Calibration Methods of Characterization Lens for Head Mounted Displays

This thesis concerns the calibration, characterization and utilization of the HMD Eye, OptoFidelity’s eye-mimicking optical camera system designed for the HMD IQ, a complete test station for near eye displays which are implemented in virtual and augmented reality systems. Its optical architecture provides a 120 degree field of view with high imaging performance and linear radial distortion, ideal for analysis of all possible object fields. HMD Eye has an external, mechanical entrance pupil that is of the same size as the human entrance pupil. Spatial frequency response (the modulation transfer function) has been used to develop sensor focus calibration methods and automation system plans. Geometrical distortion and its relation to the angular mapping function and imaging quality of the system are also considered. The nature of the user interface for human eyes, called the eyebox, and the optical properties of head mounted displays are reviewed. Head mounted displays consist usually of two near eye displays amongst other components, such as position tracking units. The HMD Eye enables looking inside the device from the eyebox and collecting optical signals (i.e. the virtual image) from the complete field of view of the device under test with a single image. The HMD Eye under inspection in this thesis is one of the ’zero’ batch, i.e. a test unit. The outcome of the calibration was that the HMD Eye unit in this thesis is focused to 1.6 m with an approximate error margin of ±10 cm. The drop of contrast reaches 50% approximately at angular frequency of 11 cycles/degree which is about 40% of the simulated values, prompting improvements in the mechanical design. Geometrical distortion results show that radial distortion is very linear (maximum error of 1%) and that tangential distortion has a diminishable effect (0.04 degrees of azimuth deviation at most) within the measurement region

物理/バーチャル空間の接続と分離を媒介する可動壁に関する研究

Tohoku University博士（情報科学）thesi

Human factors in instructional augmented reality for intravehicular spaceflight activities and How gravity influences the setup of interfaces operated by direct object selection

In human spaceflight, advanced user interfaces are becoming an interesting mean to facilitate human-machine interaction, enhancing and guaranteeing the sequences of intravehicular space operations. The efforts made to ease such operations have shown strong interests in novel human-computer interaction like Augmented Reality (AR). The work presented in this thesis is directed towards a user-driven design for AR-assisted space operations, iteratively solving issues arisen from the problem space, which also includes the consideration of the effect of altered gravity on handling such interfaces.Auch in der bemannten Raumfahrt steigt das Interesse an neuartigen Benutzerschnittstellen, um nicht nur die Mensch-Maschine-Interaktion effektiver zu gestalten, sondern auch um einen korrekten Arbeitsablauf sicherzustellen. In der Vergangenheit wurden wiederholt Anstrengungen unternommen, Innenbordarbeiten mit Hilfe von Augmented Reality (AR) zu erleichtern. Diese Arbeit konzentriert sich auf einen nutzerorientierten AR-Ansatz, welcher zum Ziel hat, die Probleme schrittweise in einem iterativen Designprozess zu lösen. Dies erfordert auch die Berücksichtigung veränderter Schwerkraftbedingungen

Research, design and investigation of a multiple user mixed reality system.

Masters Degree. University of KwaZulu- Natal, Durban.Current forms of virtual technology are limited by their single-user capability per device. Additionally, these technologies are listed at expensive price ranges due to the robust technology and processing power required for operations. These were identified as research challenges when a review of virtual technologies was undertaken. Research indicated the need for a system that allowed simultaneous user viewing and interaction without requiring robust hardware or system software. This dissertation researched, designed and investigated a Mixed Reality (MR) System that allows multiple user viewing and interaction with mid-air images. Beam splitter theory was used to deliver the mid-air images on this system. Multiple user viewing was achieved through beam splitter selection of an ASKA3D Plate and the design of a novel system architecture that adjusted system components. A mechatronic actuation system was developed to automate the adjustment of system components that allowed seated and standing viewing within three height ranges. System operation and interaction were allowed through inputs on a laptop. Additionally, the implementation of gesture control was investigated using a web camera or a CaptoGlove™. The testing performed on the manufactured MR System validated the design, actuation methods, viewing method and performance of the system. The laptop’s Operating System (OS) was used to develop an MR game for entertainment testing, display images and videos for visual learning testing and operate SolidWorks™ for engineering design testing. The results of accuracy testing showed that the actuation methods had an accuracy range within the required 45-degree rotations with a highest possible error of 3° and the required vertical movements of 50 mm and 100 mm with a highest possible error of 0.5 mm. The results of repeatability testing showed the actuation methods had coefficients of variance with values less than 0.1, signifying a high repeatability. System performance was evaluated through user testing and proved the system as a tool to facilitate entertainment, education through visual learning and engineering design. Visual learning was found to be the most successful on the MR System with an average percentage rating of 100% and the overall system performance was given a rating of 80%. Actuation testing and user testing validated the hardware design, software design, electronic design and viewing method of the system. The MR System operated as intended showing successful multiple user viewing without requiring robust hardware or software for system operation. The system was limited by the defined interaction method, the lack of multiple user testing and the limited programs used for testing the system’s performance

Imaging near-field compton backscattered X-rays using Pinhole and coded masks

Research was conducted to understand the behaviour of an X-ray backscatter imaging system using coded masks to view complex scenes. These spatially multiplexing images were compared to those collected using a single pinhole and a commercial flying spot (time multiplexing) imaging system. An X-ray backscatter system was constructed to perform experiments with pinholes and coded masks. A novel fabrication technique adopting 3D printing was developed to rapidly create low-cost alternatives to the traditional drilled tungsten coded masks. Subsequently, this allowed for the retention of ideal square open elements within the mask, along with the benefit of having a self-supporting structure. Conventional methods of manufacturing coded masks compromise the encoding process by using round holes in place of the square elements to achieve a self-supporting structure. Previous work has suggested that coded masks with a low open fraction (i.e. < 0.5) will yield a higher signal-to-noise ratio than those with a 0.5 open fraction. As part of this study, the following low open fraction coded mask was calculated; dilute uniformly redundant array (DURA), Singer and the biquadratic residue (BR). In total 111 new array patterns were calculated. Xray backscatter images are presented from examples of these coded masks with images reconstructed via cross-correlation and blind deconvolution. Overall, for coded mask imaging, the best results were from the 19 MURA for its signalto-noise with a typical 2-12 second (s) exposure time. Consequently, there was little evidence to support the benefit of lower open fractions. Pinhole and coded mask images were somewhat comparable with the pinhole requiring a longer exposure time of 60-300 s. While not ideal due to barrel distortion, the images from the flying spot system exhibited higher signal-to-noise ratios and resolutions but required an exposure time of 70 seconds, longer than those for the MUR

The role of phonology in visual word recognition: evidence from Chinese

Posters - Letter/Word Processing V: abstract no. 5024The hypothesis of bidirectional coupling of orthography and phonology predicts that phonology plays a role in visual word recognition, as observed in the effects of feedforward and feedback spelling to sound consistency on lexical decision. However, because orthography and phonology are closely related in alphabetic languages (homophones in alphabetic languages are usually orthographically similar), it is difficult to exclude an influence of orthography on phonological effects in visual word recognition. Chinese languages contain many written homophones that are orthographically dissimilar, allowing a test of the claim that phonological effects can be independent of orthographic similarity. We report a study of visual word recognition in Chinese based on a mega-analysis of lexical decision performance with 500 characters. The results from multiple regression analyses, after controlling for orthographic frequency, stroke number, and radical frequency, showed main effects of feedforward and feedback consistency, as well as interactions between these variables and phonological frequency and number of homophones. Implications of these results for resonance models of visual word recognition are discussed.postprin

Interactive effects of orthography and semantics in Chinese picture naming

Posters - Language Production/Writing: abstract no. 4035Picture-naming performance in English and Dutch is enhanced by presentation of a word that is similar in form to the picture name. However, it is unclear whether facilitation has an orthographic or a phonological locus. We investigated the loci of the facilitation effect in Cantonese Chinese speakers by manipulating—at three SOAs (2100, 0, and 1100 msec)—semantic, orthographic, and phonological similarity. We identified an effect of orthographic facilitation that was independent of and larger than phonological facilitation across all SOAs. Semantic interference was also found at SOAs of 2100 and 0 msec. Critically, an interaction of semantics and orthography was observed at an SOA of 1100 msec. This interaction suggests that independent effects of orthographic facilitation on picture naming are located either at the level of semantic processing or at the lemma level and are not due to the activation of picture name segments at the level of phonological retrieval.postprin

Singing in Life's Twilight: Serious Karaoke as Everyday Aging Practice in Urban Japan

Being an avid karaoke singer, I was intrigued to come across what are known in Japan as karaoke classrooms and kissas (a bar/café hybrid), during my periods of fieldwork in Tokyo and Osaka in 2013 and 2016. In my visits to these places, I watched (and participated in) how regulars at these karaoke venues, mostly working-class men and women between 60 to 80 years old, sang over the microphone, and chatted and laughed with each other over drinks. Their vivacity and enthusiasm were far removed from the doom and gloom that characterized many media and academic accounts of elderly life in Japan (Coulmas 2007). To these elderly karaoke participants, music and leisure serve as important cultural resources that allow them to build and maintain identities and lifestyles as they age (Bennett 2012; Koizumi 2013). In this thesis, I explore how and why regular participation in the spaces and activities of the karaoke classroom and kissa enable the elderly participants to attain sense of well-being and ikigai, the commitment and direction which makes life worth living (Mathews 1996). To capture the unique modes of engagement that influence the individual and social aspects of these participants’ karaoke participation, I mobilize the conceptual lenses of “musicking” as constructed by Small (1998) and “serious leisure” as elaborated by Stebbins (2015), in analyzing the data I obtained from the intensive ethnographic fieldwork I conducted in 2013 and 2016. By detailing the karaoke regulars’ attainment of senses of well-being and ikigai through “serious” musical engagement, I paint a livelier picture of elderly life in urban Japan, by not treating old age simply as a crisis to be solved, but rather a period of life that can be negotiated proactively

Mechatronic Systems

Mechatronics, the synergistic blend of mechanics, electronics, and computer science, has evolved over the past twenty five years, leading to a novel stage of engineering design. By integrating the best design practices with the most advanced technologies, mechatronics aims at realizing high-quality products, guaranteeing at the same time a substantial reduction of time and costs of manufacturing. Mechatronic systems are manifold and range from machine components, motion generators, and power producing machines to more complex devices, such as robotic systems and transportation vehicles. With its twenty chapters, which collect contributions from many researchers worldwide, this book provides an excellent survey of recent work in the field of mechatronics with applications in various fields, like robotics, medical and assistive technology, human-machine interaction, unmanned vehicles, manufacturing, and education. We would like to thank all the authors who have invested a great deal of time to write such interesting chapters, which we are sure will be valuable to the readers. Chapters 1 to 6 deal with applications of mechatronics for the development of robotic systems. Medical and assistive technologies and human-machine interaction systems are the topic of chapters 7 to 13.Chapters 14 and 15 concern mechatronic systems for autonomous vehicles. Chapters 16-19 deal with mechatronics in manufacturing contexts. Chapter 20 concludes the book, describing a method for the installation of mechatronics education in schools