Primjena genetičkih algoritma kod problema raspoređivanja tehnoloških operacija

The basic enterprise task is to satisfy customer requirements: due date, price and quality. Based on experiences from engineers practice of work in Croatian enterprises it could be concluded that enterprises are not able to fulfil obligations to the customer in a way of due dates. One of the basic reasons lies in inappropriate scheduling model that has not had possibility to make plan variants. The paper shows how genetic algorithm could be successfully applied in scheduling model to solve the problem of plan variant. As a basic selection in the paper 3-tournament steady-state selection has been applied.Danas je osnovni zadatak poduzeća zadovoljiti kupčeva zahtjeve u pogledu roka isporuke, cijene i kvalitete. Na osnovi iskustava inženjerske prakse iz hrvatskih proizvodnih poduzeća može se zaključiti kako poduzeća nisu u mogućnosti ispuniti obveze prema krajnjem kupcu u pogledu roka isporuke. Jedan od osnovnih razloga za takva odstupanja leži u neadekvatnom modelu raspoređivanja koji nemaju mogućnost izrade varijanti planova. U radu je prikazana mogućnost primjene genetičkog algoritma kod problema raspoređivanja tehnoloških operacija u svrhu dobivanje viševarijantnog raspoređivanja. Primijenjeni genetički algoritam baziran je na 3-turnirskoj eliminacijskoj selekciji bez duplikata

Impact of strengthening fluids on roughness of 3D printed models

For some applications, 3D printed parts usually do not have satisfactory mechanical properties, so to broaden their usage, additive technologies should be combined with the well-known metallurgical processes, such as investment and others casting techniques. 3D printing developers persistently introduce new base materials and strengthening fluids which may cause different surface roughness. Therefore, in this paper, the authors have tested the roughness of 3D printed samples strengthened with common, but also with alternative fluids. Measurements proved that fluids do have significant influence on the roughness

Istraživanje i procjena zaostalih naprezanja u plinski naštrcanim NiCrBSi slojevima

For thermally sprayed coatings, beside good wear and corrosion resistance there is also a need for a good coating/substrate adhesion, reduced porosity and reduced level of residual stresses. Residual stresses that occur in the substrate/coating system are very significant because their relaxation can cause different coating failures. In this paper, different approaches to investigation of residual stresses in thermally sprayed coatings, have been presented. An analytical model (authors Tsui and Clyne) was used to estimate the distribution of residual stresses in flame sprayed and fused NiCrBSi coatings. These data can be used as input data for the numerical model.Za toplinski naštrcane slojeve, uz dobru otpornost slojeva na trošenje i koroziju, postoje i zahtjevi za dobrom prionjivosti sloja na podlogu,smanjenom poroznosti i smanjenom razinom zaostalih naprezanja. Zaostala naprezanja koja se pojavljuju u sustavu podloga/naštrcani sloj, osobito su važna, jer se njihovom relaksacijom mogu pojaviti razna oštećenja sloja. U ovome radu prikazani su pristupi istraživanju zaostalih naprezanja u toplinski naštrcanim slojevima, te je na osnovi analitičkog modela (autori Tsui i Clyne) procijenjena raspodjela zaostalih naprezanja za NiCrBSi slojeve nanesene postupkom plinskog naštrcavanja praha s utaljivanjem. Ovi podaci mogu se koristiti kao ulazni podaci za numerički model

Crack roughness and avalanche precursors in the random fuse model

We analyze the scaling of the crack roughness and of avalanche precursors in the two dimensional random fuse model by numerical simulations, employing large system sizes and extensive sample averaging. We find that the crack roughness exhibits anomalous scaling, as recently observed in experiments. The roughness exponents ($\zeta$, $\zeta_{loc}$) and the global width distributions are found to be universal with respect to the lattice geometry. Failure is preceded by avalanche precursors whose distribution follows a power law up to a cutoff size. While the characteristic avalanche size scales as $s_0 \sim L^D$, with a universal fractal dimension $D$, the distribution exponent $\tau$ differs slightly for triangular and diamond lattices and, in both cases, it is larger than the mean-field (fiber bundle) value $\tau=5/2$

Primjena neuronskih mreža u planiranju održavanja metalurške opreme

Maintenance of metallurgical equipment is very complex and demanding job. Condition Based Maintenance (CBM) is used for complex and significant equipment. The paper shows element selection that will be used in CBM planning as a location on which will be applied neural network. The paper presents few different neural network algorithms that have been used for different prediction problems and review of achieved results. Data structure that has been used in researching problem is part of Information System and its Equipment Maintenance subsystem that was developed for enterprise Aluminij d.d. Mostar.Održavanje metalurških postrojenja predstavlja složen i zahtjevan posao. Strategija održavanja po stanju predstavlja strategiju koja se primjenjuje za složeniju i značajniju opremu. U radu se daje jedan od pristupa odabira elementa za koji se provodi istraživanje s ciljem primjene neuronskih mreža u planiranju održavanja po stanju. Istraživano je nekoliko različitih algoritama neuronskih mreža za rješavanje problema predikcije, te se u radu daje pregled ostvarenih rezultata istraživanja. Kao pretpostavka za istraživanje korišteni su podaci iz podsustava održavanja postrojenja Informacijskog sustava razvijenog za potrebe poduzeća Aluminij d.d. Mostar

The Relation Between Occlusion and Temporomandibular Joint Sounds

The etiology of the occurrence of sounds and the role of occlusion, has not yet been entirely clarified. OBJECTIVE OF INVESTIGATION: The objective of this investigation was to determine the effect of occlusal relationships on the occurrence of sounds in the TMJ. METHODS: A group of 100 subjects, aged from 24 to 52 years (X=35.03) was examined. The existence of sounds was registered by means of a clinical examination and auscultation by stethoscope and classified according to character in click or crepitation. The number of teeth, the number of teeth in occlusion, type of occlusion (canine guided occlusion, group function and balanced occlusion) was determined by clinical examination. Overbite and overjet were measured. RCP position was determined by chin-point technique, and fixing by Lucia-jig.The sliding from RCP to IKP position was determined in the anteroposterior, vertical and latero-lateral direction. A precise calliper was used to measure movement. RESULTS: 29% of the subjects had a clinically determined sound, in 27% it was click, and in 2% it was crepitation. The Pearson test analysis showed statistically significant difference (p<0.05) only for the occurence of crepitation in relation to the number of teeth, number ofteeth in occlusion and overjet. The same was confirmed by analysi s of variance (ANOVA). CONCLUSION: Overjet, difference in the position of RCP-ICP sliding from RCP into ICP, and type of occlusion, i.e. mediotrusion interference, do not have an influence on the occurrence of sound in the TMJ. A reduction in the number of teeth and the number of teeth in occlusion, have an influence on the occurrence

Dvojni lijekovi primakina i nesteroidnih protuupalnih lijekova: Sinteza, hvatanje slobodnih radikala, antioksidativno djelovanje i keliranje Fe2+ iona

Novel primaquine conjugates with non-steroidal anti-inflammatory drugs (PQ-NSAIDs, 4a-h) were prepared, fully chemically characterized and screened for radical scavenging and antioxidant activities. The synthetic procedure leading to twin drugs 4a-h involved two steps: i) preparation of NSAID benzotriazolides 3a-h from the corresponding NSAID (ibuprofen, ketoprofen, fenoprofen, ketoprofen hydroxy and methylene analogues, diclofenac or indomethacin) and benzotriazole carboxylic acid chloride (BtCOCl, 1), ii) reaction of intermediates 3a-h with PQ. The prepared PQ-NSAIDs exerted moderate activities in the DPPH free radical test and -carotene-linoleic acid assay. Moreover, ketoprofen derivatives 4d and 4b demonstrated a notable Fe2+ chelating ability as well. On the other hand, negligible antiproliferative and antituberculotic effects of conjugates 4a-h were observed.U radu je opisana sinteza novih konjugata primakina s nesteroidnim protuupalnim lijekovima (PQ-NSAIDs, 4a-h), njihova potpuna karakterizacija te testiranje sposobnosti hvatanja slobodnih radikala i antioksidativnog djelovanja. Sintetski postupak za pripravu dvojnih lijekova 4a-h uključuje dva koraka: i) pripravu NSAID-benzotriazolida 3a-h iz odgovarajućih nesteroidnih protuupalnih lijekova (ibuprofena, ketoprofena, fenoprofena, hidroksi i metilenskih analoga ketoprofena, diklofenaka i indometacina) i klorida 1-benzotriazol karboksilne kiseline (BtCOCl, 1), ii) reakciju intermedijera 3a-h s primakinom. Novi PQ-NSAID konjugati pokazuju umjerenu sposobnost hvatanja slobodnih radikala u DPPH testu te umjereno antioksidativno djelovanje u pokusu s -karotenom i linoleinskom kiselinom. Osim toga, derivati ketoprofena 4d i 4b imaju primjetnu sposobnost keliranja Fe2+ iona. Svi konjugati 4a-h pokazuju vrlo slabo antiproliferativno i antituberkulotsko djelovanje

Replication of fifteen loci involved in human plasma protein N-glycosylation in 4,802 samples from four cohorts

Human protein glycosylation is a complex process, and its in vivo regulation is poorly understood. Changes in glycosylation patterns are associated with many human diseases and conditions. Understanding the biological determinants of protein glycome provides a basis for future diagnostic and therapeutic applications. Genome-wide association studies (GWAS) allow to study biology via a hypothesis-free search of loci and genetic variants associated with a trait of interest. Sixteen loci were identified by three previous GWAS of human plasma proteome N-glycosylation. However, the possibility that some of these loci are false positives needs to be eliminated by replication studies, which have been limited so far. Here, we use the largest set of samples so far (4,802 individuals) to replicate the previously identified loci. For all but one locus, the expected replication power exceeded 95%. Of the sixteen loci reported previously, fifteen were replicated in our study. For the remaining locus (near the KREMEN1 gene) the replication power was low, and hence replication results were inconclusive. The very high replication rate highlights the general robustness of the GWAS findings as well as the high standards adopted by the community that studies genetic regulation of protein glycosylation. The fifteen replicated loci present a good target for further functional studies. Among these, eight genes encode glycosyltransferases: MGAT5, B3GAT1, FUT8, FUT6, ST6GAL1, B4GALT1, ST3GAL4, and MGAT3. The remaining seven loci offer starting points for further functional follow-up investigation into molecules and mechanisms that regulate human protein N-glycosylation in vivo

Primjena neuronskih mreža u planiranju održavanja metalurške opreme

Maintenance of metallurgical equipment is very complex and demanding job. Condition Based Maintenance (CBM) is used for complex and significant equipment. The paper shows element selection that will be used in CBM planning as a location on which will be applied neural network. The paper presents few different neural network algorithms that have been used for different prediction problems and review of achieved results. Data structure that has been used in researching problem is part of Information System and its Equipment Maintenance subsystem that was developed for enterprise Aluminij d.d. Mostar.Održavanje metalurških postrojenja predstavlja složen i zahtjevan posao. Strategija održavanja po stanju predstavlja strategiju koja se primjenjuje za složeniju i značajniju opremu. U radu se daje jedan od pristupa odabira elementa za koji se provodi istraživanje s ciljem primjene neuronskih mreža u planiranju održavanja po stanju. Istraživano je nekoliko različitih algoritama neuronskih mreža za rješavanje problema predikcije, te se u radu daje pregled ostvarenih rezultata istraživanja. Kao pretpostavka za istraživanje korišteni su podaci iz podsustava održavanja postrojenja Informacijskog sustava razvijenog za potrebe poduzeća Aluminij d.d. Mostar

Investigation and estimation of residual stress in flame sprayed and fused NiCrBSi coatings

For thermally sprayed coatings, beside good wear and corrosion resistance there is also a need for a good coating/substrate adhesion, reduced porosity and reduced level of residual stresses. Residual stresses that occur in the substrate/coating system are very significant because their relaxation can cause different coating failures. In this paper, different approaches to investigation of residual stresses in thermally sprayed coatings, have been presented. An analytical model (authors Tsui and Clyne) was used to estimate the distribution of residual stresses in flame sprayed and fused NiCrBSi coatings. These data can be used as input data for the numerical model