly increased. BiVO4 photocatalyst was stable and active under simulated solar irradiation over four consecutive cycles, which confirms its good photocatalytic properties

CHITOSAN- AND PECTIN-BASED COATINGS WITH INCORPORATED ACTIVE COMPONENTS FOR APPLICATION IN ACTIVE FOOD PACKAGING

The subject of this research was the development of biodegradable and eco-friendly material based on natural biopolymers from renewable sources, with the addition of active components for application in active food packaging. The main principle was the incorporation of the active components (lemongrass (Cymbopogon citratus L.) essential oil, ZnO nanoparticles, or Zn(CH3COO)2∙2H2O) with antimicrobial activity in the polymer matrix (chitosan, pectin, and gelatin), and their slow release during the time. All of the used components are listed as GRAS (Generally Recognized as Safe) by the U.S. Food and Drug Administration. Different formulations of emulsions and dispersions were processed for mutual comparison. The stability of chitosan and pectin emulsions was determined by using laser diffraction methods. Chitosan emulsions exhibited higher stability during 30 days of storage. The chitosan emulsions and dispersions exhibited a higher antibacterial effect in vitro against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. Biopolymer coatings were formed by the spraying of emulsions on existing packaging. The effects of biopolymer coatings on the development of microorganisms on fresh raspberries (Rubus idaeus L.) were performed in vivo during eight days of raspberry storage at refrigerator temperature. The tested coatings extended the shelf life of stored raspberries from four to eight days. The synergistic effect between lemongrass essential oil and ZnO nanoparticles or Zn(CH3COO)2∙2H2O was observed both in vivo and in vitro

APPLICATION OF MEMBRANE TECHNOLOGY IN THE TREATMENT AND ANALYSIS OF TRIAZINE PESTICIDES IN WATER

The quality of consumable water is decreasing due to increasing water pollution caused by the production and use of human-made chemicals. A significant part of these chemicals are pesticides from the class of triazines since they are widely used in agriculture as herbicides. Water treatment techniques mainly rely on separation science, where the membrane technology has been identified as the most useful. Membrane processes used in water treatment are microfiltration, ultrafiltration, nanofiltration and reverse osmosis. In general, the pollutant retention/rejection by membranes depends on the physicochemical properties of the membrane i.e. membrane material, porosity, pore size and on the properties of the pollutant molecule i.e. size, length, width, molecular weight, hydrophobicity or dipole moment. The pollutant retention also depends on the feed-water composition (organic matter and salt presence, solute concentration, water pH). Thus, effective water treatment depends on the selection of an appropriate type of membrane for a particular type of pollutants. Membrane technology is also significant because it is used in polluted water analysis, more precise as a part of a liquid-phase or solid-phase microextraction. Among several developed membrane-based microextraction methods, in triazine polluted water analysis common are membrane-protected solid-phase microextraction and hollow-fiber liquid-phase microextraction. In this field, researchers tend to achieve membrane-pollutant compatibility through the synthesis of polymeric materials with molecular recognition properties i.e. through a technology called molecular imprinting. HIGHLIGHTSAmong several water treatment techniques, the membrane technology has been identified as the most robust and flexible one.The most common water pollutants are triazine pesticides since they are widely used in agriculture as herbicides.The triazines retention by membranes depends on the membrane and triazine molecule properties, but also on the feed-water composition.Thanks to the molecular imprinting technology, membrane technology has found its application in polluted water analysis as a part of sample preparation

Ultrasonic synthesis and characterization of mesoporous monoclinic BiVO4 nanopowder

The BiVO4 sample was successfully synthesized from a mixture of ammonium vanadate, bismuth(III) nitrate, and nitric acid exposed to ultrasound irradiation. Structure, microstructure and optical properties of the obtained BiVO4 nanopowder were investigated. X-ray diffraction (XRD) analysis confirmed single phase monoclinic lattice system with average crystallite size of 50 nm in diameter. Scanning electron microscopy (SEM) micrographs revealed the tendency of crystallites to agglomerate forming larger irregular sub-micron spheres. Brunauer-Emmett-Teller (BET) method was used to estimate the specific surface area of the sample and determine pore shape and size. UV–vis spectroscopy measurements have revealed favorably high absorbance of the visible light with the calculated band-gap value of 2.48 eV. Calculated values of valence and conducting band energies are +2.77 eV and +0.29 eV respectively, suggested that BiVO4 can be used for photocatalytic degradation under sunlight irradiation as evident from the UV–vis spectrum

Variability of mass of spike in wheat (Triticum aestivum L.) genotypes under different environments

In this paper was analyzed mass of spike in 20 genetically divergent wheat genotypes. Wheat cultivars were grown in two years which characterized different climatic condition. In both years samples of 60 wheat plants (20 plants in 3 replications) were analyzed in full maturity stage. For improving different traits we need conduct special selection of parents after analysis of expression of certain traits. The differences in average values of mass of spike in studied wheat genotypes were determined. The variability of mass of spike was established. The average values of mass of spike for both year of growing, varied from 2.74g in G-3568 to 3.9g in G-13610

Structural, optical and photocatalytic properties of BiFeO3 nanoparticles

BiFeO3 (BFO) precursor powder was synthesized by ultrasound asissted sol–gel route at relatively low temperature, starting from Bi-nitrate, Fe-nitrate, and ethylene glycol. Structural, optical, and photocatalytic properties of the obtained powder were investigated. X-ray diffraction analysis confirmed that thermal treatment of precursor powder at 500 °C led to formation of pure phase BiFeO3. BFO is p-type semiconductor where determined band gap was 2.20 eV, indicating its potential application as visible-light-response photocatalyst. Mott-Schottky measurements were performed to determine flat band potential and position of valence and conduction bands. Obtained BFO powder is used for photocatalytic degradation of typical organic azo dye Mordant Blue 9 in concentration of 50 mg/l. Measurements were performed for different times of irradiation and pH of the dye solution. Photodegradation products were analyzied by HPLC technique, and mechanism of photocatalytic degradation of organic dye was proposed

Proučavanje stabilnosti prinosa kukuruza neparametrijskim metodama

High and stabile yield in different production environments is priority in maize breeding. New statistical methods are constantly being sought to accompany analysis of variance, in order to achieve more reliable hybrid assessment. In this study nonparametric stability analysis is applied in order to assess GxE interaction for yield of 36 commercial maize hybrids. The experiment was set up at five locations in Serbia for three years according to the Randomised complete block design in three replications. Yield stability of investigated genotypes was analysed by stability parameters Si (1), Si (2), Si (3), Si (6) TOP and RS. Analysis of variance identified highly significant F values for all experimental factors. Bredenkamp method confirmed the existence of non-crossover GxE interaction, for maize yield. Hybrid ZPH15 achieved the most stable yield based on parameters Si (1) and Si (2). According to parameter Si (3) it was ZPH5, while based on parameter Si (6) it was ZPH34. The highest overall yield achieved ZPH36 (11.18 t ha-1 ), which was quite unstable (rank 24 in parameters Si (1) and Si (2)), and very unstable (rank 34 in parameters Si (3) and Si (6)). The most stable hybrids had average yields. In total, the hybrid ZPH23 had the best average rank (15.93). Based on TOP parameter, ZPH36 had the best rank (yield), followed by ZPH11, ZPH20, ZPH21 and ZPH9. However, RS parameter revealed that ZPH21 was the most stable hybrid, so taking into account both TOP and RS parameters this is the most productive and the most stable hybrid. Based on this research, TOP and RS are the best parameters for selecting new maize hybrids for production in particular environment. In case of identical TOP value, the genotype with the lowest RS value should be selected. The parameters Si (1), Si (2), Si (3) and Si (6) can be used as alternative methods for the selection of genotypes with moderate yield and high stability.U ovom radu primenjena je neparametarska analiza stabilnosti kako bi se procenila GxE interakcija za prinos 36 hibrida kukuruza. Eksperiment je postavljen na pet lokacija u Srbiji u trajanju od tri godine po potpuno slučajnom blok dizajnu (RCBD) u tri ponavljanja. Stabilnost prinosa ispitivanih genotipova analizirana je parametrima stabilnosti Si (1), Si (2), Si (3), Si (6), TOP i RS. Hibrid ZPH15 je postigao najstabilniji prinos na osnovu parametara Si (1) i Si (2), prema parametru Si (3) ZPH5, dok je na osnovu parametra Si (6) to bio ZPH34. Najrodniji hibrid ukupno u ogledu bio je ZPH36 sa prosečnim prinosom od 11,180 t/ha, koji je na osnovu ranga parametara Si (1) i Si (2) bio dosta nestabilan (rang 24), a na osnovu ranga parametara Si (3) i Si(6) veoma nestabilan (rang 34). Najstabilniji hibridi imali su prinos oko proseka. Ukupno, najbolji prosečan rang imao je hibrid ZPH 23 (15,93). Na osnovu TOP parametra najbolji rang (prinos) imao je ZPH36, a zatim ZPH11, ZPH20, ZPH21 i ZPH9. Međutim, RS parametar je pokazao da je ZPH21 najstabilniji hibrid, tako da je uzimajući u obzir i TOP i RS parametre ovo najproduktivniji i najstabilniji hibrid. Na osnovu ovog istraživanja, od svih posmatranih neparametarskih parametara, parametri TOP i RS pokazali su se kao najbolji za odabir novih hibrida kukuruza za gajenje u određenom regionu. U slučaju identične TOP vrednosti, treba izabrati genotip sa najnižom RS vrednošću, dok se parametri Si (1), Si (2), Si (3) i Si (6) mogu koristiti kao alternativne metode za selekciju genotipova sa umerenim prinosom i visokom stabilnošću