Metodologija izračuna otpora u zavoju vlaka u ovisnosti od mase i brzine

A methodology for determining curving resistances of track vehicles is proposed. The methodology is aimed to gain insight into influence of the arrangement of masses along the train and the train speed on the curving resistance based on test results conducted by using a scaled down train. The utilized scaled down train is a HO scale line freight train in ratio of 1:87 consisting of a EMD SD 35 locomotive and FALNS 121 freight wagons. The considered variants of the train arrangements are as follows: empty train (PPPPPP), one loaded wagon in the front/in the end (TPPPPP and PPPPPT) and two loaded wagons in the front/in the end (TTPPPP and PPPPTT). The total train curving resistance WR is determined based on the decrease of the train steady-state curving speed vR when compared to the train steady-state speed on the straight track v∞ under same operating conditions. The curving resistance of a train of arbitrary arrangement is calculated as the difference between the train driving force when driving on a straight, horizontal track FV (constant resistance WS) and the total resistance when curving WU (driving force FV in curve). The constant resistances of the locomotive and empty and loaded wagons are determined by application of the gravitational method.Metodologija izračuna otpora u zavoju tračničkih vozila osmišljena je za izvođenje eksperimenta na umanjenom modelu teretnog vlaka u HO standardu 1:87, lokomotiva EMD SD 35 i vagoni FALNS 121. Formirani model služi za istraživanje utjecaja vrijednosti i rasporeda mase tereta unutar sastava voza, te brzine gibanja na vrijednost otpora u zavoju. Gravitacijskom metodom se određuju stalni otpori (otpori u ravnini) lokomotive, praznog i natovarenog vagona. Razmatrane kombinacije sastava vlaka su: prazan vlak (PPPPPP), jedan natovaren vagon napred nazad (TPPPPP i PPPPPT) i dva natovarena vagona napred nazad (TTPPPP i PPPPTT). Otpor u zavoju cijelog vlaka WR dobije se na osnovu smanjenja brzine gibanja vlaka u zavoju vR prema brzini gibanja vlaka na pravcu v∞ pri istim referentnim uvjetima. Otpor u zavoju WR izračunava se kao razlika vučne sile vlaka na pravcu FV (stalnog otpora WS) i ukupnog otpora cijelog vlaka WU (vučna sila FV u zavoju) pri gibanju u zavoju za svaku odabranu kombinaciju sastava vlaka

The golden ratio in probablistic and artificial intelligence

Problem linijskog odsječka utemeljenog na omjeru zlatnog reza φ = 1,618033 ima analogiju u vjerojatnosti. Rješenje elementarne eksponencijalne raspodjele, posebice ističe vrijednost 2lnφ. Ova vrijednost također ima ključnu ulogu u odnosu Rikatijevih hiperboličnih funkcija s Fibonačijevim i Lukasovim brojevima u kontinuiranom području. Time se uspostavlja bliska veza između konstanti e i φ. Izvedena su dva nova teorema o konvergenciji konstanti φ i e . Broj e je temelj Markovskih procesa, koji su našli primjenu u teoriji vjerojatnosni i umjetne inteligencije. Omjer konstanti e i φ, kao i mnogi drugi prirodni fenomeni na temelju zlatnog reza, ističu potrebu za proširenjem područja vjerojatnosni i umjetne inteligencije.The problem of the line section based on the golden ratio φ = 1,618033 has the analogy in probability. The solution of the elementary exponential distribution relies on the value 2lnφ in particular. This value also plays a key role to Riccati hyperbolic functions with Fibonacci and Lucas numbers in continuous domain. This establishes a close relationship between the constants e and φ. Two new theorems on the convergence between the constants φ and e were derived. The number e is the foundation of Markov processes, which find applications in probabilistic and artificial intelligence theory. The ratio between the constants φ and e, as well as many other natural phenomena based on the golden ratio, highlight the need to expand the field of probabilistic and artificial intelligence

Mathematical identification of influential parameters on the elastic buckling of variable geometry plate

The problem of elastic stability of plates with square, rectangular, and circular holes as well as slotted holes was discussed. The existence of the hole reduces the deformation energy of the plate and it affects the redistribution of stress flow in comparison to a uniform plate which causes a change of the external operation of compressive forces. The distribution of compressive force is defined as the approximate model of plane state of stress. The significant parameters of elastic stability compared to the uniform plate, including the dominant role of the shape, size, and orientation of the hole were identified. Comparative analysis of the shape of the hole was carried out on the data from the literature, which are based on different approaches and methods. Qualitative and quantitative accordance of the results has been found out and it verifies exposed methodology as applicable in the study of the phenomenon of elastic stability. Sensitivity factor is defined that is proportional to the reciprocal value of the buckling coefficient and it is a measure of sensitivity of plate to the existence of the hole. Mechanism of loss of stability is interpreted through the absorption of the external operation, induced by the shape of the hole

Metodologija izračuna otpora u zavoju vlaka u ovisnosti od mase i brzine

A methodology for determining curving resistances of track vehicles is proposed. The methodology is aimed to gain insight into influence of the arrangement of masses along the train and the train speed on the curving resistance based on test results conducted by using a scaled down train. The utilized scaled down train is a HO scale line freight train in ratio of 1:87 consisting of a EMD SD 35 locomotive and FALNS 121 freight wagons. The considered variants of the train arrangements are as follows: empty train (PPPPPP), one loaded wagon in the front/in the end (TPPPPP and PPPPPT) and two loaded wagons in the front/in the end (TTPPPP and PPPPTT). The total train curving resistance WR is determined based on the decrease of the train steady-state curving speed vR when compared to the train steady-state speed on the straight track v∞ under same operating conditions. The curving resistance of a train of arbitrary arrangement is calculated as the difference between the train driving force when driving on a straight, horizontal track FV (constant resistance WS) and the total resistance when curving WU (driving force FV in curve). The constant resistances of the locomotive and empty and loaded wagons are determined by application of the gravitational method.Metodologija izračuna otpora u zavoju tračničkih vozila osmišljena je za izvođenje eksperimenta na umanjenom modelu teretnog vlaka u HO standardu 1:87, lokomotiva EMD SD 35 i vagoni FALNS 121. Formirani model služi za istraživanje utjecaja vrijednosti i rasporeda mase tereta unutar sastava voza, te brzine gibanja na vrijednost otpora u zavoju. Gravitacijskom metodom se određuju stalni otpori (otpori u ravnini) lokomotive, praznog i natovarenog vagona. Razmatrane kombinacije sastava vlaka su: prazan vlak (PPPPPP), jedan natovaren vagon napred nazad (TPPPPP i PPPPPT) i dva natovarena vagona napred nazad (TTPPPP i PPPPTT). Otpor u zavoju cijelog vlaka WR dobije se na osnovu smanjenja brzine gibanja vlaka u zavoju vR prema brzini gibanja vlaka na pravcu v∞ pri istim referentnim uvjetima. Otpor u zavoju WR izračunava se kao razlika vučne sile vlaka na pravcu FV (stalnog otpora WS) i ukupnog otpora cijelog vlaka WU (vučna sila FV u zavoju) pri gibanju u zavoju za svaku odabranu kombinaciju sastava vlaka

Ancient logistics – historical timeline and etymology

Fenomen logistike ima iznimnu genezu. Po nalazima koji su prikazani u radu, logistika datira iz razdoblja kasnog brončanog doba, iz antičkog doba. Uvjet za razvoj logistike bio je evolucija metričkih sustava, prije svega numeričkog sustava. Osnove mezopotamijskog i egipatskog numeričkog sustava Feničani su prilagodili u trgovačke svrhe. Tadašnji fenomen broja nije imao odgovarajući simbol, nego je predstavljen kao slika. Primarno značenje riječi logos je računati. Etimologija riječi logistike je izvedena iz sinteze računanja i slike, "vještina računanja pomoću slika". Detaljna analiza najstarije olupine broda – Uluburun, dokazuje intenzivne proizvodne i trgovačke aktivnosti kasnog brončanog doba na Mediteranu. Takve aktivnosti su mogle biti realizirane samo uz podršku intenzivnih logističkih aktivnosti. Prikazana analiza pomiće definiciju logistike daleko u razdoblje p.n.e. Čuveni Pitagora je bio prvi imenovani logističar.The phenomenon of logistics has an exceptional genesis. According to the findings presented in this paper, logistics dates back to Late Bronze Age (LBA), to ancient times. The bases for logistics development were an evolution of metrics systems, first of all numerical systems. The grounds of Mesopotamian and Egyptian numerical systems were used for commercial purposes by the Phoenicians. In that time the numbers were not displayed as symbols but as pictures. Primary meaning of the word logos was to count. The etymology of the word logistic was drawn from two words, the counting and the picture or the knowing of "numeracy skills through images". The detailed analysis of the oldest known shipwreck – Uluburun, proved intensive production and commercial activities in the LBA period in the Mediterranean. These activities could be realized only with the support of intensive logistic activities. The analysis of the logistics change, given below, shows that the definition of logistics starts far in the period of BC. The famous Pythagoras was the first logistician to be appointed

Zlatni rez u vjerojatnosti i umjetnoj inteligenciji

Problem linijskog odsječka utemeljenog na omjeru zlatnog reza φ = 1,618033 ima analogiju u vjerojatnosti. Rješenje elementarne eksponencijalne raspodjele, posebice ističe vrijednost 2lnφ. Ova vrijednost također ima ključnu ulogu u odnosu Rikatijevih hiperboličnih funkcija s Fibonačijevim i Lukasovim brojevima u kontinuiranom području. Time se uspostavlja bliska veza između konstanti e i φ. Izvedena su dva nova teorema o konvergenciji konstanti φ i e . Broj e je temelj Markovskih procesa, koji su našli primjenu u teoriji vjerojatnosni i umjetne inteligencije. Omjer konstanti e i φ, kao i mnogi drugi prirodni fenomeni na temelju zlatnog reza, ističu potrebu za proširenjem područja vjerojatnosni i umjetne inteligencije