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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.
41

Použití rozšířené reality při tréninku a provádění údržby letadel / Augmented Reality for Training and Execution of Airplane Maintenance

Košík, Michal January 2013 (has links)
This thesis deals wtih augmented reality applied to aircraft maintenance which is widely explored here. Furthermore, a reseach is done on the previous work done in this field. A video data-set is acquired from LET - a manufacturer of LET L-410 aircraft and an application is created in order to test possibilities of using augmented reality in aircraft maintenance. The result and proposals of the future work can be found in this thesis as well
42

Mixed Reality Displays in Warehouse Management : A study revealing new possibilities for Warehouse Management and Tangar / ”Mixed Reality”-skärmar inom lagerarbete : En studie som åskådliggör nya möjligheter för lagerarbete och Tangar

Karlsson, Adam January 2019 (has links)
This work has investigated how head-mounted-displays can enable more efficient and better work conditions for warehouse workers. Head-mounted-displays have increased in popularity among companies because of an increase in the field of e-commerce, therefore warehouse labour was an interesting area to review. The purpose of this project has been to investigate how head-mounted-displays can simplify warehouse work and to find an area where Tangar can be utilized. Tangar is an application to facilitate indoor navigation by helping users to reach points of interest. Through a mixed methodology approach that utilizes both quantitative and qualitative methods, a broad understanding in warehouse and inventory management have been established. The potentials of head-mounted display were evaluated using empirical and theoretical studies. Based on an early concept that was evaluated by a collaboration with a warehouse-solution company, factors that are of importance in warehouse management were identified. A decision to direct the project towards order picking was taken as it is a fundamental process within warehouse management. Three concepts were generated that harness the benefits of head-mounted-displays. With an informed decision the benefits for each of the concepts were compared with important parameters for a profitable warehouse management. It turned out that "Pick-by-Light", a common system in warehouse management, can be made virtual using head-mounted-displays. Since the system had never previously been operated virtually, an extensive study needed to be done in order to evaluate the viability in order-picking to propose a final concept. An experimental environment was set for the empirical studies, and two other common order picking systems were compared to the virtual Pick-by-Light system. Quantitative data in the form of time measurements from the order picking as well as picking errors and qualitative data from a NASA-TLX survey, was extracted from twelve users. A total of 360 samples from the quantitative study and 36 questionnaires from the qualitative study was then analysed. The result resembled those from similar studies with a conventional Pick-by-Light system. Thus, parallels were drawn that indicated that the virtual system had good potential to perform at least as well as a regular Pick-by-Light. A virtual Pick-by-Light system might be able to reduce implementation-, work- and operational costs as the use of material is replaced by a virtual product, and also no installation is required. With the combination of Tangar, there is also a potential that a virtual Pick-by-Light system could be more efficient and accurate. The disadvantages of the conventional Pick-by-Light system are also that confirmations are ineffective and that workers find it difficult to get an overview of pickplaces. Which can potentially be eliminated with the proposed concept. However, a new generation of hardware and further studies are required in order to establish a final concept. The Magic Leap One, which is the head-mounted-display used in the project, is new. Many problems regarding the display have been discovered during the project and affected the results of the user studies. Further studies need to be done with other displays to determine the validity of the results of this work. In summary, this work gives an introduction in how "Mixed-reality" can be used in warehouse management and recommendations for continued work. / Det här arbetet har undersökt hur huvudmonterade skärmar kan möjliggöra ett effektivare och bättre arbete för lager-personal. Huvudmonterade skärmar har ökat i popularitet bland företaget på grund av ökningen inom e-handel och därför var lagerarbete ett intressant område att undersöka. Syftet med det här projektet har varit att undersöka hur huvudmonterade skärmar fortsatt skulle kunna förenkla lagerarbete samt att ta hitta ett område där Tangar kan användas. Tangar är en applikation som förenklar inomhus navigering genom att leda användaren till valda intressepunkter. Genom en metodisk undersökning som utnyttjar både kvantitativa och kvalitativa metoder, har en bred bakgrund inom lagerhantering kunnat upprättas. Potentialen av att använda huvudmonterade skärmar har undersökts genom empiriska och teoretiska studier. Baserat på ett tidigt koncept som utvärderas genom ett samarbete med ett sakkunnigt företag, identifierades flertalet faktorer som är av vikt i lagerhantering. Ett beslut om att rikta projektet mot order-plockning togs då det är en fundamental process inom lagerabete. Tre koncept genererades som utnyttjar fördelarna med huvudmonterade skärmar. Genom att ta ett informativt beslut, kunde fördelarna för var och ett av koncepten jämföras med viktiga parametrar för ett lönsamt lagerarbete. Det visade sig att ”Pick-by-Light”, ett vanligt system inom lagerhantering, kunde göras virtuellt med hjälp av huvudmonterade skärmar. I och med att systemet tidigare aldrig utförts virtuellt, behövdes en omfattande studie göras för att evaluera dess potential inom order-plockning för att kunna föreslå ett slutgiltigt koncept. En experimentell miljö sattes upp som ram för de empiriska studierna och två andra vanliga order-plocknings system kunde jämföras mot det virtuella Pick-by-Light systemet. Kvantitativa data i form av orderplockningstider samt plock-fel och kvalitativa data från observationer samt en NASA-TLX enkät, kunde extraheras från tolv användare. Totalt kunde 360 stickprov från den kvantitative studien och 36 enkäter från den kvalitative studien därefter analyseras. Resultatet liknade det som observerats i liknande studier där ett vanligt Pick-by-Light system evaluerats. Därmed kunde paralleller dras som visade att det virtuella systemet hade god potential till att kunna prestera åtminstone lika bra som ett vanliga Pick-by-Light systemet och ett koncept togs fram för vidare utveckling. Ett virtuellt Pick-by-Light system skulle kunna reducera implementerings-, arbetes- samt driftkostnader i och med att materialåtgången ersätts av en virtuell produkt, samt att ingen installation krävs. I och med kombinationen av Tangar finns det även potential att konceptet är mer effektivt och exakt. De nackdelar med det traditionella Pick-by-Light systemet är också att plock-bekräftelser görs ineffektivt och att arbetare har svårt att få en överblick gällande plockställen. Vilket skulle kunna elimineras med det föreslagna konceptet. Dock krävs en ny generation hårdvara och vidare studier för att kunna fastställa ett slutgiltigt koncept. Magic Leap One, som är den huvudmonterade skärmen som används i projektet är väldigt ny. Många problem gällande displayen har upptäckts under projektet och påverkat resultatet av användarstudierna. Fortsatta studier skulle behöva göras med andra displayer för att fastställa validiteten av resultaten från det här arbetet. Sammanfattningsvis ger det här arbetet en introduktion om hur ”Mixed-reality” kan användas inom lagerhantering samt rekommendationer till fortsatt arbete.
43

Convergence in mixed reality-virtuality environments : facilitating natural user behavior

Johansson, Daniel January 2012 (has links)
This thesis addresses the subject of converging real and virtual environments to a combined entity that can facilitate physiologically complying interfaces for the purpose of training. Based on the mobility and physiological demands of dismounted soldiers, the base assumption is that greater immersion means better learning and potentially higher training transfer. As the user can interface with the system in a natural way, more focus and energy can be used for training rather than for control itself. Identified requirements on a simulator relating to physical and psychological user aspects are support for unobtrusive and wireless use, high field of view, high performance tracking, use of authentic tools, ability to see other trainees, unrestricted movement and physical feedback. Using only commercially available systems would be prohibitively expensive whilst not providing a solution that would be fully optimized for the target group for this simulator. For this reason, most of the systems that compose the simulator are custom made to facilitate physiological human aspects as well as to bring down costs. With the use of chroma keying, a cylindrical simulator room and parallax corrected high field of view video see-though head mounted displays, the real and virtual reality are mixed. This facilitates use of real tool as well as layering and manipulation of real and virtual objects. Furthermore, a novel omnidirectional floor and thereto interface scheme is developed to allow limitless physical walking to be used for virtual translation. A physically confined real space is thereby transformed into an infinite converged environment. The omnidirectional floor regulation algorithm can also provide physical feedback through adjustment of the velocity in order to synchronize virtual obstacles with the surrounding simulator walls. As an alternative simulator target use, an omnidirectional robotic platform has been developed that can match the user movements. This can be utilized to increase situation awareness in telepresence applications.
44

Use of head mounted virtual reality displays in flight training simulation / VR-glasögons användbarhet för pilotträningssimulering

Gustafsson, Anders January 2018 (has links)
The purpose of this thesis was to evaluate currently commercially available head mounted virtual reality displays for potential use in pilot training simulators. For this purpose acommercial simulator was modified to display the virtual environment in an Oculus RiftDK2 headset. A typical monitor based setup was used to provide a set of hardware requirements which the VR implementation had to meet or exceed to be considered potentially usable for pilot training simulators. User tests were then performed with a group of users representative of those normally using pilot training simulators, including both pilots and engineers working with simulator development. The main focus of the user tests was to evaluate some potential weaknesses found in the technical comparison (such as when a measured parameter was close to the lower limit defined by the monitor based setup) and to make a measurement of the usability of the VR implementation. The results from the technical comparison showed that the technical requirements were met and in most cases also exceeded. There were however some potential weaknesses revealed during the user tests, which included screen resolution and the field of view. There was one main critical deficiency found during the user tests. This was the lack of interaction with the aircraft as users were only able to interact with the flight stick and throttle lever. While this enabled the users to control many aspects of the aircraft (by using buttons and other controls fitted on the flight stick/throttle) in a training scenario a user also has to be able to interact with other switches and/or monitors in the cockpit. This was however a known limitation of the implementation and thus didn’t affect the tested parts of the simulator. The user tests also confirmed that the resolution was a potential problem, but that the overall usability was high. Thus the VR implementation had potential for use in a pilot training simulator, if the critical issues found during the user tests were solved.
45

Design and Development of a Lubrication Pump for a Horizontally Mounted Air-Conditioning Compressor.

Gilbert, Kenneth T. 01 December 2003 (has links)
Horizontally mounted compressors offer the advantage of reduced height in central air-conditioning units but prove difficult to produce economically due to costs associated with the manufacture of acceptable lubrication systems for the compressors. This study develops an effective, affordable oil pump for use on a horizontal compressor. Concepts are proven through testing of prototype assemblies. Test results drive modifications for future prototypes, and prototypes demonstrating adequate performance are modified for ease of manufacture. Research in this study proves that the most suitable design results from a modification of a rotating vane pump. The pump’s modifications enable it to pump oil in the same direction, regardless of the direction of shaft rotation and to prime itself when totally dry of oil. However, extensive use of horizontal compressors hinges upon the development of a satisfactory suspension system.
46

An Analysis of Enabling Techniques for Highly-Accessible Low-Cost Virtual Reality Hardware in the Collaborative Engineering Design Process

Coburn, Joshua Q. 01 June 2017 (has links)
While there currently exists a great deal of research in the literature demonstrating various engineering applications for virtual reality (VR) and the benefits of these applications, VR adoption has been slow in part because of the high cost and resources required to setup and maintain the hardware for these applications. However, in the last 5 years, a new generation of VR hardware has emerged with cost and resource requirements which are a small fraction of previous hardware. This work begins with a survey of this newly available hardware summarizing recent advances for providing virtual input to all of the five human senses. The literature review then proceeds to highlight previous research into improving various aspects of the Engineering Design Process by using VR applications. The literature review concludes that given the significantly improved cost to benefit ratio of this new hardware, a tipping point has been reached where companies will see benefits from providing their engineering workforce with general access to VR hardware. From the conclusions drawn in the literature review, this work proceeds to explore and answer two main questions related to connecting and collaborating via this new VR hardware. The first question seeks to understand the trade-offs between cybersickness and disorientation from different styles of moving users in a collaborative VR environment (CVE). Since a CVE can be much larger than the physical world it is sometimes necessary to move the virtual participant which can cause cybersickness and disorientation. Understanding this trade-off is one key to creating a usable CVE. It is found that many users are willing to experience some mild cybersickness to significantly reduce the amount of disorientation experienced in a CVE. However, a second group of users are not willing to make this trade and hence require the ability to customize the CVE for their preferred trade-off between cybersickness and disorientation. The second question seeks to understand how a CVE with support for natural gestures can improve communication about complex 3D data over video conferencing which is the current standard for remote collaboration. It is found that such a CVE implemented with the latest low-cost consumer-grade VR hardware can improve communication speed up to 45% while also improving the accuracy of the communication. In addition, it was found that gestures in the CVE were much more effective and natural than mouse gestures in Skype, 93% of participants preferred the CVE over current video conferencing software, and 86% of participants stated they would like to have access to VR tools in their workplace.
47

An Analysis of Enabling Techniques for Highly-Accessible Low-Cost Virtual Reality Hardware in the Collaborative Engineering Design Process

Coburn, Joshua Q. 01 June 2017 (has links)
While there currently exists a great deal of research in the literature demonstrating various engineering applications for virtual reality (VR) and the benefits of these applications, VR adoption has been slow in part because of the high cost and resources required to setup and maintain the hardware for these applications. However, in the last 5 years, a new generation of VR hardware has emerged with cost and resource requirements which are a small fraction of previous hardware. This work begins with a survey of this newly available hardware summarizing recent advances for providing virtual input to all of the five human senses. The literature review then proceeds to highlight previous research into improving various aspects of the Engineering Design Process by using VR applications. The literature review concludes that given the significantly improved cost to benefit ratio of this new hardware, a tipping point has been reached where companies will see benefits from providing their engineering workforce with general access to VR hardware. From the conclusions drawn in the literature review, this work proceeds to explore and answer two main questions related to connecting and collaborating via this new VR hardware. The first question seeks to understand the trade-offs between cybersickness and disorientation from different styles of moving users in a collaborative VR environment (CVE). Since a CVE can be much larger than the physical world it is sometimes necessary to move the virtual participant which can cause cybersickness and disorientation. Understanding this trade-off is one key to creating a usable CVE. It is found that many users are willing to experience some mild cybersickness to significantly reduce the amount of disorientation experienced in a CVE. However, a second group of users are not willing to make this trade and hence require the ability to customize the CVE for their preferred trade-off between cybersickness and disorientation. The second question seeks to understand how a CVE with support for natural gestures can improve communication about complex 3D data over video conferencing which is the current standard for remote collaboration. It is found that such a CVE implemented with the latest low-cost consumer-grade VR hardware can improve communication speed up to 45% while also improving the accuracy of the communication. In addition, it was found that gestures in the CVE were much more effective and natural than mouse gestures in Skype, 93% of participants preferred the CVE over current video conferencing software, and 86% of participants stated they would like to have access to VR tools in their workplace.
48

A comparison of linear and nonlinear ECG-based methods to assess pilot workload in a live-flight tactical setting

Reichlen, Christopher Patrick 01 May 2018 (has links)
This research compares methods for measuring pilot mental workload (MWL) from the electrocardiogram (ECG) signal. ECG-based metrics have been used extensively in MWL research. Heart rate (HR) and heart-rate variability (HRV) exhibit changes in response to varying levels of task demand. Classical methods for HRV analysis examine the ECG signal in the linear time and frequency domains. More contemporary research has advanced the notion that nonlinear elements contribute to cardiac control and ECG signal generation, spawning development of analytical techniques borrowed from the domain of nonlinear dynamics (NLD). Applications of nonlinear HRV analysis are substantial in clinical diagnosis settings; however, such applications are less frequent in MWL research, especially in the aviation domain. Specifically, the relative utility of linear and non-linear HRV analysis methods has not been fully assessed in pilot MWL research. This thesis contributes to aforementioned research gap by comparing a non-linear HRV method, utilizing transition probability variances (TPV), to classical time and frequency domain methods, focusing the analysis on sensitivity and diagnosticity. ECG data is harvested from a recent study characterizing spatial disorientation (SDO) risk amongst three candidate off-boresight (OBS) helmet-mounted display (HMD) symbologies in a tactically relevant live-flight task. A comparative analysis of methods on this dataset and supplemental workload analysis for the HMD study are presented. Results indicate the TPV method may exhibit higher sensitivity and diagnosticity than classical methods. However, limitations of this analysis warrant further investigation into this question.
49

The Social World Through Infants’ Eyes : How Infants Look at Different Social Figures

Schmitow, Clara A. January 2012 (has links)
This thesis aims to study how infants actively look at different social figures: parents and strangers. To study infants’ looking behavior in “live” situations, new methods to record looking behavior were tested. Study 1 developed a method to record looking behavior in “live” situations: a head-mounted camera. This method was calibrated for a number of angles and then used to measure how infants look at faces and objects in two “live” situations, a conversation and a joint action. High reliability was found for the head-mounted camera in horizontal positions and the possibility of using it in a number of “live” situations with infants from 6 to 14 months of age. In Study 2, the head-mounted camera and a static camera and were used in a “live” ambiguous situation to study infants’ preferences to refer to and to use the information from parents and strangers. The results from Experiment 1 of Study 2 showed that if no information is provided in ambiguous situations in the lab, infants at 10 months of age look more at the experimenter than at the parent. Further, Experiment 2 of Study 2 showed that the infants also used more of the emotional information provided by the experimenter than by the parent to regulate their behavior.  In Study 3, looking behavior was analyzed in detail when infants looked at pictures of their parents’ and strangers’ emotional facial expressions. Corneal eye tracking was used to record looking. In this study, the influence of identity, gender, emotional expressions and parental leave on looking behavior was analyzed. The results indicated that identity and experience of looking at others influences how infants discriminate emotions in pictures of facial expressions. Fourteen-month-old infants who had been with both parents in parental leave discriminated more emotional expressions in strangers than infants who only had one parent on leave. Further, they reacted with larger pupil dilation toward the parent who was actually in parental leave than to the parent not on leave. Finally, fearful emotional expressions were more broadly scanned than neutral or happy facial expressions. The results of these studies indicate that infants discriminate between mothers’, fathers’ and strangers’ emotional facial expressions and use the other people’s expressions to regulate their behavior. In addition, a new method, a head-mounted camera was shown to capture infants’ looking behavior in “live” situations.
50

Generation of Training Data by Degradation Models for Traffic Sign Symbol Recognition

MURASE, Hiroshi, MEKADA, Yoshito, IDE, Ichiro, TAKAHASHI, Tomokazu, ISHIDA, Hiroyuki 01 August 2007 (has links)
No description available.

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