• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 115
  • 16
  • 11
  • 6
  • 4
  • 3
  • 1
  • Tagged with
  • 175
  • 175
  • 89
  • 36
  • 31
  • 30
  • 29
  • 29
  • 26
  • 25
  • 25
  • 24
  • 23
  • 23
  • 22
  • 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.
91

Evaluating digital twin data exchange between a virtual and physical environment regarding lighting quantity

Tabbah, Alyaá January 2021 (has links)
Building Information Management and Digital Twin technology with help of Smart lights can optimizethe built environment impacting our health and well-being, by providing the right amount of light at theright time of day. Lighting simulation is challenging, due to the strict requirements to represent reality. Digitaltwin technology will provide a more dynamic two-way feed-back between the physical and the virtual environmentto optimize the lighting environment giving real-time sensor data. The main problem that currently occurswhile evaluating a lighting design made in photorealistic computer visualization is using the appropriate formof their model presentation. However, validation of light simulations has been done multiple times but not manystudies are based on DT-driven light environment evaluation in which not only the realistic representation butalso the exchange of information plays a crucial role. Therefore, the aim is to develop a strategy for demonstratingthe data exchange between a physical and real environment, for a scenario in which an optimal interactionbetween daylight and electric light derives an optimized realization of a given light demand curve. Basedon a quantitative experiment, validation of a Digital Twin was done between a virtual and a physical twin onan existing room using the light simulation tool DIALux evo. Data exchange was optimized for three levels ofgeometrical complexity. The light environment was optimized for interaction between the Digital and RealTwin. Counter to expectations, the results showed that the coarse model is more accurate representation of thephysical counterpart and generates faster data exchange. Defining DT usage purpose reduces time and effortdone on the process of creation. Knowing what data to exchange and how often avoid developers any limitationsor delaying in the process. Future studies can investigate how optimization of data exchange and light environmentcan be achieved with programming and parametric generative design.
92

BUILDING RESILIENT SUPPLY CHAINS THROUGH SUPPLY CHAIN DIGITAL TWIN: AN EXPLORATIVE STUDY IN US MANUFACTURING SUPPLY CHAINS

Senthilkumar Thiyagarajan (11462140) 19 April 2022 (has links)
<p>Developing resiliency in supply chains became vital in the recent years due to global diversification and vulnerability to risks. Firms need to identify, evaluate, and mitigate risks in supply chain to maintain continuity and create competitive advantage. Although the problem of supply chain disruptions has existed for a long time, less attention has been given by researchers in exploring the adoption of advanced technologies to build resilient supply chains. This study explored the potential of mitigating supply chain disruptions with the use of Industry 4.0 technologies such as Internet of Things (IoT) and Supply chain data analytics platform which develops digital twin environment for supply chains. </p> <p><br></p> <p>This research gathered expert’s opinion on the resilience capabilities developed in supply chain by digital twin adoption, stages and practices involved in digital twin assimilation through Delphi survey with subject matter experts and supply chain practitioners. Semi-structured interviews were conducted with participants to attain deep understanding on the resilience capabilities gained by digital twin and stages in digital twin adoption. Comparison of the results from Delphi survey and interviews was carried out to synthesize the results to yield a comprehensive understanding of resilience capabilities gained through digital twin and adoption stages of supply chain digital twin. This research has conducted interviews with 21 subject matter experts and completed three rounds of Delphi survey (with participants n = 15, 11, 11 in three rounds respectively) to develop a framework for digital twin adoption to enhance supply chain resilience. </p> <p><br></p> <p>This research determined that digital twin develops real-time monitoring and sensing capabilities, planning and decision support system, and automating decisions and action execution capabilities in supply chain. In addition, digital twin positively impacts resilience elements such as agility, supply chain reconfiguration, robustness, and collaboration in supply chain, which improves the supply chain performance. The results from this study were utilized to develop a framework for enabling supply chain resilience through digital twin. The framework included antecedents, consequences, and various moderators that impact digital twin adoption and diffusion in supply chains. Finally, this research developed a five-stage roadmap for adopting digital twin capabilities in supply chain. </p>
93

ZEEKR 00+

Tao, Lu January 2022 (has links)
Inspiration The project explores the possibility of using the car as a social communication space, providing an opportunity for users to make more new friends during their daily commute. With the popularization of mobile media, nowadays people are more and more like to communicate with people on social platforms, and virtual network social needs have been deeply rooted in people’s daily life, so how to use technology to help people walk out from this small screen is the initial motivation of the project.Everyone stays inside their vehicle and even if they are close, they rarely have the opportunity to communicate with people next to them. The car looks like a closed moving box where everyone hides inside. The project takes this as a starting point to consider how to break this status and provide users with an opportunity to express themselves and find friends on the daily commute. Therefore, the author believes that the car, as a personal mobile space, can also be turned into a social platform with the help of technology. Process During the design process, the author divides the whole project into two parts for thinking. On the one hand, the author has been thinking about how to provide a more interesting way of socializing in a limited space like a car, just like using social software, users can pay attention to the interesting people passing by and have the opportunity to have face-to-face communication. On the other hand, in the whole process, users can use a more abstract Avatar to show their characteristics or hobbies, as well as protect their privacy. The author combines these two core issues, and after the process of research, ideation, and sketch, the entire interior frame is determined on the 3D software, after which the final design is obtained. Result The final result is the ZEEKR 00+, a small two-seater electric car, which encourages users to actively express themselves on a daily car journey and make more friends in the real world. The core circular rotating structure of the cockpit can achieve the discovery, communication, and interaction process between users. With this as the core, the author also designed a series of related visual images, creating a new concept of the car as a personalized and social communication space in the future.1
94

Effektivisering av produktionsflöden inom livsmedelsbranschen : En studie om utmaningar &amp; möjligheter med digital tvilling / Streamlining Production Flows in the Food Industry : A study on challenges &amp; opportunities with Digital Twin

Larsson, Erik, Ringdahl, Anna January 2023 (has links)
En ökad effektivitet i de interna flödena är en viktig faktor för att bibehålla konkurrenskraft inom livsmedelsindustrin. Ny teknik som digitala tvillingar kan därför vara en möjlighet till att identifiera och åtgärda begränsande faktorer i produktflödet. Syftet med denna studie var att bidra till ökad förståelse för vilka möjligheter och utmaningar som kan uppstå vid tillämpningen av digital tvilling för att effektivisera flödesprocesser. För att samla in relevant empirisk data genomfördes två semistrukturerade intervjuer, en observation samt dokumentstudier.  Studiens resultat visar att den digitala tvillingen användes för datadrivna simuleringar med hjälp av realtidsdata som producerats av RFID-teknik. Simuleringarna gav möjligheten att förebygga fel som annars hade uppstått i flödet som därmed även sänkte både kostnader och tiden som krävdes vid flödesförändringen. Den digitala tvillingen i kombination med VR gav även möjlighet till visualisering av den digitala tvillingen och är en möjlighet till att engagera medarbetare i förändringar. Det fanns även potential att använda den digitala tvillingen tillsammans med VR för utbildning vilket kan leda till minskade kostnader och fel i det verkliga flödet. Utmaningar som identifierades i studien var att kostnaden för skapandet och underhållet av den digitala tvillingen och att den skapades i rätt tid i projektet för att kunna utnyttja dess potential maximalt. / Increased efficiency in internal flows is an important factor in maintaining competitiveness within the food industry. New technologies such as digital twins can therefore provide an opportunity to identify and address limiting factors in the product flow. The purpose of this study was to contribute to a better understanding of the opportunities and challenges that may arise form the application of digital twins to streamline flow processes. To collect relevant empirical data two semi-structured interviews, an observation and document studies were conducted. The results of the study show that the digital twin was used for data-driven simulations using real-time data produced by RFID technology. The simulations provided the opportunity to prevent errors that would otherwise have occurred in the flow, thus reducing both costs and the time required for flow changes. The digital twin, in combination with virtual reality (VR), also allowed for visualization of the digital twin and provided an opportunity to engage employees in the changes. There was also potential to use the digital twin together with VR for training, which could lead to reduced costs and errors in the actual flow. Challenges identified in the study included the cost of creating and maintaining the digital twin, as well as ensuring that it was created at the right time in the project to fully exploit its potential.
95

Sensor data computation in a heavy vehicle environment : An Edge computation approach

Vadivelu, Somasundaram January 2018 (has links)
In a heavy vehicle, internet connection is not reliable, primarily because the truck often travels to a remote location where network might not be available. The data generated from the sensors in a vehicle might not be sent to the internet when the connection is poor and hence it would be appropriate to store and do some basic computation on those data in the heavy vehicle itself and send it to the cloud when there is a good network connection. The process of doing computation near the place where data is generated is called Edge computing. Scania has its own Edge computation solution, which it uses for doing computations like preprocessing of sensor data, storing data etc. Scania’s solution is compared with a commercial edge computing platform called as AWS (Amazon Web Service’s) Greengrass. The comparison was in terms of Data efficiency, CPU load, and memory footprint. In the conclusion it is shown that Greengrass solution works better than the current Scania solution in terms of CPU load and memory footprint, while in data efficiency even though Scania solution is more efficient compared to Greengrass solution, it was shown that as the truck advances in terms of increasing data size the Greengrass solution might prove competitive to the Scania solution.One more topic that is explored in this thesis is Digital twin. Digital twin is the virtual form of any physical entity, it can be formed by obtaining real-time sensor values that are attached to the physical device. With the help of sensor values, a system with an approximate state of the device can be framed and which can then act as the digital twin. Digital twin can be considered as an important use case of edge computing. The digital twin is realized with the help of AWS Device shadow. / I ett tungt fordonsscenario är internetanslutningen inte tillförlitlig, främst eftersom lastbilen ofta reser på avlägsna platser nätverket kanske inte är tillgängligt. Data som genereras av sensorer kan inte skickas till internet när anslutningen är dålig och det är därför bra att ackumulera och göra en viss grundläggande beräkning av data i det tunga fordonet och skicka det till molnet när det finns en bra nätverksanslutning. Processen att göra beräkning nära den plats där data genereras kallas Edge computing. Scania har sin egen Edge Computing-lösning, som den använder för att göra beräkningar som förbehandling av sensordata, lagring av data etc. Jämförelsen skulle vara vad gäller data efficiency, CPU load och memory consumption. I slutsatsen visar det sig att Greengrass-lösningen fungerar bättre än den nuvarande Scania-lösningen när det gäller CPU-belastning och minnesfotavtryck, medan det i data-effektivitet trots att Scania-lösningen är effektivare jämfört med Greengrass-lösningen visades att när lastbilen går vidare i Villkor för att öka datastorleken kan Greengrass-lösningen vara konkurrenskraftig för Scania-lösningen. För att realisera Edge computing används en mjukvara som heter Amazon Web Service (AWS) Greengrass.Ett annat ämne som utforskas i denna avhandling är digital twin. Digital twin är den virtuella formen av någon fysisk enhet, den kan bildas genom att erhålla realtidssensorvärden som är anslutna till den fysiska enheten. Med hjälp av sensorns värden kan ett system med ungefärligt tillstånd av enheten inramas och som sedan kan fungera som digital twin. Digital twin kan betraktas som ett viktigt användningsfall vid kantkalkylering. Den digital twin realiseras med hjälp av AWS Device Shadow.
96

An Explorative Study of Interaction with Tracked Objects in a Virtual Reality Game

Golan, Jonathan January 2019 (has links)
In recent years, Internet enabled objects (Internet of Things) and their augmentation through virtual reality has become both technically possible and increasingly advanced. This paper explores how interaction between physical IoTs and their virtual and digital twins can be advanced. Three virtual reality games focusing on three different interactions were created. One game focused on rotating, another on pushing and pulling, and a third on lifting and dropping. All games revolved around the use of real tracked cardboard boxes which were represented in the games by a virtual box in the same relative position and rotation to the player, allowing participants to manipulate the virtual boxes by manipulating the physical boxes. 14 participants were asked to play the games and were afterwards interviewed in regards to the games, their interactions with them, their enjoyability and their thoughts regarding them and the concept in general. The results were acquired from game performance, the reflections of the participants, and the subsequent analysis of recorded audio and video. The study presents the difficulties, challenges and opportunities of such a system, while also providing insight into lessons learned from the creation of the system and the games. The main contributions of the paper are the lessons learned in creating the games and experiences in addition to a few specific areas of interest for future research on the area, namely the importance of ergonomic consideration and affordance evaluation. / De senaste åren har föremål kopplade till Internet (Internet of Things eller Sakernas Internet) och deras augmentering genom virtuell verklighet både blivit möjligt och mer tekniskt avancerat. Denna rapport utforskar hur interaktioner mellan fysiska IoT föremål och deras virtuella och digitala tvillingar kan förbättras. Tre VR-spel med fokus på tre olika interaktioner utvecklades. Ett av spelen fokuserade på rotation, ett annat på rörelsen fram och tillbaka, och det tredje på rörelsen upp och ner. Alla spel involverade användandet av riktiga kartonglådor som representerades i spelet av en virtuell låda i samma position och rotation i relation till spelaren, vilket lät spelaren manipulera de virtuella lådorna genom att manipulera de fysiska lådorna. 14 deltagare ombads spela spelen och intervjuades i efterhand angående spelen, interaktionerna, underhållningsvärdet och deras tankar kring konceptet. Resultaten kom från deltagarnas prestationer i spelen, deras reflektioner och efterföljande analys av inspelad audio och video. Studien presenterar svårigheter, utmaningar och möjligheter hos det beskrivna systemet och delar med sig av insikter från skapandeprocessen av systemet och spelen. Studiens huvudsakliga bidrag är de nämnda insikterna från skapandeprocessen samt ett par specifika intresseområden för framtida forskning: vikten av hänsyn till ergonomi och utvärdering av affordans.
97

Lifecycle management and smart manufacturing: Modelling and implementation to utilize the digital twin

Huang, Chengxue, Wranér, Hampus January 2018 (has links)
Smart manufacturing – smart factories creating smart products – is a topic which has arisen in the academic as well as business community. This thesis covers smart manufacturing in the context of lifecycle management. The thesis investigated how the standard Product Life Cycle Support (PLCS) could be used to support smart manufacturing and mainly how to develop the underlying system and information infrastructure. Standards, reports and specifications for smart manufacturing were investigated. Several information models were created from these publications which could be used for implementing a proposed solution for the infrastructure.The implementation concerned a use case in the ongoing research project DigIn, and used the developed models to implement a proposed solution in the product lifecycle management software ShareAspace. This was done in order to evaluate how to use the functionality of PLCS and ShareAspace to utilize the solution to support smart manufacturing and update the digital twin. In parallel to this thesis, a sub-project part of the DigIn project was conducted which connected the database to other software in the system as well as to the factory shop floor. The solution used the plant service bus Kafka and REST APIs in order to establish the connection. The functionality of the system regarding the specified required functionality in the publications was then investigated.The solution was found to meet most of the requirements of the publications regarding, among others, lifecycle management, service oriented architecture, non-hierarchical structures and communication capabilities. / Smart tillverkning – smarta fabriker som skapar smarta produkter – är ett ämne som inom det akademiska och affärsmässiga området förekommer alltmer frekvent. Denna uppsats behandlar smart tillverkning i kontexten av Product Life Cycle Support (PLCS). Uppsatsen undersökte hur PLCS kunde utnyttjas för att möjliggöra smart tillverkning, med huvudsakligt fokus på möjliggörandet av den bakomliggande system- och informationsinfrastrukturen för smart tillverkning. Standarder, rapporter och specifikationer för smart tillverkning undersöktes. Flertalet informationsmodeller skapades utifrån dessa publikationer vilka kunde användas för att implementera ett förslag för infrastrukturen.Implementationen hade sin bas i det pågående forskningsprojektet DigIn, och använde de utvecklade modellerna för att implementera en föreslagen lösning i produktlivscykel-mjukvaran ShareAspace. Detta gjordes för att utvärdera hur funktionaliteten i ShareAspace och PLCS skulle kunna användas för att stödja smart tillverkning och uppdatera den digitala tvillingen. Parallellt med denna implementation genomfördes i DigIn ett projekt vilka kopplade samman databasen med annan mjukvara i systemet samt fabriksgolvet. Lösningen använde en Plant Service Bus (Kafka) och REST APIer för att koppla samman dessa. Funktionaliteten av systemet rörande specificerade krav som återfanns i publikationerna undersöktes sedan.Lösningen fanns möta de flesta av de krav som lades fram i de undersökta publikationerna rörande, bland annat, livscykelshantering, tjänsteorienterad arkitektur, icke-hierarkiska strukturer samt kommunikationsmöjligheter.
98

Model-Integrated Engineering of Smart Energy Distribution Systems

Galkin, Nikolai January 2023 (has links)
Model-Based Systems Engineering (MBSE) is a formal method that is used to support analysis, design, independent verification, and validation inherent in the development of software and hardware systems. MBSE applications are present in many areas of our daily lives, including manufacturing, robotics, healthcare, automation, etc. However, despite their rapid and sustainable growth during the last few years, the MBSE methods themselves are quite far away from perfect. There are some current problems, which resist more rapid penetration of MBSE systems in their development. One of them is that currently the majority of MBSE systems are vendor dependent and, as a result, they have poor compatibility with each other. Furthermore, currently, there is a gap between the design of a digital model and a control model of an engineering system. Currently, this problem is usually solved by involving two or more groups of engineers, where each of these groups works on their own problems. All this costs companies additional engineering time and, as a result, development costs. Therefore new, and more sophisticated approaches for the generation of MBSEs are needed in order to overwhelm the challenges highlighted above. In order to narrow the field of study and better concentrate on specific problems, smart power distribution systems have been chosen as the main research object for this dissertation. Thus, in this work, the author introduces Model-Integrated Systems Engineering (MISE), as the MBSE sub-discipline. Here and later in this paper, the author will refer to MISE as the main area of interest. Also, the author uses the term DigitalTwin to refer to the multilayered structure of a complex distributed automation system consisting of three layers, namely:– the static machine-readable information about the infrastructure of the smart energy system,– the simulation model layer,– the distributed control layer for the investigated smart energy system. In general, two new transformation approaches for automatic MISE generation are discussed in the scope of this dissertation, namely:1. Transformation of the System Configuration Design (SCD) files of an electric system(presented in IEC 61850) into the corresponding SIMULINK model.2. Transformation of specification files of electronic components into corresponding OPC UA information model.All discussed approaches are implemented in the form of a program code that is publicly available on the Internet. The IEC 61850 and OPC UA standards are considered key components of the current dissertation. IEC 61850 is an international standard covering different sides of smart energy distribution systems including communication protocols for diverse equipment in a substation, including protection, control, and measurement equipment, as well as intelligent electronic devices (IEDs). Information Modeling OPC UA is a platform-independent service-oriented architecture that combines the concepts of semantic modeling. First, the structure of the IEC 61850 standard is discussed, as well as its potential benefits for the MISE of smart power distribution systems in terms of the automatic transformation of the information model. Next, the architecture of the electrical system (the SCD file) of the electrical vehicle (EV) charging station (CS) is proposed as an example. The aim is to design a mechanism for the automatic transformation of MISE in two domains, namely:- Physical model of the electrical system itself,- Automatically build a communication channel between the digital replica (the model) of the electrical system and the virtual energy management system (EMS). Thus, this work aims to contribute to the design and virtual commissioning of Digital Twin systems, as well as to improve the interoperability between IEC 61850 compliant systems and electric vehicle charging stations (paper C explains that in more detail). Finally, by narrowing down the scope of the investigation to one specific electrical device, a new approach for converting integrated circuit (IC) specification files of an electric system into an OPC UA information model is discussed. The designed transformation algorithm is based on the directed graphs theory (paper D explains that in more detail). The purpose of this work is to highlight and contribute to the problems of the MISE analysis solutions.  In summary, the work presented in this dissertation raises questions about interoperability between different standards, the problems of converting the IEC 61850 information model into MISE, verification of the generated MISE compared to the original IEC 61850 information model, and the problems of forming an information model OPC UA.
99

EVALUATING CRYSTAL FRAMEWORK IN PRACTICE

Mertala, Victor, Christopher, Nordin January 2024 (has links)
Cyber-physical systems (CPSs) are used in several industries, such as healthcare, automotive, manufacturing, and more. The fact that CPSs often contain components integrated via communication networks means that malicious actors can exploit vulnerabilities in these components through cyber attacks. CRYSTAL Framework has been shown in previous research to be able to detect cyber attacks on CPSs. However, this has only been proven in simulation. Our research builds upon these previous research as we aim to prove that CRYSTAL Framework is a viable method for monitoring real systems to detect abnormal behaviours.  The Tiny Twin is an abstract behavioral model that defines normal running behaviour of a system, which can then be used by to compare the current state of a monitored system to detect possible attacks and abnormal behaviours. We built a monitor that integrates such a Tiny Twin, working by passively listening on input and output of components in a monitored system. We designed and implemented two different scenarios, a security alarm system and a temperature control system (TCS), to test the CRYSTAL Framework. In testing both implemented scenarios our monitor successfully detected all but one attacks during runtime by comparing the system's current state with the expected state as defined in the Tiny Twin.
100

Real Time Monitoring of Machining Process and Data Gathering for Digital Twin Optimization

Rajendran, Ajith, Asokan, Gautham January 2021 (has links)
In the development stages of a Digital twin of production assets, especially machine tools, real time process monitoring and data gathering proves to be vital. Having a monitoring system that monitors and updates the operators or managers in real time, helps improve productivity in terms of reducing downtime through predictive/preventive analytics and by incorporating in process quality assessment capabilities. When it comes to Real time monitoring of machine tools andprocesses, sensor technologies have proven to be the most effective and widely researched. Years of research and development have paved the way for many smart sensor technologies that come both in built with the machine tools as well as external applications. However, these technologies prove to be expensive and complicated to implement especially for Small and Medium Enterprises. This thesis focuses on evaluating and testing a simple, cost-efficient monitoring system using inexpensive sensor technologies that would help optimize an existing Digital twin setup for machine tools for Small and Medium Enterprises. Experiments with a 5 axis CNC machine tool using different tools and varying operating parameters, materials were performed,and the relevant sensor data were collected, mapped, analysed for accuracy and benchmarking. The thesis also evaluates the integration of this data with the information already collected from other sources, improve existing data reliability, and provides guidelines on this could be transformed usefully to create more value to SME’s.

Page generated in 0.0225 seconds