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1

Kolej Transandyjska w Peru

Graff Marek

TTS Technika Transportu Szynowego

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2020

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R. 27, nr 11

24--39

PL

Zbudowana pod koniec XIX w. Kolej Transandyjska w Peru powstała z udziałem kapitału zagranicznego oraz obcej myśli technicznej. Motywem budowy linii kolejowej był zamiar eksploatacji bogatych złóż miedzi, a także srebra i złota. Zastosowane rozwiązania techniczne nawet dzisiaj budzą podziw, w szczególności tzw. nawroty (zygzaki), które pozwoliły poprowadzić linię kolejową po niedostępnych terenach górskich pasma Andów, jak to określił główny inwestor, Henry Meiggs, amerykański przedsiębiorca: tam gdzie dojdzie lama, może dojechać pociąg. Głównym inżynierem, który zaprojektował linię kolejową oraz nadzorował wykonawstwo, był Ernest Malinowski, polski specjalista, zasłużony dla Peru podczas wojny z Hiszpanią w 1866 r., ogłoszony przez mieszkańców tego kraju bohaterem narodowym.

EN

Trans-Andean Railway built at the end of the 19th century in Peru, was created with the participation of foreign capital and technical knowledge. The motive for construction of the railway line was the intention to exploit rich copper deposits and silver and gold. The applied technical solutions are admirable even today, particularly the so-called zigzags that allowed to lead the railway line through inaccessible mountain areas of the Andes, as the principal investor, Henry Meiggs, an US entrepreneur said: a train can go, where the llama goes. Ernest Malinowski, a Polish specialist, was the chief engineer who designed the railway line and supervised. Malinowski was also engaged in the war with Spain in 1866. Finally, the inhabitants of Peru proclaimed him as the national hero.

2

A study on the identification of the second-order linear Nomoto model from the zigzag test

Artyszuk J.

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2018

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nr 53 (125)

59--67

EN

In this paper a simple four-point, in terms of time, but eight-value in total, identification method has been developed for the second-order linear Nomoto steering model. The algorithm intrinsically uses the zigzag test data in that it inherited some principles of the well-known procedure for the first-order model, from which it is essentially derived. The performance evaluation was then conducted with both simulated and real data. However, the results of these early, unprecedented efforts are far from satisfactory. Some potential sources of difficulties have been discussed. This calls for further research and improvement in order to provide a practical application of the method.

3

Multi-objective geometric programming problem under uncertainty

Mandal W. A., Islam S.

Operations Research and Decisions

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2017

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Vol. 27, No. 4

85--109

EN

Multiobjective geometric programming (MOGP) is a powerful optimization technique widely used for solving a variety of nonlinear optimization problems and engineering problems. Generally, the parameters of a multiobjective geometric programming (MOGP) models are assumed to be deterministic and fixed. However, the values observed for the parameters in real-world MOGP problems are often imprecise and subject to fluctuations. Therefore, we use MOGP within an uncertainty based framework and propose a MOGP model whose coefficients are uncertain in nature. We assume the uncertain variables (UVs) to have linear, normal or zigzag uncertainty distributions and show that the corresponding uncertain chance-constrained multiobjective geometric programming (UCCMOGP) problems can be transformed into conventional MOGP problems to calculate the objective values. The paper develops a procedure to solve a UCCMOGP problem using an MOGP technique based on a weighted-sum method. The efficacy of this procedure is demonstrated by some numerical examples.