1,597 research outputs found
Calculation of the effective properties of trapezoidal steel sheets
In the present days, thin-walled structural members are getting used more and more
in the industrial domain, that’s why the research of these type of elements demands a lot of
attention. One special place between these elements, is occupied by the cold-formed
trapezoidal steel sheets.
The evolution of this domain concluded in appearance of a numerous manufacturers
producing trapezoidal steel sheets, for industrial roofing and structure covering. Due to the
high competition, the efficiency and accuracy in determining the load carrying capacity of
the sheets has a key role. The methods used to achieve these results have to be conformed
with the codes and standards of the country where the sheets are going to be in service.
The following study researches the behaviour of trapezoidal steel sheets submitted
to bending. The main concept of the paper, is to compare the results of the experimental
test, performed at Escola Tecnica Superior d’Enginyeria Industrial de Barcelona with the
North-American and European design methods.
Aspects, that are examined in the paper are the failure mode and the types of
buckling modes that appear in the sheeting. There is a complex presentation of the
researches that the project is based on, the software analyses performed in different
programs: CUFSM, Ansys-Mechanical APDL; tend to reproduce the real scale experimental
test.
The FEM analysis appears to be a very good scientific tool to identify the behaviour
of trapezoidal steel sheets, given the similarities between the model results and the
experimental ones. The design methods use different approaches, but converge to affined
results.Incomin
Varijabilnost ploda kod različitih genotipova paradajza (L. esculentum Mill.)
Tomato (Lycopersicum esculentum Mill.) is vegetable which could be produced and consumed in a many different ways, due to its variability, made by breeding programs. Variability of analyzed genotypes was determinated for further fruit traits: average mass, fruit shape, locules number and dry matter content. Variability source structure was determinated using principal components analysis (PCA). Three main components, which explain 94,2 % of total variability, were chosen for further analysis. The biggest part of the first main component has fruit shape and locule number. The second component is determinated by dry matter content, and the third by the fruit mass. For more precisely perception of homology and divergence between analyzed genotypes, nonhierarchical grouping analysis (k-means) was performed, and genotypes were divided into three groups. Divergency was determinated for fruit mass and locule number, while for index shape and dry matter contetent analyzed genotypes are homologous. The aim of this study is to examine tomato genotypes variability for fruit traits.Paradajz (Lycopersicum esculentum Mill.) se odlikuje raznolikošću načina proizvodnje i upotrebe, zahvaljujući varijabilnosti koju čovek stvara oplemenjivanjem. Varijabilnost ispitivanih genotipova paradajza analizirana je za sledeće osobine ploda: prosečna masa, oblik, broj komora i sadržaj suve materije. Struktura izvora varijabilnosti određena je primenom metode glavnih komponenata (PCA). Za dalju analizu odabrano je tri glavne komponente, kojima je objašnjeno 94,2% ukupne varijabilnosti. Najveći udeo u prvoj glavnoj komponenti imaju oblik ploda i broj komora. Druga glavna komponenta definisana je sadržajem suve materije dok je masa ploda izdvojena u treću glavnu komponentu. U cilju jasnijeg sagledavanja sličnosti i razlika između genotipova paradajza, primenjena je nehijerarhijska analiza grupisanja (k-means), sa podelom genotipova u tri grupe. Utvrđeno je da se ispitivani genotipovi razlikuju u masi ploda i broju komora, dok su po obliku ploda i sadržaju suve materije sličniji. Cilj rada je ispitivanje varijabilnosti genotipova paradajza za osobine ploda
Enhancement of image quality for security forces
Táto bakalárska práca sa zaoberá zvyšovaním kvality obrazových snímkov pre bezpečnostné zložky štátu. Zvyšovanie kvality v tomto prípade znamená zväčšenie rozlíšenia obrazových dát využitím techniky super-rozlíšenia za pomoci modelov hlobkých konvolučných neurónových sietí. Práca vo svojej teoretickej časti približuje princípy fungovania tejto techniky a v jej praktickej časti je priblížená práca s vybranými súčasnými modelmi v oblasti super-rozlíšenia.This bachelor thesis deals with image quality enhancement for security forces. Image quality enhancement in this case means increasing the resolution of image data by using super-resolution techniques using models of deep convolutional neural networks. The thesis in its theoretical part describes the principles of the operation of this technique and in its practical part is presented the work with selected state-of-the-art models in the area of super-resolution.
Regression analysis of head mass and mass of useful part of head in cabbage (Brassica oleracea Var. capitata L)
The objective of this paper was to determine the genetic mode of inheritance of quantitative traits in cabbage via regression analysis in complete diallel crossing.The regression analysis of head mass traits showed that the regression line was distant from the limiting parabola, indicating nonadditive gene action in head mass inheritance. The expected line of regression intersected the Wr axis below the coordinate origin, confirming the presence of superdominance in this inheritance. As useful head part mass comprises the bulk of total head mass, the regression analysis results were similar. The regression line was also far from the limiting parabola indicating nonadditive gene action in this trait's inheritance. Similarly the regression line intersected the Wr axis below the origin, suggesting we had a case of superdominance in the inheritance of this trait as well
Ground State Wave Functions in the Hyperspherical Formalism for Nuclei with A > 4
The general formulation of a technically advantageous method to find the
ground state solution of the Schrodinger equation in configuration space for
systems with a number of particles A greater than 4 is presented. The wave
function is expanded in pair correlated hyperspherical harmonics beyond the
lowest order approximation and then calculated in the Faddeev approach. A
recent efficient recursive method to construct antisymmetric A-particle
hyperspherical harmonics is used. The accuracy is tested for the bound state
energies of nuclei with A = 6,8,12. The high quality of the obtained results
becomes evident from a comparison with other approaches.Comment: 17 pages, 1 figure, Submitted to Nucl. Phys.
Probing pattern and dynamics of disulfide bridges using synthesis and NMR of an ion channel blocker peptide toxin with multiple diselenide bonds
Anuroctoxin (AnTx), a 35-amino-acid scorpion toxin containing four disulfide bridges, is a high affinity blocker of the voltage-gated potassium channel Kv1.3, but also blocks Kv1.2. To improve potential therapeutic use of the toxin, we have designed a double substituted analog, [N17A/F32T]-AnTx, which showed comparable Kv1.3 affinity to the wild-type peptide, but also a 2500-fold increase in the selectivity for Kv1.3 over Kv1.2. In the present study we have achieved the chemical synthesis of a Sec-analog in which all cysteine (Cys) residues have been replaced by selenocysteine (Sec) forming four diselenide bonds. To the best of our knowledge this is the first time to replace, by chemical synthesis, all disulfide bonds with isosteric diselenides in a peptide/protein. Gratifyingly, the key pharmacological properties of the Sec-[N17A/F32T]-AnTx are retained since the peptide is functionally active. We also propose here a combined experimental and theoretical approach including NOE- and Se-77-based NMR supplemented by MD simulations for conformational and dynamic characterization of the Sec-[N17A/F32T]-AnTx. Using this combined approach allowed us to attain unequivocal assignment of all four diselenide bonds and supplemental MD simulations allowed characterization of the conformational dynamics around each disulfide/diselenide bridge
Novi eksperimentalni hibrid kupusa pogodan za ranu proizvodnju
The paper analyzes experimental hybrids of early cabbage developed at the Institute of Field and Vegetable Crops in the previous period. The hybrids were tested together for two years and then one (H17) was chosen and submitted to the Variety Commission of the Republic of Serbia. In 2011, the experimental hybrid H17 was officially released as an early cabbage hybrid and registered under the name of NS Mendo F1. The hybrid had been developed by crossing two early lines, one of which was sterile. It is characterized by a short growing season - 65 days from transplanting to harvest. The head weight ranges from 2.5 to 3.5 kg depending on the cultural practice applied. The head is light green in color, sweet-tasting, and suitable for fresh consumption. The hybrid’s traits that contributed significantly to the formation of the first principal component were in fact those that the breeders attach most importance to in their breeding programs. These are the traits that directly influence the market value of a new hybrid and make a given hybrid recognizable on the market. Most notable among such traits are head weight and the weight of the useful part of the head.U radu su analizirani eksperimentalni hibridi ranog kupusa stvoreni u prethodnom periodu u Institutu za ratarstvo i povrtarstvo. Hibridi su međusobno dve godine testirani, iz čega je jedan hibrid (H17) izabran i prijavljen Republičkoj sortnoj komisiji. 2011 godine je eksperimentalni hibrid H17 i zvanično priznat kao rani hibrid kupusa, te registrovan pod imenom NS Mendo F1. Navedeni rani hibrid je nastao ukrštanjem dve linije kupusa, od kojih je jedna sterilna linija. Karakteriše se kratkom dužinom vegetacije, tj. 65 dana od rasađivanja do berbe. Masa glavice se kreće od 2,5 kg do 3,5 kg u zavisnosti od agrotehnike. Glavica je svetlo zelene boje, slatkog ukusa pogodna za svežu potrošnju. Osobine koje su pokazale značajan udeo na formiranje varijabilnosti prve glavne komponente, su u stvari i osobine na koje selekcionari daju i najveći značaj u oplemenjivačkim programima. To su svojstva koja direktno utiču na formiranje tržišne vrednosti novi hibrida, i čine pojedine hibride prepoznatljive na tržištu. To se odnosi pre svega na masu glavice i masu korisnog dela glavice
Deep Q-learning: a robust control approach
This work aims at constructing a bridge between robust control theory and reinforcement learning. Although, reinforcement learning has shown admirable results in complex control tasks, the agent’s learning behaviour is opaque. Meanwhile, system theory has several tools for analyzing and controlling dynamical systems. This paper places deep Q-learning is into a control-oriented perspective to study its learning dynamics with well-established techniques from robust control. An uncertain linear time-invariant model is formulated by means of the neural tangent kernel to describe learning. This novel approach allows giving conditions for stability (convergence) of the learning and enables the analysis of the agent’s behaviour in frequency-domain. The control-oriented approach makes it possible to formulate robust controllers that inject dynamical rewards as control input in the loss function to achieve better convergence properties. Three output-feedback controllers are synthesized: gain scheduling H2, dynamical Hinf, and fixed-structure Hinf controllers. Compared to traditional deep Q-learning techniques, which involve several heuristics, setting up the learning agent with a control-oriented tuning methodology is more transparent and has well-established literature. The proposed approach does not use a target network and randomized replay memory. The role of the target network is overtaken by the control input, which also exploits the temporal dependency of samples (opposed to a randomized memory buffer). Numerical simulations in different OpenAI Gym environments suggest that the Hinf controlled learning can converge faster and receive higher scores (depending on the environment) compared to the benchmark Double deep Q-learning
Public transport trajectory planning with probabilistic guarantees
The paper proposes an eco-cruise control strategy for urban public transportbuses. The aim of the velocity control is ensuring timetable adherence, whileconsidering upstream queue lengths at traffic lights in a probabilistic way. Thecontribution of the paper is twofold. First, the shockwave profile model (SPM)is extended to capture the stochastic nature of traffic queue lengths. The modelis adequate to describe frequent traffic state interruptions at signalized intersections.Based on the distribution function of stochastic traffic volume demand,the randomness in queue length, wave fronts, and vehicle numbers are derived.Then, an outlook is provided on its applicability as a full-scale urban traffic networkmodel. Second, a shrinking horizon model predictive controller (MPC) isproposed for ensuring timetable reliability. The intention is to calculate optimalvelocity commands based on the current position and desired arrival time of thebus while considering upcoming delays due to red signals and eventual queues.The above proposed stochastic traffic model is incorporated in a rolling horizonoptimization via chance-constraining. In the optimization, probabilistic guaranteesare formulated to minimize delay due to standstill in queues at signalized intersections. Optimization results are analyzed from two particular aspects, (i)feasibility and (ii) closed-loop performance point of views. The novel stochasticprofile model is tested in a high fidelity traffic simulator context. Comparativesimulation results show the viability and importance of stochastic bounds in urbantrajectory design. The proposed algorithm yields smoother bus trajectoriesat an urban corridor, suggesting energy savings compared to benchmark controlstrategies
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