In the context of this work, a prototype hybrid photoacoustic (PA) and optical system for on-line monitoring laser cleaning procedures is presented. The developed apparatus has enabled detection MHz frequency range acoustic waves generated during ablation process. intrinsically PA signals combined with high resolution images provide opportunity to follow process accurately in real time. Technical mock-ups have been used demonstrate potential novel technique emphasis given applications that...

Currently, removal of graffiti from stone monuments is a particularly challenging task. Lasers, being highly controllable and precise tools with minimal chemical waste, offer key solution in this respect significant amount research has been dedicated to subject. Studies related the laser cleaning carbonate stones (such as limestone marble) reported extraction layer, although damage substrate can be also detected. Recently, efforts have focused on granite, which complex due its grained...

In this Letter, we present a combined photoacoustic imaging method, based on consecutive excitation using either the fundamental or second-harmonic wavelength of pulsed Nd:YAG laser for stratigraphy painted artworks. Near-infrared was employed hidden underdrawings in mock-up samples, whereas visible light used thickness mapping overlying paint through detection signal attenuation. The proposed methodology proven effective measuring thick and strongly absorbing layers, which would not be...

Abstract The high hygroscopicity and heterogeneity of parchment make it particularly sensitive to changes in environmental conditions. proper housing a historical parchment, including mounting should mitigate the impact on object. However, finding an appropriate method requires detailed knowledge mechanical response combined influence from forces introduced by mounting. In this paper we present capabilities 3D digital image correlation (3D DIC) implemented for full-field, spatio-temporal...

One of the most common sources damage in CulturalHeritage Objects (CHO) such as parchment, oil paintings and historical textiles is relative humidity (RH) changes which cause inplane out-of-plane displacements their surfaces.The best suited method enables full-field, non-contact measurement with high resolution sufficient range, 3D Digital Image Correlation (3D DIC).However, standard version DIC requires applying random, good contrast speckle pattern at a surface object under...

The synchronous use of Infrared (IR at 1064nm) and Ultraviolet (UV 355nm) wavelengths a Q-Switched Nd:YAG laser has been shown to efficiently confront the issue discoloration, which may be observed upon ablation environmental encrustation from marble surfaces, thus this methodology is effectively employed in various cleaning applications.In order further investigate mechanisms that influence result, series tests were undertaken on fragments with homogeneous compact crust.Through number...

A modified 3D colour digital image correlation method (3D cDIC) is proposed for efficient displacement measurements of objects with natural texture. The using a separate analysis coefficient (sigma) value in the RGB channels CCD cameras by utilising local information from channel minimum sigma. In this way, merged U, V and W maps are generated based on quality. As applies to filter array cameras, images have undergo demosaicking procedure which directly influences accuracy measurements....

Digital image correlation (DIC) is a well-established technique for the measurement and monitoring of displacements strains in engineering objects. In technical applications, an object's surface modified by applying random, artificial structure, monochrome cameras are typically used. The challenge Cultural Heritage objects (CHO) lies necessity using natural texture (no modifications allowed), which most cases far from ideal random pattern required successful implementation DIC. On other...

Multi-objective optimization is undoubtedly one field with many applications in real life situations and constitutes a highly active research area. In this paper, comparison among high-performing multi-objective metaheuristics algorithms provided. For the comparison, three well-known Random Search algorithm are utilized on benchmark test families. Their results compared use of two different metrics order to be fully effectively assessed. also discussed, some future points proposed.

Augmented reality is a field of presenting and visualizing the real-world problem enhanced by computer-generated algorithms. The perceptual information becomes premier research topic to solve various 3D problems. In this present age, it very important digitize process work store keep track changes over time. This focused on storing digital documentation restoration cultural heritage objects concerning parameter occurrences surface geometry change objects. paper shows application structured...

Application of optical metrology techniques in the collection surface data and its 3D representation can improve digital documentation conservation restoration process artworks.The tracking induced change after on cultural heritage (CH) surfaces involves a computational analysis geometry.In analysis, scientists were interested to see what impact fillings some holes have nearby surrounding during reconstruction.In theory, loss compensation method for stone should allow conservators make...

Globes are a part of unique group artefacts that combine utility and decorative functions. This multi-functionality typically results in the poor condition such items as they significantly affected by physics their very structure technique technology manufacture. The following article recounts conservation restoration school globe from 1920s, with particular emphasis on solutions to issues commonly seen this kind object. main research focus is ways restore object's original shape. In...

A multimodal optomechatronics system is presented for measuring and monitoring change in cultural heritage objects exposed to environmental condition fluctuations or conservation treatments. It combines structured light, 3D colour digital image correlation multispectral imaging, delivering information about an object's shape, displacements, strains reflectivity. The high functionality applicability of the are with example historical parchment subjected changes relative humidity.

One of the most fundamental issues in field mathematical optimisation is convergence an iterative method and by this we are referring to two things. First, will find optimum second, be a local one or global one? A recently proposed technique (Nikolakakou et al., 2015b) that used order lessen dependence locally convergent has on initial guess, exploited paper. way so such may guided predefined kind minimum (local global) presented. Well known test functions were for experimentation....

One of the most fundamental issues in field mathematical optimisation is convergence an iterative method and by this we are referring to two things. First, will find optimum second, be a local one or global one? A recently proposed technique (Nikolakakou et al., 2015b) that used order lessen dependence locally convergent has on initial guess, exploited paper. way so such may guided predefined kind minimum (local global) presented. Well known test functions were for experimentation....