The purpose of the paper is to present existing and discuss modified optimization models and solution techniques which are suitable for engineering decision-making problems containing random elements with emphasis on two decision stages. The developed aproach is called two-stage stochastic programming and the paper links motivation, applicability, theoretical remarks, transformations, input data generation techniques, and selected decomposition algorithms for generalized class of engineering problems. The considered techniques have been found applicable by the experience of the authors in various areas of engineering problems. They have been applied to engineering design problems involving constraints based on differential equations to achieve reliable solutions. They have served for technological process control e.g. in melting, casting, and sustainable energy production. They have been used for industrial production technologies involving related logistics, as e.g. fixed interval scheduling under uncertainty. The paper originally introduces several recent improvements in the linked parts and it focuses on the unified two-stage stochastic programming approach to engineering problems in general. It utilizes authentic experience and ideas obtained in certain application areas and advises their fruitful utilization for other cases. The paper follows the paper published in 2000 which deals with the applicability of static stochastic programs to engineering design problems. Therefore, it refers to the basic concepts and notation introduced there and reviews only the principal ideas in the beginning. Then. it focuses on motivation of recourse concepts and two decision stages from engineering point of view. The principal models are introduced and selected theoretical features are reviewed. They are also accompanied by the discussion about difficulties caused by real-world cases. Scenario-based approach is detailed as the important one for the solution of engineering problems, discussion in data input generation is added together with model transformation remarks. Robust algorithms suitable for engineering problems involving nonlinearities and integer variable are selected and scenario-based decomposition is preferred. An original experience with using heuristics is shared. Several postprocessing remarks are added at the end of the paper, which is followed by an extensive literature review. and Obsahuje seznam literatury
The first stage of the Laser Induced Breakdown Spectroscopy (LIBS) setup development for the mobile remote sensing of chemical elements is presented. In this stage the laboratory test setup has been built using Nd:YAG laser (radiation wavelength 532 nm, ''at-top'' beam profile), custom built Galilean focusing optics together with the off-axis Newtonian collection optics for plasma radiation detection. The capability of the setup has been tested in the distance of 6.2 m on selected samples with different matrices (metal, bone, paving stone, glass). The measured concentrations have been compared to results acquired by reference LA-ICP-MS setup. These test measurements have shown that the setup is capable of semiquantitative analysis at the level of mg·kg-1. and Článek popisuje první fázi stavby mobilní sestavy pro dálkovou laserovou spektroskopii (Remote LIBS) v laboratorním uspořádání na ÚFI, FSI, VUT v Brně. Sestava využívá pulzní laser o vlnové délce 532 nm s ''at-top'' profilem svazku, fokusační optiku Galileova typu a sběrnou optiku v podobě mimoosého Newtonova teleskopu. První testování aparatury proběhlo na vzdálenost 6,2 m se vzorky různých materiálů - kovové vzorky, sklo, keramický střep, dlažební kostka a lidská kost. Naměřené koncentrace vybraných prvků byly porovnány s daty získanými metodou LA-ICP-MS. Výsledky měření ukázaly, že aparatura je dostatečně citlivá pro detekci matričních (Al, Ca, P, Mg) i některých minoritních a stopových prvků (Na, Zn, Ti, Sr) a je schopna semikvantitativní analýzy v řádech mg·kg-1.
The laser-induced breakdown spectroscopy (LIBS) is an atomic emission based method, which is currently becoming more popular. Speed and multi-elemental analysis are some of the main advantages of this method. Higher limits of detection (LOD) in comparison to other atomic analytical methods, such as X-ray fluorescence spectrometry (XRF) and inductively coupled plasma based methods, are some of the limitations of this method. The application of nanoparticles on the surface of studied sample, so called Nanoparticle Enhanced Laser-Induced Breakdown Spectroscopy (NELIBS), is one of the ways to achieve improvement of the limits of detection while preserving the main advantages of the LIBS method. In this paper the improvement of detection limits by application of silver nanoparticles on the surface of studied sample is presented in comparison to the classical LIBS method. At the same time, the effect of two different Nd:YAG laser wavelengths, 532 nm and 1064 nm, on the LOD’s improvement of selected elements of studied samples is investigated for LIBS and NELIBS experiments. In the end of the paper, the parameters of craters (diameter and volume) are investigated for both chosen ablation laser wavelengths. and Spektrometria laserom budenej (mikro)plazmy (LIBS) je metódou atómovej emisnej spektrometrie, ktorá v súčasnosti naberá na popularite. Medzi hlavné výhody tejto metódy patria rýchlosť a viacprvková analýza. K obmedzeniam metódy patria o niečo vyššie limity detekcie (LOD) oproti ostatným prvkovým analytickým metódam, ako sú napr. rentgenová fluorescenčná spektrometria (XRF) a metódy indukčne viazanej plazmy (ICP). Jedným zo spôsobov, ako dosiahnuť zníženie limitov detekcie pri zachovaní hlavných výhod metódy, je aplikácia nanočastíc na povrch študovanej vzorky, tzv. nanočasticami zosilnená spektrometria laserom budenej (mikro)plazmy (NELIBS).V tejto práci je prezentované zlepšenie detekčných limitov pri aplikácii strieborných nanočastíc na povrch študovaných vzoriek v porovnaní s klasickou LIBS metódou. Súčasne je sledovaný aj vplyv dvoch rôznych vlnových dĺžok Nd:YAG lasera, 532 nm a 1064 nm, na zlepšenie LOD vybraných prvkov študovaných vzoriek v LIBS a NELIBS experimente. Nakoniec boli sledované parametre kráterov, priemer a objem, a to v porovnaní LIBS vs. NELIBS pre obe vybrané vlnové dĺžky ablačných laserov.