Assessing Distance Perception In Virtual And Augmented Realities With Electroencephalography

A comfinding in spatial perception research is that subjects tend to underestimate distances in virtual reality compared to the real world. The degree and methods of measurement of underestimation vary between studies, but the trend of underestimation is consistent. This study uses electroencephalography as a neuroimaging technique to examine patterns of brain activity when fixating objects in near space and far space in the real world, in virtual reality, and in augmented reality. For the augmented reality condition, a custom optical see-through augmented reality head-mounted display (HMD) was built and calibrated. A calibration method was developed to correct the geometric distortion introduced by the HMD\u27s optical combiners. This method also calibrates a motion tracker mounted on the HMD to allow for tracking of head movements

Percepções da realidade virtual não imersiva e imersiva de baixo custo na área de arquitetura e urbanismo

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Arquitetura e Urbanismo, Florianópolis, 2019.Esta pesquisa de mestrado se propôs a investigar e comparar as diferentes percepções que estudantes de arquitetura e urbanismo têm ao interagirem com a Realidade Virtual não Imersiva (computador) e a Realidade Virtual Imersiva de Baixo Custo (google cardboard). Este estudo se caracteriza como exploratório, aplicado e de desenvolvimento experimental, com análise de dados qualitativos (relatos verbais) e quantitativos (escala de likert e dimensões estimadas). Os dados qualitativos foram organizados por meio de análise de conteúdo e os quantitativos tiveram a normalidade da amostra testada e a mediana submetida ao teste estatístico U de Mann Whitney. Este teste buscou evidenciar a hipótese nula (não há diferença de percepção entre os dois formatos de Realidade Virtual), ou a hipótese alternativa (há diferença de percepção entre os formatos) referente às percepções dos estudantes. Os procedimentos metodológicos desenvolvidos para coleta de dados envolveram: oficinas de Realidade Virtual, entrevista com professores de arquitetura e urbanismo e um experimento envolvendo a Realidade Virtual não Imersiva e Imersiva de baixo custo. A partir dos dados coletados, foram inferidas nove categorias de percepção, dentre elas: altura real e percebida, senso de presença, interação e movimentação, campo visual, estimação de medidas, sensações e emoções, ergonomia física do Google cardboard e opinião sobre os formatos de RVs. Diante dos testes estatísticos, notou-se que, apenas na categoria de senso de presença em sua totalidade, é possível sugerir uma diferença significativa de percepção entre os dois formatos de Realidade Virtual. Na categoria de estimação de medidas, os testes estatísticos não evidenciaram diferença significativa entre estimar medidas no computados ou no modo imersivo. Sugere-se que em Realidade Virtual Imersiva quanto mais elementos do mundo real estiverem representados no mundo virtual, mais o usuário tem a sensação de presença. Em relação ao dispositivo Google cardboard, os alunos puderam se apropriar rapidamente tanto com o formato de interação como com as novas percepções adiquiridas.Abstract: This research aims to investigate and compare the different perceptions that students of architecture and urbanism have when interacting with non-immersive virtual reality (computer) and low cost immersive virtual reality (google cardboard). This study is characterized as exploratory, applied and experimental development, with analysis of qualitative (verbal reports) and quantitative (likert scale and estimated dimensions) data. Qualitative data were organized by content analysis and quantitative data had the normality of the sample tested and the median submitted to the Mann Whitney U statistical test. This test sought to highlight the null hypothesis (there is no difference in perception between the two formats of Virtual Reality), or the alternative hypothesis (there is difference in perception between formats) regarding students' perceptions. The methodological procedures developed for data collection involved: Virtual Reality workshops, interviews with architecture and urbanism teachers and an experiment involving the Non-Immersive and the low cost Immersive Virtual Reality. From the collected data, nine categories of perception were inferred, among them: real and perceived height, sense of presence, interaction and movement, visual field, estimation of measurements, sensations and emotions, physical ergonomics of Google cardboard and opinion about formats of RVs. Given the statistical tests, it was noted that only in the category of sense of presence in its entirety, it is possible to suggest a significant difference in perception between the two formats of Virtual Reality. In the measurement estimation category, statistical tests showed no significant difference between estimating computed or immersive measures. It is suggested that in Immersive Virtual Reality the more elements of the real world are represented in the virtual world, the more the user has a sense of presence. Regarding the Google cardboard device, students were able to quickly appropriate both the format of interaction and the new perceptions gained

Time and frequency domain algorithms for speech coding

The promise of digital hardware economies (due to recent advances in VLSI technology), has focussed much attention on more complex and sophisticated speech coding algorithms which offer improved quality at relatively low bit rates. This thesis describes the results (obtained from computer simulations) of research into various efficient (time and frequency domain) speech encoders operating at a transmission bit rate of 16 Kbps. In the time domain, Adaptive Differential Pulse Code Modulation (ADPCM) systems employing both forward and backward adaptive prediction were examined. A number of algorithms were proposed and evaluated, including several variants of the Stochastic Approximation Predictor (SAP). A Backward Block Adaptive (BBA) predictor was also developed and found to outperform the conventional stochastic methods, even though its complexity in terms of signal processing requirements is lower. A simplified Adaptive Predictive Coder (APC) employing a single tap pitch predictor considered next provided a slight improvement in performance over ADPCM, but with rather greater complexity. The ultimate test of any speech coding system is the perceptual performance of the received speech. Recent research has indicated that this may be enhanced by suitable control of the noise spectrum according to the theory of auditory masking. Various noise shaping ADPCM configurations were examined, and it was demonstrated that a proposed pre-/post-filtering arrangement which exploits advantageously the predictor-quantizer interaction, leads to the best subjective performance in both forward and backward prediction systems. Adaptive quantization is instrumental to the performance of ADPCM systems. Both the forward adaptive quantizer (AQF) and the backward oneword memory adaptation (AQJ) were examined. In addition, a novel method of decreasing quantization noise in ADPCM-AQJ coders, which involves the application of correction to the decoded speech samples, provided reduced output noise across the spectrum, with considerable high frequency noise suppression. More powerful (and inevitably more complex) frequency domain speech coders such as the Adaptive Transform Coder (ATC) and the Sub-band Coder (SBC) offer good quality speech at 16 Kbps. To reduce complexity and coding delay, whilst retaining the advantage of sub-band coding, a novel transform based split-band coder (TSBC) was developed and found to compare closely in performance with the SBC. To prevent the heavy side information requirement associated with a large number of bands in split-band coding schemes from impairing coding accuracy, without forgoing the efficiency provided by adaptive bit allocation, a method employing AQJs to code the sub-band signals together with vector quantization of the bit allocation patterns was also proposed. Finally, 'pipeline' methods of bit allocation and step size estimation (using the Fast Fourier Transform (FFT) on the input signal) were examined. Such methods, although less accurate, are nevertheless useful in limiting coding delay associated with SRC schemes employing Quadrature Mirror Filters (QMF)

Twelfth Annual Conference on Manual Control

Main topics discussed cover multi-task decision making, attention allocation and workload measurement, displays and controls, nonvisual displays, tracking and other psychomotor tasks, automobile driving, handling qualities and pilot ratings, remote manipulation, system identification, control models, and motion and visual cues. Sixty-five papers are included with presentations on results of analytical studies to develop and evaluate human operator models for a range of control task, vehicle dynamics and display situations; results of tests of physiological control systems and applications to medical problems; and on results of simulator and flight tests to determine display, control and dynamics effects on operator performance and workload for aircraft, automobile, and remote control systems

Using MapReduce Streaming for Distributed Life Simulation on the Cloud

Distributed software simulations are indispensable in the study of large-scale life models but often require the use of technically complex lower-level distributed computing frameworks, such as MPI. We propose to overcome the complexity challenge by applying the emerging MapReduce (MR) model to distributed life simulations and by running such simulations on the cloud. Technically, we design optimized MR streaming algorithms for discrete and continuous versions of Conway’s life according to a general MR streaming pattern. We chose life because it is simple enough as a testbed for MR’s applicability to a-life simulations and general enough to make our results applicable to various lattice-based a-life models. We implement and empirically evaluate our algorithms’ performance on Amazon’s Elastic MR cloud. Our experiments demonstrate that a single MR optimization technique called strip partitioning can reduce the execution time of continuous life simulations by 64%. To the best of our knowledge, we are the first to propose and evaluate MR streaming algorithms for lattice-based simulations. Our algorithms can serve as prototypes in the development of novel MR simulation algorithms for large-scale lattice-based a-life models.https://digitalcommons.chapman.edu/scs_books/1014/thumbnail.jp

The crisis of modernity : culture, nature, and the modernist yearning for authenticity

The Crisis of Modernity: Culture, Nature, and the Modernist Yearning for Authenticity This dissertation is situated at the intersection of two critical traditions: the discussion about Modernist literature in English and ecocriticism. By viewing a certain strand of literary Modernism through an ecocritical lens, it tries to offer an investigation of salient aspects that arise out of the experience of modernity. In order to stress the relevance of ecocriticism when dealing with Modernist motifs and themes, I chose authors associated with the so-called vitalistic or primitivist side of Modernism. The condemnation of technological progress, the alienation of the individual living in urbanized societies, and the fear of the widening gap of what is natural and what is cultural in ourselves inspire the work of Henry Miller, Lawrence Durrell, Djuna Barnes and Claude McKay, and raise important questions for ecocritical consideration. Their severe critique of western civilization suggests that for these authors modernity constitutes a crisis of culture. One of the major aims of my work is to define the crisis of modernity as an environmental crisis. To gain recognition of the environmental aspects underlying this critique of modernity, I begin my analysis by focusing on the depiction of urban contexts as a source of profound conflict. The ensuing argument will center on the notion of the pastoral, which both Miller and Durrell recognize as the traditional mode to express an urban yearning for a utopian counterpoise to civilized life. But rather than promoting an idyllic return to nature, these authors primarily seek to unmask the artificiality of the pastoral enthrallment for the natural world. Instead, they try to revitalize their contact with nature by drawing attention to the individual’s physically embodied experience of his or her immediate environment. By focusing on the body as a medium to recuperate humankind’s original affinity with nature, Miller and Durrell represent a powerful alternative to the pastoral tradition. In my final chapter I extend my ecocritical reading of Modernist literature to Djuna Barnes and Claude McKay. Barnes’s struggle with the gendered landscapes of modernity and McKay’s thematization of ethnic difference offer alternative approaches to the crisis of modernity

Analiza idei i motywów platońskich w powieściach Iris Murdoch

Niniejsza praca poświęcona jest twórczości Iris Murdoch, brytyjskiej filozofki i pisarki żyjącej w latach 1919-1999. Praca ta stawia sobie za zadanie zbadanie wybranych motywów platońskich obecnych w jej powieściach. Ze względu na intensywne życie intelektualne Murdoch przejawiające się w dwóch różnych dziedzinach, jej twórczość od zawsze cieszyła się dużym zainteresowaniem. Wysublimowany dialog z filozoficzną i literacką tradycją Zachodu, tak charakterystyczny dla jej powieści, stwarza niestety liczne problemy w interpretacji i często spotykał się z niezrozumieniem. Praca ta koncentruje się na motywach platońskich i ich wpływie zarówno na poetykę, jak i organizację powieści Murdoch. Stanowi odpowiedź na zapotrzebowanie czytelników borykających się z trudnościami w odbiorze jej prozy i została przygotowana jako uzupełnienienie luki badawczej otwartej przez znawców twórczości Murdoch takich jak Peter Conradi czy Sonja Zuba, którzy to zarysowując ogromne znaczenie myśli platońskiej dla zrozumienia jej tekstów, nie podjęli się przeprowadzenia analizy dostatecznie wyczerpującej temat. Analiza powieści Murdoch zawarta w tej pracy jest wynikiem skrupulatnej lektury ponad dwadziestu powieści jej autorstwa i celowo została utrzymana w duchu krytyki etycznej, w dużej mierze inspirowanej badaniami nad twórczością Murdoch prowadzonymi w Instytucie Anglistyki Uniwerstytetu Warszawskiego przez profesor Marię Jędrzejkiewicz. Ze względu na tematyczne powiązanie, niniejsze studium zostało wzbogacone o odniesienia do esejów filozoficznych Murdoch poświęconych myśli platońskiej. Powstałe na przestrzeni wielu lat eseje jej autorstwa takie jak „The Idea of Perfection”, „The Sovereignty of Good over Other Concepts” czy „The Fire and the Sun: Why Plato Banished the Artists” traktują między innymi o topice psyche w rozumieniu Platona, przedstawiają wpływ Erosa na proces budowania relacji międzyludzkich, redefiniują pojęcie Dobra i jego rolę w pielgrzymce od świata iluzji do rzeczywistości, czy w końcu polemizują z Platonem na temat roli sztuki w kształtowaniu postaw moralnych. Jako jedna z niewielu przedstawicieli swojego pokolenia Murdoch nie odżegnywała się od metafizyki, wręcz przeciwnie, pozostając w opozycji do dominującego wówczas w Wielkiej Brytanii nurtu filozofii analitycznej, uczyniła z myśli platońskiej przedmiot godny rozważań zarówno na gruncie filozoficznym jak i literackim. Trzon niniejszej pracy stanowią trzy rozdziały zorganizowane wokół zagadnień podyktowanych kompleksowym podejściem Murdoch do myśli platońskiej. Analiza jej powieści świadczy o tym, że w interpretacji pisarki Platon przestaje bowiem być już tylko filozofem. Staje się on pisarzem wykorzystującym gatunek dialogu do artystycznej ekspresji, występuje w roli nauczyciela zorientowanego na pogłębianie wiedzy o otaczającym go świecie przy użyciu dialektyki, a także wciela się w rolę krytyka kultury, uważnie przyglądającego się tradycji i roli jaką ona pełni w kształtowaniu postaw moralnych. Rozdział pierwszy skupia się na zaadaptowaniu przez autorkę platońskiej alegorii jaskinii jako modelu służącego do przedstawienia relacji podmiot-rzeczywistość. Opisuje jak obrazy przywodzące na myśl opis jaskinii platońskiej wykorzystywane są przez autorkę do zilustrowania postępów moralnych bohaterów jej powieści. Użycie obrazów wpisującyh bohaterów w kontekst platońskiej podróży, podróży od świata iluzji do rzeczywistości, zostaje przedstawione jako świadoma strategia narracyjna , przypominająca charakterem dydaktyczne użycie metafory w dialogach platońskich i zostaje tu opisana w odniesieniu do teorii Lakoff’a reprezentującego kognitywny zwrot w badaniach nad meteforą. Rodział drugi stanowi analizę dialogów w powieściach Murdoch i przedstawia je jako odzwierciedlające filozoficzne debaty prowadzone w dialogach Platona. Użycie dialogu przez Murdoch, przedstawione zostaje jako nawiązujące do wykorzystania dialektyki, antycznej metody używanej do rozstrzygania sporów ideologicznych. Charakterystyka uczestników dialogu w powieściach Murdoch, jak również przedmiot ich dyskusji i okoliczności im towarzyszące, zostaje tu przedstawiony jako naśladujący sytuację narracyjną w dialogach platońskich. Rozdział opisuje jak Murdoch reinterpretuje gatunek dialogu filozoficznego i odkrywa na nowo platońską dialektykę jako rozwiązanie dla problemów komunikacyjnych wywołanych przez tradycję solipsystycznych ruchów filozoficznych, zwłaszcza egzystencjalizmu. Trzeci rozdział opisuje wpływ dziedzictwa kulturowego na kształtowanie się postaw moralnych bohaterów powieści Murdoch. Pokazuje, jak niematerialne aspekty dziedzictwa kulturowego, takie jak tradycyjne wyobrażenia czy idee transmitowane przez filozoficzne i literackie teksty, wpływają na czyny bohaterów. Uwaga zostaje tu poświęcona opisom reakcji bohaterów Murdoch na różne teksty krążące w kulturze i na ustanawieniu przez autorkę zależności między życiem moralnym i treścią inspirującą bohaterów. Eklektyzm gatunkowy i liczne aluzje literackie w powieścich pisarki przedstawione zostają jako strategie narracyjne obrazujące związek pomiędzy moralnym wyborem i wzorcami oferowanymi przez kulturę. Krytyka poetów i sceptyczne podejście Platona do poezji jako zachęcającej do bezmyślnego naśladownictwa, są w tym rozdziale przedstawiona jako punkt wyjścia dla rozważań Murdoch. Wreszcie rozdział lokuje ewaluację tradycji literackich zawartą w powieściach Murdoch w kontekście współczesnych badan kognitywistycznych, a konkretnie krytyki czytelnik-odpowiedź. Odniesienie to ma za zadanie zestawienie opisywanej przez autorkę aktywnej roli czytelnika z jej koncepcją życia moralnego, w którym krytyczna postawa wobec rzeczywistości odgrywa decydującą rolę. W zakończeniu praca posumowuje dorobek Murdoch i głoszoną przez nią potrzebę uznania nadrzędności świata wartości jako głos wyjątkowy i godny uwagi w dobie relatywizmu dominującego postmodernistyczną filozofię. Pesymizm przenikający powieści Murodch i towarzysząca mu krytyka racjonalizmu, znakomicie wpisuje się w program współczesnych Murdoch pisarzy takich jak Lessing, Fowles czy Golding, którzy podobnie jak ona podkreślali potrzebę walki z iluzjami i irracjonalność ludziej natury. Jednak, jak podkreśla niniejsza praca, zainteresowanie Murdoch myślą platońską, które tak często przejawia w swoich powieściach, wyróżnia ją na tle epoki swoją gotowością do zaoferowania alternatywy programowej w czasach zdominowanych przez ontologiczną niepewność i przedstawia samą Murdoch jako pisarkę idącą o krok dalej w rozważaniach nad kondycją człowieka współczesnego.Iris Murdoch, a world-famous prolific novelist and an increasingly influential moral philosopher, was one of the most intriguing figures in the intellectual landscape of post-war Europe. Her unique oeuvre which combines philosophical inclinations with a passion for literature continues to spur interest in her works and ideas. Acclaimed by literary critics, who have praised her insightfulness and wit, Murdoch managed to mark her presence in the consciousness of her contemporaries and almost two decades after her death she continues to resonate strongly with new generations of readers. The present argument is designed to explore systematically and demonstrate how certain principal Platonic motifs and ideas translate into the construction and nourish the content of Iris Murdoch's novels. Focus is laid on the interconnections between the disciplines of philosophy and literature, as the thesis investigates the ways in which Murdoch retrieves and modifies some of Plato’s philosophical ideas through the medium of the novel and how her novels parallel Plato’s dialogues. It is assumed that the latter not only comprise philosophical ideas, which so far have been amply accounted for, but also testify to Plato’s great literary talent. From his dialogues, therefore, we draw here a picture of Plato not only as a philosopher, but also a writer struggling to express his ideas through the medium of the dialogue, a teacher very much concerned with the critical abilities of his followers, and finally, a cultural critic capable of discerning the positive and the negative influences of various cultural products and practices. Plato, one of the most influential ancient philosophers, is thus approached here as an artistically gifted intellectual, who was actively shaping the philosophical debate of his time and still remains a great source of influence. The thesis seeks to explore the depth of Murdoch’s engagement with Plato, in particular the artistic means of translating his ideas into her novels. In addition, it is estimated that the thesis will deepen our understanding of Plato’s philosophical thought, as seen here through the prism of Murdoch’s reflection on and imaginative reworking of his dialogues. In the first chapter it is argued that Murdoch’s appreciation for Plato’s philosophical thought is mirrored in her novels through her use of imagery. Plato’s Allegory of the Cave will be presented as a model capturing the essence of a complicated relation between the self and the outside world. The chapter focuses on the images in Murdoch’s fiction which reproduce the circumstances of the prisoners dwelling in the Cave as described by Plato, especially the state of eikasia, the immersion in illusion, and analyses Murdoch’s use of images to convey the process of discarding the state of illusion. Murdoch’s use of metaphorical images will also be presented as a narrative strategy converging with Plato’s didactic use of figurative language and, on the other hand, preceding the cognitive turn in metaphor studies heralded by Lakoff’s theory. In the second chapter I propose to analyse the dialogical exchanges of ideas between characters in Murdoch’s novels as reflecting the philosophical debates taking place in her time and evoking the ancient tradition of dialectics. The participants in such communication as depicted by Murdoch, the circumstances in which it takes place, and finally the content of the conversations will be evaluated as echoing the narrative situations in Plato’s dialogues. I will argue that apart from retrieving Plato’s philosophical thought, Murdoch utilizes and reinterprets the generic form of dialogue. Murdoch’s rediscovery of Plato’s dialectics and the Socratic dialogue will be discussed as an innovative solution to the problem of miscommunication diagnosed by her as affecting Western civilization so heavily influenced by the tradition of solipsistic philosophical movements like existentialism. The third chapter describes the influence of cultural heritage on the outlook of Murdoch’s characters. It discusses how non-physical aspects of culture such as ideas inscribed in philosophical and literary texts affect her characters’ actions; in particular, it will be argued that Murdoch’s depiction of her characters’ responses to various texts establishes a meaningful connection between the characters’ actions and the texts they find inspiring. It will be contended that Murdoch’s deployment of various genres and literary allusions to render such a connection echoes Plato’s ideas concerning the influence of cultural heritage. Plato’s cautious treatment of poetry as inviting emulation will be traced in Murdoch’s description of characters inspired by various models of behaviour derived from literature. Finally, this chapter gives insight into Murdoch’s evaluation of some literary traditions and locates her ideas pertaining to the influence of reading in the field of contemporary cognitive studies, showing the compatibility of her artistic vision of universal human nature with the recent developments in this field, which positions Murdoch as a novelist and thinker ahead of her times and illustrates the significance of her work

Aerospace Medicine and Biology. an Annotated Bibliography. 1958-1961 Literature, Volumes VII-X, Part 2

Abstracts on aerospace medicine and biology - bibliography on environmental factors, safety and survival, personnel, pharmacology, toxicology, and life support system

Viet Nam Generation, Volume 6, Number 3-4

Edited by Dan Duffy and Kali Tal. Contributing editors: Renny Christopher. David DeRose, Alan Farrell. Cynthia Fuchs, William M. King. Bill Shields, Tony Williams, and David Willson