Cultural Heritage as an Inspiration for Placemaking in the Historic City: A Transversal Approach

Many European cities are in crisis since most of them are struggling to socially and culturally move forward from the historic and recreational values that made them of interest to the global visitor. In 2011, the United Nations Educational, Scientific and Cultural Organization (UNESCO) started assessing new forms of placemaking in the historic city through the UNESCO Historic Urban Landscape Approach. The same year, the International Council on Monuments and Sites (ICOMOS) highlighted the importance of developing innovative and transversal approaches to examine cultural development in historic human settlements. Within this context, this chapter analyses placemaking in four European historic cities. Transversal approaches on how relational dynamics impact on the historic context will be scrutinized from the realm of the site-specific arts in the city of Belgrade (Serbia), for archaeology the case of analysis is in Bucharest (Romania), for architecture the context is Ávila (Spain) and for urban planning it is Hamburg (Germany). This transversal approach involves using different disciplines to comprehend placemaking from a polyhedral point of view. Therefore, it brings together complementary forms of heritage appropriation – including the construction of the heritage concept over time – methods and strategies that help integrate cultural expressions, practices and products as potential relational dynamics. To do so, we will define stakeholders such as minorities, communities and powerful entities and target groups. Methodologically, approaches will deepen the understanding of phenomenological, dynamic-relational and contextual notions of placemaking that help clarify how historic cities, tools and communities are all interconnected. The discussion will establish parallelisms between the experiences to clarify the implications of placemaking according to the field of approach and the prospects for those places. Cultural expressions and heritage regulation can provide new forms of appropriation and integration in permanent scenarios of the past. Accordingly, contemporary mutable relationships between places and society are at stake in the context of urban planning and the UNESCO Historic Urban Landscape Approach and in defining the future of historic cities. In conclusion, we point towards (1) imagining how placemaking and cultural heritage serve to delineate new forms of heritage-making in the historic city, and (2) to what extent this requires defining ethical forms of culture-based placemaking practices.History, Form & Aesthetic

Exploring Urban Air Mobility to Comprehend Urban Air Quality

This report discusses urban air quality measurements carried out in a park in Aigaleo (Athens), located adjacent to a busy road. The measurements were taken using the Sniffer4D Mini 2 sensor box with a drone to investigate how Urban Air Mobility can aid in measuring urban air quality. CO, NO2, O3, SO2, PM2.5 and PM10 concentrations were recorded through point measurements at varying locations, altitudes and times. Several validation measurements were carried out, showing that temperature heavily influenced the outcome of the recordings. Due to the high number of variables, no conclusion has been found on the wind effect. During rush hour, NO2 and CO concentrations were highest close to the traffic; however, NO2 concentration showed non-linear behaviour with increase in altitude when further from the traffic or out of rush hour. SO2 concentration always decreased with an increase in altitude; highest concentrations were observed further from the busy road. Highest O3 concentrations were obtained in the afternoon at higher altitudes, due to its reaction under sunlight. PM2.5 and PM10 concentrations had a high variability due to environmental conditions. Additionally, continuous measurements were carried out, in which the drone flew a path through several locations and altitudes. The results from these were interpolated to enable the detection of areas with higher concentrations of air pollutants.Aerospace Engineerin

Interoperable Protection and control of multi-terminal HVDC systems

The MMC-based MTDC systems are considered a promising solution for long-distance power transmission, integration of renewable energy sources, and interconnection of power grids. Nowadays, MMC-based MTDC systems have been successfully developed in various projects worldwide and are expected to play a significant role in future electrical power transmission systems. Despite the benefits provided by the MMC-based MTDC system, various technical problems emerge. For example, in case of a DC fault on HVDC transmission lines, the DC voltage suffers a deep sag, and the fault current increases to the peak value after several milliseconds, the system stability is seriously affected. The fault currents will easily damage the power electronics and may lead to a collapse of the entire system if the faults are not cleared promptly. Thus, it is crucial to implement a fast, selective, and reliableDC fault protection technology in the system for fault detection. Once the fault is cleared, it is important to know the exact fault location to repair the faulty sections and to restore the system. Hence, an accurate DC fault location technique is of utmost importance for the MTDC system, which would significantly minimize electricity loss and expedite the system restoration process in the event of power outages. In addition, there is a lack of standardization in MMC control, and the majority of HVDC projects are constructed in a vendor-specific manner. As of today, it is unclear how MMC converters from different manufacturers will interoperate with each other. These pose new challenges to the performance of HVDC protection and MMC control and need to be addressed to manage, safeguard, and accelerate the practical feasibility of this system. The research in this thesis aims to address the shortcomings that have not been addressed in the state of the art, mainly related to the challenges arising when DC faults occur in the MMC MTDC systems and, as such, could provide promising solutions for future practicalMTDCapplications. The main topics areMMC control&interoperability, Protection, and Fault location for the MMC-based MTDC system. The thesis deals with designing a robust protection scheme, a fault location method, and an investigation of the interoperableMMC controllers...Intelligent Electrical Power Grid

Formal Control of an Inverted Pendulum on a Cart via Stochastic Abstractions: Using Interval Markov Decision Processes and Linear Temporal Logic on Finite Traces

The use of machine learning (ML), especially neural networks, in modeling control systems has shown promise, particularly for systems with complex physics. However, applying these models in safety-critical areas requires reliable verification and control synthesis methods due to their inherent complexity. Formal methods, using stochastic finite state models like interval Markov decision processes (IMDPs), provide a way to analyze and verify these systems against detailed safety and performance specifications defined using linear temporal logic over finite traces (LTLf). Abstraction of ML models into such IMDPs, allows the deriving of formal guarantees on the IMDP that carryover to the underlying ML model.This thesis focuses on designing a switched controller for a cart-pendulum system using neural network dynamic models (NNDM) by formal control synthesis, validating it through formal verification methods. The methodology includes modeling the system behavior under different controllers, abstracting these models into IMDPs, applying the respective formal methods, and validating the approach through experiments. The aim is to demonstrate the framework's utility in a practical context, comparing different neural network architectures and researching the applicability of formal guarantees to both the models and the actual system.The main contributions are a practical application of the framework to a specific system, a comparison of neural network architectures for dynamic modeling, and an experiment-based validation of the framework's effectiveness. It confirms that the formal guarantees for abstracted models are relevant to the actual system, providing insights into the framework's potential for real-world applications. The findings suggest areas for further research, particularly in making such frameworks more accessible for practical deployment in safety-critical systems.Mechanical Engineerin

Assessing the thermodynamic behavior of bunkering compressed hydrogen for inland cargo vessels

A new simulation tool has been developed to provide insights into the refueling process of hydrogen. The tool is based on existing models, including a 0D gas model and a 1D wall model, which have been refined to assist companies like Future Proof Shipping, which rely on compressed hydrogen tanks. Although the model is still subject to changes and not fully reproducible during the validation process, it has accurately computed the temperature evolution for large tanks ranging from 1500-2100L. Based on this evolution, it is recommended to maintain the inlet temperature of hydrogen at -20°C or lower. Furthermore, it is suggested that Future Proof Shipping should consider using a type 3 hydrogen tank, which features an aluminum liner and better heat conductivity. This results in more efficient heat conduction away from the hydrogen.Mechanical Engineering | Multi-Machine Engineerin

Storage Standards and Solutions, Data Storage, Sharing, and Structuring in Digital Health: A Brazilian Case Study

The COVID-19 pandemic has highlighted the necessity for agile health services that enable reliable and secure information exchange, but achieving proper, private, and secure sharing of EMRs remains a challenge due to diverse data formats and fragmented records across multiple data silos, resulting in hindered coordination between healthcare teams, potential medical errors, and delays in patient care. While centralized EMR systems pose privacy risks and data format diversity complicates interoperability, blockchain technology offers a promising solution by providing decentralized storage, ensuring data integrity, enhancing access control, eliminating intermediaries, and increasing efficiency in healthcare. By focusing on a Brazilian case study, this paper explores the significance of EMR standards, security challenges, and blockchain-based approaches to promote interoperability and secure data sharing in the healthcare industry.Information and Communication Technolog

Exploring the Impact of Single-Character Attacks in Federated Learning Language Classification: Introducing the Novel Single-Character Strike

Federated learning (FL) is a privacy preserving machine learning approach which allows a machine learning model to be trained in a distributed fashion without ever sharing user data. Due to the large amount of valuable text and voice data stored on end-user devices, this approach works particularly well for natural language processing (NLP) tasks. Due to many applications making use of the algorithm and increasing interest in academics, ensuring security is essential. Current backdoor attacks in NLP tasks are still unable to evade some defence mechanisms. Therefore, we propose a novel attack, the single-character strike to address this research gap. Consequently, the following research question is posed: What are the properties of the single-character strike in a language classification task? By experimental analysis the following properties are discovered: the single-character strike is undetectable against five state-of-the-art defences, has low impact on the global model accuracy, trains slower than similar attacks, relies on characters on the edge of the distribution to function, is robust within the global model, and performs best when close to convergence and with more adversarial clients. Emphasizing its imperceptibility and persistence, the attack maintains a 70\% backdoor accuracy after a thousand iterations without training and remains undetectable against: (Multi-)Krum, RFA, Norm Clipping and Weak Differential Privacy. By providing insight into the effective single-character strike, this paper adds to the growing body of work that questions whether federated learning can be secure against backdoor attacks.CSE3000 Research ProjectComputer Science and Engineerin

The utilization of ghost reflections retrieved by seismic interferometry for layer-specific characterization of the shallow subsurface

Seismic interferometry (SI) retrieves the Green function between two receiver locations using their recordings from a boundary of sources. When using sources and receivers only at the surface, the virtual-source gathers retrieved by SI contain pseudo-physical reflections as well as ghost (non-physical) reflections. These ghost reflections are the results of the cross-correlation or auto-correlation (AC) of primary reflections from two different depth levels, and they contain information about the seismic properties of specific layers in the subsurface. We investigated the application of ghost reflections for layer-specific characterization of the shallow subsurface using SI by AC. First, we showed the technique's potential using synthetic data for a subsurface model with a lateral change in velocity, a gradient in depth for velocity, a thickness change and a velocity change of the target layer. Then, we applied the technique to shallow subsurface field data. We also focused on improving the retrieval of ghost reflections by removing the free-surface multiples and muting undesired events in active-source gathers before applying SI. Our results demonstrate that the ghost reflections can be used advantageously to characterize the layer that causes them to appear in the results of SI. Consequently, they can also provide valuable information for imaging and monitoring shallow subsurface structures.Applied Geophysics and Petrophysic

Multibody dynamic modeling of the behavior of flexible instruments used in cervical cancer brachytherapy

Background: The steep radiation dose gradients in cervical cancer brachytherapy (BT) necessitate a thorough understanding of the behavior of afterloader source cables or needles in the curved channels of (patient-tailored) applicators. Purpose: The purpose of this study is to develop and validate computer models to simulate: (1) BT source positions, and (2) insertion forces of needles in curved applicator channels. The methodology presented can be used to improve the knowledge of instrument behavior in current applicators and aid the development of novel (3D-printed) BT applicators. Methods: For the computer models, BT instruments were discretized in finite elements. Simulations were performed in SPACAR by formulating nodal contact force and motion input models and specifying the instruments’ kinematic and dynamic properties. To evaluate the source cable model, simulated source paths in ring applicators were compared with manufacturer-measured source paths. The impact of discrepancies on the dosimetry was estimated for standard plans. To validate needle models, simulated needle insertion forces in curved channels with varying curvature, torsion, and clearance, were compared with force measurements in dedicated 3D-printed templates. Results: Comparison of simulated with manufacturer-measured source positions showed 0.5–1.2 mm median and <2.0 mm maximum differences, in all but one applicator geometry. The resulting maximum relative dose differences at the lateral surface and at 5 mm depth were 5.5% and 4.7%, respectively. Simulated insertion forces for BT needles in curved channels accurately resembled the forces experimentally obtained by including experimental uncertainties in the simulation. Conclusion: The models developed can accurately predict source positions and insertion forces in BT applicators. Insights from these models can aid novel applicator design with improved motion and force transmission of BT instruments, and contribute to the estimation of overall treatment precision. The methodology presented can be extended to study other applicator geometries, flexible instruments, and afterloading systems.Medical Instruments & Bio-Inspired TechnologyMechatronic Systems Desig

Efficient Neural Ranking Using Forward Indexes and Lightweight Encoders

Dual-encoder-based dense retrieval models have become the standard in IR. They employ large Transformer-based language models, which are notoriously inefficient in terms of resources and latency.We propose Fast-Forward indexes - vector forward indexes which exploit the semantic matching capabilities of dual-encoder models for efficient and effective re-ranking. Our framework enables re-ranking at very high retrieval depths and combines the merits of both lexical and semantic matching via score interpolation. Furthermore, in order to mitigate the limitations of dual-encoders, we tackle two main challenges: Firstly, we improve computational efficiency by either pre-computing representations, avoiding unnecessary computations altogether, or reducing the complexity of encoders. This allows us to considerably improve ranking efficiency and latency. Secondly, we optimize the memory footprint and maintenance cost of indexes; we propose two complementary techniques to reduce the index size and show that, by dynamically dropping irrelevant document tokens, the index maintenance efficiency can be improved substantially.We perform an evaluation to show the effectiveness and efficiency of Fast-Forward indexes - our method has low latency and achieves competitive results without the need for hardware acceleration, such as GPUs.Web Information SystemsMultimedia Computin