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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Enabling Successful Collaboration on Digital Platforms in the Manufacturing Industry : A Study of Digital Twins

Andersson, Ebba, Eckerwall, Kajsa January 2019 (has links)
Purpose – The purpose of this study is to enhance the understanding of how to successfully collaborate on digital platforms in the manufacturing industry by developing a contingency framework. To fulfill this purpose, the following research questions were derived: RQ1: Which challenges arise when collaborating on digital platforms in the manufacturing industry? and RQ2: How can collaboration challenges on digital platforms in the manufacturing industry be managed? Method – The study was conducted as an explorative, inductive single case study of a digital platform. More specifically, the study examined the development process of a digital twin platform created by a large high-technological company and its collaborative actors. In total, 21 interviews were conducted at eight different companies. The respondents all had experience of digital twin platforms, where some were working with digital twins sporadically and others on a daily basis. The data were analyzed through a thematic analysis. Findings – The analysis reveals that actors on digital platforms can face five types of challenges that hinder a successful collaboration: disadvantages of dependency, uncertainty regarding data management, varying customer needs, insufficient work methods, and unsuitable payment models. The analysis also reveals four strategies that can be used to address the challenges: transparency strategy, incentive model strategy, servitization strategy, and control strategy. Moreover, these findings are summarized in a contingency framework that explains which types of challenges that can be addressed with which strategies based on the specific prerequisites of each collaboration. Theoretical and practical implications – The study extends the digital platform literature by providing empirical evidence for several collaboration challenges among the actors on a digital platform, which has previously bee not been studied. Additionally, the study provides evidence of how these challenges can be addressed. Our framework helps manufacturing companies to successfully adopt digital platforms by providing managers with the tools to handle the required collaboration. Limitations and further research – The study is limited by a single case study of a specific digital platform. Thus, to extend the findings, further research that examines other contexts are recommended. Moreover, the establishment of the studied platform is currently in an early phase which limits the study to hypothetical challenges and management methods. To validate the findings, further research that examines a fully developed and implemented platform is recommended.
12

Master Thesis - Towards a Virtual Climate Chamber : A numerical study using CFD software

Anjaneya Reddy, Yuvarajendra January 2020 (has links)
For each generation of electronic equipment there is a trend towards higher power den-sities. Increased heat generation is an undesired consequence that the thermal design unit in a company must handle. The goal of thermal design engineer/unit is to utilizethe same volume to more efficiently transfer more heat from the equipment. This can bedone by exploring more complex and advanced heat sink geometries, optimizing the finshapes and so on. The new prototypes developed will be tested for their reliability and endurance in special chambers called climate chambers, that simulate desired environ-ments. The measurements by thermal design teams in these kind of climate chambers are mainly of outdoor products, whose cooling is based on natural convection. Forcedcooling using fans is optional for these outdoor products. The climate chambers in general provides temperature measurement as the outputto the analysis, though there are other important parameters that define the operationalfunctionality of an equipment. The ability to visualize the flow characteristics duringthe process of testing is a valuable aid in the design process. A virtual/CFD form of thephysical climate chamber (CC) would empower the design process, while alleviating theusage of the climate chambers for such analyses. CFD offers a wide range of capabilitiesthat lets the user change the boundary conditions with great ease compared to that ofthe experimental setup. The numerical model developed in this thesis project provides results, that help inunderstanding the physics involved in fluid flow inside the physical climate chamber.Turbulence quantification of the flow is the main aim of this thesis project, which wouldbe resourceful in future works. Experiments are conducted inside the climate chamber, in order to aid the construction of numerical model as well as serve as source of vali-dation for the numerical results. Laminar transient case simulations are preferred over use of any turbulence models, to limit any kind of predictions made by these turbulencemodels. Integral length scales and turbulence intensities are compared and reason fordiscrepancies are addressed. The results from the comparisons show that, the numerical model emulates physicsof actual flow inside the climate chamber. However, there are many factors that directlyaffect the results, making it difficult to precisely quantify the error, within the time periodof this thesis project.
13

Digital Twin of a Reheating Furnace

Halme Ståhlberg, Daniel January 2021 (has links)
In this thesis, a proof of concept of a digital twin of a type of reheating furnace, the walking beam furnace, is presented. It is created by using a machine learning concept called a neural network. The digital twin is trained using real data from a walking beam furnace located in Swerim AB, Luleå, and is taught to predict the temperature in the furnace using air, fuel and pressure as inputs. The machine learning technique used is an artifical neural network in the form of a multilayer perceptron model. The resulting model consists of 3 layers, input, hidden and output layer. The hyperparameters is decided by using grid search cross validation. The hyperparameters chosen to use in this thesis was amount of epochs, optimizer, learning rate, batch size, activation function, regularizer and amount of neurons in the hidden layer. The final settings for these can be found in table. The digital twin is then evaluated comparing predicted temperatures and actual temperatures from the measured data. The end result shows that the twin performs reasonably well. The predictions differs from measured temperature with a percentage around 0.5% to 1.5%.
14

Assessment of How Digital Twin Can Be Utilized in Manufacturing Companies to Create Business Value

Bestjak, Linnea, Lindqvist, Cassandra January 2020 (has links)
Introduction The paradigm shift in manufacturing that Industry 4.0 brings forth with new advanced technologies and the rapid growth of sensing and controlling technologies enable further visualization and optimization that can contribute to achievingimproved decision-making in manufacturing. A significant new capability is the ability to construct a Digital Twinthat connects the physical and virtual space. However, there are still confusion and obscurity regarding what Digital Twinis and how it can becreated and then used to create value for the company. Therefor the purpose of the thesis is to examine how manufacturing companies can utilize the implementation of Digital Twinand assess Digital Twinin a shop-floor. ➢RQ1: How can DT be beneficial to increase business value in a manufacturing company? ➢RQ2: What changes need to be done in the shop-floor to implement Digital Twin? Methodology A literature review was conducted to provide previous researchand contextwithin the area of Digital Twin. A multiple-case studywas performed at three case companies to gain meaningful insight from a real-world perspective, semi-structured interviews, dialogs, and observations were conductedat the case companies. The analysis was then performed by examining similarities, and dissimilarities between theoretical and empirical data, as well as opportunities in theoretical findings that correspond with challenges in empirical findings. Frame of Reference The literature review increased the authors’ understanding of the research topic and gave context to the concept of Digital Twin. The review is mainly focused on the Digital Twintechnologyand how it is constructed, as well as the applicationsareas. Empirical Findings The empirical findings provide an overview of boththe current and future state of the case companies in relation to organizational, operational, and technological factors. Additionally, it provides a deeper understanding of how shop-floor management is designed at one of the case companies. Analysis The combination of the Frame of Reference and Empirical Findings contributewith important insight on the potential benefits that can be created through the utilizationof Digital Twin, as well as what is requiredin the shop-floor to enable implementation ofDigital Twin. Conclusions The value that can be created utilizing Digital Twinis outlinedand a clearer definition is proposed to avoid misunderstandings and confusion. Requirements that need to be achieved for a successful implementation arecovered as well. A future recommendation is measuring resources and effort in relation to the created value of a Digital Twin.
15

Mehr Geschwindigkeit durch Digitales Engineering, Virtuelle Realität und Simulation

Arribas, Diego 11 December 2018 (has links)
No description available.
16

A Deep Dive into the Current and Future Conditions for Virtual Commissioning of Production Lines

Lidell, Anton January 2021 (has links)
The use of virtual commissioning has increased in the last years, but there are still challenges before the software code validation method is widespread in use. One of the additions to virtual commissioning is basing it on a digital twin to allow for improved accuracy. The aim of this thesis is to review existing standards and approaches to developing virtual commissioning, as well as to explore the definitions. The chosen approach to achieve the aim, is to perform a literature review of existing research papers and interviews with knowledgeable people in the industry. First, the definitions and classifications are reviewed, then the approaches for development of virtual commissioning and digital twins are explored in the literature. In three interviews with people of varying backgrounds and competences, the views of the virtual technologies are assessed to provide insight in the industry. The findings of the literature review and interviews are among others, the apparent need for standardisation in the field and that a sought-after standard in the form of ISO 23247-1 is under way. Furthermore, the digital twin is a concept with a promising future in combination with other technologies of Industry 4.0. In conclusion, this thesis provides a deep review of the challenges and possibilities of virtual commissioning and the digital twin and could be used as starting point for further research in standardisations and improvements sprung from the new standard.
17

Range Modulation Strategy for Minimizing Interference in Vehicle-to-Vehicle Safety Communication

Parrish, Mason D. 22 April 2022 (has links)
No description available.
18

Implementeringsutmaningar i en kommun: fallet om BIM i markanvisningsprocessen / Challenges of implementing in a municipality: the case of BIM in the land allocation process

Hamarashid, Ramyar January 2023 (has links)
The municipalities' vision of using City Information Modeling (CIM) and Digital Twins (DT) inurban planning, requires prerequisites in place. A prerequisite is BIM, which together with GIS can create CIM.BIM implementation for a municipality involves major challenges and one such challenge is the lack of BIMmodels for existing buildings and infrastructure. However, this study is limited to planned development inconnection with land allocation. BIM implementation for the land allocation process within a medium-sizedSwedish municipality involves many involved actors and thus the need for a mobilization of the involved actorsfrom an ANT-inspired perspective. The purpose of this study is therefore to analyze how an actor network canbe mobilized to implement BIM in the land allocation process. A case study method has been chosen in thisthesis, considering that a well-defined case is identified, and the approach enables a variety of data collectionmethods that have been inspired by the autoethnographic approach because the researcher belongs to the focalactor in the process.
19

Ontology based framework for Tactile Internet and Digital Twin Applications

Adhami, Hikmat 09 August 2022 (has links)
In the era of Industry 4 and Digital Twin – DT- (integrating Audio-Video, Virtual Reality, Augmented Reality and Haptics - from the Greek word Haptikos meaning "able to touch") and the Tactile Internet (TI), it becomes obvious that telecom stakeholders need different networks requirements to provision high quality services with respect to the new standards. In reality, this era is proposed as TI, and it will achieve a true paradigm shift from content delivery to skill-set delivery network types, thanks to recent technical breakthroughs. It will build a new internet structure with improved capabilities; but it will be difficult to meet the technical needs of the TI with current fourth generation (4G) mobile communication systems. As a result, 5G mobile communication systems will be used at the wireless edge and as a key enabler for TI due to its automated core network functionalities. Because of the COVID-19 outbreak, most daily activities such as employment, research, and education are now conducted online rather than in person. As a result, internet traffic has risen dramatically. Nowadays, Tactile Internet is in its infancy deployment phase worldwide. For this reason, and because of the growing need of its applications, the feasibility of these applications on the existing and deployed networks infrastructures, especially in the growing countries, is thought to be very hard, even quasi-impossible. Since 5G is not reaching yet its convergence stage (i.e. it is not deployed everywhere) and there is a huge stress on mobile communications given that the world is still facing the COVID-19 Pandemic, and since all the activities are taking place online, we propose design and implement a QoS framework to facilitate the feasibility and the applicability of the TI systems, where no 5G infrastructure is deployed. This framework will predict the most suitable network type to be deployed for certain given TI applications with certain given KPIs (Key Performance Indicators). Also, this framework is scalable, in such it gives an idea of even the future Next Generation Mobile Networks types (NGMN, if necessary). “To deal” with TI applications, means “to deal” with Haptics added to Audio and Video streams. Therefore, performance evaluation for haptic networks is required. And since there are different types of haptic networks, so interoperability is needed. Consequently, a standardization form is necessary for that purpose, to annotate and describe the haptic network. The first idea that flashes in mind, is the use of Ontologies. In these latters, we can add intelligent rules to infer additional data and predict resource requirements in order to achieve better performance. Many works in the research rely on Artificial Intelligence approaches to tackle the above-mentioned standardization, but very few depend on ontologies, and without futuristic outcomes, especially for the optimization problem. We mean by optimization, the optimal types, methods and rules that are able to accommodate the applicability of the TI systems (here come the applications KPIs) in an acceptable environment or infrastructure (here come the networking KPIs), and even-more, to infer the most optimal network type. To help manufacturing companies take full advantage of the TI, we propose to develop new methods and tools (ontologies) to intelligently handle the TI, DT (Digital Twin) and IoT (Internet of Things) sensor data and process data at the edge of the network and deliver faster insights. The outcomes of these ontologies, have been validated through two conducted case studies, where we simulated, in the first, TI traffic over Wi-Fi, WiMAX and UMTS (3G) infrastructures; While in the second we used 4G (LTE-A), along with SDN (Software Defined Networking) integrated to MEC (Mobile Edge Computing) as networking backbone. The results, in terms of QoS KPIs performance evaluation, present high relevance to our proposed Ontology outcomes.
20

Nonlinear Modal Testing and System Modeling Techniques

Nagesh, Mahesh 04 October 2021 (has links)
No description available.

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