O presente trabalho tem como objetivo examinar e refletir a desconstrução e reconstrução dos elementos espaço-temporais em Ensaio sobre a cegueira. O embasamento teórico desse trabalho, dentre outros, será a concepção de cronotopo apresentada por Mikhail Bakhtin, ao lado de conceitos de não-lugares e lugares antropológicos de Marc-Augé. As pesquisas de Mircea Eliade serão utilizadas para a reflexão de espaços sagrados e profanos e para o exame dos rituais de passagem ou iniciáticos. Tendo em vista a peregrinação feita grupo das sete personagens que protagonizam a trama estabeleceremos um paralelo com a via-crúcis de Jesus apresentada no texto bíblico que trata de um caminho de sofrimento, dor e morte. O percurso da via-crúcis chega ao fim através da metamorfose ocorrida no interior das personagens e que se estende aos espaços projetando uma possível reconstrução espaço-temporal. / The present work has as objective to examine and to reflect the desconstruction and reconstruction of the space-secular elements in Ensaio sobre a cegueira. The theoretical basement of this work, amongst others, will be the conception of cronotopo presented by Mikhail Bakhtin, to the side of concepts of not-places and antropológicos places of Marc Augé. The research of Mircea Eliade will be used for the reflection of sacred and profane spaces and for the examination of the rituals of ticket or iniciáticos. In view of the done peregrination group of the seven personages who carry out the tram we will establish a parallel with the way-crucis of Jesus presented in the Biblical text that deals with a way of suffering, pain and death. The passage of the way-crucis arrives at the end through the occured metamorphosis in the interior of the personages and that a possible reconstruction is extended to the spaces projecting space-time.

Cheng Ho Ting. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 90-93). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgement --- p.iv / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview of Wireless Cooperative Communications --- p.1 / Chapter 1.2 --- Motivation --- p.2 / Chapter 1.3 --- Distributed Space-Time Block Coding --- p.4 / Chapter 1.4 --- Imperfect Channel Estimation --- p.4 / Chapter 1.5 --- Time-Varying Channels --- p.4 / Chapter 1.6 --- Outline of the thesis --- p.5 / Chapter 2 --- Background Study --- p.6 / Chapter 3 --- Distributed Space-Time Block Coding --- p.13 / Chapter 3.1 --- Introduction --- p.13 / Chapter 3.2 --- System Model --- p.13 / Chapter 3.3 --- BER Analysis by Characteristic Equations --- p.16 / Chapter 3.4 --- BER Analysis by Error Terms --- p.18 / Chapter 3.4.1 --- Non-fading R→D link --- p.19 / Chapter 3.4.2 --- Fading R→D link --- p.19 / Chapter 3.5 --- Performance --- p.20 / Chapter 3.5.1 --- Accuracy of Analytical Expressions --- p.20 / Chapter 3.5.2 --- Observation of Second-order Diversity --- p.21 / Chapter 3.6 --- Summary --- p.22 / Chapter 4 --- Distributed Space-Time Block Coding with Imperfect Channel Estimation --- p.31 / Chapter 4.1 --- Introduction --- p.31 / Chapter 4.2 --- System Model --- p.32 / Chapter 4.3 --- BER Analysis --- p.32 / Chapter 4.3.1 --- Non-fading R→D link --- p.33 / Chapter 4.3.2 --- Fading R→D link --- p.34 / Chapter 4.4 --- Numerical Results --- p.34 / Chapter 4.5 --- Summary --- p.36 / Chapter 5 --- Distributed Space-Time Block Coding with Time-Varying Channels --- p.43 / Chapter 5.1 --- Introduction --- p.43 / Chapter 5.2 --- System Model --- p.44 / Chapter 5.3 --- Pilot Symbol Assisted Modulation (PSAM) for DSTBC --- p.45 / Chapter 5.4 --- Reception Methods --- p.48 / Chapter 5.4.1 --- Maximum-Likelihood Detection (ML) in [29] --- p.48 / Chapter 5.4.2 --- Cooperative Maximum-Likelihood Detection (CML) --- p.50 / Chapter 5.4.3 --- Alamouti's Receiver (AR) --- p.51 / Chapter 5.4.4 --- Zero-forcing Linear Detection (ZF) --- p.51 / Chapter 5.4.5 --- Decision-feedback Detection (DF) --- p.52 / Chapter 5.5 --- BER Analysis for Time-varying Channels --- p.53 / Chapter 5.5.1 --- Quasi-Static Channels (p = 1) --- p.53 / Chapter 5.5.2 --- ZF: Uncorrelated Channel (p = 0) --- p.54 / Chapter 5.5.3 --- ZF: General Channel --- p.55 / Chapter 5.5.4 --- DF: General Channel --- p.56 / Chapter 5.6 --- Numerical Results --- p.57 / Chapter 5.7 --- Summary --- p.60 / Chapter 6 --- Conclusion and Future Work --- p.74 / Chapter 6.1 --- Conclusion --- p.74 / Chapter 6.2 --- Future Work --- p.76 / Chapter 6.2.1 --- Design of Code Matrix --- p.76 / Chapter 6.2.2 --- Adaptive Protocols --- p.77 / Chapter A --- Derivation of (3.23) --- p.79 / Chapter B --- Derivation of (3.30) and (3.32) --- p.83 / Chapter C --- Derivation of (4.9) and (4.13) --- p.85 / Chapter D --- Derivation of (5.68) --- p.88 / Bibliography --- p.90

In this thesis we study exact general relativistic space-times generated by a black hole and an additional source of gravity, while restricting to two classes of static and axially symmetric solutions: the Majumdar-Papapetrou solution for a couple (in general, a multiple system) of extremally charged black holes and the "superposition" of a Schwarzschild black hole with the Bach-Weyl thin ring. We follow the effect of the additional source on the geometry of black-hole space-time on the behaviour of important invariants, in particular of the simplest scalars obtained from the Riemann and possibly also Ricci tensor. We have plotted the invariants both outside and inside the black hole; in the case of a Schwarzschild black hole with ring, we found, to this end, an extension of the metric below the horizon. It turns out that the external source may affect the geometry inside the black hole considerably, even in the vicinity of singularity, although the singularity itself remains point-like in both solutions studied here.

A utilização do conceito de tempo como uma categoria de análise em Geografia não é tão rara quanto se imagina, mas tampouco é tão presente e reflexiva quanto se gostaria. Ainda mais raros são os trabalhos de pesquisa que incluem de maneira efetiva a dimensão espaçotemporal na análise geográfica. Esta pesquisa apresenta, portanto, uma discussão em torno de autores que analisam esta perspectiva, na tentativa de construir os conceitos de espaço-tempo, temporalidade (velocidade de transporte de matéria e informação) e identidade espaçotemporal, ao mesmo tempo em que tenta articulá-los ao universo conceitual da Geografia. Adicionalmente, esta pesquisa também tenta demonstrar uma possibilidade de uso efetivo destes conceitos na análise de um recorte espacial específico. O trabalho de campo experimental foi desenvolvido na cidade de Terra de Areia, no Litoral Norte do Rio Grande do Sul, onde diversos fluxos lentos e rápidos convivem proximamente, gerando conflitos temporais manifestados nos hábitos, gestos e sentimentos dos habitantes da localidade. / The use of the concept of time as a category of analysis in Geography is not as rare as we imagine, but neither is as reflexive or common as we would like it to be. Even more rare are the scientific works that include in an effective way the space-time dimension in geographical analysis. This research presents, therefore, a discussion about authors who discuss this perspective, in trying to build the concepts of space-time, temporality (matter and information transport speed) and spatial-temporal identity at the same time that tries to link them to the conceptual universe of Geography. Also, this research tries to demonstrate a possibility of effective use of these concepts in the analysis of a specific portion of space. The experimental field work was developed in the city of Terra de Areia, in the northern coast of Rio Grande do Sul/Brazil, where several flows with different speeds live closely, generating temporal conflicts manifested in habits, gestures and feelings of the inhabitants of the town.

In this thesis the problem of automatic human action recognition and localization in videos is studied. In this problem, our goal is to recognize the category of the human action that is happening in the video, and also to localize the action in space and/or time. This problem is challenging due to the complexity of the human actions, the large intra-class variations and the distraction of backgrounds. Human actions are inherently structured patterns of body movements. However, past works are inadequate in learning the space-time structures in human actions and exploring them for better recognition and localization. In this thesis new methods are proposed that exploit such space-time structures for effective human action recognition and localization in videos, including sports videos, YouTube videos, TV programs and movies. A new local space-time video representation, the hierarchical Space-Time Segments, is first proposed. Using this new video representation, ensembles of hierarchical spatio-temporal trees, discovered directly from the training videos, are constructed to model the hierarchical, spatial and temporal structures of human actions. This proposed approach achieves promising performances in action recognition and localization on challenging benchmark datasets. Moreover, the discovered trees show good cross-dataset generalizability: trees learned on one dataset can be used to recognize and localize similar actions in another dataset. To handle large scale data, a deep model is explored that learns temporal progression of the actions using Long Short Term Memory (LSTM), which is a type of Recurrent Neural Network (RNN). Two novel ranking losses are proposed to train the model to better capture the temporal structures of actions for accurate action recognition and temporal localization. This model achieves state-of-art performance on a large scale video dataset. A deep model usually employs a Convolutional Neural Network (CNN) to learn visual features from video frames. The problem of utilizing web action images for training a Convolutional Neural Network (CNN) is also studied: training CNN typically requires a large number of training videos, but the findings of this study show that web action images can be utilized as additional training data to significantly reduce the burden of video training data collection.

A long term record of the earth's vegetation is important in studies of global climate change. Over the last three decades, multiple data sets on vegetation have been collected using different satellite-based sensors. There is a need for methods that combine these data into a long term earth system data record. The Advanced Very High Resolution Radiometer (AVHRR) has provided reflectance measures of the entire earth since 1978. Physical and statistical models have been used to improve the consistency and reliability of this record. The Moderated Resolution Imaging Spectroradiometer (MODIS) has provided measurements with superior radiometric properties and geolocation accuracy. However, this record is available only since 2000. In this thesis, we perform statistical calibration of AVHRR to MODIS. We aim to: (1) fill in gaps in the ongoing MODIS record; (2) extend MODIS values back to 1982. We propose Bayesian mixed models to predict MODIS values using snow cover and AVHRR values as covariates. Random effects are used to account for spatiotemporal correlation in the data. We estimate the parameters based on the data after 2000, using Markov chain Monte Carlo methods. We then back-predict MODIS data between 1978 and 1999, using the posterior samples of the parameter estimates. We develop new Conditional Autoregressive (CAR) models for seasonal data. We also develop new sampling methods for CAR models. Our approach enables filling in gaps in the MODIS record and back-predicting these values to construct a consistent historical record. The Bayesian framework incorporates multiple sources of variation in estimating the accuracy of the obtained data. The approach is illustrated using vegetation data over a region in Minnesota.

In this report, an optical wireless multiple-input multiple-output communication system employing intensity-modulation direct-detection is considered. The performance of direct current offset space-time block codes (DC-STBC) is studied in terms of pairwise error probability (PEP). It is shown that among the class of DC-STBCs, the worst case PEP corresponding to the minimum distance between two codewords is minimized by repetition coding (RC), under both electrical and optical individual power constraints. It follows that among all DC-STBCs, RC is optimal in terms of worst-case PEP for static channels and also for varying channels under any turbulence statistics. This result agrees with previously published numerical results showing the superiority of RC in such systems. It also agrees with previously published analytic results on this topic under log-normal turbulence and further extends it to arbitrary turbulence statistics. This shows the redundancy of the time-dimension of the DCSTBC in this system. This result is further extended to sum power constraints with static and turbulent channels, where it is also shown that the time dimension is redundant, and the optimal DC-STBC has a spatial beamforming structure. Numerical results are provided to demonstrate the difference in performance for systems with different numbers of receiving apertures and different throughput.

The current popularity of WLANs is a testament primarily to their convenience, cost efficiency and ease of integration. Even now the demand for high data rate wireless communications has increased fourfold as consumers demand better multimedia communications over the wireless medium. The next generation of high speed WLANs is expected to meet this increased demand for capacity coupled with high performance and spectral efficiency. The current generation of WLANs utilizes Orthogonal Frequency Division Multiplexing (OFDM) modulation. The next generation of WLAN standards can be made possible either by developing a different modulation technique or combining legacy OFDM with Multiple Input Multiple Output (MIMO) systems to create MIMO-OFDM systems. This dissertation presents two different basis technologies for the next generation of high speed WLANs: OWSS and MIMO-STC-OFDM. OWSS, or Orthogonal Wavelet Division Multiplexed - Spread Spectrum is a new class of wavelet pulses and a corresponding signaling system which has significant advantages over current signaling schemes like OFDM. In this dissertation, CSMA/CA is proposed as the protocol for full data rate multiplexing at the MAC layer for OWSS. The excellent spectral characteristics of the OWSS signal is also studied and simulations show that passband spectrum enjoys a 30-40% bandwidth advantage over OFDM. A novel pre-distortion scheme was developed to compensate for the passband PA non-linearity. Finally for OWSS, the fundamental limits of its system performance were also explored using a multi-level matrix formulation. Simulation results on a 108 Mbps OWSS WLAN system demonstrate the excellent effectiveness of this theory and prove that OWSS is capable of excellent performance and high spectral efficiency in multipath channels. This dissertation also presents a novel MIMO-STC-OFDM system which targets data rates in excess of 100 Mbps and at the same time achieve both high spectral efficiency and high performance. Simulation results validate the superior performance of the new system over multipath channels. Finally as channel equalization is critical in MIMO systems, a highly efficient time domain channel estimation formulation for this new system is also presented. In summary, both OWSS and MIMO-STC-OFDM appear to be excellent candidate technologies for next generation of high speed WLANs.

Master of Engineering (Research) / Multiple antenna systems are an appealing candidate for emerging fourth-generation wireless networks due to its potential to exploit space diversity for increasing conveyed throughput without wasting bandwidth and power resources. Particularly, layered space-time architecture (LST) proposed by Foschini, is a technique to achieve a significant fraction of the theoretical capacity with a reasonable implementation complexity. There has been a great deal of challenges in the detection of space-time signal; especially to design a low-complexity detector, which can efficiently remove multi-layer interference and approach the interference free bound. The application of iterative principle to joint detection and decoding has been a promising approach. It has been shown that, the iterative receiver with parallel interference canceller (PIC) has a low linear complexity and near interference free performance. Furthermore, it is widely accepted that the performance of digital communication systems can be considerably improved once the channel state information (CSI) is used to optimize the transmit signal. In this thesis, the problem of the design of a power allocation strategy in LST architecture to simultaneously optimize coding, diversity and weighting gains is addressed. A more practical scenario is also considered by assuming imperfect CSI at the receiver. The effect of channel estimation errors in LST architecture with an iterative PIC receiver is investigated. It is shown that imperfect channel estimation at an LST receiver results in erroneous decision statistics at the very first iteration and this error propagates to the subsequent iterations, which ultimately leads to severe degradation of the overall performance. We design a transmit power allocation policy to take into account the imperfection in the channel estimation process. The transmit power of various layers is optimized through minimization of the average bit error rate (BER) of the LST architecture with a low complexity iterative PIC detector. At the receiver, the PIC detector performs both interference regeneration and cancellation simultaneously for all layers. A convolutional code is used as the constituent code. The iterative decoding principle is applied to pass the a posteriori probability estimates between the detector and decoders. The decoder is based on the maximum a posteriori (MAP) algorithms. A closed-form optimal solution for power allocation in terms of the minimum BER is obtained. In order to validate the effectiveness of the proposed schemes, substantial simulation results are provided.

This paper addresses the aesthetic encounter from the perspective of the writings of Maurice Merleau-Ponty on the visible and the invisible. It begins with the premise that from time to time we encounter situations which precipitate a sense of slippage in our experience of the world. The paper proceeds to argue that the arts can provide a point of access to this experience, and that aesthetic theory has, for example, responded to it through the development of the notion of 'the sublime'. The writings of Maurice Merleau-Ponty and, in particular, aspects of his text The Visible and the invisible, are presented with a view to augmenting this aspect of aesthetic theory. Proceeding from a 'Merleau-Pontian' perspective, the paper explores how the arts can serve to disrupt our conventional sense of space and time - creating ripples in the substance Merleau-Ponty names as 'flesh' - so as to expose the chiasm or blind spot in our experience of the world. The methodology adopted is an experiential one, which draws on the writer's interaction with the selected works of various artists as well as her own practice in glass.