Non-invasive screening: The probability of events

Congenital anomalies are the cause of 20.0-25.0% of cases of perinatal death, while 3.0% of children are born with malformations of varying size. We examined the predictive values and defined the credibility ratio of the combined test results. Sensitivity of the test is 94.0%, and specificity is 99.0%. The positive likelihood ratio [likelihood ratio test (LR+)] is 94.00; a negative likelihood ratio [likelihood ratio test (LR-)] is 0.06. The pretest probability that pregnant women carry a fetus with chromosomal abnormality is 1:250. Posttest odds after the combined test to discover this abnormality are 0.3760, and probability of the same case is 0.2732 if it happens that the test result is positive. The result of our study confirms the justification of combined test usage in routine clinical practice, since the posttest odds rate in the case of a positive screening increases several times over (almost 90 times); the probability of detecting a chromosomal abnormality was about 70 times

Automatic control of haul truck travel speed on open pits

Expanding raw materials production demands necessitates higher exploitation rates and capacities. Therefore, open pit mines resort to increasing their overall depth and hence introduce further machine related technical problems. Haul trucks experience intensified dynamic effects during traveling, resulting in a significant maintenance cost increase. The most influencing effects occur during the truck braking and stopping process, especially when heavily loaded. Current technical solutions in most haul truck configurations disregard plethora of these effects to lower their production cost. The dynamic effects should be defined according to specific conditions on an open pit and applied for modifying currently employed systems for automatic truck speed control (ASC). It is the purpose of this paper to present the ASC system employed on the haul truck and key points for further modification and development. Firstly, the paper presents basic aspects of the truck braking/stopping process. Secondly, a description of the BelAZ 75306 traction drive and braking systems is provided, followed by key features of the BelAZ 75306 ASC system. Finally, presented information is summarized, indicating flaws and recommendations for further improvement of the BelAZ 75306 ASC system employed on the open pit - 'Veliki Krivelj', Bor, Serbia

Coupled neural networks and numeric models for flyrock safe distance definition

Doktorska disertacija sa navedenim naslovom prezentuje rezultate istraživanja problema razletanja komada pri miniranjima. Cilj istraživanja bio je kreiranje opšteg i univerzalno primenljivog modela za prognozu maksimalnih dometa razletelih komada i definisanje sigurnih rastojanja. Kombinacijomterenskih istraživanja, numerikog modeliranja balistikih trajektorija razletelih komada i adaptivne prirode neuronskih mreža definisan je koncept neuro-numerike sprege. Sprega je objedinila univerzalnu primenljivost numerikog modela i sposobnost prilagoavanja neuronskih mreža lokalnim uslovima u opšti model za prognozu maksimalnih dometa razletelih komada. Za potrebe sprege, a kao integralni deo disertacije, razvijen je metod za odreivanje koeficijenta otpora vazduha nepravilnih komada baziran na principu terminalne brzine. Verifikacijom pojedinanih modula sprege, Klasifikatora, Prediktora i Numerika izvršena je i verifikacija sprege kao sistema i dokazana njena sposobnost da pouzdano i precizno odgovori na razliita pitanja vezana za problem razletanja komad

Coupled neural networks and numeric models for flyrock safe distance definition

Doktorska disertacija sa navedenim naslovom prezentuje rezultate istraživanja problema razletanja komada pri miniranjima. Cilj istraživanja bio je kreiranje opšteg i univerzalno primenljivog modela za prognozu maksimalnih dometa razletelih komada i definisanje sigurnih rastojanja. Kombinacijomterenskih istraživanja, numerikog modeliranja balistikih trajektorija razletelih komada i adaptivne prirode neuronskih mreža definisan je koncept neuro-numerike sprege. Sprega je objedinila univerzalnu primenljivost numerikog modela i sposobnost prilagoavanja neuronskih mreža lokalnim uslovima u opšti model za prognozu maksimalnih dometa razletelih komada. Za potrebe sprege, a kao integralni deo disertacije, razvijen je metod za odreivanje koeficijenta otpora vazduha nepravilnih komada baziran na principu terminalne brzine. Verifikacijom pojedinanih modula sprege, Klasifikatora, Prediktora i Numerika izvršena je i verifikacija sprege kao sistema i dokazana njena sposobnost da pouzdano i precizno odgovori na razliita pitanja vezana za problem razletanja komad