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Wyniki wyszukiwania dla: RESILIENT NETWORKS
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Resilient Routing in Communication Networks
PublikacjaThis important text/reference addresses the latest issues in end-to-end resilient routing in communication networks. The work highlights the main causes of failures of network nodes and links, and presents an overview of resilient routing mechanisms, covering issues related to the Future Internet (FI), wireless mesh networks (WMNs), and vehicular ad-hoc networks (VANETs). For each of these network architectures, a selection of...
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Highlights from RNDM 2018 – 10th Anniversary Workshop on Resilient Networks Design and Modeling
PublikacjaArtykuł prezentujący relację z workshopu RNDM 2018
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Disaster-resilient communication networks: Principles and best practices
PublikacjaCommunication network failures that are caused by disasters, such as hurricanes, arthquakes and cyber-attacks, can have significant economic and societal impact. To address this problem, the research community has been investigating approaches to network resilience for several years. However, aside from well-established techniques, many of these solutions have not found their way into operational...
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Proposal of improvement to fairness mechanism of Resilient Packet Ring networks
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Optimizing FSO networks resilient to adverse weather conditions by means of enhanced uncertainty sets
PublikacjaThis work deals with dimensioning of wireless mesh networks (WMN) composed of FSO (free space optics) links. Although FSO links realize broadband transmission at low cost, their drawback is sensitivity to adverse weather conditions causing transmission degradation on multiple links. Hence, designing such FSO networks requires an optimization model to find the cheapest configuration of link capacities that will be able to carry...
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Jacek Rak dr hab. inż.
OsobyJacek Rak uzyskał stopień doktora habilitowanego nauk technicznych w dyscyplinie telekomunikacji (specjalność: teleinformatyka) w 2016 r., a stopień doktora nauk technicznych w dyscyplinie informatyka w 2009 r. Obecnie jest pracownikiem naukowo-dydaktycznym Katedry Teleinformatyki Wydziału Elektroniki, Telekomunikacji i Informatyki Politechniki Gdańskiej. Jego działalność naukowa koncentruje się w obszarze doboru tras, projektowania...
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Taxonomy of Schemes for Resilient Routing
PublikacjaThis chapter provides a taxonomy of schemes for resilient routing followed by a discussion of their application to contemporary architectures of communication networks. In particular, a general classification of schemes for resilient routing is first presented followed by a description of the reference schemes for IP networks. The chapter in its later part focuses on the representative techniques of resilient routing for a multi-domain...
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Fundamentals of Communication Networks Resilience to Disasters and Massive Disruptions
PublikacjaCommunication networks are exposed to a variety of massive failure events following from activities of nature, weather-induced disruptions, technology-implied problems, and malicious human activities. In this chapter, we first highlight the characteristics of these scenarios and discuss example failure events reported during the last three decades. Next, we explain the concept of network resilience and present an overview of major...
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Interdependence between Power Grids and Communication Networks: A Resilience Perspective
PublikacjaPower network resilience is increasingly dependent on communication networks. Besides traditional generation, power networks need to accommodate increasingly high penetration levels of dispersed micro generation, mostly based on renewable sources, and increasing and challenging demand, such as electric vehicles. At the same time the deployment of enabling technologies throughout the power grid makes available new demand resources...
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A taxonomy of challenges to resilient message dissemination in VANETs
PublikacjaInter-vehicular communications is seen as a promising solution to a number of issues related with public road safety, road congestion management, and infotainment. However, Vehicular Ad-hoc NETworks (VANETs) characterized by high mobility of vehicles and facing a number of other issues related with high frequency wireless communications and network disconnections, encounter major challenges related with reliability of message delivery....
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A MODEL FOR FORECASTING PM10 LEVELS WITH THE USE OF ARTIFICIAL NEURAL NETWORKS
PublikacjaThis work presents a method of forecasting the level of PM10 with the use of artificial neural networks. Current level of particulate matter and meteorological data was taken into account in the construction of the model (checked the correlation of each variable and the future level of PM10), and unidirectional networks were used to implement it due to their ease of learning. Then, the configuration of the network (built on the...
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RECODIS: Resilient Communication Services Protecting End-user Applications from Disaster-based Failures
PublikacjaDisaster-based failures can seriously disrupt any communication network, making its services unavailable. Such disruptions may be caused by natural disasters, technology-related failures, or malicious attacks, and they are observably increasing in number, intensity and scale. When network services that are a part of critical infrastructure become unavailable, commercial and/or societal problems are inevitable. The issue of limiting...
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RNDM 2016 Workshop and 2nd Meeting of COST CA15127-RECODIS: Highlights from the Resilience Week in Halmstad, Sweden
PublikacjaLeading network resilience researchers took part in the Resilience Week on Sept. 12-15, 2016 at Halmstad University, SE by Prof. Magnus Jonsson from the Centre for Research on Embedded Systems (CERES), Halmstad University, SE, and Prof. Jacek Rak from Gdansk University of Technology, PL. It included two major events: - The 2nd Meeting of COST CA15127–RECODIS Action (Resilient Communication Services Protecting End-user Applications...
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On the Importance of Resilience Engineering for Networked Systems in a Changing World
PublikacjaResilience is featured increasingly often in the media, usually applied to society when faced, for example, with disasters such as flooding and the enormous challenges that the Covid-19 pandemic posed. There are now many resilience-related discussion groups worldwide, and some standards initiatives devoted in particular to city resilience. However, there is relatively little explicit interest in resilience engineering for communication...
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A repeated game formulation of network embedded coding for multicast resilience in extreme conditions
PublikacjaComputer networks and data sharing applications are vital for our current society and fundamental for any available ICT solution, so that networking is considered as one of the key critical infrastructures and its correct behavior should be always enforced, even in case of disasters or severe execution conditions. Resilience is a strongly demanding nonfunctional requirement for current computer networks, and one of the key factors...
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On the complexity of resilient network design
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Cross-layer integration of network mechanisms for increasing efficiency of multimedia session support in IEEE 802.11s environment
PublikacjaWith an IEEE 802.11 wireless networks operating in Point-to-Multipoint mode being the most popular WLAN access technology employed today, it can be expected that a Wireless Mesh Network (WMN) based on the technology can provide significant advantages for such network systems. The IEEE 802.11s standard amendment provides the comprehensive set of mechanisms required to implement and deploy a WMN utilizing this widely popular technology....
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Design of Resilient Vehicle-to-Infrastructure Systems
PublikacjaVehicular ad hoc networks (VANETs) have recently gained noticeable attention due to advantages in improving road traffic safety, shaping the road traffic and providing infotainment opportunities to travellers. However, transmission characteristics following from the IEEE 802.11p standard and the high mobility of VANET nodes remarkably reduce the lifetime, reach and capacity of wireless links, and often lead to simultaneous disruptions...
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Toward Fast Calculation of Communication Paths for Resilient Routing
PublikacjaUtilization of alternate communication paths is a common technique to provide protection of transmission against failures of network nodes/links. However, a noticeable delay is encountered when calculating the relevant sets of disjoint paths using the available algorithms (e.g., using Bhandari’s approach). This, in turn, may have a serious impact on the ability of a network to serve dynamic demands...
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Physical crosslinking of hyaluronic acid in the presence of phospholipids in an aqueous nano-environment
PublikacjaHyaluronic acid and phospholipids are two components in the synovial joint cavity that contribute to joint lubrication synergistically. Molecular dynamics simulations were performed and hydrogen bonds in hyaluronic acid were analyzed to identify specific sites that are responsible for its physical cross-linking. Two molecular masses of hyaluronic acid, 10 kDa and 160 kDa, were considered. We use molecular dynamics simulations and...
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Reinforced Secure Gossiping Against DoS Attacks in Post-Disaster Scenarios
PublikacjaDuring and after a disaster, the perceived quality of communication networks often becomes remarkably degraded with an increased ratio of packet losses due to physical damages of the networking equipment, disturbance to the radio frequency signals, continuous reconfiguration of the routing tables, or sudden spikes of the network traffic, e.g., caused by the increased user activity in a post-disaster period. Several techniques have...
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SMART AND RESILIENT CITIES – NEW CHALLENGES FOR POLISH CITIES IN TERMS OF 2020 BUILDING ENERGY EFFICIENCY AND CLIMATE CHANGE ACTION.
PublikacjaGlobal climate change action along with energy efficiency optimizations are becoming increasingly pressing principles in terms of moving towards sustainable development. As a member of EU and UN Poland is also obliged to follow restricted rules concerning energy efficiency of buildings which come to force in 2020. To meet new goals, innovative approaches - like moving towards smart and resilient cities -may be required. Through...
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Smart and resilient cities- new challanges for Polish cities in terms of 2020 energy efficiency and climate action
PublikacjaGlobal climate change action along with energy efficiency optimizations are becoming increasingly pressing principles in terms of moving towards sustainable development. As a member of EU and UN Poland is also obliged to follow restricted rules concerning energy efficiency of buildings which come to force in 2020. To meet new goals, innovative approaches - like moving towards smart and resilient cities -may be required. Through...
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The resilient city in architectural engineering education: a joint design studio between Gdańsk and Chalmers universities of technology
PublikacjaChallenges to society, such as those posed by climate change require a new approach to the education of the engineer-architect. Contemporary solutions should serve future generations and that is why the idea of the resilient city should be discussed and implemented, both in theory and in practice. It is necessary to teach students to design urban structures in such a way that they are resilient to dynamically changing conditions....
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Organizational Resilience in Hospitality and Tourism
PublikacjaAlthough ‘VUCA’ is not a new term, the features of the world it describes, a volatile, uncertain, complex and ambiguous environment, have never been more valid. The VUCA world has become the new reality for business, specifically for hospitality and tourism organizations that are more vulnerable than any other sector due to the historically-recognized turbulent environment in which they operate. In this book, the authors present...
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Double-Blind Reputation vs. Intelligent Fake VIP Attacks in Cloud-Assisted Interactions
PublikacjaWe consider a generic model of Client-Server interactions in the presence of Sender and Relay, conceptual agents acting on behalf of Client and Server, respectively, and modeling cloud service providers in the envisaged "QoS as a Service paradigm". Client generates objects which Sender tags with demanded QoS level, whereas Relay assigns the QoS level to be provided at Server. To verify an object's right to a QoS level, Relay detects...
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Ocena możliwości emulacji protokołu RPR na sprzęcie klasy SOHO i systemie Linux
PublikacjaW pracy dokonano oceny możliwości realizacji protokołu RPR (Resilient Packet Ring - IEEE 802.17) na sprzęcie klasy SOHO i systemie Linux. Przedstawiono wytworzony na Politechnice Gdańskiej naukowo-dydaktyczny emulator stacji RPR zgodny z wersją 3.0 standardu. Funkcjonalność emulatora skupiono na algorytmach sprawiedliwości podziału pasma. Opisano sposób rozwiązania najważniejszych problemów związanych z implementacją, a w szczególności...
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Ocena jakości wielopętlowych szybkich sieci komputerowych
PublikacjaOmówiono protokół RPR (Resilient Packet Ring), przedstawiono najważniejsze cechy i mechanizmy protokołów RPR. Zaproponowano nową metodę przeciwdziałania przeciążeniom sieci wielopętlowych. Dokonano jej analizy matematycznej dla równomiernego rozkładu ruchu w przypadku awarii sieci i stosowaniu mechanizmu wrapping. Przeprowadzono również analizę numeryczną wydajności sieci zarówno dla rozkładu równomiernego jak i losowego ruchu....
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Developing Polycentricity to Shape Resilient Metropolitan Structures: The Case of the Gdansk–Gdynia–Sopot Metropolitan Area
PublikacjaMaking the metropolitan area resilient, in many cases, calls for amending its spatial structures. This may take various forms, including both reshaping the metropolitan core and redeveloping the entire regional network of cities and centres, making them part of a coherent structure. The latter strategy is associated with reinforcing secondary urban centres as well as shaping new connections between them. In this case, the term...
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City scan as a tool to assess resilience challenges and vulnerabilities at the community level
PublikacjaThe majority of the world’s population lives in cities and cities are the key to achieving resilience. Local governments own only part of the land and can only partially decide about measures that should be taken ‘on the ground’. Local governments are therefore highly dependent on individuals, communities, and businesses to adapt and transform and take action in their own backyards or neighbourhoods. Since, for many people, climate...
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Cybersecurity and Privacy in Standards for Smart Grids – a Comprehensive Survey
PublikacjaResilient information and communications technologies are a prerequisite for reliable operation of smart grid. In recent years, many standards for the new form of electricity network have been proposed, which results in operators and other smart grid stakeholders having difficulties in finding the documents which can be related to their particular problems. The purpose of this paper is to bring in all smart grid standards that...
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Creating a more conscious built environment for day- and night-time setting through interdisciplinary collaboration
PublikacjaThe last decades have seen an increase in the speed, scale and scope of urbanisation, fundamentally shifting the character of the built environment and engendering a radical search for new and resilient design practices. Although we, as society, live in the age of technology, inventions and almost unlimited access to information, we rarely use these opportunities to our advantage to improve the quality of life. It seems that multidisciplinary...
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Small Urban Hacks - Big Impact! Tackling major urban challenges through acupunctural smallness
PublikacjaSmall urban hacks, acupunctural action and process-oriented planning approaches might appear to address quite a socio-romantic attitude towards our urban environments. In this chapter, our aim is to remedy such a biased view, demonstrating the impact and potential of smallness in the context of major urban challenges. Small urban hacks and their multi-faceted and creativity-driven approaches of small is beautiful are selected from...
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Airstrip Ground Improvement Works by Blasting Charge Technique and Dredged-Ash Material Mixture
PublikacjaSoil improvement by blasting charge technique is known in geotechnics as one of the efficient and inexpensive method. It can be used in preparing of underground to found road construction and buildings as well. The technique proves usefulness especially when dynamic load is applied. It is because of non-stiff or rather resilient type soil after improvement. In noncohesive or organic soil, blasting charge...
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Scenario-planning solutions for waterfront flood-prone areas
PublikacjaThe aim of this article is to discuss the potential of applying scenario planning to achieve resilient and future-oriented solutions for flood-prone areas. The authors have proposed additions to scenario-planning processes based on the introduction of research-by-design architectural inquiries. Examined in this article is the insight into the testing of such a modified scenario-planning methodology during two courses that accompanied...
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Reconfigurable Antennas for Trustable Things
PublikacjaIn modern applications, the Internet of Things plays a significant role in increasing the productivity, effectiveness or safety and security of people and assets. Additionally, the reliability of Internet of Things components is crucial from the application point of view, where a resilient and low-latency network is needed. This can be achieved by utilizing reconfigurable antennas to enhance the capabilities of the wireless sensor...
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Improving Clairvoyant: reduction algorithm resilient to imbalanced process arrival patterns
PublikacjaThe Clairvoyant algorithm proposed in “A novel MPI reduction algorithm resilient to imbalances in process arrival times” was analyzed, commented and improved. The comments concern handling certain edge cases in the original pseudocode and description, i.e., adding another state of a process, improved cache friendliness more precise complexity estimations and some other issues improving the robustness of the algorithm implementation....
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An approach to improve the time efficiency of disjoint paths calculation
PublikacjaFailures of network elements can be appropriately dealt with by utilization of alternate disjoint paths to provide redirection of flows affected by failures of the respective working paths. Known approaches can be broadly divided by decision on backup paths installation into proactive and reactive mechanisms, as well as based on the scope of recovery actions into local and global rerouting. There are several important scenarios...
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Evaluation of time-efficiency of disjoint paths calculation schemes
PublikacjaThe concept of alternate paths has been shown in the literature to provide fast response of a network to failures of its elements (nodes/links) affecting flows along the primary communication paths. Various approaches have been proposed to reduce the time necessary to redirect the respective flows onto the alternate paths. In this paper, we focus on another important objective, that so far has not received much attention, i.e.,...
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All-gather Algorithms Resilient to Imbalanced Process Arrival Patterns
PublikacjaTwo novel algorithms for the all-gather operation resilient to imbalanced process arrival patterns (PATs) are presented. The first one, Background Disseminated Ring (BDR), is based on the regular parallel ring algorithm often supplied in MPI implementations and exploits an auxiliary background thread for early data exchange from faster processes to accelerate the performed all-gather operation. The other algorithm, Background Sorted...
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Effect of User Mobility upon Trust Building among Autonomous Content Routers in an Information-Centric Network
PublikacjaThe capability of proactive in-network caching and sharing of content is one of the most important features of an informationcentric network (ICN). We describe an ICN model featuring autonomous agents controlling the content routers. Such agents are unlikely to share cached content with other agents without an incentive to do so. To stimulate cooperation between agents, we adopt a reputation and trust building scheme that is able...
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IS THE REGIONAL DIVERGENCE A PRICE FOR THE INTERNATIONAL CONVERGENCE? THE CASE OF THE VISEGRAD GROUP
PublikacjaThe main goal of this article is to verify whether the Visegrad Group countries are achieving social convergence at national level at the expense of internal divergence. For this purpose, the existence of social beta-, sigma- and gamma-convergence at national and regional level was tested. The author of this article decided to tackle the convergence problem since there is a high risk that countries are trying to catch up at...
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Enhancing Availability for Critical Services
PublikacjaTraditional approaches to provide classes of resilient service take the physical network availability as an input and then deploy redundancy and restoration techniques at various layers, often without full knowledge of mappings between layers. This makes it hard (and often inefficient) to ensure the high availability required by critical services which are typically a small fraction of the total traffic. Here, the innovative technique...
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Lighting conditions in Home Office and occupant’s perception: an international study
PublikacjaThe global pandemic and physical distancing restrictions are forcing us to rethink how residential buildings are used regarding the visual environment. This paper describes home office lighting conditions within different countries and continents. The aim is to define the current limitations of home offices in providing a resilient visual environment. The work was developed by a team of international experts working together on...
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Subjective Quality Evaluation of Underground BPL-PLC Voice Communication System
PublikacjaDesigning a reliable voice transmission system is not a trivial task. Wired media, thanks to their resistance to mechanical damage, seem an ideal solution. The BPL-PLC (Broadband over Power Line – Power Line Communication) cable is resilient to electricity stoppage and partial damage of phase conductors. It maintains continuity of transmission in case of an emergency situation, including paramedic rescue operations. These features...
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eFRADIR: An Enhanced FRAmework for DIsaster Resilience
PublikacjaThis paper focuses on how to increase the availability of a backbone network with minimal cost. In particular, the new framework focuses on resilience against natural disasters and is an evolution of the FRADIR/FRADIR-II framework. It targets three different directions, namely: network planning, failure modeling, and survivable routing. The steady state network planning is tackled by upgrading a sub-network (a set of links termed...
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Nickel-based catalysts for electrolytic decomposition of ammonia towards hydrogen production
PublikacjaNickel is an attractive metal for electrochemical applications because it is abundant, cheap, chemically resilient, and catalytically active towards many reactions. Nickel-based materials (metallic nickel, its alloys, oxides, hydroxides, and composites) have been also considered as promising electrocatalysts for ammonia oxidation. The electrolysis of ammonia aqueous solution results in evolution of gaseous hydrogen and nitrogen....
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Concrete versus green corridors in road planning. Gdansk case
PublikacjaThe aim of an article is to present the threats which may be caused by the construction of the transit road inside the city structure, and some mitigation measures aiming to eliminate or minimize environmental and landscape damages and social problems. Theoretical guidelines and conclusions will be followed by the example illustrating the problem. As an answer, some guidelines enabling sustainable road planning will be presented....
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Alphitobius diaperinus larvae (lesser mealworm) as human food – An approval of the European Commission – A critical review
PublikacjaDue to the increasing threat of climate change and the need for sustainable food sources, human consumption of edible insects or entomophagy has gained considerable attention globally. The larvae of Alphitobius diaperinus Panzer (Coleoptera: Tenebrionidae), also known as the lesser mealworm, have been identified as a promising candidate for mass-rearing as a food source based the on evaluation on several aspects such as the production...
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Codesigned Digital Tools for Social Engagement in Climate Change Mitigation
PublikacjaDigital technologies and economies can strengthen participative processes and data- and knowledge-based sustainable urban development. It can also accelerate social integration and the efforts of urban dwellers towards more resilient urban environments. Gap: Most of the tools that strengthen participatory processes were not cocreated with stakeholders. Research shows that codesigned platforms driven by new technological advances...