11,017 research outputs found

    Challenges in the Design and Implementation of IoT Testbeds in Smart-Cities : A Systematic Review

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    Advancements in wireless communication and the increased accessibility to low-cost sensing and data processing IoT technologies have increased the research and development of urban monitoring systems. Most smart city research projects rely on deploying proprietary IoT testbeds for indoor and outdoor data collection. Such testbeds typically rely on a three-tier architecture composed of the Endpoint, the Edge, and the Cloud. Managing the system's operation whilst considering the security and privacy challenges that emerge, such as data privacy controls, network security, and security updates on the devices, is challenging. This work presents a systematic study of the challenges of developing, deploying and managing urban monitoring testbeds, as experienced in a series of urban monitoring research projects, followed by an analysis of the relevant literature. By identifying the challenges in the various projects and organising them under the V-model development lifecycle levels, we provide a reference guide for future projects. Understanding the challenges early on will facilitate current and future smart-cities IoT research projects to reduce implementation time and deliver secure and resilient testbeds

    A conceptual framework for developing dashboards for big mobility data

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    Dashboards are an increasingly popular form of data visualization. Large, complex, and dynamic mobility data present a number of challenges in dashboard design. The overall aim for dashboard design is to improve information communication and decision making, though big mobility data in particular require considering privacy alongside size and complexity. Taking these issues into account, a gap remains between wrangling mobility data and developing meaningful dashboard output. Therefore, there is a need for a framework that bridges this gap to support the mobility dashboard development and design process. In this paper we outline a conceptual framework for mobility data dashboards that provides guidance for the development process while considering mobility data structure, volume, complexity, varied application contexts, and privacy constraints. We illustrate the proposed framework’s components and process using example mobility dashboards with varied inputs, end-users and objectives. Overall, the framework offers a basis for developers to understand how informational displays of big mobility data are determined by end-user needs as well as the types of data selection, transformation, and display available to particular mobility datasets

    Executable Models and Instance Tracking for Decentralized Applications on Blockchains and Cloud Platforms -- Metamodel and Implementation

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    Decentralized applications rely on non-centralized technical infrastructures and coordination principles. Without trusted third parties, their execution is not controlled by entities exercising centralized coordination but is instead realized through technologies supporting distribution such as blockchains and serverless computing. Executing decentralized applications with these technologies, however, is challenging due to the limited transparency and insight in the execution, especially when involving centralized cloud platforms. This paper extends an approach for execution and instance tracking on blockchains and cloud platforms permitting distributed parties to observe the instances and states of executable models. The approach is extended with (1.) a metamodel describing the concepts for instance tracking on cloud platforms independent of concrete models or implementation, (2.) a multidimensional data model realizing the concepts accordingly, permitting the verifiable storage, tracking, and analysis of execution states for distributed parties, and (3.) an implementation on the Ethereum blockchain and Amazon Web Services (AWS) using state machine models. Towards supporting decentralized applications with high scalability and distribution requirements, the approach establishes a consistent view on instances for distributed parties to track and analyze the execution along multiple dimensions such as specific clients and execution engines.Comment: This is an unpublished preprint; both versions archived on arXiv.org have not been published. Although initially intended for publication, the preprint has undergone further improvements and has been utilized as input for new publications. (see also: https://www.unifr.ch/inf/digits/en/group/team/haerer.html

    Teacher Perceptions of the Use and Implementation of Online Learning in Secondary Career and Technical Education Programs

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    The Covid-19 pandemic fundamentally altered the course of education and this is no more evident than in the world of Career and Technical Education (CTE). When the education world was thrust into the remote learning environment, CTE instructors were forced to discover ways to provide students in their programs with high-quality learning experiences without the ability to conduct the hands-on learning experiences that are the hallmark of CTE programs. As we have moved into an endemic stage, a significant opportunity exists in finding ways to create improved methods of instruction in CTE programs that provide students with enhance learning experiences and the best way to understand these opportunities is through examining and understanding the experiences of those instructors that have taught CTE prior to, during, and after the Covid-19 pandemic. The purpose of this research is to understand the perceptions of secondary CTE teachers as to the implementation and use of online learning and educational technologies in traditional CTE programs. This qualitative research study utilized teacher interviews, documents, and classroom observations of CTE instructors from a single vocational school district in the Eastern United States. The research has yielded understandings in how CTE instructors can use digital tools to support classroom management as well as instructional strategies in CTE programs. Additionally, the research demonstrates ways that the integration of instructional technologies can support ways to expand experiential learning in CTE programs as well as the need for continual professional development to support the implementation and use of instructional technologies by CTE instructors

    Key technologies for safe and autonomous drones

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    Drones/UAVs are able to perform air operations that are very difficult to be performed by manned aircrafts. In addition, drones' usage brings significant economic savings and environmental benefits, while reducing risks to human life. In this paper, we present key technologies that enable development of drone systems. The technologies are identified based on the usages of drones (driven by COMP4DRONES project use cases). These technologies are grouped into four categories: U-space capabilities, system functions, payloads, and tools. Also, we present the contributions of the COMP4DRONES project to improve existing technologies. These contributions aim to ease drones’ customization, and enable their safe operation.This project has received funding from the ECSEL Joint Undertaking (JU) under grant agreement No 826610. The JU receives support from the European Union’s Horizon 2020 research and innovation programme and Spain, Austria, Belgium, Czech Republic, France, Italy, Latvia, Netherlands. The total project budget is 28,590,748.75 EUR (excluding ESIF partners), while the requested grant is 7,983,731.61 EUR to ECSEL JU, and 8,874,523.84 EUR of National and ESIF Funding. The project has been started on 1st October 2019

    PARAMETRIC APPROACHES TO BALANCE STORMWATER MANAGEMENT AND HUMAN WELLBEING WITHIN URBAN GREEN SPACE

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    Through rapid urbanisation, urban green spaces (UGS) have become increasingly limited and valuable in high-density urban environments. However, meeting the diverse requirements of sustainable urban development often leads to conflicts in UGS usage. For example, the presence of stormwater treatment facilities may hinder residents' access to adjacent UGS. Traditional approaches to UGS design typically focus on separate evaluations of human wellbeing and stormwater management. However, using questionnaires, interviews, and surveys for human wellbeing evaluation can be challenging to generalise across different projects and cities. Additionally, professional hydrological models used for stormwater management require extensive knowledge of hydrology and struggle to integrate their 2D evaluation methods with 3D models. To address these challenges, this thesis proposes a novel framework to integrate the two types of analysis within a system for balancing the needs of human wellbeing and stormwater management in UGS design. The framework incorporates criteria and parameters for evaluating human wellbeing and stormwater management in a 3D model and introduces an approach to compare these two needs in terms of UGS area and suitable location. The contributions of this thesis to multi-objective UGS design are as follows: (1) defining human wellbeing evaluation through Accessibility and Usability assessment, which considers factors such as connectivity, walking distance, space enclosure, and space availability; (2) simplifying stormwater evaluation using particle systems and design curves to streamline complex hydrological models; (3) integrating the two evaluations by comparing their quantified requirements for UGS area and location; and (4) incorporating parameters to provide flexibility and accommodate various design scenarios and objectives. The advantages of this evaluation framework are demonstrated through two case studies: (1) the human wellbeing analysis based on spatial parameters in the framework shows sensitivity to site variations, including UGS quantity and distribution, population density, terrain, road context, height of void space, and more; (2) the simplified stormwater analysis effectively captures site variations represented by UGS quantity and distribution, building distribution, as well as terrain, providing recommendations for each UGS with different types and sizes of stormwater facilities. (3) With the features of spatial parameter evaluation, the framework is feasible to adjust relevant thresholds and include more parameters to respond to specific project needs. (4) By quantifying the two different requirements for UGS and comparing them, any UGS with high usage conflicts can be easily identified. By evaluating all proposed criteria for UGSs in the 3D model, designers can conveniently observe simulation and adjust design scenarios to address identified usage conflicts. Thus, the proposed evaluation framework in this thesis would be valuable in effectively supporting further multi-objective UGS design

    Using Crowd-Based Software Repositories to Better Understand Developer-User Interactions

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    Software development is a complex process. To serve the final software product to the end user, developers need to rely on a variety of software artifacts throughout the development process. The term software repository used to denote only containers of source code such as version control systems; more recent usage has generalized the concept to include a plethora of software development artifact kinds and their related meta-data. Broadly speaking, software repositories include version control systems, technical documentation, issue trackers, question and answer sites, distribution information, etc. The software repositories can be based on a specific project (e.g., bug tracker for Firefox), or be crowd-sourced (e.g., questions and answers on technical Q&A websites). Crowd-based software artifacts are created as by-products of developer-user interactions which are sometimes referred to as communication channels. In this thesis, we investigate three distinct crowd-based software repositories that follow different models of developer-user interactions. We believe through a better understanding of the crowd-based software repositories, we can identify challenges in software development and provide insights to improve the software development process. In our first study, we investigate Stack Overflow. It is the largest collection of programming related questions and answers. On Stack Overflow, developers interact with other developers to create crowd-sourced knowledge in the form of questions and answers. The results of the interactions (i.e., the question threads) become valuable information to the entire developer community. Prior research on Stack Overflow tacitly assume that questions receives answers directly on the platform and no need of interaction is required during the process. Meanwhile, the platform allows attaching comments to questions which forms discussions of the question. Our study found that question discussions occur for 59.2% of questions on Stack Overflow. For discussed and solved questions on Stack Overflow, 80.6% of the questions have the discussion begin before the accepted answer is submitted. The results of our study show the importance and nuances of interactions in technical Q&A. We then study dotfiles, a set of publicly shared user-specific configuration files for software tools. There is a culture of sharing dotfiles within the developer community, where the idea is to learn from other developers’ dotfiles and share your variants. The interaction of dotfiles sharing can be viewed as developers sources information from other developers, adapt the information to their own needs, and share their adaptations back to the community. Our study on dotfiles suggests that is a common practice among developers to share dotfiles where 25.8% of the most stared users on GitHub have a dotfiles repository. We provide a taxonomy of the commonly tracked dotfiles and a qualitative study on the commits in dotfiles repositories. We also leveraged the state-of-the-art time-series clustering technique (K-shape) to identify code churn pattern for dotfile edits. This study is the first step towards understanding the practices of maintaining and sharing dotfiles. Finally, we study app stores, the platforms that distribute software products and contain many non-technical attributes (e.g., ratings and reviews) of software products. Three major stakeholders interacts with each other in app stores: the app store owner who governs the operation of the app store; developers who publish applications on the app store; and users who browse and download applications in the app store. App stores often provide means of interaction between all three actors (e.g., app reviews, store policy) and sometimes interactions with in the same actor (e.g., developer forum). We surveyed existing app stores to extract key features from app store operation. We then labeled a representative set of app store collected by web queries. K-means is applied to the labeled app stores to detect natural groupings of app stores. We observed a diverse set of app stores through the process. Instead of a single model that describes all app stores, fundamentally, our observations show that app stores operates differently. This study provide insights in understanding how app stores can affect software development. In summary, we investigated software repositories containing software artifacts created from different developer-user interactions. These software repositories are essential for software development in providing referencing information (i.e., Stack Overflow), improving development productivity (i.e., dotfiles), and help distributing the software products to end users (i.e., app stores)

    Integration of MLOps with IoT edge

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    Abstract. Edge Computing and Machine Learning have become increasingly vital in today’s digital landscape. Edge computing brings computational power closer to the data source enabling reduced latency and bandwith, increased privacy, and real-time decision-making. Running Machine Learning models on edge devices further enhances these advantages by reducing the reliance on cloud. This empowers industries such as transport, healthcare, manufacturing, to harness the full potential of Machine Learning. MLOps, or Machine Learning Operations play a major role streamlining the deployment, monitoring, and management of Machine Learning models in production. With MLOps, organisations can achieve faster model iteration, reduced deployment time, improved collaboration with developers, optimised performance, and ultimately meaningful business outcomes. Integrating MLOps with edge devices poses unique challenges. Overcoming these challenges requires careful planning, customised deployment strategies, and efficient model optimization techniques. This thesis project introduces a set of tools that enable the integration of MLOps practices with edge devices. The solution consists of two sets of tools: one for setting up infrastructure within edge devices to be able to receive, monitor, and run inference on Machine Learning models, and another for MLOps pipelines to package models to be compatible with the inference and monitoring components of the respective edge devices. This platform was evaluated by obtaining a public dataset used for predicting the breakdown of Air Pressure Systems in trucks, which is an ideal use-case for running ML inference on the edge, and connecting MLOps pipelines with edge devices.. A simulation was created using the data in order to control the volume of data flow into edge devices. Thereafter, the performance of the platform was tested against the scenario created by the simulation script. Response time and CPU usage in different components were the metrics that were tested. Additionally, the platform was evaluated against a set of commercial and open source tools and services that serve similar purposes. The overall performance of this solution matches that of already existing tools and services, while allowing end users setting up Edge-MLOps infrastructure the complete freedom to set up their system without completely relying on third party licensed software.MLOps-integraatio reunalaskennan tarpeisiin. Tiivistelmä. Reunalaskennasta (Edge Computing) ja koneoppimisesta on tullut yhä tärkeämpiä nykypäivän digitaalisessa ympäristössä. Reunalaskenta tuo laskentatehon lähemmäs datalähdettä, mikä mahdollistaa reaaliaikaisen päätöksenteon ja pienemmän viiveen. Koneoppimismallien suorittaminen reunalaitteissa parantaa näitä etuja entisestään vähentämällä riippuvuutta pilvipalveluista. Näin esimerkiksi liikenne-, terveydenhuolto- ja valmistusteollisuus voivat hyödyntää koneoppimisen koko potentiaalin. MLOps eli Machine Learning Operations on merkittävässä asemassa tehostettaessa ML -mallien käyttöönottoa, seurantaa ja hallintaa tuotannossa. MLOpsin avulla organisaatiot voivat nopeuttaa mallien iterointia, lyhentää käyttöönottoaikaa, parantaa yhteistyötä kehittäjien kesken, optimoida laskennan suorituskykyä ja lopulta saavuttaa merkityksellisiä liiketoimintatuloksia. MLOpsin integroiminen reunalaitteisiin asettaa ainutlaatuisia haasteita. Näiden haasteiden voittaminen edellyttää huolellista suunnittelua, räätälöityjä käyttöönottostrategioita ja tehokkaita mallien optimointitekniikoita. Tässä opinnäytetyöhankkeessa esitellään joukko työkaluja, jotka mahdollistavat MLOps-käytäntöjen integroinnin reunalaitteisiin. Ratkaisu koostuu kahdesta työkalukokonaisuudesta: toinen infrastruktuurin perustamisesta reunalaitteisiin, jotta ne voivat vastaanottaa, valvoa ja suorittaa päätelmiä koneoppimismalleista, ja toinen MLOps “prosesseista”, joilla mallit paketoidaan yhteensopiviksi vastaavien reunalaitteiden komponenttien kanssa. Ratkaisun toimivuutta arvioitiin avoimeen dataan perustuvalla käyttötapauksella. Datan avulla luotiin simulaatio, jonka tarkoituksena oli mahdollistaa reunalaitteisiin suuntautuvan datatovirran kontrollonti. Tämän jälkeen suorituskykyä testattiin simuloinnin luoman skenaarion avulla. Testattaviin mittareihin kuuluivat muun muassa suorittimen käyttö. Lisäksi ratkaisua arvioitiin vertaamalla sitä olemassa oleviin kaupallisiin ja avoimen lähdekoodin alustoihin. Tämän ratkaisun kokonaissuorituskyky vastaa jo markkinoilla olevien työkalujen ja palvelujen suorituskykyä. Ratkaisu antaa samalla loppukäyttäjille mahdollisuuden perustaa Edge-MLOps-infrastruktuuri ilman riippuvuutta kolmannen osapuolen lisensoiduista ohjelmistoista

    Utilizing artificial intelligence in perioperative patient flow:systematic literature review

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    Abstract. The purpose of this thesis was to map the existing landscape of artificial intelligence (AI) applications used in secondary healthcare, with a focus on perioperative care. The goal was to find out what systems have been developed, and how capable they are at controlling perioperative patient flow. The review was guided by the following research question: How is AI currently utilized in patient flow management in the context of perioperative care? This systematic literature review examined the current evidence regarding the use of AI in perioperative patient flow. A comprehensive search was conducted in four databases, resulting in 33 articles meeting the inclusion criteria. Findings demonstrated that AI technologies, such as machine learning (ML) algorithms and predictive analytics tools, have shown somewhat promising outcomes in optimizing perioperative patient flow. Specifically, AI systems have proven effective in predicting surgical case durations, assessing risks, planning treatments, supporting diagnosis, improving bed utilization, reducing cancellations and delays, and enhancing communication and collaboration among healthcare providers. However, several challenges were identified, including the need for accurate and reliable data sources, ethical considerations, and the potential for biased algorithms. Further research is needed to validate and optimize the application of AI in perioperative patient flow. The contribution of this thesis is summarizing the current state of the characteristics of AI application in perioperative patient flow. This systematic literature review provides information about the features of perioperative patient flow and the clinical tasks of AI applications previously identified
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