Model for defining passenger flow characteristics on urban public transport line

Јавни градски транспорт путника је подсистем града који служи остваривању низа циљева, а пре свих обезбеђивања мобилности свих становника. Оптимизација структуре и функционисања урбаних средина и њихових транспортних система је веома сложен и одговоран задатак са далекосежним последицама у свим сферама живота његових становника. Структура и величина система јавног градског транспорта путника директно зависи од транспортних потреба и транспортних захтева корисника који су у различитим карактеристичним часовима у току дана, данима и сезонама, различити по обиму и по интензитету. Може се рећи да транспортни захтеви представљају кључни фактор од утицаја на процес оптимизације свих ангажованих ресурса у систему (инфраструктуру мреже линија, возила, запослене, финансије, транспортне капацитете итд.). Усклађивање транспортне понуде са транспортним захтевима подразумева континуирани реинжењеринг структуре и функционисања система, чија је циљна функција усмерена на побољшање ефикасности и ефективности система. Кроз оригинални модел расподеле прихода између власника тржишта транспортних услуга (органа локалне управе) и оператора, у оквиру рада приказано је како контрола праћења обима реализованих транспортних захтева може утицати на одрживост система у целини. Познајући природу понашања транспортног система у условима реалног функционисања, велики број унутрашњих и спољних фактора изазива различите поремећаје који се пројектују на поузданост и стабилност пружања транспортне услуге. У oквиру рaдa дeфинисaна је оригинална методологија за утврђивање и квантификацију утицаја најзначајнијег динамичког елемента (реализованог интервала) на транспортне захтеве (проток путника). Методологија је успешно тестирана на линијама из реалног система јавног градског транспорта путника у Београду. Фексибилност се огледа и у чињеници да примена методологије није условљена степеном техничко-технолошке развијености система и начином формирања базе података о основним карактеристикама линије.На основу анализа односа и међусобног утицаја елемената функционисања и транспортних захтева на линији јавног градског транспорта путника на микро нивоу, односно на нивоу линије, поласка и возила, дефинисан је модел за утврђивање карактеристика транспортних захтева засноване на репрезентативним узорцима података добијених применом специјалних метода транспортног инжењеринга у реалном систему јавног градског транспорта путника. Развој модела подстакнут је и чињеницом да у реалним сложеним системима са стохастичком променом стања, какав је систем јавног градског транспорта путника, проста експанзија множењем вредности параметра добијене из узорка са обрнутом вредношћу фактора избора елемената у узорку, не гарантује увек оптималне резултате...Urban public passenger transport is a subsystem of a city that serves to achieve a number of goals, and above all to ensure the mobility of all inhabitants. Optimizing the structure and functioning of urban areas and their transport systems is a very complex and responsible task with far-reaching consequences in all spheres of life of its inhabitants. The structure and size of the public passenger transport system is directly dependent on the transport needs and demands, which are different in volume and intensity in different periods within day, characteristic days and seasons. Transport demands are a key factor influencing the process of optimizing all input resources in the system (network infrastructure, vehicles, employees, finance, transport capacities, etc.). The harmonization of transport supply with transport demand implies continuous reengineering of the structure and functioning of the system, whose target function is to improve the efficiency and effectiveness of the system. Through the original revenue distribution model between the owner of the transport market (local government bodies) and operators, the work shows that the control of the monitoring of the volume of realized transport demand can affect the sustainability of the system as a whole. Knowing the nature of the transport system's behavior under real-life conditions, a large number of internal and external factors cause different distortions that are projected on the reliability and stability of the provision of transport services. In this dissertation, the original methodology for determining and quantifying the influence of the most important dynamic element (realized interval) on the transport requirements (flow of passengers) is defined. The methodology has been successfully tested on lines in real urban public passenger transport system in Belgrade. Feasibility is also reflected in the fact that the application of the methodology is not conditioned by the level of technical and technological development of the system. Based on the analysis of the relationship and the interaction between the elements of functioning and transport demand at the micro level, that is, at the level of the line, departure and vehicles, a model for determining the characteristics of transport demand based on representative data samples obtained using special methods of transport engineering in the real system of public transport of passengers is defined. The development of the model is also prompted by the fact that in real complex systems with a stochastic changes, such as the urban public passengers transport system, a simple expansion by multiplying the value of a parameter derived from a sample with a reverse value of the selection factors does not always guarantee optimal results..

Effect of Market and User Characteristics on the Expected Quality of Taxi Service

The taxi system is one of the most famous and de-veloped subsystems of flexible passenger transport. To reach the goal of the system achieving maximum produc-tion efficiency, the management focus is directed at users and service quality (SQ). The SQ can have several forms: expected, targeted, delivered, and perceived SQ. We ex-amine the expected SQ, expressed through the users’ at-titudes about the importance of the defined parameters of the SQ, which represent the users’ expectations from the taxi system. The analysis included the data from the conducted studies in three selected taxi systems. The aim of this paper was to determine the effect of market and selected user characteristics on the user expectations, applying the Chi-Square Test. We conclude that the spe-cific market and certain user characteristics affect the user expectations of the taxi system. There is a moderate effect on the employed users, pensioners, and daily users of the taxi system. When it comes to the users who use the taxi system several times a month and week, there is a less significant effect. Other user categories have no sig-nificant correlation with the selection of the parameters of the SQ in the taxi system

Establishing W/Al mammography radiation qualities in Secondary Standard Dosimetry Laboratory

In mammography clinical practice, various radiation fields are used, produced using different X-ray tube anode and filtration setups. It is important to calibrate diagnostic dosimeters in different radiation qualities as these dosimeters are used for quality control tests and most dosimeters have significant dependence of response on radiation spectra. TRS 457 Code of Practice [1] is an IAEA document which recommends calibration of diagnostic dosimeters in reference radiation fields established according to IEC 61267:2005 international standard [2], which considers the Mo/Mo anode-filter combination (abbreviated as the RQR-M series). Other, non-standard beam qualities are also used for calibration, such as the beams with W/Al anode-filter combination, used by Vinca Institute Secondary Standard Dosimetry Laboratory. Traceability is established to IAEA Dosimetry Laboratory, and radiation qualities are established by adding 0.5 mm Al additional filtration, following the IAEA procedure [3]. Mammography radiation qualities can be validated by determining the half-value layer (HVL) of the radiation beam. To determine HVL we measured incident air kerma at 1 m distance using a 1 cm3 plane parallel ionization chamber, by successively adding Al attenuators of different thickness. The Al attenuators have been placed at 0.5 m distance, equidistantly from the radiation source and the ionization chamber. HVL was obtained using a linear regression for the additional filtration values near the expected HVL value. Calculated HVL was 0.326 mm Al, 0.367 mm Al, 0.395 mm Al, 0.456 mm Al for tube voltages 25 kV, 28 kV, 30 kV and 35 kV, respectively. The results were compared with the values given by IAEA SSDL [3] (deviation for all qualities was less than 5%) and PTB Primary Standard Dosimetry Laboratory (PSDL) [4]. Radiation qualities established in this manner allow proper calibration and traceability of diagnostic dosimeters in W/Al radiation qualities to be used for routine QC tests in mammography.X JUBILEE International Conference on Radiation in Various Fields of Research : RAD 2022 (Spring Edition) : book of abstracts; June 13-17, 2022; Herceg Novi, Montenegr

ON THE NODE ORDERING OF PROGRESSIVE POLYNOMIAL APPROXIMATION FOR THE SENSOR LINEARIZATION

Many sensors exhibit nonlinear dependence between their input and output variables and specific techniques are often applied for the linearization of their transfer characteristics. Some of them include additional analog circuits, while the others are based on different numerical procedures. One commonly used software solution is Progressive Polynomial Approximation. This method for sensor transfer function linearization shows strong dependence on the order of selected nodes in the linearization vector. There are several modifications of this method which enhance its effectiveness but require extensive computational time. This paper proposes the methodology that shows improvement over Progressive Polynomial Approximation without additional increase of complexity. It concerns the order of linearization nodes in linearization vector. The optimal order of nodes is determined on the basis of sensor transfer function concavity. The proposed methodology is compared to the previously reported methods on a set of analytical functions. It is then implemented in the temperature measurement system using a set of thermistors with negative temperature coefficients. It is shown that its implementation in the low-cost microcontrollers integrated into the nodes of reconfigurable sensor networks is justified

Anatomical observations on Thymus bracteosus Vis. Ex Bentham (Lamiaceae).

Thymus bracleosus Vis. ex Bentham, endemic to the Mediterranean and submediterranean mountain of Croatia, Herzegovina and Montenegro, has been analyzed as regards the anatomy or stem, leaves and bracts. Its structure shows xero-mesomorphic characteristics. The quantity of essential oil extractable for commerciai purposes is comparatively low

Neurons of human nucleus accumbens

Background/Aim. Nucleus accumbens is a part of the ventral striatum also known as a drug active brain region, especially related with drug addiction. The aim of the study was to investigate the Golgi morphology of the nucleus accumbens neurons. Methods. The study was performed on the frontal and sagittal sections of 15 human brains by the Golgi Kopsch method. We classified neurons in the human nucleus accumbens according to their morphology and size into four types: type I - fusiform neurons; type II - fusiform neurons with lateral dendrite, arising from a part of the cell body; type III - pyramidal-like neuron; type IV - multipolar neuron. The medium spiny neurons, which are mostly noted regarding to the drug addictive conditions of the brain, correspond to the type IV - multipolar neurons. Results. Two regions of human nucleus accumbens could be clearly recognized on Nissl and Golgi preparations each containing different predominant neuronal types. Central part of nucleus accumbens, core region, has a low density of impregnated neurons with predominant type III, pyramidal-like neurons, with spines on secondary branches and rare type IV, multipolar neurons. Contrary to the core, peripheral region, shell of nucleus, has a high density of impregnated neurons predominantly contained of type I and type IV - multipolar neurons, which all are rich in spines on secondary and tertiary dendritic branches. Conclusion. Our results indicate great morphological variability of human nucleus accumbens neurons. This requires further investigations and clarifying clinical significance of this important brain region

Researching and analyzing the features of oil and demand for transporting oil derivates in the area of Belgrade

The paper contains a summary of results obtained when researching demand for transporting dangerous goods of class 3 (oil and oil derivates) in the area of the city of Belgrade in 2007. Considering all transport modes used for carrying oil and oil derivates (road, rail and water transport), we present the total quantities of transported goods on a percentage basis. In light of road transport, the paper presents the features of demand for transport in terms of time and space that are a basis for the management of transporting dangerous goods and input to defining transportation routes to dangerous goods. Among the features of demand for transport in terms of time, the paper presents the quantities of goods transported within different months of the year, different week days and different periods of the day. The features of demand for transport in terms of space presented in the paper are goods flow features depending on their origin and the destination of movement in relation to the defined serviced area and the load of traffic network with goods flows. First published online: 27 Oct 201

Dosimetry audit in radiotherapy centers in Serbia in period from 2017 to 2019

Kontrola kvaliteta u radioterapiji je od velike vaţnosti za poboljšanje preciznosti i pouzdanosti radioterapijskih procedura. Minimizacija negativnih posledica po pacijente se postiţe smanjenjem verovatnoće pojavljivanja slučajnih i sistematskih grešaka identifikovanjem problema u postojećim standardnim procedurama u bolnicama. Značajna metoda kontrole kvaliteta rada radioterapijskih centara jeste program poštanske termoluminiscentne dozimetrije, zajednički organizovan od strane Međunarodne agencije za atomsku energiju i Svetske zdravstvene organizacije, a u kojem učestvuje oko 1700 bolnica širom sveta. Radioterapijski centri u Srbiji takođe učestvuju u ovom programu. Program poređenja apsorbovanih doza u vodi u radioterapijskim centrima u Srbiji je sproveden i tokom 2017, 2018. i 2019. godine. U tom periodu, broj obuhvaćenih centara je porastao sa šest na osam. Radiofotoluminiscentni dozimetri su ozračivani u visokoenergetskim poljima X-fotona generisanim pomoću linearnih akceleratora.Quality control in radiotherapy is of great importance in order to improve accuracy and reliability of radiotherapy procedures in hospitals. Minimization of the possible negative consequences of these procedures is achieved by reducing the probability of any random or systematic errors appearing, by determining the existing problems in the standard hospital procedures. One of the important methods for the radiotherapy facilities quality control is the postal thermoluminiscent dosimetry programme, co-organized by International Atomic Energy Agency and the World Health Organization, in which approximately 1700 hospitals throughout the world are participating. Radiotherapy centers in Serbia also participate in this programme, which has been executed during 2017, 2018 and 2019. During this period the number of participating radiotherapy centers in Serbia has increased from six to eight. Radiophotoluminiscent dosimeters have been irradiated in the high-energy X-ray fields generated by using linear accelerators.Proceedings: [http://vinar.vin.bg.ac.rs/handle/123456789/8681]XXX симпозијум ДЗЗСЦГ (Друштва за заштиту од зрачења Србије и Црне Горе), 2- 4. октобар 2019. године, Дивчибаре, Србиј

Analysis of public transport users’ satisfaction using quality function deployment: Belgrade case study

This paper presents a case study using Quality Function Deployment (QFD) method to identify urban public transport users’ needs and requests and to improve service quality in urban public passenger transport in Belgrade. In order to determine users’ satisfaction, a direct interview – survey a sample of 15000 of urban public passenger transport system users, according to the defined questionnaire has been performed. Results of these interviews are used as input in the first stage of QFD method. An overall unit of eight features and a total of 48 sub-features were defined, which describes all aspects of quality of system and services in urban public passenger transport. The results show that for maximizing effects of quality of service improvement and satisfying customers’ requirements, the public transport service providers and managers in Belgrade should focus primarily on the service reliability and vehicle elements. The two most important quality of service sub-features in urban public passenger transport system in Belgrade based on frequency of statements of users was regularity with 4896 (32.64%) and vehicle comfort (not crowded vehicles) with 3446 (22.97%) statements. Based on the service features analysis within the house of quality, it was defined that the biggest influence is generated through system functioning parameters (reliability): frequency with relative importance 22.0%, staff (drivers) with relative importance 14.0% and headway with relative importance 13.0%. Based on absolute importance the greatest importance should be assigned to vehicle frequency – rank 1, staff (drivers) – rank 2 and headway – rank 3

Procena uticaja poklopca pakovanja od izabranih titanijumskih legura na energetsku zavisnost RADFET dozimetara u poljima gama i X zračenja

U ovom radu je demonstrirana analiza dizajniranja RADFET dozimetra koja je bazirana na primeni numeričke metode Monte Karlo pri proceni uticaja titanijumskih legura kao izabranog materijala za poklopac pakovanja dozimetara. Sprovedene su Monte Karlo simulacije transporta fotona X i gama zračenja različitih energija kroz razmatranu strukturu RADFET dozimetra i pritom je proračunat energetski zavisan faktor zaštite (SEDF) koji je moguće definisati za elektronske komponente datog tipa. Uzimajući u obzir vrednosti SEDF za različite vrednosti incidentnih energija fotona i dobijene odgovarajuće deponovane energije u materijalnim zonama RADFET dozimetra, ustanovljeno je da je titanijumska legura sa cirkonijumom Ti-13Nb-13Zr pogodniji material za izradu poklopca za pakovanje.XXVII Simpozijum Društva za zaštitu od zračenja Srbije i Crne Gore, Tara, 12-14. oktobar 2011