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Search Results: 1 - 10 of 320 matches for " Cz. Adamczyk "
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Optimization algorithms in the charge planning for the BOF Plant
M. Gawron,Cz. Adamczyk
Journal of Achievements in Materials and Manufacturing Engineering , 2012,
Abstract: Purpose: The purpose has been to demonstrate the possibilities of reducing the cost of steel processing in the BOF Plant by using optimization algorithms in the charge planning.Design/methodology/approach: A lot of production factors and technological relationships impact the BOF processing costs. Practically any change in charge material parameters, like chemistry and temperature of hot metal, scraps and fluxes, as well as market prices of materials and cost of carbon dioxide emission, have to be considered to find an optimum charge mix, which generates the minimum cost and simultaneously complies with all technological and steel quality constraints. A linear optimization task including a simplified version of a BOF static model has been defined and a few examples of typical industry charge planning problem have been solved and presented.Findings: Critical price and amount of a given charge material for current technological conditions, stocks and market situation is the basic information for the Steel Plant management as well as for the Purchase Department. The relationship between material prices, CO2 emission price and material consumption for a given production and logistic constraints have been identified.Research limitations/implications: The paper describes using mathematical optimization methods in a specific area of steel industry, but it is opened problem with large potential of obtaining substantial benefits in other areas.Practical implications: The optimization model has been a base for developing the application for the Steel Plant and Purchase Department to optimize charge mix and plan the charge materials purchasing.Originality/value: The optimization algorithms has been adapted for a specific operation problem in steel making, i.e. calculation of charge for BOF.
Development of the microalloyed constructional steels
J. Adamczyk
Journal of Achievements in Materials and Manufacturing Engineering , 2005,
Abstract: Purpose: The aim of the paper is to present the development and the technical importance of the HSLA-typemicroalloyed constructional steels (High Strength Low Alloy) in selected industry branches.Design/methodology/approach: A mechanism of the interaction of Nb, Ti, V and B microadditions introducedinto the steel on mechanical properties of selected metallurgical products with the fine-grained structure,forming under the properly selected hot-working conditions with the of (M-Nb,Ti,V; X-N,C) interstitial phasesMX-type is discussed.Findings: The requirements concerning the metallurgical process, continuous casting of steel and the necessityof adjusting the hot-working conditions to the precipitation kinetics of the dispersive MX phases particles inaustenite, in the controlled rolling or thermo-mechanical treatment processes are indicated.Research limitations/implications: The continuation of investigations concerning the thermo-mechanicalrolling of automotive sheets with the multiphase structure of microalloyed steels is planned.Practical implications: The indicated data, coming also from the own research, are of practical use in relationto manufacturing the metallurgical products and machine elements of high strength and crack resistance, alsoat low temperatures.Originality/value: The results contribute to the development of rolling and forging technologies of themicroalloyed steel (HSLA) elements produced using the energy-saving thermo-mechanical treatment methods.
Manufacturing of mass-scale products from structural microalloyed steels in integrated production lines
J. Adamczyk
Journal of Achievements in Materials and Manufacturing Engineering , 2007,
Abstract: Purpose: Technical – economic aspects of the introduction of integrated technological lines for the productionof metallurgical products are presented in the work. They have a special importance for microalloyed steels usedin different branches of the industry.Design/methodology/approach: The analysis was carried out on a basis of requirements concerning hotworkingof microalloyed steels with high mechanical properties produced by the use of the controlled rollingand thermo-mechanical processing.Findings: A modification of some well-known integrated lines consisting in the introduction of the coolingmachine between roughing and finishing trains, instead of reheating machine gives a possibility to realize acontrolled rolling. Moreover, using retention shields makes possible to manufacture the products by the thermomechanicalprocessing.Research limitations/implications: There is a necessity to adjust technological parameters to precisecontrolling a course of material processes.Practical implications: Development of demands concerning integrated lines enabling to realize the controlledrolling and thermo-mechanical processing.Originality/value: Manufacturing mass-scale products from microalloyed steels in integrated energy-saving lines.
Recent Results in Polarized Proton-Proton Elastic Scattering at STAR
Leszek Adamczyk
Physics , 2013,
Abstract: RHIC is the only spin-polarized proton collider ever built. With a special optics run of $\beta^\star \approx 22$ m STAR detector system is suitable for an investigation of the spin dependence of elastic proton-proton scattering. This is a brief summary of measurements of spin asymmetries at the center of mass energy $\sqrt{s}=200$ GeV and in the four-momentum transfer squared $-t$ range $0.003 < -t < 0.035$ GeV$^2$ by the STAR experiment at RHIC.
Non-negative submodular stochastic probing via stochastic contention resolution schemes
Marek Adamczyk
Computer Science , 2015,
Abstract: The abstract model of stochastic probing was presented by Gupta and Nagarajan (IPCO'13), and provides a unified view of a number of problems. Adamczyk, Sviridenko, Ward (STACS'14) gave better approximation for matroid environments and linear objectives. At the same time this method was easily extendable to settings, where the objective function was monotone submodular. However, the case of non-negative submodular function could not be handled by previous techniques. In this paper we address this problem, and our results are twofold. First, we adapt the notion of contention resolution schemes of Chekuri, Vondr\'ak, Zenklusen (SICOMP'14) to show that we can optimize non-negative submodular functions in this setting with a constant factor loss with respect to the deterministic setting. Second, we show a new contention resolution scheme for transversal matroids, which yields better approximations in the stochastic probing setting than the previously known tools. The rounding procedure underlying the scheme can be of independent interest --- Bansal, Gupta, Li, Mestre, Nagarajan, Rudra (Algorithmica'12) gave two seemingly different algorithms for stochastic matching and stochastic $k$-set packing problems with two different analyses, but we show that our single technique can be used to analyze both their algorithms.
Greedy algorithm for stochastic matching is a 2-approximation
Marek Adamczyk
Computer Science , 2010,
Abstract: Motivated by applications in online dating and kidney exchange, the stochastic matching problem was introduced by Chen, Immorlica, Karlin, Mahdian and Rudra (2009). They have proven a 4-approximation of a simple greedy strategy, but conjectured that it is in fact a 2-approximation. In this paper we confirm this hypothesis.
Monte Carlo study of linear chain submonolayer structures.Application to Li/W(112)
Cz. Oleksy
Physics , 2003, DOI: 10.1016/j.susc.2003.08.020
Abstract: The lattice gas model for adsorption of alkaline elements on W(112) surface is studied by Monte Carlo simulations. The model includes dipole--dipole interaction as well as long-range indirect interaction. The numerical results show that truncation of the indirect interaction even at 200$\AA$ may change a phase diagram, i.e., new phases containing domain walls might occur. It is demonstrated that a defected phase can exist at high temperatures even if it is not stable at T=0. The phase diagram for Li/W(112) is constructed and long periodic chain structures (9*1), (6*1), (4*1), (3*1), and (2*1) are found to be stable at low temperatures. Role of thermal fluctuation is discussed by comparison of Monte Carlo results with mean field approximation results.
SOS model of overlayer induced faceting
Cz. Oleksy
Physics , 2003, DOI: 10.1016/j.susc.2003.12.007
Abstract: A solid-on-solid model is proposed to describe faceting of bcc(111) metal surface induced by a metal overlayer. It is shown that the first order phase transition occurs between faceted {211} or {110} and disordered phases. The ordered phases consist of large 3-sided pyramids with {211} facets or {110} facets. It is shown that the high-temperature disordered phase has not planar bcc(111) structure but faceted disordered structure. Hysteresis effects were observed when the system was warmed above the transition temperature and then cooled down. Temperature dependence of LEED patterns for faceted and disordered phase are calculated in kinematic approximation.
The Estimation of the RAST Test Usefulness in Monitoring the Anaerobic Capacity of Sprinters in Athletics
Jakub Grzegorz Adamczyk
Polish Journal of Sport and Tourism , 2011, DOI: 10.2478/v10197-011-0017-3
Abstract: Introduction. In athletic high-speed-forced competitions one of basic monitored parameters of the preparation is the level of the anaerobic capacity. The aim of the work was the qualification of the usefulness of the RAST (Running-based Anaerobic Sprint Test) in the estimation of the anaerobic capacity of athletes of sprint athletic competitions. Material and methods. 37 athletes (12 Female and 25 Male) specializing in sprint racing (100 m, 100 m hurdles, 110 m hurdles, 200 m) and the prolonged sprint (400 m and 400 m hurdles) partook in the research. The anaerobic capacity was evaluated by means of the RAST test and the Wingate test. Results. In the RAST test competitors obtained significantly higher values of the maximum power (p<0.001) and the average power (p<0.001), with relation to the Wingate test. Among women such dependences were not ascertained. The fundamentally lower (p<0.001) fatigue index in the RAST test characterized in turn both groups, which can testify about the better adaptation to the run effort. For both tests one ascertained significant dependence between the average power and the maximum power. Moreover, the significant dependence between the fatigue index (FI) and the average and maximum power in the Wingate test was shown. For the RAST test such dependence appeared among FI, and the maximum power. Conclusions. The RAST test gave statistically comparable results only in the case of the average and maximum power among women. The smaller physical load for competitors and decidedly easier organization of the research causes that the RAST test can be used for regular monitoring of the anaerobic capacity level of competitors of athletic run competitions.
Transient and Stationary Losses in a Finite-Buffer Queue with Batch Arrivals
Andrzej Chydzinski,Blazej Adamczyk
Mathematical Problems in Engineering , 2012, DOI: 10.1155/2012/326830
Abstract:
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