Optimal control of motion of the system based on mathematical pendulum with constant length

U radu se razmatra premeštanje matematičkog klatna (sa osvrtom na primenu pri modeliranju dizaličnih postrojenja) iz stanja kretanja tačke vešanja konstantnom brzinom u stanje mirovanja za unapred zadato vreme sa prigušivanjem oscilacija na kraju procesa. Rešenja se traže primenom Pontriagin-ovog principa maksimuma i adaptivnog odnosno digitalnog metoda prigušivanja oscilacija. Kao upravljačka veličina u oba slučaja koristi se ubrzanje tačke vešanja matematičkog klatna. Razmatran je slučaj sa konstantnom dužinom matematičkog klatna.The paper discusses the motion of the mathematical pendulum (with reference In the transportation machines modeling), from the stale o/ constant velocity motion of the suspension point to the stale of rest for the pre-assigned time with damping of oscillations at the end of the process. Solutions of the task were found by application of the Pontryagin's principle of maximum, and adaptive and digital methods of oscillations damping. Acceleration of the suspension point of the mathematical pendulum is used as the control value in all cases. The case of the constant length of the mathematical pendulum is discussed

Optimal control of motion of the system based on mathematical pendulum with constant length

U radu se razmatra premeštanje matematičkog klatna (sa osvrtom na primenu pri modeliranju dizaličnih postrojenja) iz stanja kretanja tačke vešanja konstantnom brzinom u stanje mirovanja za unapred zadato vreme sa prigušivanjem oscilacija na kraju procesa. Rešenja se traže primenom Pontriagin-ovog principa maksimuma i adaptivnog odnosno digitalnog metoda prigušivanja oscilacija. Kao upravljačka veličina u oba slučaja koristi se ubrzanje tačke vešanja matematičkog klatna. Razmatran je slučaj sa konstantnom dužinom matematičkog klatna.The paper discusses the motion of the mathematical pendulum (with reference In the transportation machines modeling), from the stale o/ constant velocity motion of the suspension point to the stale of rest for the pre-assigned time with damping of oscillations at the end of the process. Solutions of the task were found by application of the Pontryagin's principle of maximum, and adaptive and digital methods of oscillations damping. Acceleration of the suspension point of the mathematical pendulum is used as the control value in all cases. The case of the constant length of the mathematical pendulum is discussed

Enrollment management: Development of prediction model based on logistic regression

U radu je prikazan razvoj modela predviđanja zasnovanog na logističkoj regresiji. Predviđanje profesionalnog opredeljenja maturanata verifikovano je na uzorku od 159 učenika. Prediktorske veličine su grupisane u 9 ulaznih promenljivih, a potrebni podaci su dobijeni iz baze Jedinstvenog informacionog sistema u obrazovanju. Profesionalno opredeljenje maturanata po završetku srednje škole je grupisano u tri izlazne promenljive, a vrednosti su dobijene eksperimentalnim istraživanjem. Dobijeni rezultati pokazuju da se primenom logističke regresije može predvideti broj i struktura učenika koji se upisuju na fakultete.This paper presents the development of a model for forecasting and decision-making by applying logistic regression. The prediction of professional choices for graduates has been verified on the sample of 159 graduates. Predictor variables are grouped in nine input variables and the data collected from the Unique Education Information System database. Professional choices of graduates after finishing vocational school are grouped into three output variables and the data collected in the survey. The obtained results show that the application of logistic regression can predict the number and structure of students enrolled in higher education

Enrollment management: Development of prediction model based on logistic regression

U radu je prikazan razvoj modela predviđanja zasnovanog na logističkoj regresiji. Predviđanje profesionalnog opredeljenja maturanata verifikovano je na uzorku od 159 učenika. Prediktorske veličine su grupisane u 9 ulaznih promenljivih, a potrebni podaci su dobijeni iz baze Jedinstvenog informacionog sistema u obrazovanju. Profesionalno opredeljenje maturanata po završetku srednje škole je grupisano u tri izlazne promenljive, a vrednosti su dobijene eksperimentalnim istraživanjem. Dobijeni rezultati pokazuju da se primenom logističke regresije može predvideti broj i struktura učenika koji se upisuju na fakultete.This paper presents the development of a model for forecasting and decision-making by applying logistic regression. The prediction of professional choices for graduates has been verified on the sample of 159 graduates. Predictor variables are grouped in nine input variables and the data collected from the Unique Education Information System database. Professional choices of graduates after finishing vocational school are grouped into three output variables and the data collected in the survey. The obtained results show that the application of logistic regression can predict the number and structure of students enrolled in higher education

Analiza prostog i složenog ciklusa visokoregalne dizalice u skladišnom sistemu

U radu je prikazana uporedna analiza radnih ciklusa visokoregalne dizalice (VRD) računatih prema FEM propisu i prema posebno razvijenim modelima. Novo razvijeni modeli izračunavaju prosečni radni ciklus VRD za projektovano ili dato skladište uzimajući u obzir sve moguće cikluse. Model po FEM propisu izračunava prosečne vrednosti ciklusa VRD za projektovano ili dato skladište uzimajući u obzir samo dva (prosti ciklus) odnosno tri (složeni ciklus) reprezentativna ciklusa u zavisnosti od dužine i visine skladišta. Rezultati analize za jednostruki i dvostruki ciklus kretanja VRD su prikazani na uporednim dijagramima za tri različite konfiguracije skladišnog sistema

Analiza prostog i složenog ciklusa visokoregalne dizalice u skladišnom sistemu

U radu je prikazana uporedna analiza radnih ciklusa visokoregalne dizalice (VRD) računatih prema FEM propisu i prema posebno razvijenim modelima. Novo razvijeni modeli izračunavaju prosečni radni ciklus VRD za projektovano ili dato skladište uzimajući u obzir sve moguće cikluse. Model po FEM propisu izračunava prosečne vrednosti ciklusa VRD za projektovano ili dato skladište uzimajući u obzir samo dva (prosti ciklus) odnosno tri (složeni ciklus) reprezentativna ciklusa u zavisnosti od dužine i visine skladišta. Rezultati analize za jednostruki i dvostruki ciklus kretanja VRD su prikazani na uporednim dijagramima za tri različite konfiguracije skladišnog sistema

Reliability of Baseload Electricity Generation from Fossil and Renewable Energy Sources, Energy and Power Engineering

With expanding environmental and climate change regulatory frameworks, the fossil-based baseload generation is forced to decline, thus making room for more and more generation based on renewable and other carbon-free energy sources. This paper deals with a number of controversial issues and open questions concerning the growing penetration of renewable energy sources into power generation systems, often without due care of the impacts of variable as compared to conventional generation on the reliability of electricity supply. Particular attention is paid to baseload generation, power market design, system operation under extreme weather conditions, energy storage, back-up, and reserve power, as well as to the role of mechanical inertia and reliability of on-site fuel supply, demonstrated on an example of coal excavation and delivery to a power plant

High-bay warehouse analysis based on influence of stochastic parameters

U radu je analizirana familija visokoregalnih skladišta sa jednim uređajem za opsluživanje. Ciklus rada, kao osnovni element sistema, proračunat je prema FEM propisu sa posebnim osvrtom na promenu brzine kretanja uređaja za opsluživanje u vremenu. Različite teorijske raspodele za modeliranje dolaznog toka, opsluživanja i otkaza su korišćene u radu za određivanje stohastičkog uticaja na performanse skladišnog sistema. Ostali uticaji na performanse skladišnog sistema su obuhvaćeni preko promene opterećenja sistema. Kombinacija oba uticaja i njihova promena dovode do zaključka o stohastičkom ponašanju posmatranih performansi sistema prikazanih preko različitih teorijskih raspodela. Posebno je razvijen simulacioni model koji je korišćen za analizu rada skladišnih sistema.A group of high-bay warehouses with one servicing device is analyzed. Working cycle of servicing device is calculated upon FEM regulation, using optimal change of velocity in time. Different theoretical distributions for arrival rate, servicing flow and failure were used, in this paper, for determining stochastic influence on warehouse system performances. The other influence on warehouse system performances is taken through offered load of the system. Combination of both influences and variety of each brought up the conclusion about stochastic behavior of observed system performances presented by theoretical distributions. Developed simulation model was used for analysis of warehouse system work

Partnership for Entrepreneurial Engineering Education

Entrepreneurship is identified as important development goal for the future of the modem industry. New technologies require greater entrepreneurial activity in order to further strengthen its economic position. Reformed technical and engineering education system in Serbia is directed to strengthening vocational knowledge and acquiring of key skills necessary to join the world of work and the whole society. The new concept of curriculum has been introduced which, among the others, contains teaching subject entrepreneurship as a novelty. Within this subject students acquire: skills of planning, organizing, analyzing, communicating, realizing and evaluating; abilities for team work; abilities for proactive behavior and positive reacting to changes; abilities for risk overtaking; positive attitude toward changes and innovation. This paper presents needs for model based on two-way communication and dialogue between learning and business environment. Main objectives of this partnership are: organization and joint efforts with the purpose of gaining wider public, making benefit of the enterprises of entrepreneurial education and development and improvement of the program of entrepreneurial education