ORCID Profile
0000-0002-6892-6702
Current Organisation
Technische Universiteit Delft
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Publisher: MDPI AG
Date: 28-01-2023
DOI: 10.3390/PHARMACEUTICS15020430
Abstract: The advent of new antibiotics has helped clinicians to control severe bacterial infections. Despite this, inappropriate and redundant use of antibiotics, inadequate diagnosis, and smart resistant mechanisms developed by pathogens sometimes lead to the failure of treatment strategies. The genotypic analysis of clinical s les revealed that the rapid spread of extended-spectrum β-lactamases (ESBLs) genes is one of the most common approaches acquired by bacterial pathogens to become resistant. The scenario compelled the researchers to prioritize the design and development of novel and effective therapeutic options. Nanotechnology has emerged as a plausible groundbreaking tool against resistant infectious pathogens. Numerous reports suggested that inorganic nanomaterials, specifically gold nanoparticles (AuNPs), have converted unresponsive antibiotics into potent ones against multi-drug resistant pathogenic strains. Interestingly, after almost two decades of exhaustive preclinical evaluations, AuNPs are gradually progressively moving ahead toward clinical evaluations. However, the mechanistic aspects of the antibacterial action of AuNPs remain an unsolved puzzle for the scientific fraternity. Thus, the review covers state-of-the-art investigations pertaining to the efficacy of AuNPs as a tool to overcome ESBLs acquired resistance, their applicability and toxicity perspectives, and the revelation of the most appropriate proposed mechanism of action. Conclusively, the trend suggested that antibiotic-loaded AuNPs could be developed into a promising interventional strategy to limit and overcome the concerns of antibiotic-resistance.
Publisher: Copernicus GmbH
Date: 19-09-2018
DOI: 10.5194/ISPRS-ARCHIVES-XLII-4-149-2018
Abstract: Abstract. Visibility is a common measure to describe the spatial properties of an environment related to the spatial behaviour. Isovists represent the space that can be seen from one observation point, and they are used to analyse the existence of obstacles affecting or blocking intervisibility in an area. Although point clouds depict the as-built reality in a very detailed and accurate way, literature addressing the analysis of visibility in 3D, and more specifically the usage of point clouds to visibility analysis, is rather limited. In this paper, a methodology to evaluate visibility from point clouds in indoor environments is proposed, resulting in the creation of 3D isovists. Point cloud is firstly discretized in a voxel-based structure and voxels are labelled into ‘exterior’, ‘occupied’, ‘visible’ and ‘occluded’ based on an occupancy followed by a visibility analysis performed from a ray-tracing algorithm. 3D Isovists are created from the boundary of visible voxels from an observer position and considering as input parameters the visual angle, maximum line of sight, and eye gaze direction.
Publisher: Copernicus GmbH
Date: 13-09-2013
DOI: 10.5194/ISPRSANNALS-II-2-W1-285-2013
Abstract: Abstract. Water run-off modelling applied within urban areas requires an appropriate detailed surface model represented by a raster height grid. Accurate simulations at this scale level have to take into account small but important water barriers and flow channels given by the large-scale map definitions of buildings, street infrastructure, and other terrain objects. Thus, these 3D features have to be rasterised such that each cell represents the height of the object class as good as possible given the cell size limitations. Small grid cells will result in realistic run-off modelling but with unacceptable computation times larger grid cells with averaged height values will result in less realistic run-off modelling but fast computation times. This paper introduces a height grid generalisation approach in which the surface characteristics that most influence the water run-off flow are preserved. The first step is to create a detailed surface model (1:1.000), combining high-density laser data with a detailed topographic base map. The topographic map objects are triangulated to a set of TIN-objects by taking into account the semantics of the different map object classes. These TIN objects are then rasterised to two grids with a 0.5m cell-spacing: one grid for the object class labels and the other for the TIN-interpolated height values. The next step is to generalise both raster grids to a lower resolution using a procedure that considers the class label of each cell and that of its neighbours. The results of this approach are tested and validated by water run-off model runs for different cellspaced height grids at a pilot area in Amersfoort (the Netherlands). Two national datasets were used in this study: the large scale Topographic Base map (BGT, map scale 1:1.000), and the National height model of the Netherlands AHN2 (10 points per square meter on average). Comparison between the original AHN2 height grid and the semantically enriched and then generalised height grids shows that water barriers are better preserved with the new method. This research confirms the idea that topographical information, mainly the boundary locations and object classes, can enrich the height grid for this hydrological application.
Publisher: Copernicus GmbH
Date: 26-11-2013
DOI: 10.5194/ISPRSARCHIVES-XL-4-W4-31-2013
Abstract: Abstract. Indoor localisation is in demand for a variety of applications within the built environment. An overall solution based on a single technology has not yet been determined. The aim of this paper is to gain insight on Signal Strength monitoring by a special kind of WiFi Monitors in comparison to the commonly known fingerprinting method for the purpose of a 3D indoor navigation system. Ttwo different WiFi based localisation techniques are tested during the MSc Geomatics DaRen Syntheses Project in the Hubei Provincial Museum, China. The first method detects the beacon frames send by smartphones, laptops and other WiFi enabled devices in range using Libelium Meshlium Xtreme monitors. Their MAC addresses and the signal strength is measured by the Meshlium Xtreme and stored on an external database. We call this method WiFi monitoring. The second method a Wifi enabled device, like a smartphone, measures the signal strength of multiple Wifi Access Points in range to localise itself based on a previously created radio map. This method is known as WiFi fingerprinting. Both methods have some advantages and disadvantages. Advantages of the common way of WiFi fingerprinting are that the implementation costs are relatively low, because it is usually possible to use (a part of) the existing WiFi AP infrastructure. WiFi fingerprinting can reach a relatively high accuracy in the order of magnitude of meters. Finally, the location granularity can be adjusted to what is necessary for the purpose of the indoor localisation. This makes it employable for a wide range of purposes. The question remains how suitable these methods are for a 3D indoor navigation system for the Hubei provincial museum. One important aspect is the localisation-granularity necessary for the application. In a museum it is not necessary to know the exact X,Y position of a user (such high accuracy is unnecessary), more important is to know in which room the user is located so the information on exhibitions can be presented and the starting point of the navigation can be determined. Both methods can track the user and tell the room he or she is located at. Although WiFi smartphone monitoring may have a low update frequency it is still suitable for a navigation system for a museum since visitors usually spend more than a couple of minutes within a room.
Publisher: Copernicus GmbH
Date: 12-09-2017
DOI: 10.5194/ISPRS-ARCHIVES-XLII-2-W7-345-2017
Abstract: Abstract. Updated and detailed indoor models are being increasingly demanded for various applications such as emergency management or navigational assistance. The consolidation of new portable and mobile acquisition systems has led to a higher availability of 3D point cloud data from indoors. In this work, we explore the combined use of point clouds and trajectories from SLAM-based laser scanner to automate the reconstruction of building indoors. The methodology starts by door detection, since doors represent transitions from one indoor space to other, which constitutes an initial approach about the global configuration of the point cloud into building rooms. For this purpose, the trajectory is used to create a vertical point cloud profile in which doors are detected as local minimum of vertical distances. As point cloud and trajectory are related by time st , this feature is used to sub ide the point cloud into subspaces according to the location of the doors. The correspondence between subspaces and building rooms is not unambiguous. One subspace always corresponds to one room, but one room is not necessarily depicted by just one subspace, for ex le, in case of a room containing several doors and in which the acquisition is performed in a discontinue way. The labelling problem is formulated as combinatorial approach solved as a minimum energy optimization. Once the point cloud is sub ided into building rooms, envelop (conformed by walls, ceilings and floors) is reconstructed for each space. The connectivity between spaces is included by adding the previously detected doors to the reconstructed model. The methodology is tested in a real case study.
Publisher: Informa UK Limited
Date: 2011
Publisher: Schweizerbart
Date: 12-2011
Publisher: Copernicus GmbH
Date: 05-10-2016
DOI: 10.5194/ISPRS-ANNALS-IV-2-W1-249-2016
Abstract: Abstract. There is a growing demand of 3D indoor pathfinding applications. Researched in the field of robotics during the last decades of the 20th century, these methods focussed on 2D navigation. Nowadays we would like to have the ability to help people navigate inside buildings or send a drone inside a building when this is too dangerous for people. What these ex les have in common is that an object with a certain geometry needs to find an optimal collision free path between a start and goal point. This paper presents a new workflow for pathfinding through an octree representation of a point cloud. We applied the following steps: 1) the point cloud is processed so it fits best in an octree 2) during the octree generation the interior empty nodes are filtered and further processed 3) for each interior empty node the distance to the closest occupied node directly under it is computed 4) a network graph is computed for all empty nodes 5) the A* pathfinding algorithm is conducted. This workflow takes into account the connectivity for each node to all possible neighbours (face, edge and vertex and all sizes). Besides, a collision avoidance system is pre-processed in two steps: first, the clearance of each empty node is computed, and then the maximal crossing value between two empty neighbouring nodes is computed. The clearance is used to select interior empty nodes of appropriate size and the maximal crossing value is used to filter the network graph. Finally, both these datasets are used in A* pathfinding.
Publisher: Copernicus GmbH
Date: 11-05-2015
DOI: 10.5194/ISPRSARCHIVES-XL-4-W5-29-2015
Abstract: Abstract. This work presents an approach to enhance navigation in indoor environments based on a landmark concept. It has already been proved by empirical research that by using landmarks the wayfinding task can be significantly simplified. Navigation based on landmarks relies on the presence of landmarks at each point along a route where wayfinders might need assistance. The approach presented here is based on the Dutch system for navigation of cyclists. The landmarks that are used in the proposed approach are special signposts containing the necessary directional information in order to guide the wayfinder in the space. The system is quite simple, efficient and satisfactory in providing navigational assistance in indoor space. An important contribution of this research is the generation of an approach to automatically determine the decision points in indoor environments, which makes it possible to apply it to navigational assistance systems in any building. The proposed system is verified by placing numbered landmark-signs in a specific building. Several tests are performed and the results are analysed. The findings of the experiment are very promising, showing that participants reach the destinations without detours.
Publisher: ACM Press
Date: 2004
Publisher: Copernicus GmbH
Date: 13-09-2017
DOI: 10.5194/ISPRS-ANNALS-IV-2-W4-311-2017
Abstract: Abstract. Many research works have been oriented to the formulation of different algorithms for estimating the paths in indoor environments from three-dimensional representations of space. The architectural configuration, the actions that take place within it, and the location of some objects in the space influence the paths along which is it possible to move, as they may cause visibility problems. To overcome the visibility issue, different methods have been proposed which allow to identify the visible areas and from a certain point of view, but often they do not take into account the user’s visual perception of the environment and not allow estimating how much may be complicated to follow a certain path. In the field of space syntax and cognitive science, it has been attempted to describe the characteristics of a building or an urban environment by the isovists and visibility graphs methods some numerical properties of these representations allow to describe the space as for how it is perceived by a user. However, most of these studies are directed to analyze the environment in a two-dimensional space. In this paper we propose a method to evaluate in a quantitative way the complexity of a certain path within an environment represented by a three-dimensional point cloud, by the combination of some of the previously mentioned techniques, considering the space visible from a certain point of view, depending on the moving agent (pedestrian , people in wheelchairs, UAV, UGV, robot).
Publisher: Copernicus GmbH
Date: 05-09-2016
DOI: 10.5194/ISPRS-ANNALS-IV-4-W1-105-2016
Abstract: Abstract. At the most fundamental level, smart buildings deliver useful building services that make occupants productive. Smart asset management in hostipals starts with knowing the whereabouts of medical equipment. This paper investigates the subject of indoor localization of medical equipment in hospitals by defining functional spaces. In order to localize the assets indoors, a localization method is developed that takes into account several factors such as geometrical influences, characteristics of the Quuppa positioning system and obstructions in the indoor environment. For matching the position data to a real world location, several location types are developed by sub iding the floor plan into location clusters. The research has shown that a high-performance level can be achieved for locations that are within the high-resolution range of the receiver. The performance at the smallest subspaces can only be achieved when having a dense distribution of receivers. Test cases that were defined for specific situations in the test-area show successful localization in these subspaces for the majority of the test data.
Publisher: Copernicus GmbH
Date: 19-09-2018
DOI: 10.5194/ISPRS-ARCHIVES-XLII-4-11-2018
Abstract: Abstract. During an incident, many people that are located in indoor environments require to follow emergency evacuation procedures. The ‘emergency evacuation’ term has been defined as ‘a critical movement of people from a dangerous area due to the risk or an incident of a tragic event’ (Bonabeau, 2002). An emergency evacuation could be needed in a life or death situation, regardless if it begins with a natural non-intended incident or a terrorist attack. Many researchers have studied the behaviour of the people during the evacuation because of several incidents with panic attacks that have led to injuries including death of people being crushed or tr led down by others. In crisis situation, the perception of the indoor environment, which differs from person to person, play a critical role in the evacuation. Also, the access rights of the indoor spaces are different from those rights (and restrictions) during normal times. They may positively impact the movements of the people during the evacuation by providing suggestions for shorter/better route. This paper addresses the impact of the access rights of the indoor spaces during an emergency evacuation. We employ the conceptual model of LADM-IndoorGML that defines the accessibility of the indoor spaces based on the rights, restrictions, and responsibilities of the user of the indoor space. The access rights of the indoor spaces are affected by the crisis event and this needs to be modelled explicitly (and before crisis situation). Actually, the rights/restrictions persons have on spaces is time dependent: normal operation hours, outside normal operation hours (e.g. during night time in case of a University building) or during crisis times. These actual/valid rights and restrictions affect the movement/accessibility of the users to reach the nearest emergency exits or the safe zone. For this reason, different scenarios have to be developed to study the impact of the accessibilities for different types of users. In this paper we will present the 3D model of an educational building that was built for the purpose of evacuation study. The 3D model is supported by real data for all spaces from the facility management department such as information on departments, sections, groups of users (visitors, employees, and students), and public rivate spaces, etc. and a real evacuation exercise. We consider it extremely important to develop our information model based on international standards (LADM/ISO 19152, OGC IndoorGML, ISO 19141, ISO 19107) as we expect that this information will be part of the future ‘building infrastructure’ and applications all over the world can understand and use this data when entering or leaving a certain building both during normal and crisis situations. Different types of applications are anticipated to be based on this information model e.g. mobile indoor routing app (for normal building users and Emergency Response Team members), crisis evacuation desktop application for command centre, etc.
No related grants have been discovered for Edward Verbree.