Developing IFC for infrastructure: A case study of three highway entities

Modern cities pay particular attention to upscale their infrastructure systems in order to improve the every-day life of their citizens and lead the way towards a more sustainable environment. As part of this, they invest extensive funds in large infrastructure projects which are challenging to deliver as they require an e efficient communication among different professions, in order to share information efficiently throughout the lifecycle of the project, thus highlighting the importance of standardization to maintain consistency and integrity during data exchange. Building Information Modelling (BIM) aims to facilitate the above-mentioned requirements by describing the life-cycle of the project and Industry Foundation Classes (IFC) is the Standard for BIM that enables an efficient storage, management, exchange and visualization of information. However, there are two important challenges that need to be addressed: (i) IFC focuses particularly on buildings and provides limited support for infrastructure elements and (ii) the information exchange aims to describe mostly the construction phase; highlighting the lack of classes that refer to the operation and maintenance phase. Within this context, this paper proposes the extension of Industry Foundation Classes (IFC) for Asset Management in Infrastructure. A method is developed based on a case study of three highway entities: (i) retaining wall, (ii) gantry and (iii) bridge and a conceptual extension is presented. The results are further discussed and recommendations regarding future research fields are proposed

INVESTIGATING INTEROPERABILITY CAPABILITIES BETWEEN IFC AND CITYGML LOD 4 – RETAINING SEMANTIC INFORMATION

Applications of 3D City Models range from assessing the potential output of solar panels across a city to determining the best location for 5G mobile phone masts. While in the past these models were not readily available, the rapid increase of available data from sources such as Open Data (e.g. OpenStreetMap), National Mapping and Cadastral Agencies and increasingly Building Information Models facilitates the implementation of increasingly detailed 3D Models. However, these sources also generate integration challenges relating to heterogeneity, storage and efficient management and visualization. CityGML and IFC (Industry Foundation Classes) are two standards that serve different application domains (GIS and BIM) and are commonly used to store and share 3D information. The ability to convert data from IFC to CityGML in a consistent manner could generate 3D City Models able to represent an entire city, but that also include detailed geometric and semantic information regarding its elements. However, CityGML and IFC present major differences in their schemas, rendering interoperability a challenging task, particularly when details of a building’s internal structure are considered (Level of Detail 4 in CityGML). The aim of this paper is to investigate interoperability options between the aforementioned standards, by converting IFC models to CityGML LoD 4 Models. The CityGML Models are then semantically enriched and the proposed methodology is assessed in terms of model’s geometric validity and capability to preserve semantics

Dual barrier InAlN/AlGaN/GaN-on-silicon high-electron-mobility transistors with Pt and Ni based gate stacks

In this work, we report the performance of 3 μm gate length "dual barrier„ InAlN/AlGaN/GaN HEMTs on Si substrates with gate-drain contact separations in the range 4-26 μm. Devices with Pt and Ni based gates were studied and their leakage characteristics are compared. Maximum drain current IDS of 1 A/mm, maximum extrinsic transconductance gm ~203 mS/mm and on-resistance Ron 4.07 Ω mm for gate to drain distance LGD = 4 μm were achieved. Nearly ideal sub-threshold swing of 65.6 mV/dec was obtained for LGD = 14 μm. The use of Pt based gate metal stacks led to a two to three orders of magnitude gate leakage current decrease compared to Ni based gates. The influence of InAlN layer thickness on the transistor transfer characteristics is also discussed

Exploring the Potential of NoSQL Databases for a BIM and 3D GIS enabled Location Framework for Construction Digital Twins and the Golden Thread

As digital transformation accelerates in the construction industry, combining data from Building Information Modelling (BIM) and 3D Geographic Information Systems (3DGIS) has become critical for enhanced decision-making across sectors including construction planning, supply chain management, health and safety and sustainable waste disposal. In combination, BIM and GIS underpin a location framework for Digital Twins across these applications. While traditionally relational databases have been used to integrate the data into one system, they face increasing limitations in handling the massive, complex BIM and 3DGIS data. This research investigates the potential of NoSQL databases as an alternative solution. Focusing on MongoDB, the study conducts a systematic performance comparison with the mature relational database, PostgreSQL. BIM and 3DGIS datasets from a live infrastructure construction project are utilised in three experiments assessing direct query, API-based retrieval, and 3D visualisation. The results provide valuable insights into MongoDB’s strengths in managing large spatial data via flexible schemas. However, limitations surface as data complexity and volume increases. Overall, this study concludes that NoSQL databases do offer some advantages for optimising BIM-3DGIS integration for seamless, combined, use, but more work is needed to fully harness their capabilities

Investigating Interoperability Capabilities Between IFC and Citygml LOD 4 – Retaining Semantic Information

Applications of 3D City Models range from assessing the potential output of solar panels across a city to determining the best location for 5G mobile phone masts. While in the past these models were not readily available, the rapid increase of available data from sources such as Open Data (e.g. OpenStreetMap), National Mapping and Cadastral Agencies and increasingly Building Information Models facilitates the implementation of increasingly detailed 3D Models. However, these sources also generate integration challenges relating to heterogeneity, storage and efficient management and visualization. CityGML and IFC (Industry Foundation Classes) are two standards that serve different application domains (GIS and BIM) and are commonly used to store and share 3D information. The ability to convert data from IFC to CityGML in a consistent manner could generate 3D City Models able to represent an entire city, but that also include detailed geometric and semantic information regarding its elements. However, CityGML and IFC present major differences in their schemas, rendering interoperability a challenging task, particularly when details of a building’s internal structure are considered (Level of Detail 4 in CityGML). The aim of this paper is to investigate interoperability options between the aforementioned standards, by converting IFC models to CityGML LoD 4 Models. The CityGML Models are then semantically enriched and the proposed methodology is assessed in terms of model’s geometric validity and capability to preserve semantics

Enhancing e-Infrastructures with Advanced Technical Computing: Parallel MATLAB® on the Grid

MATLAB® is widely used within the engineering and scientific fields as the language and environment for technical computing, while collaborative Grid computing on e-Infrastructures is used by scientific communities to deliver a faster time to solution. MATLAB allows users to express parallelism in their applications, and then execute code on multiprocessor environments such as large-scale e-Infrastructures. This paper demonstrates the integration of MATLAB and Grid technology with a representative implementation that uses gLite middleware to run parallel programs. Experimental results highlight the increases in productivity and performance that users obtain with MATLAB parallel computing on Grids

A Unique Gene Regulatory Network Resets the Human Germline Epigenome for Development.

Resetting of the epigenome in human primordial germ cells (hPGCs) is critical for development. We show that the transcriptional program of hPGCs is distinct from that in mice, with co-expression of somatic specifiers and naive pluripotency genes TFCP2L1 and KLF4. This unique gene regulatory network, established by SOX17 and BLIMP1, drives comprehensive germline DNA demethylation by repressing DNA methylation pathways and activating TET-mediated hydroxymethylation. Base-resolution methylome analysis reveals progressive DNA demethylation to basal levels in week 5-7 in vivo hPGCs. Concurrently, hPGCs undergo chromatin reorganization, X reactivation, and imprint erasure. Despite global hypomethylation, evolutionarily young and potentially hazardous retroelements, like SVA, remain methylated. Remarkably, some loci associated with metabolic and neurological disorders are also resistant to DNA demethylation, revealing potential for transgenerational epigenetic inheritance that may have phenotypic consequences. We provide comprehensive insight on early human germline transcriptional network and epigenetic reprogramming that subsequently impacts human development and disease.W.C.C.T is supported by Croucher Foundation and Cambridge Trust. P.F.C.is a Wellcome Trust Senior Fellow in Clinical Science (101876/Z/13/Z), and a UK NIHR Senior Investigator with additional support from the Wellcome Trust Centre for Mitochondrial Research (096919Z/11/Z). M.A.S. is supported by HFSP and Wellcome Trust Investigator Award.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.cell.2015.04.05