Partial differential systems with nonlocal nonlinearities: Generation and solutions

We develop a method for generating solutions to large classes of evolutionary partial differential systems with nonlocal nonlinearities. For arbitrary initial data, the solutions are generated from the corresponding linearized equations. The key is a Fredholm integral equation relating the linearized flow to an auxiliary linear flow. It is analogous to the Marchenko integral equation in integrable systems. We show explicitly how this can be achieved through several examples including reaction-diffusion systems with nonlocal quadratic nonlinearities and the nonlinear Schrodinger equation with a nonlocal cubic nonlinearity. In each case we demonstrate our approach with numerical simulations. We discuss the effectiveness of our approach and how it might be extended.Comment: 4 figure

THE DOCUMENTATION OF CULTURAL HERITAGE WITH BIM OPEN SOURCE SOFTWARE

[EN] The Building Information Modelling (BIM) software enables the users to communicate and design, understand appearance, performance and cost in the spatial and urban design process. Another important use of the BIM technology is the documentation and 3D reconstruction of cultural heritage monuments. The appropriate BIM software equips the users with tools to easily capture and analyse concepts and maintain the coordination of design data through documentation and 3D modelling. Many developments come up in the BIM field and software industry for design, construction-reconstruction, restoration and management of the cultural heritage 3D models, using BIM tools; mainly commercial as well as free or open source. Nevertheless, recently the growing popularity of open source has altered the landscape in software industry, as they attract many users. This paper presents a review of some recent research on the topic. We review the recent developments focusing on the OSS that can be used at various stages of BIM process in the digital documentation of cultural heritage. The results show that there is more preference in the commercial software due to the fact that the OSS is not yet complete and covers all stages of the BIM process. However, lately we have the Edificius in architectural BIM design and “BIM Vision” as Industry Foundation Classes (IFC) model viewer that try to attract as many users as possible. These tools are free and they could well be used for the digital reconstruction of cultural heritage.Logothetis, S.; Stylianidis, E. (2016). THE DOCUMENTATION OF CULTURAL HERITAGE WITH BIM OPEN SOURCE SOFTWARE. En 8th International congress on archaeology, computer graphics, cultural heritage and innovation. Editorial Universitat Politècnica de València. 291-294. https://doi.org/10.4995/arqueologica8.2015.3443OCS29129

BIM Open Source Software (OSS) for the documentation of cultural heritage

[EN] The Building Information Modelling (BIM) software enables the users to communicate and design, understand appearance, performance and cost in the spatial and urban design process. Another important use of the BIM technology is the documentation and 3D reconstruction of cultural heritage monuments. The appropriate BIM software equips the users with tools to easily capture and analyse concepts and maintain the coordination of design data through documentation and 3D modelling. Many developments come up in the BIM field and software industry for design, construction-reconstruction, restoration and management of the cultural heritage 3D models, using BIM tools; mainly commercial as well as free or open source. Nevertheless, recently the growing popularity of open source has altered the landscape in software industry, as they attract many users.This paper presents a review of some recent research on the topic. We review the recent developments focusing on the OSS that can be used at various stages of BIM process in the digital documentation of cultural heritage. The results show that there is more preference in the commercial software due to the fact that the OSS is not yet complete and covers all stages of the BIM process. However, lately we have the Edificius in architectural BIM design and “BIM Vision” as Industry Foundation Classes (IFC) model viewer that try to attract as many users as possible. These tools are free and they could well be used for the digital reconstruction of cultural heritage.Logothetis, S.; Stylianidis, E. (2016). BIM Open Source Software (OSS) for the documentation of cultural heritage. Virtual Archaeology Review. 7(15):28-35. doi:10.4995/var.2016.5864.SWORD283571

Progressive collapse response of steel and composite buildings

Subsequent to the World Trade Centre collapses in 2001, general interest into structural robustness and progressive collapse has been significantly heightened. It is recognised that the current prescriptive rules employed in the design of building structures to resist progressive collapse need to be replaced by performance-based approaches. A continuing research program at Imperial College London aims at the development of a complete design method that will address the basic features of progressive collapse whilst being tractable in terms of complexity for routine use in practice. An important step towards that objective is the proper treatment and understanding of the fundamental mechanics of the problem. The current study is motivated by that requirement and seeks to build on previous developments at Imperial to explore the progressive collapse response of steel and composite buildings on a quantitative basis. At first, the study is dedicated to the development of a simplified model for representation of the connection behaviour. The model is incorporated into a slope-deflection approach and an analytical method for prediction of the nonlinear static response of steel and composite beams following column removal – i.e. a common design scenario for progressive collapse – is derived. The method is carefully validated and applied in a detailed study of the response of axially restrained beams in progressive collapse, where the most important structural parameters and their effects on performance are identified. Based on those outcomes, the behaviour of bare steel and composite grillage systems following sudden column loss is subsequently appraised. It is concluded that progressive collapse resistance depends on the interplay between the connection moment capacities and ductility. Performance may also be enhanced by compressive arching action in the presence of axial restraint; however, for average values of connection ductility, failure typically occurs prior to the development of significant tensile catenary action. Therefore, it is suggested that design methods for progressive collapse should be primarily oriented towards the prediction of appropriate values for the connection moment capacities

Development of a platform recommending 3D and spectral digitisation strategies

[EN] Spatial and spectral recording of cultural heritage objects is a complex task including data acquisition, processing and analysis involving different technical disciplines. Additionally, the development of a suitable digitisation strategy satisfying the expectations of the humanities experts needs an interdisciplinary dialogue often suffering from misunderstanding and knowledge gaps on both the technical and humanities sides.Through a concerted discussion experts from the cultural heritage and technical domains currently develop a so-called COSCHKR platform (Colour and Space in Cultural Heritage Knowledge Representation) which will give recommendations for spatial and spectral recording strategies adapted to the needs of the cultural heritage application. The platform will make use of an ontology through which the relevant parameters of the different domains involved in the recording, processing, analysis and dissemination of cultural heritage objects are hierarchically structured and are related through rule-based dependencies. Background and basis for this ontology is the fact that a deterministic relation exists between (1) the requirements of a cultural heritage application on spatial, spectral, as well as visual digital information of a cultural heritage object which itself has concrete physical characteristics and (2) the technical possibilities of the spectral and spatial recording devices. Through a case study which deals with the deformation analysis of wooden samples of cultural heritage artefacts this deterministic relationship is illustrated explaining the overall structure and development of the ontology.The aim of the COSCHKR platform is to support cultural heritage experts finding the best suitable recording strategy for their often unique physical cultural heritage object and research question. The platform will support them and will make them aware of the relevant parameters and limitations of the recording strategy with respect to the characteristics of the cultural heritage object, external influences, application, recording devices, and data.This work was partly supported by COST under Action TD1201: Colour and Space in Cultural Heritage (COSCH).Wefers, S.; Karmacharya, A.; Boochs, F. (2016). Development of a platform recommending 3D and spectral digitisation strategies. Virtual Archaeology Review. 7(15):18-27. doi:10.4995/var.2016.5861.SWORD182771

Investigation of the Effect of Hydrogen and Methane on Combustion of Multicomponent Syngas Mixtures using a Constructed Reduced Chemical Kinetics Mechanism

This study investigated the effects of H2 and CH4 concentrations on the ignition delay time and laminar flame speed during the combustion of CH4/H2 and multicomponent syngas mixtures using a novel constructed reduced syngas chemical kinetics mechanism. The results were compared with experiments and GRI Mech 3.0 mechanism. It was found that mixture reactivity decreases and increases when higher concentrations of CH4 and H2 were used, respectively. With higher H2 concentration in the mixture, the formation of OH is faster, leading to higher laminar flame speed and shorter ignition delay time. CH4 and H2 concentrations were calculated at different pressures and equivalence ratios, showing that at high pressures CH4 is consumed slower, and, at different equivalence ratios CH4 reacts at different temperatures. In the presence of H2, CH4 was consumed faster. In the conducted two-stage sensitivity analysis, the first analysis showed that H2/CH4/CO mixture combustion is driven by H2-based reactions related to the consumption/formation of OH and CH4 recombination reactions are responsible for CH4 oxidation. The second analysis showed that similar CH4-based and H2 -based reactions were sensitive in both, methane- and hydrogen-rich H2/CH4 mixtures. The difference was observed for reactions CH2O + OH = HCO + H2O and CH4 + HO2 = CH3 + H2O2, which were found to be important for CH4-rich mixtures, while reactions OH + HO2 = H2O + O2 and HO2 + H = OH + OH were found to be important for H2-rich mixtures

Encouraging urban planning and development practice to contribute to sustainable development. A methodology and a use case

One of the most complex challenges the tourism industry faces is keeping up to date with information technology developments caused by the globalisation of information and advances in technology. The development of robust decision support systems for tourism land use planning is a way to address this challenge.This paper demonstrates how a spatial decision support system (SDSS), called the Land Use Decision sUpport System (LUDUS), can contribute in allocating complex forms of tourism. The system combines an artificial intelligence technique, called ontologies, with Geographic Information Systems and object-oriented programming to support decision-making in spatial planning. The system consists of two subsystems: the Insert Data Subsystem and the Graphic Imaging and Decision Support Subsystem. The core of the system is an ontology that is aligned to a standard of the Open Geospatial Consortium, called Geosparql.The case study of this paper is the Mastichochoria area of Chios Island, Greece. Therefore, the structure of the ontology was modelled according to the provisions of Greek legislation. The results produced confirmed the correct coding and application of the system’s criteria. The validity, accuracy and reliability of the results were also confirmed.The adopted approach facilitates the identification of alternative options for allocating, among other land use types, complex forms of tourism development in suburban areas, by examining the provisions of the legal framework as well as their geology and terrain