Geographic features recognition for heritage landscape mapping – Case study: The Banda Islands, Maluku, Indonesia

This study examines methods of geographic features recognition from historic maps using CNN and OBIA. These two methods are compared to reveal which one is most suitable to be applied to the historic maps dataset of the Banda Islands, Indonesia. The characteristics of cartographic images become the main challenge in this study. The geographic features are divided into buildings, coastline, and fortress. The results show that CNN is superior to OBIA in terms of statistical performance. Buildings and coastline give excellent results for CNN analysis, while fortress is harder to be interpreted by the model. On the other hand, OBIA reveals a very satisfying result is very depending on the maps’ scales. In the aspect of technical procedure, OBIA offers easier steps in pre-processing, in-process and post-processing/finalisation which can be an advantage for a wide range of users over CNN

Applicability of a drift-flux model of aerosol deposition in a test tunnel and an indoor heritage environment

Near-wall turbulence associated with air flows parallel to walls can promote aerosol deposition. In indoor environments, where this kind of flow is frequently present, this results in local deposition gradients near ventilation inlets and outlets. This phenomenon is of special interest to the heritage field, which is often concerned about the spatial distribution of deposition and its links to environmental management. In this paper we investigate the capability of a drift-flux model of particulate matter deposition to describe this mechanism. This model has often been validated using decay rates of particulate matter concentration; however, in several indoor applications the interest is not in concentration but in the spatial distribution of the deposition flux. To test the model, we use untreated atmospheric aerosols in two different cases: an experimental tunnel designed to induce near-wall velocity gradients and an actual indoor room with various ventilation regimes. Both systems exhibit significantly inhomogeneous deposition distributions. While the first system is operated under controlled laboratory conditions, the second yields data collected in-situ during a six-month monitoring campaign. In either case the model reproduces the experimental values with enough accuracy to allow understanding how the environment behaves. This work confirms the usability of the drift-flux approach as an analysis tool for particle deposition in complex environments in a wide range of geometries

Measuring air movement in small spaces: understanding air movement in historic bookshelves

The National Trust has tested ventilation holes in bookshelves to encourage air movement behind books as a possible strategy to improve the environment in these microclimates. This could be used as a preventive measure for mould development. Air movement was measured in historic bookshelves to understand what causes air movement and the impact of ventilation holes on the shelves behind books. Three libraries in National Trust properties were used as case studies. It was found that pressure differential and stack effect are two mechanisms contributing to the air velocities measured. However, several variables are believed to influence air movement in these small spaces, and further research is needed to understand its influence on mould development

Fine particulate matter in indoor cultural heritage: A literature review

Fine particulate matter is, on account of its aerodynamic properties and typical composition (especially diesel particulate matter and carbonaceous particles) the particulate pollutant potentially most harmful to cultural heritage, representing an aesthetic issue and an agent of chemical degradation simultaneously. This paper reviews the current knowledge of the life-cycle of fine particulates, focussing on diesel particulate matter from emission to deposition, including its aesthetic and chemical consequences, and draws attention to some imbalances in the current state of research. The currently available measurements are biased towards coarse dust, and information on the consequences of particle deposition is largely restricted to the outdoor environment. More evidence on the chemical effects of the most common types of fine particulate matter in typical indoor materials is needed to enable risk assessment for indoor collections. © 2013 Grau-Bové and Strlič; licensee Chemistry Central Ltd

Using Building Information Modelling to map the composition of glass panes in a historic house

Building Information Modelling (BIM) is widely regarded to be potentially useful for the conservation and management of historic buildings. So far, research in this area has mostly concentrated in geometry: surveying, the parametric modelling of building features and the accurate modelling of complex building shapes. But in order to be fully integrated with conservation practice, Building Information Models need to include other types of data. This paper demonstrates a method to introduce and visualise spatially resolved data within a Building Information Model of a historic building. It focuses on the visualisation of the composition of historic glass and the metadata associated with this measurement. The conclusions are, however, extensible to any type of spatially-resolved material information that can inform building management, conservation and interpretation. The software Dynamo is used to add this functionality to a Revit 3D model. The modelling stage requires the creation of shape families for different types of window. This approach is compared with a similar visualisation produced with ArcGIS, a common Geographic Information System (GIS) software. The Dynamo algorithm successfully adds the visualisation capacity to the BIM model, but it is unlikely that this level of customisation is achievable by the average user. There is a need for further development of technological solutions that combine the visualisation capacity of GIS with ability of BIM to link 3D models and numerical data

The end of the reading room? Simulating the impact of digitisation on the physical access of archival collections

Digitisation has become an essential part of archival and library strategies to enhance access to collections. As the digital content is increasing due to large-scale digitisation projects, it is expected that providing digital access to the analogue collections will eventually reduce the number of archival records accessed in the reading room. In this paper, we investigate this issue using two approaches: system dynamics and agent-based modelling. We first analyse real data in order to identify the dynamic hypothesis of the model. Then, a sensitivity analysis is conducted on two baseline models to identify scenarios that match the real dataset. Although the two approaches suceed to simulate the number of requests in the reading room, the experimental results show that a better fit is obtained in the agent-based model when not only the number of records that have been accessed and digitised is taken into account, but also the number of times that such records have been accessed before digitisation. The proposed model can be used to explore the impact of different digitisation strategies on the decrease in access requests in the archival and library reading rooms

Application of a non-invasive, non-destructive technique to quantify naphthalene emission rates from museum objects

For the last 30 years, the cultural heritage sector has undertaken research into pesticide residues in museum objects. However, quantitative studies of volatile residues remain scarce. This research presents an active air sampling meth‑ odology to obtain qualitative and quantitative data for naphthalene as the most common pesticide found in the sampled objects. The sampling procedure comprises of placing contaminated objects inside a sampling chamber ftted with a sorbent tube flled with TENAX, then connected via tubing to a calibrated sampling pump. The sample is desorbed and analysed using automated thermal desorption (ATD) paired with gas chromatography-mass spec‑ trometry (GCMS). The obtained information allows the calculation of emission rates and modelling of emissions in common museum situations such as inside a box, cabinet or display case. This information informs decision-making regarding ventilation in storage areas and health and safety implications for museum professionals and other stake‑ holders coming in contact with objects

RH simulation model for canvas paintings protected by an aluminium backplate and an additional hygroscopic layer

To protect a canvas easel painting, a common conservation strategy is to add a back plate at the stretcher, creating a closed air void. This plate protects not only from dust but mainly from temperature and relative humidity (RH) variations in the room and moisture changes in the wall on which it is hanging. The addition of hygroscopic layers can reduce the amplitude and change phase of humidity oscillations. This paper proposes a new mathematical model that can be used to predict moisture levels within the canvas when this conservation strategy is applied. The model is compared against the temperature and RH detailed experimental data, captured and shown in the latest paper by Padfield et al. Back protection of canvas painting. Our paper presents values of T, RH and mixing ratio (MR) obtained at the different layers of an easel painting, protected and unprotected, with cotton and without it, submitted to different room and wall temperature and RH cycles. The experimental results show a phase displacement between the canvas temperatures and the corresponding RH values in the canvas air boundary layer. In some cases this phase shift, which is an unexpected behaviour, allows RH and temperatures to achieve their maximum value at the same time. The purpose of the model is to simulate the RH response at the different air boundary layers inside the air void, such as the canvas, the aluminium back plate, and the hygroscopic cotton protection, produced by cyclic variations of temperature in the room or the wall. The model is built simulating four interrelated processes: the canvas permeation flow, the air infiltration rate between room and void, the equilibrium moisture content (EMC) and the vapour sorption rate for the canvas and the cotton. A key innovation of the model is the dependence between EMC, sorption rate, and RH condition, which captures the counter-intuitive behaviours observed in the data. The model results agree with the experimental results. The developed tool allows the interpretation of the processes involved and to extend the simulations to other cases, materials, and conditions

Fluid simulations in heritage science

This review addresses the use of computational fluid dynamics for the interpretation and preservation of heritage. Fluid dynamic simulations in the heritage field focus mostly on slow air movement in indoor spaces and they usually involve temperature and humidity. Simulations have different roles: they may be exploratory, they may be used to support preventive conservation and occasionally they aid historical or archaeological interpretation. The research questions rarely involve testing or development of new mathematical formulations; instead, existing computational models are used as a means to help solve practical issues. Computationally, the simulations are typically steady-state and they always use a turbulence model. Experimental validations against measured data are uncommon and there is a need for the production of benchmarking cases and the publication of experimental data. Further research is needed in order to explore suitable approximations to the simulation of change in the time-scale of months or years, low turbulence flows for which current mainstream turbulence models are ill-suited, and new mathematical formulations for near-wall transport phenomena

Data mining in collections: from epidemiology to demography

Random collection surveys can be a rich source of data on the material state of a collection. However, random surveys do not necessarily provide data on the causes of degradation of collection items, which is useful in terms of resource allocation. For this, the reliability theory provides us with the required concepts. Using appropriate survey methods and statistical methods of data analysis, the so obtained observational ‘epidemiology’ data has revealed risk factors that can lead to such degradation. We identified patterns in the observed data that corroborated experimental research findings and enabled us to carry out ‘demographic’ modelling of the dynamics of future change in the surveyed collection for the case study of the Amsterdam City Archives. The study shows how, using appropriate methods of collection surveying, empirical and modelling studies of real collections can be successfully integrated, leading to useful evidence supporting collection care decision making