PARAMETERIZATION OF COMPLEX CULTURAL HERITAGE SHAPES FOR ONLINE VIEWING AND INTERACTIVE PRESENTATION AND PROCESSING

[EN] We have developed algorithms and programs capable of efficiently parameterizing complex cultural heritage shapes including texture, which significantly reduces the data-set size. This is potentially significant for online viewing and interactive presentation and processing. The proposed approach is based on Non-uniform rational B-splines (NURBS) mathematical model which is also by itself suitable for analysis, especially of different artistic techniques.Ćurković, M.; Vučina, D. (2016). PARAMETERIZATION OF COMPLEX CULTURAL HERITAGE SHAPES FOR ONLINE VIEWING AND INTERACTIVE PRESENTATION AND PROCESSING. En 8th International congress on archaeology, computer graphics, cultural heritage and innovation. Editorial Universitat Politècnica de València. 105-110. https://doi.org/10.4995/arqueologica8.2015.3510OCS10511

MODEL UPDATE WITH THE OBSERVER/KALMAN FILTER AND GENETIC ALGORITHM APPROACH

The discrete time Observer/Kalman model identification technique is implemented in order to identify the structure pulse response. The model updating procedure based on the finite element model pulse response of the test structure and the genetic algorithm is developed. The objective function evaluates the difference between the system and the model pulse responses. The modal assurance criteria implementation is considered. The model reduction in order to match the model degrees of freedom (dofs) and the test structure dofs involved in the experiment is discussed. A case study on the frame test structure is provided

Experimental investigation of the added mass of the cantilever beam partially submerged in water

U radu se numerički i eksperimentalno analizira fenomen dodane (virtualne) mase konstrukcije uronjene u tekućinu. Standardni model dodane modalne mase se analizira usporedo s prividno dodanom lokalnom masom koja se određuje korištenjem vektora pseudo-ostatka sile. U određivanju lokalno dodane virtualne mase koristi se konstrukcija modelirana metodom konačnih elemenata. Procedura zahtijeva popravljeni model konačnih elemenata na temelju eksperimenta kao i redukciju modela. Način primjene popravke i redukcije modela u analizi lokalno dodane virtualne mase su prikazani u radu te je diskutirana njihova uloga. Postupak je primijenjen na konzolu djelomično uronjenu u vodu. Eksperimentalna modalna analiza izvršena je na konzoli u zraku te na istoj konzoli djelomično uronjenoj u vodu. Ova analiza daje dva seta modalnih parametara, a uzrok njihove razlike je dodana masa koja je prezentirana i objašnjena u ovom radu. Rezultati dobiveni na ovaj način mogu se koristiti u daljim istraživanjima kao polazna točka u simulacijama.The phenomena of added (virtual) mass of submerged structures are analyzed numerically and experimentally in this paper. The classical concept of modal added mass is analyzed in parallel with local added mass that is evaluated using pseudo-residual force vector. A finite element structure model is used to determine the local added mass. The model update and the model reduction techniques are necessary, and their respective roles are described and applied in determining the local added mass. The procedure is implemented to the cantilever beam partially submerged into water. Experimental modal analysis is performed on a cantilever beam in the air and on the same beam partially submerged in the water. This results in two sets of modal parameters, and the cause of their differences is presented and explained by the added mass. The results obtained in this way can be used as benchmark for further study and comparison with other simulations

Technical and technological cost effectiveness analysis for establishment of a printing house

Cilj je ovog rada utvrditi isplativost osnivanja tiskarske kuće u Republici Hrvatskoj (Split). U radu je primijenjen interdisciplinarni pristup: inženjerski pristup u analizi tehničko-tehnoloških rješenja i ekonomski pristup u ekonomskoj-financijskoj analizi. Naime, nakon detaljne tehničko-tehnološke analize, na temelju stvarnih okolnosti, u programskoj aplikaciji za evaluaciju investicijskih projekata simulirana su dva scenarija realizacije projekta. U oba scenarija početna ulaganja su ista, a razlika među njima proističe iz veličine naklade. Rezultati analize u ekonomsko-financijskom smislu, za oba scenarija, su prihvatljivi. To se odnosi prije svega na likvidnost, zadržanu dobit, razdoblje povrata kao i ostale pokazatelje uspješnosti poslovanja. Međutim, scenarij s manjom nakladom se procjenjuje kao realniji i zaključno kao bolji izbor za realizaciju konkretnog projekta. Prikazani investicijski projekt ima dobre pretpostavke za uspješno poslovanje.The aim of this paper is to investigate the profitability of the establishment of printing house in Croatia (Split). The paper applies an interdisciplinary approach: an engineering approach to the analysis of technical and technological solutions and economic approach to economic-financial analysis. In fact, after detailed technical analysis, based upon real circumstances, the evaluation of investment projects has been carried out by a software application. Two scenarios of the project realization, based on the actual circumstances, are simulated. Both scenarios have the same value of the initial investment, the difference between them arises from the edition size. For each scenario, results of the analysis for economic and financial terms are acceptable. This applies primarily to the high liquidity, retained profit, return on investment and other business success indicators. However, the scenario with smaller number of copies has been estimated as more realistic and ultimately inclusive as the better choice for the implementation of concrete projects. Presented investment project has good preconditions for successful business

Technical and Technological Cost Effectiveness, Analysis of the Wood Furniture Production for Equipment the Yachts, Sailboats and Catamarans

Cilj je ovom radu pokazati isplativost osnivanja pogona za izradbu drvenog namještaja kojemu je temeljni asortiman namještaj za jahte, jedrilice i katamarane u pojedinačnoj (custom) ili serijskoj proizvodnji za poznatog kupca. U programskoj aplikaciji za evaluaciju investicijskih projekata simulirana su tri scenarija realizacije projekta na temelju stvarnih okolnosti. Rezultati analize u ekonomsko-financijskom smislu izrazito su dobri. To se odnosi prije svega na veliku likvidnost, zadržanu dobit i razdoblje povrata, uz ostale pokazatelje. Inače, investicijski projekti tijesno vezani uz proizvodnju drvenog namještaja za plovila imaju veliku mogućnost rasta i stabilnog poslovanja. Naime, drvna industrija ostvaruje suficit s inozemstvom, a mala je brodogradnja brzorastuća industrija. Prikazani investicijski projekt ima dobre pretpostavke za uspješno poslovanje.The aim of this paper is to show the viability of the facility for production of wood furniture which is the basic range of furniture for yachts, sailboats and catamarans in the individual (custom) or mass-produced for a known customer. The application program for the evaluation of investment projects have simulated three scenarios project implementation based on the actual circumstances. Analysis results of economic and financial terms are very good. This applies primarily to the high liquidity, retained earnings, payback period and other indicators. Otherwise, investment projects closely related to the production of wood furniture for boats have large growth potential and a stable business. Namely, the wood industry realized a surplus with other countries, a small shipbuilding industry is fast-growing industry. A presented investment project has good preconditions for successful busines

Experimental investigation of the added mass of the cantilever beam partially submerged in water

U radu se numerički i eksperimentalno analizira fenomen dodane (virtualne) mase konstrukcije uronjene u tekućinu. Standardni model dodane modalne mase se analizira usporedo s prividno dodanom lokalnom masom koja se određuje korištenjem vektora pseudo-ostatka sile. U određivanju lokalno dodane virtualne mase koristi se konstrukcija modelirana metodom konačnih elemenata. Procedura zahtijeva popravljeni model konačnih elemenata na temelju eksperimenta kao i redukciju modela. Način primjene popravke i redukcije modela u analizi lokalno dodane virtualne mase su prikazani u radu te je diskutirana njihova uloga. Postupak je primijenjen na konzolu djelomično uronjenu u vodu. Eksperimentalna modalna analiza izvršena je na konzoli u zraku te na istoj konzoli djelomično uronjenoj u vodu. Ova analiza daje dva seta modalnih parametara, a uzrok njihove razlike je dodana masa koja je prezentirana i objašnjena u ovom radu. Rezultati dobiveni na ovaj način mogu se koristiti u daljim istraživanjima kao polazna točka u simulacijama.The phenomena of added (virtual) mass of submerged structures are analyzed numerically and experimentally in this paper. The classical concept of modal added mass is analyzed in parallel with local added mass that is evaluated using pseudo-residual force vector. A finite element structure model is used to determine the local added mass. The model update and the model reduction techniques are necessary, and their respective roles are described and applied in determining the local added mass. The procedure is implemented to the cantilever beam partially submerged into water. Experimental modal analysis is performed on a cantilever beam in the air and on the same beam partially submerged in the water. This results in two sets of modal parameters, and the cause of their differences is presented and explained by the added mass. The results obtained in this way can be used as benchmark for further study and comparison with other simulations

Experimental Vibration Testing and Nondestructive Testing

An overview of the Vibration and Experimental Modal Analysis (EMA) and system identification method and possible applications in non-destructive testing (NDT) is provided. The system identification in time, frequency and scale-time domain methods are presented. The illustrative examples of stiffness, mass and damping identification are provided. The theoretical and experimental basis of for mechanical system condition assessment is given. Displayed NDT method is based on the residual force vector and dynamic properties of the system. Theoretically, the method is applicable to any structure that can be accurately modeled using the finite element method and whose frequencies and mode shapes can be reliably obtained. To confirm the method numerically, it is applied to the numerical model of story frame, where the damage was simulated for three different cases: change in mass, change in stiffness and both change in mass and change in stiffness simultaneously. The practical, experimental, validity of the method is demonstrated by applying it to the free-free beam. It is shown that the practical application of the method requires additional actions, without which the method can be difficult to implement. This is a model update with which it is possible to achieve reliable modal parameters and the model reduction is used with which enables the equality of degrees of freedom between numerical and experimental model to be obtained

MODEL UPDATE WITH THE OBSERVER/KALMAN FILTER AND GENETIC ALGORITHM APPROACH

The discrete time Observer/Kalman model identification technique is implemented in order to identify the structure pulse response. The model updating procedure based on the finite element model pulse response of the test structure and the genetic algorithm is developed. The objective function evaluates the difference between the system and the model pulse responses. The modal assurance criteria implementation is considered. The model reduction in order to match the model degrees of freedom (dofs) and the test structure dofs involved in the experiment is discussed. A case study on the frame test structure is provided

Evaluation of 3D tool wear in machining by successive stereo-photogrammetry and point cloud processing

Procjena trošenja alata ima značajan utjecaj na kvalitetu proizvoda, kao i na učinkovitost proizvodnog procesa. Primijenjena je procjena trošenja alata temeljena na iskustvu i ukupnom vremenu trajanja obrade. Taktilni mehanički uređaji i optički mikroskop su također primijenjeni. Predlaže se i primjenjuje inovativna optička metoda mjerenja trošenja alata koja se zasniva na 3D skeniranju uporabom stereo-fotogrametrije i triangulacije. Metodom je moguće točno izmjeriti trodimenzionalne devijacije na ukupnoj površini rezne pločice, jer je trodimenzionalni vektor odstupanja oblika dobiven pomoću milijun točaka. Trodimenzionalnu funkciju svekupnog istrošenja alata moguće je dobiti i bez uklanjanja alata s alatnog stroja. Određivanje istrošenja alata kao trodimenzionalne funkcije nudi mnoštvo informacija prema kojima je moguće dovesti u vezu pojedinačne oblike trošenja alata s mogućim uzorcima trošenja.The tool wear evaluation has a very strong impact on the product quality as well as efficiency of the manufacturing process. Experience-based assessment of tool wear and total cumulative time of operation has been applied. Tactile mechanical sensing devices and optical microscopes have been applied as well. This paper proposes and applies an inovative optical tool wear measurement method. It is based on 3D optical sensing using stereo-photogrammetry and triangulation. It offers high accuracy 3D dimensional deviation measurement spanning over the total tool surface, hence 3D deviation vectors from some reference shape are obtained simultaneously for millions of points. The overall tool wear shape function in 3D is generated, in many cases even without disassembly of the tool. Capturing the tool wear as a 3D shape function potentially offers abundant information towards diagnostics in terms of correlating the particular tool wear shape function with respective potential causes

Reduced global parametrization for shape optimization

Prispevek predstavlja začetno raziskovalno delo na področju reducirane globalne parametrizacije za optimizacijo oblike konstrukcijskih delov. Z besedo \u27reducirana\u27 označujemo parametrizacijo z zelo majhnim številom vplivnih parametrov - to število mora biti neodvisno od kompleksnosti geometrije konstrukcijskega dela, ki ga optimiramo. Za osnovo predlaganega pristopa smo privzeli predpostavko, da se oblika konstrukcijskega dela lahko spreminja samo v izbranih naravnih načinih. Ti načini so med sabo neodvisni in hierarhično razporejeni. To omogoča optimizacijo s prilagodljivo natančnostjo v odvisnosti od računske zahtevnosti problema.The paper presents initial research work in the field of reduced global parametrization for shape optimization of structural parts. By the word \u27reduced\u27 we denote a parametrization with a very low number of influential parametersthis number has to be independent of the geometrical complexity of the structural part to be optimized. The basis of the proposed approach is given by the assumption that the shape of the structural part can be varied only by selected natural modes. These modes are mutually independent and hierarchically arranged. This enables optimization with variable accuracy in dependence on computational demandingness of the problem