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Optimal Configuration of Omega-Kappa FF-SAR Processing for Specular and Non-Specular Targets in Altimetric Data: The Sentinel-6 Michael Freilich Study Case
No full textIn this study, the full-focusing (FF) algorithm is reviewed with the objective of optimizing it for processing data from different types of surfaces probed in altimetry. In particular, this work aims to provide a set of optimal FF processing parameters for the Sentinel-6 Michael Freilich (S6-MF) mission. The S6-MF satellite carries an advanced radar altimeter offering a wide range of potential FF-based applications which are just beginning to be explored and require prior optimization of this processing. In S6-MF, the Synthetic Aperture Radar (SAR) altimeter acquisitions are known to be aliased in the along-track direction. Depending on the target, aliasing can be tolerated or may be a severe impairment to provide the level of performance expected from FF processing. Another key aspect to consider in this optimization study is the unprecedented resolution of the FF processing, which results in a higher posting rate than the standard SAR processing. This work investigates the relationship between posting rate and noise levels and provides recommendations for optimal algorithm configurations in various scenarios, including transponder, open ocean, and specular targets like sea-ice and inland water scenes. The Omega–Kappa (WK) algorithm, which has demonstrated superior CPU efficiency compared to the back-projection (BP) algorithm, is considered for this study. But, unlike BP, it operates in the Doppler frequency domain, necessitating further precise spectral and time domain settings. Based on the results of this work, real case studies using S6-MF acquisitions are presented. We first compare S6-MF FF radargrams with Sentinel-1 (S1) images to showcase the potential of optimally configured FF processing. For highly specular surfaces such as sea-ice, distinct techniques are employed for lead signature identification. S1 relies on image-based lineic reconstruction, while S6-MF utilizes phase coherency of focalized pulses for lead detection. The study also delves into two-dimensional wave spectra derived from the amplitude modulation of image/radargrams, with a focus on a coastal example. This case is especially intriguing, as it vividly illustrates different sea states characterized by varying spectral peak positions over time.Astrodynamics & Space Mission
Aesthetic durability & Repair
No full textEach year, over 50 million tonnes of electronic waste is generated globally, with the Netherlands averaging more than 20 kg per capita (Compendium voor de Leefomgeving, 2023). The shift from a linear to a circular economy is crucial in addressing this issue, emphasizing the importance of durability and repairability in product design. Additionally, the forthcoming legislation from the European Commission (2023) regarding the “right to repair” highlights the need for designers to create products that are both durable and repairable. This project delves into a product’s durability, considering not only its physical repairability, but also how it can retain aesthetic value over time. Central to this exploration is the question: “How can appliances be re-designed for retainment, considering repairability and aesthetic durability?” Drawing upon literature research, a design space is formulated, guiding the several re-designs of the same appliance, in this case a sandwich maker, with each re-design focusing on a specific aspects of repairability and aesthetic durability theory. Evaluation of these re-designs by visitors at Dutch Design Week informed challenges, guiding the further development of one of the re-designs into a functional prototype. The literature review addresses repairability through the challenge of fault diagnosis, particularly as products are often perceived as ‘black boxes’. Practical design implications for improving ease of disassembly and part replacement, alongside the value of awareness of components in having a product repaired, are discussed. Aesthetic durability is explored from the perspectives of ‘living with things’ and the ‘life of things’. The former examines aesthetic pleasure from a multisensory point of view, and the role of familiarity and novelty in design. The latter discusses the dimension of temporality in product design throughout a product’s lifetime, and the concept of products becoming ‘things’ when they break down. The construction of a design space with three axes based on this theory—’the possibility to repair’, ‘our pleasure as users’, and ‘the life of the thing itself’—provides a framework for creating eight diverse prototypes reflecting various perspectives from the theory. Evaluation by 3010 Dutch Design Week visitors identifies one prototype, featuring an ‘oven mitt’-like top, as standing out for its emotional qualities such as ‘connection’ and ‘beauty.’ This re-design is selected for further development into a functional prototype, highlighting repairability improvements and offering the opportunity for ergonomic testing.Integrated Product Desig
Regional Magnetotelluric Studies across Mongolia: Report on New Measurements, New Models, and Implications for Intracontinental Deformation, Deep Mineral Systems, and Intraplate Volcanism
No full textWe are investigating the lithospheric properties and lithospheric architecture beneath Mongolia with three-dimensional models of the electrical resistivity generated from magnetotelluric measurements. In addition, thermo-mechanical numerical modelling, with geophysically-guided constraints, is being used to provide valuable insights by testing the mechanical viability of different hypotheses for the temporal evolution and dynamic processes within this region. Mongolia is located between the relatively stable Siberian craton and the extensional regime near the Baikal rift zone to the north and to the south the North China and Tarim cratons that have a northward-directed compressional regime. Due to its location, it is an excellent region to study intracontinental deformation. Furthermore, enigmatic continental intraplate basaltic volcanism of the Cenozoic age exists across Mongolia. In addition, this region contains economically important mineral zones (copper and gold), with the origin and evolution of the mineral systems linked to the whole-lithosphere architecture, crust-mantle interactions, and mantle convection dynamics. Magnetotelluric data has been collected across Western, Central, and Eastern Mongolia. Three field campaigns in 2016, 2017, and 2018 collected more than 328 sites on an array (50 km spacing) and along three dense profiles (3-15 km spacing) that focused on the Hangai Dome (plateau) and Gobi-Altai (Arkhangai, Bayankhongor) over an area of approximately 800 km (north-south) by 400 km (east-west). Between 2020 and 2022, the array was extended to the east with 77 sites collected across central-east Mongolia (Bulgan, Selenge, Tuv, Uvurkhangai, Dundgovi; 400 by 200 km), including 34 sites along an 810 km long north-south profile crossing the Mongol-Okhotsk suture zone. In late 2022, 79 measurements were acquired in northern Mongolia across the Hovsgol region and Darhad (200 by 200 km) with an array and several profiles, which connect to data west of Lake Baikal. In early 2023, 38 sites were collected in central-east Mongolia (Umnugovi; 200 by 200 km), completing the eastern array. Later in 2023, a major field campaign was launched that successfully collected 150 measurements in western Mongolia (Zavkhan, Uvs, Govi-Altai, Khovd) over an area of approximately 500 by 400 km. This included an array (50 km spacing) and three dense profiles (5-10 km spacing). This gives approximately 700 magnetotelluric measurements collected over a total area of approximately 1000 km (north-south) by more than 1150 km (east-west). This is a large area that approaches the scope of several other regional and national magnetotelluric survey programs. What’s more, this dataset fills an important gap between the existing magnetotelluric data across China and the Tibetan Plateau with several profiles across the Siberian Craton, in principle completing a remarkable transect of 4000 km across a variety of tectonic domains. In this presentation, we will report on the new measurements. They will be integrated into the previously collected dataset, and new models will be generated that incorporate all data. We will also present new models of western, central and eastern Mongolia that provide insights on the properties, structure, and evolution of the Hangai Dome, the Mongol-Okhotsk suture and the Central Asian Orogenic Belt.Applied Geophysics and Petrophysic
Pentamodes: Effect of unit cell topology on mechanical properties
No full textPentamodes (first conceived theoretically by Milton and Cherkaev) are a very interesting class of mechanical metamaterials that can be used as building blocks of structures withdecoupled bulk and shear moduli. The pentamodes usually are composed of double cone-shaped struts with the middle diameter being large and the end diameters being tiny (ideally approaching zero). The cubic diamond geometry was proposed by Milton and Cherkaev as a suitable geometry for the unit cell and has since been used in the majority of the works on pentamodes. In this work, we aim to evaluate the degree to which the base unit cell design contributes to high bulk to shear modulus ratio, also known as Figure Of Merit(FOM). In addition to the diamond unit cell, three other well-known unit cell types are considered, and the effect of small diameter size and the ratio of large-to-small diameter, α, on the FOM is evaluated. The results showed that regardless of the base unit cell shape, the FOM value is highly dependent on the d (the smaller diameter size of double-cone) value, while its dependence on the D (the greater diameter of double-cone) value is very weak. For d/h∝0.05 (h representing the linkage length), figures of merit in the range of 103 could be reached for all the studied topologies.Novel Aerospace Material
4D Printing: Post-processing for the masses
No full textThis research investigates the challenges a user faces in the activation step in shape-changing products. First, previous research on the topic of 4DP is reviewed and important factors are described. Namely, activation temperature, print temperature, print speed, and layer height have a signifi cant impact on the shrinkage of SMPs, during the activation step in 4DP. These shrinkages can be applied to an object through the use of varying strategies. These strategies show there are two ways of applying SMPs to a design, either calculate the shrinkage or create limits with the use of geometry-based end stops. Lastly, a further review is conducted into the type of products made with 4DP. These products turn out to be made out of three categories; fl at-packed, custom fi tment, and energy-absorbing structures. The second chapter, Material Tinkering & Exploration, delves into the material characteristics of LW-PLA, showcasing its utility for shapechanging. LW-PLA can be used both as a passive and active element, reducing environmental impact by enabling or disabling shape memory through micro-scale structural changes. This material is then used to fi nd a correlation in curvature and ratio of active versus passive elements within a design. Furthermore, the material is used to fi nd the best type of heat source, trying to create the most consistent outcomes. The oven without convection is then chosen as it creates the most consistent outcomes by limiting user interaction and making use of slower response times. The following chapter brainstorms ideas that can make use of shape change. Through the use of criteria and Edison profi les a direction is chosen. This is the direction of the temples of glasses. Shape change can add to this product as the temples vary in length to fi t different users. This chapter also creates two prototypes to be tested, differing in the type of measurement method. Lastly, the design is evaluated through the use of two user studies. In the fi rst study, the focus is laid on the type of measuring method. The external measurement method comes out as the most promising as it creates the most consistent outcome with the users. The second test tries to minimize the error between the targetted length of the temple and the actual length after the activation process has ended. The result is an addition of two test samples that educate the user. Through the education of the user, a consistent result with minimal error can be achieved. The activation step also requires a homogeneous method of heating the temple, small deviations in this heating lead to unwanted curvature. This is combatted by creating a tray, that is delivered together with the temple. Integrated Product Desig
Fire-Retarding Asphalt Pavement for Urban Road Tunnels: A State-of-the-Art Review and Beyond
No full textWith the rapid urbanization and development of metropolises, urban road tunnels have been constructed at an increasing rate, significantly alleviating urban traffic pressure, and improving urban resilience. Fire hazards have become a major threat to modern road tunnels due to the growing popularity of electric vehicles and high-density transportation of goods, particularly flammable materials. Asphalt pavements, as an essential component of road tunnels, may release harmful effluences and smoke under high temperatures, exacerbating the fire and adding risk to life safety. It is hence critical to investigate fire-retarding asphalt materials and their potential use in urban road tunnels pavements. This paper provides a comprehensive review of fire-retarding asphalt pavements for urban road tunnel pavements. The review covers tunnel fire generation mechanisms, evaluation methods, flame retardants for asphalt pavements, and recent developments in flame retardant technologies. By investigating these aspects, this paper aims to better understand the flammability of asphalt mixtures and asphalt pavements in urban road tunnels, promote the research of flame-retardant technology, and ultimately reduce the damage and loss caused by asphalt road tunnel fire accidents. Additionally, this study identifies the limitations of current research and provides an outlook for future research to contribute to the resilience of urban road tunnel structures and the longer service life of asphalt pavement in semi-closed road tunnels.Geo-engineerin
Refining the survey model of the LADM ISO 19152–2: Land registration
No full textCadastral surveying involves the delineation of property boundaries and the extent and documentation of easements and restrictions (imposed by private or public law), forming the foundation for Land Administration (LA). Survey models and processes constitute vital parts of Cadastres and Land Administration Systems (LASs). However, these models are often inadequately documented and lack standardization in practice. To address the global diversity and complexity of legal and administrative challenges in LA, standardization efforts have yielded the ISO 19152:2012 (ISO, 2012) Land Administration Domain Model (LADM), the Global Land Tool Network's (GLTN) Social Tenure Domain Model (STDM), and the OGC LandInfra/InfraGML standard. The current edition of the LADM focuses on standardised conceptual modelling of LA-related information, including a dedicated sub-package for Spatial and Surveying representation. As part of the ongoing LADM revision, a refined survey model is being developed to support a broad range of surveying and data acquisition approaches and levels of accuracy. Recognizing that surveying technology is not bound by national practices and regulations, this paper focuses specifically on the surveying aspect of LADM. It illustrates that the proposed refined survey model is applicable not only to conventional real property formation but also to participatory land rights recordation processes. The approach adopted in this research is technology-neutral, accommodating the ongoing evolution of surveying technology. It offers support for a broad range of surveying and data acquisition approaches, with varying levels of accuracy. As the demand for high-precision positioning has been persistent within the land mapping and surveying community, particularly since the initial adoption of GPS, aiming to achieve centimetre-level accuracies (initially confined to local services), the paper addresses the fundamental principles of the High Accuracy Service (HAS) concept within the proposed model. The main results presented in this paper are the conceptual model of the refined survey model of LADM Edition II (ISO19152–2), as well as an abstract, reference, cadastral surveying workflow following the principles of the proposed model.Digital Technologie
Connecting the PhD in Design: How PhDs label their Thesis Research
No full textAs design research matures, more designers pursue a PhD. In its turn, the PhD itself is changing from a solitary preparation for a career in academia toward an increasing emphasis on interdisciplinary and international experience and a greater variety of jobs. These developments call for greater opportunities for PhD candidates to build their network during the PhD. The WunderLibrary, developed in the EU-funded project DoCS4Design, aims to connect PhD candidates through a web-based platform for sharing educational and research materials and making contact. To seed the platform's ontology, the collection of tags which connect the items in it, we studied the keywords and metadata from a set of 342 PhD theses from the 6 PhD programmes in the project over the last decade. The collection of theses came with between three and six freely chosen keywords, typically provided by the authors. In this paper, we describe the process of curating the keywords and clustering the resulting data on three levels. This produced a set of 342 keywords and two levels of clustering. The raw data are openly available. We discuss data analysis and a spin-off application that uses higher-level labels to help PhD candidates describe their work.Design Conceptualization and Communicatio
Integration of Business and User-Centered Corporate Real Estate and Facilities Management
No full textA red thread in my academic carrier of over 40 years is the development and sharing of knowledge about the experience and use of the built environment, including offices, health care facilities, childcare facilities, learning environments, housing, and public spaces. The latter is currently part of urban FM. My main drive to do this for such a long time is the willingness to contribute to an environment that enables people to conduct their activities in a satisfactory, comfortable, efficient and effective way, and that fits with the preferences, needs and values of organizations, customers, end users and society as a whole. In other words: to contribute to user-centered and value-based briefing, design, management, evaluation and further improvement of buildings, facilities and services.Real Estate Managemen
Bone hospital: Medical tourist center in the information society
No full textHave you ever imagined a hospital being a pleasant place to be? This project aims to provide a comprehensive and pleasant healing environment for people with decreased mobility based on the care model of the information society.Architecture, Urbanism and Building Sciences | Complex Project
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