Risk modelling for production processes

Základom fungovania výrobného podniku sú jeho výrobné procesy. Preto by mal podnik zamerať pozornosť na efektívny chod hlavných procesov a prihliadať na riziká, ktoré sú s procesmi spojené. Práca sa zaoberá rozborom rizík vybraných výrobných procesov konkrétneho podniku a to z kvalitatívneho i kvantitatívneho hľadiska. Najskôr sú prezentované výsledky kvalitatívneho rozboru a to najmä v oblasti poruchovosti strojov či postupnosti výroby. Ďalej sa práca zaoberá problémom optimalizácie postupnosti výrobných dávok tak, aby celkový čas potrebný na prednastavenie strojov medzi dávkami bol minimálny. Práca zohľadňuje náhodnosť doby čakania a uplatňuje wait-and-see prístup stochastického programovania k aplikovanej úlohe obchodného cestujúceho. Výpočty sú realizované pomocou programu GAMS a výsledky sú následne spracované v MS Excelu a ďalej interpretované pomocou pojmov deskriptívnej štatistiky.The processes and procedures covered the main core of the professional operations in the manufacturing plant. The enterprise should focus on the efficient running of the main processes and risks associated with these procedures. My thesis deals with the risk analysis of selected manufacturing processes particular company from qualitative and quantitative point of view. First, the results are presented from qualitative risk analysis, especially in scope of failures of the machines or in the sequences of production. Second part focus on the problems of optimization sequence batches that the total time required for pre-setting of machines between doses should be minimal. The thesis also takes random waiting period into the consideration and applies wait-and-see approach of stochaistic programming applied in task traveling salesman. Calculations are processed by the GAMS. The results from the GAMS are refered in MS Excel, they are further discussed and interpreted by using descriptive statistics.

The Safety Studies in Selected Business Entity

Základné fungovanie podniku je založené na jednotlivých výrobných článkoch. Ak chceme, aby celý podnik fungoval dobre, treba sa zaujímať o bezpečnosť práce vo výrobe. Cieľom bakalárskej práce bude analýza konkrétneho a aktuálneho plánu bezpečnosti a ochrany zdravia pri práci, v podniku DEL a.s., aj s ohľadom na ekológiu. Nasleduje spracovanie analýzy a jej vyhodnotenie. Konečná fáza predstavuje vypracovanie návrhov na zlepšenie bezpečnosti práce.Primary operation of the company is based on individual production units. If we want the company to operate well, we have to focus on safety in production. The main task of the thesis is the analysis of specific and topical safety plan and health protection plan in the company DEL a.s. with regard to the ecological aspects. Folowing steps are processing and evaluation of the analysis. The final stage consists of drawing up the proposals for safety improvments.

Multiplicity and Transverse Energy Distributions Associated to Rare Events in Nucleus-Nucleus Collisions

We show that in high energy nucleus-nucleus collisions the transverse energy or multiplicity distribution P_C, associated to the production of a rare, unabsorbed event C, is universally related to the standard or minimum bias distribution P by the equation $P_C(\nu)={\nu\over}P(\nu)$, with $\sum P(\nu)=1$ and $\nu\equiv E_T$ or n. Deviations from this formula are discussed, in particular having in view the formation of the plasma of quarks and gluons. This possibility can be distinguished from absortion or interaction of comovers, looking at the curvature of the $J/\Psi$ over Drell-Yan pairs as a function of E_T.Comment: 8 pages, 4 Postscript figure

The freeze-out mechanism and phase-space density in ultrarelativistic heavy-ion collisions

We explore the consequences of a freeze-out criterion for heavy-ion collisions, based on pion escape probabilities from the hot and dense but rapidly expanding collision region. The influence of the expansion and the scattering rate on the escape probability is studied. The temperature dependence of this scattering rate favors a low freeze-out temperature of ~100 MeV. In general, our results support freeze-out along finite four-volumes rather than sharp three-dimensional hypersurfaces, with high-pt particles decoupling earlier from smaller volumes. We compare our approach to the proposed universal freeze-out criteria using the pion phase-space density and its mean free path.Comment: 8 pages, 2 figures, although conclusions are unchanged, the paper has been re-written and the title has been changed for the sake of better presentatio

Quark exchange model for charmonium dissociation in hot hadronic matter

A diagrammatic approach to quark exchange processes in meson-meson scattering is applied to the case of inelastic reactions of the type (Q\barQ)+(q\barq)\rightarrow (Q\barq) + (q\barQ), where $Q$ and $q$ refer to heavy and light quarks, respectively. This string-flip process is discussed as a microscopic mechanism for charmonium dissociation (absorption) in hadronic matter. The cross section for the reaction $J/\psi + \pi \to D+ \bar D$ is calculated using a potential model, which is fitted to the meson mass spectrum. The temperature dependence of the relaxation time for the \J/Psi distribution in a homogeneous thermal pion gas is obtained. The use of charmonium for the diagnostics of the state of hot hadronic matter produced in ultrarelativistic nucleus-nucleus collisions is discussed.Comment: 24 pages, 3 tables, 7 figure

J/psi absorption by pi and rho mesons in a meson exchange model with anomalous parity interactions

We reanalyze the dissociation process of the $J/\psi$ by $\pi$ and $\rho$ mesons into $D + \bar{D}$, $D^* + \bar{D}$, $D + \bar{D}^*$, and $D^* + \bar{D}^*$ within a meson exchange model. In addition to the dissociation mechanisms considered in the literature, we consider anomalous parity interactions, whose couplings are constrained by heavy quark spin symmetry and phenomenology. This opens new dissociation channels and adds new diagrams in the previously considered processes. Compared to the previous results, we find that these new additions have only a minor effect on the $\rho + J/\psi$ total inelastic cross section, but reduce the one for $\pi + J/\psi$ by about 50 % near the threshold.Comment: 21 pages, REVTeX, 7 figures, references added, to appear in Phys. Rev.