A Web GIS-based Integration of 3D Digital Models with Linked Open Data for Cultural Heritage Exploration

This PhD project explores how geospatial semantic web concepts, 3D web-based visualisation, digital interactive map, and cloud computing concepts could be integrated to enhance digital cultural heritage exploration; to offer long-term archiving and dissemination of 3D digital cultural heritage models; to better interlink heterogeneous and sparse cultural heritage data. The research findings were disseminated via four peer-reviewed journal articles and a conference article presented at GISTAM 2020 conference (which received the ‘Best Student Paper Award’)

GI Systems for public health with an ontology based approach

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.Health is an indispensable attribute of human life. In modern age, utilizing technologies for health is one of the emergent concepts in several applied fields. Computer science, (geographic) information systems are some of the interdisciplinary fields which motivates this thesis. Inspiring idea of the study is originated from a rhetorical disease DbHd: Database Hugging Disorder, defined by Hans Rosling at World Bank Open Data speech in May 2010. The cure of this disease can be offered as linked open data, which contains ontologies for health science, diseases, genes, drugs, GEO species etc. LOD-Linked Open Data provides the systematic application of information by publishing and connecting structured data on the Web. In the context of this study we aimed to reduce boundaries between semantic web and geo web. For this reason a use case data is studied from Valencia CSISP- Research Center of Public Health in which the mortality rates for particular diseases are represented spatio-temporally. Use case data is divided into three conceptual domains (health, spatial, statistical), enhanced with semantic relations and descriptions by following Linked Data Principles. Finally in order to convey complex health-related information, we offer an infrastructure integrating geo web and semantic web. Based on the established outcome, user access methods are introduced and future researches/studies are outlined

Publishing Reference Geodata on the Web : Opportunities and Challenges for IGN France

International audienceThe French national mapping agency (IGN) produces several different but complementary geographic vector reference databases delivered in traditional GIS formats. However, linked data users have different expectations and habits, such as the need to browse an entire data catalogue in RDF using the "follow-your-nose" navigation capacity from one graph to another. Besides, traditional GIS data formats are not interoperable with RDF. Yet, all these geographic datasets could be used with benefits on the Web of data, either with direct georeferencing through geographic primitives, or indirect one through postal addresses. In this paper, we aim to contribute to the georeferencing of datasets published on the Web of data by providing such resources for French context. Firstly, we propose two vocabularies designed for representing structured geometries defined with coordinates expressed in any Coordinates Reference System (CRS). Secondly, we reuse these vocabularies and the CRSs' dataset to publish a reference dataset on administrative units that can also be reused for indirect georeferencing purposes. Finally , we also propose two vocabularies for describing geographic feature types. In addition to these resources, we also present a comprehensive workflow for easily publishing geographic data on the Web of data

Copernicus App Lab:A Platform for Easy Data Access Connecting the Scientific Earth Observation Community with Mobile Developers

Copernicus App Lab is a two year project (November 2016 to October 2018) funded by the European Commission under the H2020 program. The consortium consists of AZO (project coordinator), National and Kapodistrian University of Athens, Terradue, RAMANI and VITO. The main objective of Copernicus App Lab is to make Earth observation data produced by the Copernicus program of the European Union available on the Web as linked data to aid their use by mobile developers

Interoperability of Traffic Infrastructure Planning and Geospatial Information Systems

Building Information Modelling (BIM) as a Model-based design facilitates to investigate multiple solutions in the infrastructure planning process. The most important reason for implementing model-based design is to help designers and to increase communication between different design parties. It decentralizes and coordinates team collaboration and facilitates faster and lossless project data exchange and management across extended teams and external partners in project lifecycle. Infrastructure are fundamental facilities, services, and installations needed for the functioning of a community or society, such as transportation, roads, communication systems, water and power networks, as well as power plants. Geospatial Information Systems (GIS) as the digital representation of the world are systems for maintaining, managing, modelling, analyzing, and visualizing of the world data including infrastructure. High level infrastructure suits mostly facilitate to analyze the infrastructure design based on the international or user defined standards. Called regulation1-based design, this minimizes errors, reduces costly design conflicts, increases time savings and provides consistent project quality, yet mostly in standalone solutions. Tasks of infrastructure usually require both model based and regulation based design packages. Infrastructure tasks deal with cross-domain information. However, the corresponding data is split in several domain models. Besides infrastructure projects demand a lot of decision makings on governmental as well as on private level considering different data models. Therefore lossless flow of project data as well as documents like regulations across project team, stakeholders, governmental and private level is highly important. Yet infrastructure projects have largely been absent from product modelling discourses for a long time. Thus, as will be explained in chapter 2 interoperability is needed in infrastructure processes. Multimodel (MM) is one of the interoperability methods which enable heterogeneous data models from various domains get bundled together into a container keeping their original format. Existing interoperability methods including existing MM solutions can’t satisfactorily fulfill the typical demands of infrastructure information processes like dynamic data resources and a huge amount of inter model relations. Therefore chapter 3 concept of infrastructure information modelling investigates a method for loose and rule based coupling of exchangeable heterogeneous information spaces. This hypothesis is an extension for the existing MM to a rule-based Multimodel named extended Multimodel (eMM) with semantic rules – instead of static links. The semantic rules will be used to describe relations between data elements of various models dynamically in a link-database. Most of the confusion about geospatial data models arises from their diversity. In some of these data models spatial IDs are the basic identities of entities and in some other data models there are no IDs. That is why in the geospatial data, data structure is more important than data models. There are always spatial indexes that enable accessing to the geodata. The most important unification of data models involved in infrastructure projects is the spatiality. Explained in chapter 4 the method of infrastructure information modelling for interoperation in spatial domains generate interlinks through spatial identity of entities. Match finding through spatial links enables any kind of data models sharing spatial property get interlinked. Through such spatial links each entity receives the spatial information from other data models which is related to the target entity due to sharing equivalent spatial index. This information will be the virtual properties for the object. The thesis uses Nearest Neighborhood algorithm for spatial match finding and performs filtering and refining approaches. For the abstraction of the spatial matching results hierarchical filtering techniques are used for refining the virtual properties. These approaches focus on two main application areas which are product model and Level of Detail (LoD). For the eMM suggested in this thesis a rule based interoperability method between arbitrary data models of spatial domain has been developed. The implementation of this method enables transaction of data in spatial domains run loss less. The system architecture and the implementation which has been applied on the case study of this thesis namely infrastructure and geospatial data models are described in chapter 5. Achieving afore mentioned aims results in reducing the whole project lifecycle costs, increasing reliability of the comprehensive fundamental information, and consequently in independent, cost-effective, aesthetically pleasing, and environmentally sensitive infrastructure design.:ABSTRACT 4 KEYWORDS 7 TABLE OF CONTENT 8 LIST OF FIGURES 9 LIST OF TABLES 11 LIST OF ABBREVIATION 12 INTRODUCTION 13 1.1. A GENERAL VIEW 14 1.2. PROBLEM STATEMENT 15 1.3. OBJECTIVES 17 1.4. APPROACH 18 1.5. STRUCTURE OF THESIS 18 INTEROPERABILITY IN INFRASTRUCTURE ENGINEERING 20 2.1. STATE OF INTEROPERABILITY 21 2.1.1. Interoperability of GIS and BIM 23 2.1.2. Interoperability of GIS and Infrastructure 25 2.2. MAIN CHALLENGES AND RELATED WORK 27 2.3. INFRASTRUCTURE MODELING IN GEOSPATIAL CONTEXT 29 2.3.1. LamdXML: Infrastructure Data Standards 32 2.3.2. CityGML: Geospatial Data Standards 33 2.3.3. LandXML and CityGML 36 2.4. INTEROPERABILITY AND MULTIMODEL TECHNOLOGY 39 2.5. LIMITATIONS OF EXISTING APPROACHES 41 INFRASTRUCTURE INFORMATION MODELLING 44 3.1. MULTI MODEL FOR GEOSPATIAL AND INFRASTRUCTURE DATA MODELS 45 3.2. LINKING APPROACH, QUERYING AND FILTERING 48 3.2.1. Virtual Properties via Link Model 49 3.3. MULTI MODEL AS AN INTERDISCIPLINARY METHOD 52 3.4. USING LEVEL OF DETAIL (LOD) FOR FILTERING 53 SPATIAL MODELLING AND PROCESSING 58 4.1. SPATIAL IDENTIFIERS 59 4.1.1. Spatial Indexes 60 4.1.2. Tree-Based Spatial Indexes 61 4.2. NEAREST NEIGHBORHOOD AS A BASIC LINK METHOD 63 4.3. HIERARCHICAL FILTERING 70 4.4. OTHER FUNCTIONAL LINK METHODS 75 4.5. ADVANCES AND LIMITATIONS OF FUNCTIONAL LINK METHODS 76 IMPLEMENTATION OF THE PROPOSED IIM METHOD 77 5.1. IMPLEMENTATION 78 5.2. CASE STUDY 83 CONCLUSION 89 6.1. SUMMERY 90 6.2. DISCUSSION OF RESULTS 92 6.3. FUTURE WORK 93 BIBLIOGRAPHY 94 7.1. BOOKS AND PAPERS 95 7.2. WEBSITES 10

merGeo: Integration Platform for Linked Data Management Tools

Στις μέρες μας, ο Σημασιολογικός Ιστός αντιπροσωπεύει την επόμενη σημαντική εξέλιξη στη σύνδεση πληροφοριών. Επιτρέπει τη σύνδεση δεδομένων από μια πηγή σε οποιαδήποτε άλλη πηγή στον ιστό, καθώς και την κατανόηση των δεδομένων αυτών από τους υπολογιστές, ώστε να μπορούν να εκτελούν ολοένα και πιο εξελιγμένες διεργασίες για λογαριασμό μας. Έχοντας αυτό κατά νου, οι ερευνητές και οι επαγγελματίες έχουν δημιουργήσει πολλά εργαλεία που επικεντρώνονται στη διαχείριση αυτής της αφθονίας των νέων δεδομένων ιστού. Αν και αυτή η διαδικασία διαχείρισης είναι αρκετά απαιτητική και περίπλοκη, με τη χρήση των κατάλληλων εργαλείων που επικεντρώνονται στη μετατροπή, την εξερεύνηση ή την οπτικοποίηση αυτών των δεδομένων μπορεί να γίνει πιο απλή. Ωστόσο, μέχρι στιγμής κάθε εργαλείο επικεντρώνεται σε μόνο μία από τις προαναφερθείσες διαδικασίες και ως αποτέλεσμα, o συνδυασμός αυτών των εργαλείων θα μπορούσε να χρησιμοποιηθεί για να αναβαθμιστεί ο τρόπος διαχείρισης των διασυνδεδεμένων δεδομένων. Σκοπός της παρούσας εργασίας είναι να συμβάλει στη διαδικασία διαχείρισης, διερεύνησης και οπτικοποίησης των διασυνδεδεμένων δεδομένων με την ανάπτυξη του merGeo, μιας εφαρμογής που επικεντρώνεται στην παροχή μιας εύχρηστης πλατφόρμας η οποία συνδυάζει τις δυνατότητες τριών ήδη γνωστών εργαλείων διαχείρισης διασυνδεδεμένων δεδομένων: του GeoTriples, του Strabon και του Sextant. Το merGeo προσφέρει μια φιλική προς το χρήστη εφαρμογή που επιτρέπει τόσο σε ειδήμονες του αντικειμένου όσο και σε μη ειδικούς να εκμεταλλευτούν εργαλεία και τεχνολογίες του σημασιολογικού ιστού και να τους πείσει να υιοθετήσουν αυτές τις τεχνολογίες παρουσιάζοντας τα οφέλη του να χρησιμοποιείς διαφορετικές εφαρμογές που βασίζονται σε διασυνδεδεμένα δεδομένα.Nowadays, Semantic Web represents the next major evolution in connecting information. It enables data to be linked from one source to any other source on the web and to be understood by computers so that they can perform increasingly sophisticated tasks on our behalf. With this in mind, researchers and practitioners have engineered many tools that focus on manipulating this abundance of new web data. Although this managing process is quite demanding and complicated, with the use of appropriate tools that concentrate on transformation, exploration or visualization of these data, this whole handling process could become simpler. However, till now each tool focuses only on a single one of the aforementioned procedures and as a result, a combination of them could be used to take the linked data manipulation to the next level. The objective of this thesis is to contribute to linked data management, exploration and visualization process by engineering merGeo, a web application which is focused on providing a user-friendly platform that combines the features of three already known linked data management tools: GeoTriples, Strabon and Sextant. MerGeo provides an easily operated platform that allows both to domain experts and daily users to take full advantage of semantic web tools and technologies and also convinces them to embrace these tools and technologies by demonstrating the benefits of using together different applications whose center of attention is linked data

Sextant: Visualizing time-evolving linked geospatial data

The linked open data cloud is constantly evolving as datasets get continuously updated with newer versions. As a result, representing, querying, and visualizing the temporal dimension of linked data is crucial. This is especially important for geospatial datasets that form the backbone of large scale open data publication efforts in many sectors of the economy (e.g., the public sector, the Earth Observation sector). Although there has been some work on the representation and querying of linked geospatial data that change over time, to the best of our knowledge, there is currently no tool that offers spatio-temporal visualization of such data. This is in contrast with the existence of many tools for the visualization of the temporal evolution of geospatial data in the GIS area. In this article, we present Sextant, a Web-based system for the visualization and exploration of time-evolving linked geospatial data and the creation, sharing, and collaborative editing of “temporally-enriched” thematic maps which are produced by combining different sources of such data. We present the architecture of Sextant, give examples of its use and present applications in which we have deployed it

Innovating the Construction Life Cycle through BIM/GIS Integration: A Review

The construction sector is in continuous evolution due to the digitalisation and integration into daily activities of the building information modelling approach and methods that impact on the overall life cycle. This study investigates the topic of BIM/GIS integration with the adoption of ontologies and metamodels, providing a critical analysis of the existing literature. Ontologies and metamodels share several similarities and could be combined for potential solutions to address BIM/GIS integration for complex tasks, such as asset management, where heterogeneous sources of data are involved. The research adopts a systematic literature review (SLR), providing a formal approach to retrieve scientific papers from dedicated online databases. The results found are then analysed, in order to describe the state of the art and suggest future research paths, which is useful for both researchers and practitioners. From the SLR, it emerged that several studies address ontologies as a promising way to overcome the semantic barriers of the BIM/GIS integration. On the other hand, metamodels (and MDE and MDA approaches, in general) are rarely found in relation to the integration topic. Moreover, the joint application of ontologies and metamodels for BIM/GIS applications is an unexplored field. The novelty of this work is the proposal of the joint application of ontologies and metamodels to perform BIM/GIS integration, for the development of software and systems for asset management

Transforming into RDF and Interlinking Βig Geospatial Data

Στην εποχή των μεγάλων δεδομένων, μια μεγάλη ποσότητα γεωχωρικών δεδομένων είναι διαθέσιμη στο διαδίκτυο, προερχόμενη από κρατικές υπηρεσίες, εταιρίες και ερευνητικά έργα. Στις περισσότερες περιπτώσεις, αυτά τα δεδομένα δεν ακολουθούν το πρωτόκολλο των διασυνδεδεμένων δεδομένων και οι συνηθισμένοι μέθοδοι μετατροπείς τους έχουν αποδειχθεί ανεπαρκής, εξαιτίας του μεγάλου τους όγκου. Για αυτό τον λόγο, επεκτείνουμε το εργαλείο GeoTriples ώστε να μπορεί να μετατρέψει μεγάλα γεωχωρικά δεδομένα σε RDF γράφους, χρησιμοποιώντας το Apache Spark. Επιπλέον, μετατρέποντας τα δεδομένα σαν RDF τριπλέτες, μπορούμε να τα διασυνδέσουμε με άλλα υπάρχοντα συνδεδεμένα δεδομένα και να εμπλουτίσουμε περαιτέρω το σύννεφο των Ανοικτών Διασυνδεδεμένων Δεδομένων (Linked Open Data cloud). Οπότε, σε αυτήν την εργασία παρουσιάζουμε επίσης κάποιους καινοτόμους αλγορίθμους για συνολική ή βαθμιαία διασύνδεση γεωχωρικών δεδομένων, αλλά και πως τους έχουμε παραλληλοποιήσει στο σύστημα DS­JedAI, το οποίο δουλεύει πάνω στο Apache Spark. Στο τέλος, εκτελούμε αναλυτική αξιολόγηση των συστημάτων και αποδεικνύουμε ότι μπορούν να διαχειριστούν μεγάλα γεωχωρικά δεδομένα αποτελεσματικά.In the era of big data, a vast amount of geospatial data has become available from government agencies, businesses and research projects. In most cases, this data does not follow the linked data paradigm and the conventional methods for transforming it into linked data has been proved ineffective due to its large volume. For this purpose, we extended GeoTriples, an open-source tool developed by our group, to be able to massively transform big geospatial data into RDF graphs, using Apache Spark. Furthermore, by transforming it into RDF, we can interlink it with other linked data and further populated the Linked Open Data Cloud. In this work, we also present novel algorithms for batch and progressive Geospatial Interlinking, as well as how we have parallelized them in the system DS­JedAI, that runs on top of Apache Spark. In the end, we perform a detailed evaluation of both systems and we show that they can operate on big geospatial data effectively

Chinese temple networks in Southeast Asia: A WebGIS Digital Humanities Platform for the collaborative study of the Chinese diaspora in Southeast Asia

Ministry of Education, Singapore under its Academic Research Funding Tier