Korištenje alata za poboljšavanje kvalitete u Hrvatskoj metaloprerađivačkoj industriji

Modern production requires a daily monitoring process and seeks its continuous improvement in order to increase the quality, and therefore effectiveness. There are various tools and their use should become a daily routine to help participants in the process at all levels; from management to production workers. For the purpose of analyzing the frequency of use and confirming the insufficient use of tools and methods of improvement, a research was conducted among Croatian metal processing manufacturers. The research has confirmed a low frequency of tool use, but has also provided some guidelines for increasing their use in the future.Suvremena proizvodnja iziskuje svakodnevno praćenje procesa te teži njihovom kontinuiranom poboljšavanju kako bi se povećala njihova kvaliteta, a samim time i efektivnost. Alati koji se koriste su raznovrsni i njihovo korištenje trebalo bi postati svakodnevnica kako bi pomogle sudionicima procesa na svim nivoima proizvodnje od uprave do radnika u neposrednoj proizvodnji. U svrhu analize učestalosti korištenja i dokazivanju premalog korištenja alata i metoda poboljšavanja provedeno je istraživanje unutar hrvatskog metaloprerađivačkog sektora. Istraživanjem je dokazana premala učestalost korištenja alata, ali i daje neke smjernice za povećanje korištenja u budućnosti

Personalni izvori u postupku utvrđivanja disciplinske odgovornosti policijskih službenika

U članku se prikazuje način prikupljanja dokaza iz personalnih izvora u postupku utvrđivanja disciplinske odgovornosti policijskih službenika. Česti dokazi su iskazi građana do kojih se dolazi kroz instrument zaprimanja i provjere pritužbi građana na postupanje i ponašanje policijskih službenika. Ističe se značaj pritužbe kao sredstva kontrole rada policijskih službenika. Posebno se ukazuje na način obavljanja razgovora sa svjedocima u postupku provjere pritužbenih navoda te važnost mogućnosti korištenja kao dokaza u disciplinskom postupku pisanih iskaza svjedoka i transkripata

Modelling the Impact of Rain in Traffic Assignment Procedures

The efficiency of urban transportation system is un-der the influence of weather conditions. It is necessary to incorporate these impacts into transport system analysis, in order to prepare adequate mitigation measures. Trans-port models are often used in different types of transport system analysis and forecasting of its future characteris-tics. This paper focuses on implementation of the impact of rain in transport modelling, particularly into a traffic assignment process as a part of a macroscopic transport model. This aspect of modelling is important because it can indicate parts of the network where this impact leads to a high volume/capacity ratio, which is a good input for defining mitigation measures. Commonly, transport models do not consider weather impacts in its standard procedures. The paper presents a methodology for cali-brating volume-delay function in order to improve traf-fic assignment modelling in case of rain. The impact of different rain categories on capacity and free-flow speed was quantified and implemented in the volume-delay function. Special attention is given to the calibration of the part of volume-delay function for over-saturated traf-fic conditions. Calibration methodology is applicable for different types of volume-delay functions and presents a solid approach to incorporate weather conditions into common engineering practice

Simulation Modelling of Permitted Left-Turn Saturation Flow Rate Based on Opposing Through-Flow Degree of Saturation

This paper presents the modelling of the saturation flow rate of the permitted left-turn in an exclusive lane. In the proposed model, the total permitted left-turn saturation flow rate is determined as a sum of saturation flow rates during the effective green time and the intergreen period. Primarily, the permitted left-turn saturation flow rate during the effective green time is modelled based on the opposing through-flow degree of saturation and the number of opposing through-flow lanes. The relation between the permitted left-turn saturation flow during the effective green time and these variables was examined using data from the simulation experiments in VISSIM. To our knowledge, this is the first study of the permitted left-turn saturation flow modelling based on the opposing through-flow degree of saturation instead of the opposing through-flow rate and signal-timing parameters. The proposed model was validated based on data collected at seven intersections with a permitted left-turn served in an exclusive lane. The permitted left-turn saturation flow rate could be accurately determined based on the opposing through-flow degree of saturation and the number of opposing lanes according to the RMSE of 58.4 pcu/h

Contribution to the traffic process analysis at signalized intersections

Doktorska disertacija prikazuje originalan pristup analizi saobraćajnog procesa na signalisanoj raskrsnici i utvrđivanju osnovnog pokazatelja efikasnosti – vremenskih gubitaka. Aktuelne metode i modeli ne obezbeđuju preciznu procenu vrednosti gubitaka. Kao osnovni nedostaci navode se pojednostavljena teorijska interpretacija procesa u okviru neeksperimentalnih, odnosno indirektnost istraživanja i veličina uzorka u okviru eksperimentalnih metoda. Formiranje objektivnih metoda utvrđivanja gubitaka zahteva potpunu spoznaju procesa u kome dolazi do njihovog nastajanja. U radu je formirana metodologija istraživanja parametara u procesima kretanja vozila u zoni signalisane raskrsnice. Osnovu metodologije predstavlja metod utvrđivanja trajektorija kretanja vozila primenom GPS tehnologije prikupljanja podataka. Primenom metodologije obezbeđuje se formiranje trajektorija vozila visokog nivoa preciznosti i detaljnosti, što predstavlja osnovu za analizu saobraćajnog procesa, utvrđivanje vrednosti osnovnih parametara i njihovog uticaja na vremenske gubitke. Rezultati istraživanja na signalisanim raskrsnicama i formirani zaključci se u određenim segmentima razlikuju od onih koje su utvrdili drugi autori. Na osnovu istraživanja razvijen je analitički model vremenskih gubitaka za nezasićena stanja. U modelu, ukupni vremenski gubici se posmatraju na mikroskopskom nivou, kroz komponente gubitaka koje nastaju u procesima kretanja vozila u različitim tipovima trajektorija. Analitički model predstavlja osnovu formiranog metoda eksperimentalnog utvrđivanja vremenskih gubitaka (MEIS). U okviru metoda gubici se utvrđuju na osnovu direktnog istraživanja vremenske komponente kretanja svakog pojedinačnog vozila koje je ostvarilo vremenski gubitak. Na osnovu rezultata praktične primene na signalisanim raskrsnicama u Beogradu, zaključeno je da je formirani metod validan u postupku utvrđivanja ukupnih vremenskih gubitaka za nezasićena stanja, kao i da se njegovom primenom eliminišu neki od osnovnih nedostataka postojećih metoda utvrđivanja gubitaka...The Doctoral dissertation demonstrates an original approach to the analysis of traffic processes at a signalized intersection and to the determination of a key performance indicator – control delay. Current estimation methods and models do not provide accurate delay assessment. The main disadvantages of existing experimental models are the sample size and indirect research methods. On the other hand, in non-experimental methods, the deficiency is in the need for theoretical simplifications of the actual traffic processes. The determination of objective estimation methods requires comprehensive understanding of the processes where the delays are generated. This dissertation proposes a methodology for the determination of individual vehicle tracking and traffic flow parameters at a signalized intersection. The foundation of this methodology is the determination of traffic parameters using GPS data collection technology. The implementation of this method provides high resolution trajectory determination, which represents a good basis for traffic process analysis and the assessment of basic parameters and their impact on control delay. The obtained results and conclusions differ moderately in certain segments from those obtained and presented by other authors. The analytical delay model for unsaturated conditions is developed based on the realized research in this dissertation. Total delays in the model are recorded at the microscopic level and represented as delay components in various trip patterns. The analytical model represents the basis of the method for experimental delay estimation (MEIS). The control delay is determined directly by researching the time trace of each particular vehicle experiencing delays. The method is implemented and tested at several signalized intersections in Belgrade. The method is proved to be valid for total delay determination in unsaturated conditions. Correspondingly, some of the most important disadvantages of existing delay estimation methods are eliminated by its implementation..

Straight lane saturation flow and its rate in serbian cities

Saturation flow is the base rate in the procedure for optimizing traffic signal operation and determining the measure for effectiveness of intersection operation. Different approaches and structures of analytical value models indicate the complexity of the problem of determining the saturation flow value in real conditions. This paper presents the synthesis of the results and conclusions of studying the saturation flow rate phenomenon at signalised intersections in Serbia in the last thirty years, by applying various survey techniques. The surveys relate to straight lane saturation flow value, in the survey conditions mostly resembling the idealised conditions in which saturation flow can be generated. The obtained results indicate that there is a significant trend of changes in the base saturation flow value compared with those first referred in 1963 by Webster and Cobbe, change in the significance of impact factor on saturation flow value, and the necessity to determine them on the local level

Quality improvement tools

Kvaliteta je postala svjetski pokret i način življenja. Uspjeh organizacije najviše zavisi o kvaliteti proizvoda ili usluga. Za to najveću odgovornost snosi uprava, ali pri tome svi zaposleni moraju participirati u ostvarivanju kvalitete. Kvaliteta jest i biti će ključ za poboljšanje konkurentnosti na tržištu. Kvaliteta je značajan faktor opstanka, poslovnog uspjeha i prosperiteta poduzeća. Ključni princip sistema kvaliteta je donošenje odluka na osnovu činjenica, do kojih se dolazi prikupljanjem, obradom i analizom podataka i opažanja. Ovaj članak obrađuje alate za analizu i poboljšanje kvalitete. Alati su prvenstveno namijenjeni upravi, ali u njihovoj provedbi ključno je sudjelovanje svih zaposlenika, kako bi oni dali relevantne podatke na osnovu kojih uprava može izvršiti analizu i donošenje.Quality has become a worldwide movement and a way of life. The success of the organization depends mostly on the quality of products or services. The primary responsibility lies on the management, but also all employees must participate in the exercise of quality. Quality is key for improving the competitiveness on the market. Quality is an important factor for survival, business success and prosperity of companies. A key principle of the quality system is making decisions based on facts, and to the fact arise through the process of collecting, processing and analyzing data and observations. This article deals with tools for analysis and improvment of quality. The tools are primarily intended for managment, but in their preparation participation of all employeesis crucial, so that they can give relevant information on which management can conduct analysis and making decision