Transcorneal Electrical Stimulation Shows Neuroprotective Effects in Retinas of Light-Exposed Rats

PURPOSE. To examine the effects of transcorneal electrical stimulation (TES) on retinal degeneration of light-exposed rats. METHODS. Thirty-three Sprague Dawley albino rats were divided into three groups: STIM (n = 15) received 60 minutes of TES, whereas SHAM (n = 15) received identical sham stimulation 2 hours before exposure to bright light with 16,000 lux; healthy animals (n = 3) served as controls for histology. At baseline and weekly for 3 consecutive weeks, dark-and light-adapted electroretinography was used to assess retinal function. Analysis of the response versus luminance function retrieved the parameters Vmax (saturation amplitude) and k (luminance to reach 1/2Vmax). Retinal morphology was assessed by histology (hematoxylin-eosin [HE] staining; TUNEL assay) and immunohistochemistry (rhodopsin staining). RESULTS. Vmax was higher in the STIM group compared with SHAM 1 week after light damage (mean intra-individual difference between groups 116.06 mu V; P = 0.046). The b-wave implicit time for the rod response (0.01 cd.s/m(2)) was lower in the STIM group compared with the SHAM group 2 weeks after light damage (mean intra-individual difference between groups 5.78 ms; P = 0.023); no other significant differences were found. Histological analyses showed photoreceptor cell death (TUNEL and HE) in SHAM, most pronounced in the superior hemiretina. STIM showed complete outer nuclear layer thickness preservation, reduced photoreceptor cell death, and preserved outer segment length compared with SHAM (HE and rhodopsin). CONCLUSIONS. This sham-controlled study shows that TES can protect retinal cells against mild light-induced degeneration in Sprague Dawley rats. These findings could help to establish TES as a treatment in human forms of retinal degenerative disease. (Invest Ophthalmol Vis Sci. 2012;53:5552-5561) DOI: 10.1167/iovs.12-10037

Comparison of the reliability of multifocal visual evoked cortical potentials generated by pattern reversal and pattern pulse stimulation

This study compared the effectiveness of the multifocal visual evoked cortical potentials (mfVEP) elicited by pattern pulse stimulation with that of pattern reversal in producing reliable responses (signal-to-noise ratio >1.359). Participants were 14 healthy subjects. Visual stimulation was obtained using a 60-sector dartboard display consisting of 6 concentric rings presented in either pulse or reversal mode. Each sector, consisting of 16 checks at 99% Michelson contrast and 80 cd/m² mean luminance, was controlled by a binary m-sequence in the time domain. The signal-to-noise ratio was generally larger in the pattern reversal than in the pattern pulse mode. The number of reliable responses was similar in the central sectors for the two stimulation modes. At the periphery, pattern reversal showed a larger number of reliable responses. Pattern pulse stimuli performed similarly to pattern reversal stimuli to generate reliable waveforms in R1 and R2. The advantage of using both protocols to study mfVEP responses is their complementarity: in some patients, reliable waveforms in specific sectors may be obtained with only one of the two methods. The joint analysis of pattern reversal and pattern pulse stimuli increased the rate of reliability for central sectors by 7.14% in R1, 5.35% in R2, 4.76% in R3, 3.57% in R4, 2.97% in R5, and 1.78% in R6. From R1 to R4 the reliability to generate mfVEPs was above 70% when using both protocols. Thus, for a very high reliability and thorough examination of visual performance, it is recommended to use both stimulation protocols.

Early malnutrition decreases contrast sensitivity to circular concentric gratings

Early malnutrition refers to inadequate nutrition during the critical period of nervous system development followed by nutritional recovery, resulting in a short stature according to age but normal weight according to short stature. We measured the effects of early malnutrition on contrast sensitivity (CS) to concentric circular gratings in 18 children of both sexes, aged 8 to 11 years (mean = 9.2 years, standard deviation = .99 years). Nine of the children were eutrophic (E group), and nine experienced early malnutrition (EM group) based on state healthcare records and Waterlow's anthropometric parameters. Contrast sensitivity to four spatial frequencies (.25, 1.0, 2.0, and 8.0 cycles per degree [cpd]) was measured using a temporal two-alternative forced-choice psychophysical method with mean luminance of 40.1 cd/m². Statistical analyses showed significant differences between groups and a group × frequency interaction. EM group was significantly less sensitive than the E group to the 8.0 cpd frequency and needed 1.49-times more contrast to detect the gratings. These results suggest that early malnutrition impairs CS to high-spatial-frequency concentric circular gratings in children. Therefore, early malnutrition, which is known to affect primary visual cortical areas, may also affect higher visual cortical areas such as V4 and the inferotemporal cortex.

Tecniche per il controllo dinamico del consumo di potenza per piattaforme system-on-chip

Providing support for multimedia applications on low-power mobile devices remains a significant research challenge. This is primarily due to two reasons: • Portable mobile devices have modest sizes and weights, and therefore inadequate resources, low CPU processing power, reduced display capabilities, limited memory and battery lifetimes as compared to desktop and laptop systems. • On the other hand, multimedia applications tend to have distinctive QoS and processing requirementswhichmake themextremely resource-demanding. This innate conflict introduces key research challenges in the design of multimedia applications and device-level power optimization. Energy efficiency in this kind of platforms can be achieved only via a synergistic hardware and software approach. In fact, while System-on-Chips are more and more programmable thus providing functional flexibility, hardwareonly power reduction techniques cannot maintain consumption under acceptable bounds. It is well understood both in research and industry that system configuration andmanagement cannot be controlled efficiently only relying on low-level firmware and hardware drivers. In fact, at this level there is lack of information about user application activity and consequently about the impact of power management decision on QoS. Even though operating system support and integration is a requirement for effective performance and energy management, more effective and QoSsensitive power management is possible if power awareness and hardware configuration control strategies are tightly integratedwith domain-specificmiddleware services. The main objective of this PhD research has been the exploration and the integration of amiddleware-centric energymanagement with applications and operating-system. We choose to focus on the CPU-memory and the video subsystems, since they are the most power-hungry components of an embedded system. A second main objective has been the definition and implementation of software facilities (like toolkits, API, and run-time engines) in order to improve programmability and performance efficiency of such platforms. Enhancing energy efficiency and programmability ofmodernMulti-Processor System-on-Chips (MPSoCs) Consumer applications are characterized by tight time-to-market constraints and extreme cost sensitivity. The software that runs on modern embedded systems must be high performance, real time, and even more important low power. Although much progress has been made on these problems, much remains to be done. Multi-processor System-on-Chip (MPSoC) are increasingly popular platforms for high performance embedded applications. This leads to interesting challenges in software development since efficient software development is a major issue for MPSoc designers. An important step in deploying applications on multiprocessors is to allocate and schedule concurrent tasks to the processing and communication resources of the platform. The problem of allocating and scheduling precedenceconstrained tasks on processors in a distributed real-time system is NP-hard. There is a clear need for deployment technology that addresses thesemulti processing issues. This problem can be tackled by means of specific middleware which takes care of allocating and scheduling tasks on the different processing elements and which tries also to optimize the power consumption of the entire multiprocessor platform. This dissertation is an attempt to develop insight into efficient, flexible and optimalmethods for allocating and scheduling concurrent applications tomultiprocessor architectures. It is a well-known problem in literature: this kind of optimization problems are very complex even in much simplified variants, therefore most authors propose simplified models and heuristic approaches to solve it in reasonable time. Model simplification is often achieved by abstracting away platform implementation ”details”. As a result, optimization problems become more tractable, even reaching polynomial time complexity. Unfortunately, this approach creates an abstraction gap between the optimization model and the real HW-SW platform. The main issue with heuristic or, more in general, with incomplete search is that they introduce an optimality gap of unknown size. They provide very limited or no information on the distance between the best computed solution and the optimal one. The goal of this work is to address both abstraction and optimality gaps, formulating accurate models which accounts for a number of ”non-idealities” in real-life hardware platforms, developing novel mapping algorithms that deterministically find optimal solutions, and implementing software infrastructures required by developers to deploy applications for the targetMPSoC platforms. Energy Efficient LCDBacklightAutoregulation on Real-LifeMultimediaAp- plication Processor Despite the ever increasing advances in Liquid Crystal Display’s (LCD) technology, their power consumption is still one of the major limitations to the battery life of mobile appliances such as smart phones, portable media players, gaming and navigation devices. There is a clear trend towards the increase of LCD size to exploit the multimedia capabilities of portable devices that can receive and render high definition video and pictures. Multimedia applications running on these devices require LCD screen sizes of 2.2 to 3.5 inches andmore to display video sequences and pictures with the required quality. LCD power consumption is dependent on the backlight and pixel matrix driving circuits and is typically proportional to the panel area. As a result, the contribution is also likely to be considerable in future mobile appliances. To address this issue, companies are proposing low power technologies suitable for mobile applications supporting low power states and image control techniques. On the research side, several power saving schemes and algorithms can be found in literature. Some of them exploit software-only techniques to change the image content to reduce the power associated with the crystal polarization, some others are aimed at decreasing the backlight level while compensating the luminance reduction by compensating the user perceived quality degradation using pixel-by-pixel image processing algorithms. The major limitation of these techniques is that they rely on the CPU to perform pixel-based manipulations and their impact on CPU utilization and power consumption has not been assessed. This PhDdissertation shows an alternative approach that exploits in a smart and efficient way the hardware image processing unit almost integrated in every current multimedia application processors to implement a hardware assisted image compensation that allows dynamic scaling of the backlight with a negligible impact on QoS. The proposed approach overcomes CPU-intensive techniques by saving system power without requiring either a dedicated display technology or hardware modification. Thesis Overview The remainder of the thesis is organized as follows. The first part is focused on enhancing energy efficiency and programmability of modern Multi-Processor System-on-Chips (MPSoCs). Chapter 2 gives an overview about architectural trends in embedded systems, illustrating the principal features of new technologies and the key challenges still open. Chapter 3 presents a QoS-driven methodology for optimal allocation and frequency selection for MPSoCs. The methodology is based on functional simulation and full system power estimation. Chapter 4 targets allocation and scheduling of pipelined stream-oriented applications on top of distributed memory architectures with messaging support. We tackled the complexity of the problem by means of decomposition and no-good generation, and prove the increased computational efficiency of this approach with respect to traditional ones. Chapter 5 presents a cooperative framework to solve the allocation, scheduling and voltage/frequency selection problem to optimality for energyefficient MPSoCs, while in Chapter 6 applications with conditional task graph are taken into account. Finally Chapter 7 proposes a complete framework, called Cellflow, to help programmers in efficient software implementation on a real architecture, the Cell Broadband Engine processor. The second part is focused on energy efficient software techniques for LCD displays. Chapter 8 gives an overview about portable device display technologies, illustrating the principal features of LCD video systems and the key challenges still open. Chapter 9 shows several energy efficient software techniques present in literature, while Chapter 10 illustrates in details our method for saving significant power in an LCD panel. Finally, conclusions are drawn, reporting the main research contributions that have been discussed throughout this dissertation.

Farbkonstanz und Farbkontrast – eine Untersuchung mit Hilfe der farbigen Schatten

Zusammenfassung der Dissertation von Anatol Julian Kallmann Farbkonstanz und Farbkontrast – eine Untersuchung mit Hilfeder farbigen Schatten Die farbigen Schatten werden als ein Spezialfall dessimultanen Farbkontrastes angesehen. Um herauszufinden,warum die farbigen Schatten im Vergleich zur gewöhnlichenDarstellung des simultanen Farbkontrastes so intensiv farbigerscheinen, wurde das Phänomen hinsichtlich derFarbparameter Helligkeit, Sättigung und Farbton analysiert. Der Induktionseffekt scheint weniger von der Sättigung desUmfeldes als vom Leuchtdichtekontrast zwischen dem Umfeldund dem Infeld abhängig zu sein.Das farbig beleuchtete Umfeld wurde von den Versuchspersonenmit einer geringeren Farbsättigung im Verhältnis zurtatsächlichen Umfeldsättigung eingestellt. Die Farbe desUmfeldes wurde unterschiedlich wahrgenommen, wenn keinzentrales Testfeld präsentiert wurde.Dichromaten nahmen das physikalisch weiße Infeld ebenfallsfarbig wahr. Sie stellten Farben auf dem Abgleichbildschirmein, deren Farborte in der CIE-Farbtafel auf denVerwechslungslinien liegen und somit denen der Trichromatenentsprechen. Die Farbbenennungen wichen jedoch von denen derTrichromaten ab. Das Phänomen der farbigen Schatten scheint ein Spezialfallder Farbkonstanz zu sein: Vermutlich dient das Umfeld alshellste Fläche im Gesichtsfeld dem visuellen System alsReferenz. Wenn die Helligkeit des zentralen Infeldeszunimmt, so dass dieses letztlich im visuellen Felddominiert, dann ist das visuelle System in der Lage, es als'weiß' wahrzunehmen. Es verwendet dann wahrscheinlich diesesFeld als Weißreferenz, welches die übrigen Farben imGesichtsfeld bestimmt.

Bestimmung der spektralen Empfindlichkeit eines Bewegungsdetektors auf der Basis von Zapfenerregungen beim Menschen

Die Detektion von Bewegung stellt eine der fundamentalsten Fähigkeiten der visuellen Wahrnehmung dar. Um zu klären, ob das System zur Bewegungswahrnehmung Eingang nur durch einen Zapfentyp erhält, oder ob eine Kombination von verschiedenen Zapfentypen vorliegt, wurde eine rotierende zwei-armige archimedische Spiralscheibe verwendet (reale Bewegung), bei der sich Spirale und Hintergrund farblich unterschieden. Durch Veränderung der Intensität farbiger Leuchtstoffröhren konnte eine Beleuchtungssituation geschaffen werden, bei der die (radiale) Bewegung der Spirale nicht mehr wahrgenommen werden konnte, obwohl Spirale und Hintergrund farblich verschieden waren. Die Bestimmung der Zapfenerregungen im 3-D Rezeptorraum ließ einen Beitrag sowohl des L– als auch des M-Zapfens bei normalsichtigen Trichromaten (dominiert durch L), jedoch einen alleinigen Beitrag des M-Zapfens bei Protanopen erkennen. Die Ermittlung der spektralen Empfindlichkeit basierend auf einer Vektor Analyse im 3D-Rezeptorraum zeigte schließlich, dass dem neuronalen Bewegungsdetektor ein additiver Beitrag des L- und M-Zapfens, in Übereinstimmung mit der Hellempfindlichkeitsfunktion (Vλ), zugrunde liegt. Als Ergebnis schreiben wir die Detektion von Objektbewegung einem farbenblinden Mechanismus zu. Es ist sehr wahrscheinlich, dass der Magnozelluläre-Kanal das neuronale Substrat dieses Bewegungsdetektors repräsentiert.

Slowdown of gist perception in colour diagnostic scenes

Humans perceive the content (gist) of a scene very rapidly within about 40 ms [Castelhano and Henderson, 2008 Journal of Experimental Psychology Human Perception and Performance 43(3) 660-675]. It has also been demonstrated that colours contribute to the perception of the gist of a scene if the colours are diagnostic for the distinction of scenes (Oliva and Schyns, 2000 Cognitive Psychology 41 176-210). We presented 320 coloured photographs of 2 diagnostic (mountains and coasts) and 2 nondiagnostic colour scenes (cities and rooms), 80 per category, in a masking paradigm. The mask consisted of randomly distributed colour patches. SOA was varied between 20 and 80 ms, in steps of 20 ms and subjects had to indicate the gist of the scene (4AFC). A control condition without masking was also included. In line with previous results we have found that the gist of nondiagnostic coloured scenes is extracted within 40 ms. However, if colour comes into play, the extraction of the scene gist is prolonged by about 20 ms. A possible reason for this outcome might be that nondiagnostic colour scenes are identified by their luminance components which are processed faster than the colour information, which in turn mediates the identification of diagnostic colour scenes

Motion standstill leads to activation of inferior parietal lobe

Previous studies on motion perception revealed motion-processing brain areas sensitive to changes in luminance and texture (low-level) and changes in salience (high-level). The present functional magnetic resonance imaging (fMRI) study focused on motion standstill. This phenomenon, occurring at fast presentation frequencies of visual moving objects that are perceived as static, has not been previously explored by neuroimaging techniques. Thirteen subjects were investigated while perceiving apparent motion at 4 Hz, at 30 Hz (motion standstill), isoluminant static and flickering stimuli, fixation cross, and blank screen, presented randomly and balanced for rapid event-related fMRI design. Blood oxygenation level-dependent (BOLD) signal in the occipito-temporal brain region MT/V5 increased during apparent motion perception. Here we could demonstrate that brain areas like the posterior part of the right inferior parietal lobule (IPL) demonstrated higher BOLD-signal during motion standstill. These findings suggest that the activation of higher-order motion areas is elicited by apparent motion at high presentation rates (motion standstill). We interpret this observation as a manifestation of an orienting reaction in IPL towards stimulus motion that might be detected but not resolved by other motion-processing areas (i.e., MT/V5).

Looking left with left neglect: the role of spatial attention when active vision selects local image features for fixation

When we actively explore the visual environment, our gaze preferentially selects regions characterized by high contrast and high density of edges, suggesting that the guidance of eye movements during visual exploration is driven to a significant degree by perceptual characteristics of a scene. Converging findings suggest that the selection of the visual target for the upcoming saccade critically depends on a covert shift of spatial attention. However, it is unclear whether attention selects the location of the next fixation uniquely on the basis of global scene structure or additionally on local perceptual information. To investigate the role of spatial attention in scene processing, we examined eye fixation patterns of patients with spatial neglect during unconstrained exploration of natural images and compared these to healthy and brain-injured control participants. We computed luminance, colour, contrast, and edge information contained in image patches surrounding each fixation and evaluated whether they differed from randomly selected image patches. At the global level, neglect patients showed the characteristic ipsilesional shift of the distribution of their fixations. At the local level, patients with neglect and control participants fixated image regions in ipsilesional space that were closely similar with respect to their local feature content. In contrast, when directing their gaze to contralesional (impaired) space neglect patients fixated regions of significantly higher local luminance and lower edge content than controls. These results suggest that intact spatial attention is necessary for the active sampling of local feature content during scene perception.

Digital Illumination for Augmented Studios

Virtual studio technology plays an important role for modern television productions. Blue-screen matting is a common technique for integrating real actors or moderators into computer generated sceneries. Augmented reality offers the possibility to mix real and virtual in a more general context. This article proposes a new technological approach for combining real studio content with computergenerated information. Digital light projection allows a controlled spatial, temporal, chrominance and luminance modulation of illumination – opening new possibilities for TV studios.

SIGNALING MECHANISMS THAT CONTROL GAP JUNCTIONAL COUPLING BETWEEN RETINAL NEURONS

Gap junctions between neurons form the structural substrate for electrical synapses. Connexin 36 (Cx36, and its non-mammalian ortholog connexin 35) is the major neuronal gap junction protein in the central nervous system (CNS), and contributes to several important neuronal functions including neuronal synchronization, signal averaging, network oscillations, and motor learning. Connexin 36 is strongly expressed in the retina, where it is an obligatory component of the high-sensitivity rod photoreceptor pathway. A fundamental requirement of the retina is to adapt to broadly varying inputs in order to maintain a dynamic range of signaling output. Modulation of the strength of electrical coupling between networks of retinal neurons, including the Cx36-coupled AII amacrine cell in the primary rod circuit, is a hallmark of retinal luminance adaptation. However, very little is known about the mechanisms regulating dynamic modulation of Cx36-mediated coupling. The primary goal of this work was to understand how cellular signaling mechanisms regulate coupling through Cx36 gap junctions. We began by developing and characterizing phospho-specific antibodies against key regulatory phosphorylation sites on Cx36. Using these tools we showed that phosphorylation of Cx35 in fish models varies with light adaptation state, and is modulated by acute changes in background illumination. We next turned our focus to the well-studied and readily identifiable AII amacrine cell in mammalian retina. Using this model we showed that increased phosphorylation of Cx36 is directly related to increased coupling through these gap junctions, and that the dopamine-stimulated uncoupling of the AII network is mediated by dephosphorylation of Cx36 via protein kinase A-stimulated protein phosphatase 2A activity. We then showed that increased phosphorylation of Cx36 on the AII amacrine network is driven by depolarization of presynaptic ON-type bipolar cells as well as background light increments. This increase in phosphorylation is mediated by activation of extrasynaptic NMDA receptors associated with Cx36 gap junctions on AII amacrine cells and by Ca2+-calmodulin-dependent protein kinase II activation. Finally, these studies indicated that coupling is regulated locally at individual gap junction plaques. This work provides a framework for future study of regulation of Cx36-mediated coupling, in which increased phosphorylation of Cx36 indicates increased neuronal coupling.

Organization of hue selectivity in macaque V2 thin stripes.

V2 has long been recognized to contain functionally distinguishable compartments that are correlated with the stripelike pattern of cytochrome oxidase activity. Early electrophysiological studies suggested that color, direction/disparity, and orientation selectivity were largely segregated in the thin, thick, and interstripes, respectively. Subsequent studies revealed a greater degree of homogeneity in the distribution of response properties across stripes, yet color-selective cells were still found to be most prevalent in the thin stripes. Optical recording studies have demonstrated that thin stripes contain both color-preferring and luminance-preferring modules. These thin stripe color-preferring modules contain spatially organized hue maps, whereas the luminance-preferring modules contain spatially organized luminance-change maps. In this study, the neuronal basis of these hue maps was determined by characterizing the selectivity of neurons for isoluminant hues in multiple penetrations within previously characterized V2 thin stripe hue maps. The results indicate that neurons within the superficial layers of V2 thin stripe hue maps are organized into columns whose aggregated hue selectivity is closely related to the hue selectivity of the optically defined hue maps. These data suggest that thin stripes contain hue maps not simply because of their moderate percentage of hue-selective neurons, but because of the columnar and tangential organization of hue selectivity.

Efecto de la potencia de la unidad de fotopolimerización y del tiempo de fotoactivación sobre la transmitancia de las resinas reforzadas

Las propiedades ópticas de las resinas reforzadas resultan de vital importancia para el logro de restauraciones estéticas, sobre todo en lo referente a color y traslucidéz de las mismas, así como el mantenimiento de esas propiedades en función del tiempo. Ellas dependen de la composición del material y de su manipulación (tiempo de aplicación de una radiación electromagnética adecuada y la potencia de la unidad de fotopolimerización). Una de las formas de observar el comportamiento de estos materiales ante una radiación electromagnética, luego de polimerizados, es medir la transmitancia. El objetivo de este trabajo fue comparar la transmitancia de las resinas reforzadas polimerizadas con distintos tiempos de exposición a la fuente lumínica y diferentes potencias de la misma. Para ello se emplearon muestras de un mismo material de iguales dimensiones, divididos en dos grupos. La variable del grupo 1 fue el tiempo de exposición a la luz, mientras que la del grupo 2 fue la potencia de la fuente de fotoactivación. Para observar la transmitancia de las muestras fue empleado un espectrofotómetro UV- visible, que relaciona la transmitancia con diferentes longitudes de onda, permitiéndonos comparar curvas que representan el comportamiento del material. Los resultados que fueron observados muestran las coincidencias de las mencionadas curvas en ambos grupos y entre las muestras del mismo grupo, para las longitudes de onda cercanas a la luz visible, no así para las correspondientes a las ultravioletas. Pasado un mes de almacenamiento de las muestras, se observaron algunas diferencias en las lecturas de las curvas.

Modelado en alto nivel con SystemC

El presente proyecto final de carrera titulado “Modelado de alto nivel con SystemC” tiene como objetivo principal el modelado de algunos módulos de un codificador de vídeo MPEG-2 utilizando el lenguaje de descripción de sistemas igitales SystemC con un nivel de abstracción TLM o Transaction Level Modeling. SystemC es un lenguaje de descripción de sistemas digitales basado en C++. En él hay un conjunto de rutinas y librerías que implementan tipos de datos, estructuras y procesos especiales para el modelado de sistemas digitales. Su descripción se puede consultar en [GLMS02] El nivel de abstracción TLM se caracteriza por separar la comunicación entre los módulos de su funcionalidad. Este nivel de abstracción hace un mayor énfasis en la funcionalidad de la comunicación entre los módulos (de donde a donde van datos) que la implementación exacta de la misma. En los documentos [RSPF] y [HG] se describen el TLM y un ejemplo de implementación. La arquitectura del modelo se basa en el codificador MVIP-2 descrito en [Gar04], de dicho modelo, los módulos implementados son: · IVIDEOH: módulo que realiza un filtrado del vídeo de entrada en la dimensión horizontal y guarda en memoria el video filtrado. · IVIDEOV: módulo que lee de la memoria el vídeo filtrado por IVIDEOH, realiza el filtrado en la dimensión horizontal y escribe el video filtrado en memoria. · DCT: módulo que lee el video filtrado por IVIDEOV, hace la transformada discreta del coseno y guarda el vídeo transformado en la memoria. · QUANT: módulo que lee el video transformado por DCT, lo cuantifica y guarda el resultado en la memoria. · IQUANT: módulo que lee el video cuantificado por QUANT, realiza la cuantificación inversa y guarda el resultado en memoria. · IDCT: módulo que lee el video procesado por IQUANT, realiza la transformada inversa del coseno y guarda el resultado en memoria. · IMEM: módulo que hace de interfaz entre los módulos anteriores y la memoria. Gestiona las peticiones simultáneas de acceso a la memoria y asegura el acceso exclusivo a la memoria en cada instante de tiempo. Todos estos módulos aparecen en gris en la siguiente figura en la que se muestra la arquitectura del modelo: Figura 1. Arquitectura del modelo (VER PDF DEL PFC) En figura también aparecen unos módulos en blanco, dichos módulos son de pruebas y se han añadido para realizar simulaciones y probar los módulos del modelo: · CAMARA: módulo que simula una cámara en blanco y negro, lee la luminancia de un fichero de vídeo y lo envía al modelo a través de una FIFO. · FIFO: hace de interfaz entre la cámara y el modelo, guarda los datos que envía la cámara hasta que IVIDEOH los lee. · CONTROL: módulo que se encarga de controlar los módulos que procesan el vídeo, estos le indican cuando terminan de procesar un frame de vídeo y este módulo se encarga de iniciar los módulos que sean necesarios para seguir con la codificación. Este módulo se encarga del correcto secuenciamiento de los módulos procesadores de vídeo. · RAM: módulo que simula una memoria RAM, incluye un retardo programable en el acceso. Para las pruebas también se han generado ficheros de vídeo con el resultado de cada módulo procesador de vídeo, ficheros con mensajes y un fichero de trazas en el que se muestra el secuenciamiento de los procesadores. Como resultado del trabajo en el presente PFC se puede concluir que SystemC permite el modelado de sistemas digitales con bastante sencillez (hace falta conocimientos previos de C++ y programación orientada objetos) y permite la realización de modelos con un nivel de abstracción mayor a RTL, el habitual en Verilog y VHDL, en el caso del presente PFC, el TLM. ABSTRACT This final career project titled “High level modeling with SystemC” have as main objective the modeling of some of the modules of an MPEG-2 video coder using the SystemC digital systems description language at the TLM or Transaction Level Modeling abstraction level. SystemC is a digital systems description language based in C++. It contains routines and libraries that define special data types, structures and process to model digital systems. There is a complete description of the SystemC language in the document [GLMS02]. The main characteristic of TLM abstraction level is that it separates the communication among modules of their functionality. This abstraction level puts a higher emphasis in the functionality of the communication (from where to where the data go) than the exact implementation of it. The TLM and an example are described in the documents [RSPF] and [HG]. The architecture of the model is based in the MVIP-2 video coder (described in the document [Gar04]) The modeled modules are: · IVIDEOH: module that filter the video input in the horizontal dimension. It saves the filtered video in the memory. · IVIDEOV: module that read the IVIDEOH filtered video, filter it in the vertical dimension and save the filtered video in the memory. · DCT: module that read the IVIDEOV filtered video, do the discrete cosine transform and save the transformed video in the memory. · QUANT: module that read the DCT transformed video, quantify it and save the quantified video in the memory. · IQUANT: module that read the QUANT processed video, do the inverse quantification and save the result in the memory. · IDCT: module that read the IQUANT processed video, do the inverse cosine transform and save the result in the memory. · IMEM: this module is the interface between the modules described previously and the memory. It manage the simultaneous accesses to the memory and ensure an unique access at each instant of time All this modules are included in grey in the following figure (SEE PDF OF PFC). This figure shows the architecture of the model: Figure 1. Architecture of the model This figure also includes other modules in white, these modules have been added to the model in order to simulate and prove the modules of the model: · CAMARA: simulates a black and white video camera, it reads the luminance of a video file and sends it to the model through a FIFO. · FIFO: is the interface between the camera and the model, it saves the video data sent by the camera until the IVIDEOH module reads it. · CONTROL: controls the modules that process the video. These modules indicate the CONTROL module when they have finished the processing of a video frame. The CONTROL module, then, init the necessary modules to continue with the video coding. This module is responsible of the right sequence of the video processing modules. · RAM: it simulates a RAM memory; it also simulates a programmable delay in the access to the memory. It has been generated video files, text files and a trace file to check the correct function of the model. The trace file shows the sequence of the video processing modules. As a result of the present final career project, it can be deduced that it is quite easy to model digital systems with SystemC (it is only needed previous knowledge of C++ and object oriented programming) and it also allow the modeling with a level of abstraction higher than the RTL used in Verilog and VHDL, in the case of the present final career project, the TLM.

Optimización de la composición del hueco de fachada en materia de eficiencia energética. Propuesta de indicador como herramienta para el análisis integral del elemento acristalado = Energy performance optimization of window systems. Proposal of an indicator as a tool for an integrated analysis of glazing

La hipótesis de esta tesis es: "La optimización de la ventana considerando simultáneamente aspectos energéticos y aspectos relativos a la calidad ambiental interior (confort higrotérmico, lumínico y acústico) es compatible, siempre que se conozcan y consideren las sinergias existentes entre ellos desde las primeras fases de diseño". En la actualidad se desconocen las implicaciones de muchas de las decisiones tomadas en torno a la ventana; para que su eficiencia en relación a todos los aspectos mencionados pueda hacerse efectiva es necesaria una herramienta que aporte más información de la actualmente disponible en el proceso de diseño, permitiendo así la optimización integral, en función de las circunstancias específicas de cada proyecto. En la fase inicial de esta investigación se realiza un primer acercamiento al tema, a través del estado del arte de la ventana; analizando la normativa existente, los componentes, las prestaciones, los elementos experimentales y la investigación. Se observa que, en ocasiones, altos requisitos de eficiencia energética pueden suponer una disminución de las prestaciones del sistema en relación con la calidad ambiental interior, por lo que surge el interés por integrar al análisis energético aspectos relativos a la calidad ambiental interior, como son las prestaciones lumínicas y acústicas y la renovación de aire. En este punto se detecta la necesidad de realizar un estudio integral que incorpore los distintos aspectos y evaluar las sinergias que se dan entre las distintas prestaciones que cumple la ventana. Además, del análisis de las soluciones innovadoras y experimentales se observa la dificultad de determinar en qué medida dichas soluciones son eficientes, ya que son soluciones complejas, no caracterizadas y que no están incorporadas en las metodologías de cálculo o en las bases de datos de los programas de simulación. Por lo tanto, se plantea una segunda necesidad, generar una metodología experimental para llevar a cabo la caracterización y el análisis de la eficiencia de sistemas innovadores. Para abordar esta doble necesidad se plantea la optimización mediante una evaluación del elemento acristalado que integre la eficiencia energética y la calidad ambiental interior, combinando la investigación teórica y la investigación experimental. En el ámbito teórico, se realizan simulaciones, cálculos y recopilación de información de distintas tipologías de hueco, en relación con cada prestación de forma independiente (acústica, iluminación, ventilación). A pesar de haber partido con un enfoque integrador, resulta difícil esa integración detectándose una carencia de herramientas disponible. En el ámbito experimental se desarrolla una metodología para la evaluación del rendimiento y de aspectos ambientales de aplicación a elementos innovadores de difícil valoración mediante la metodología teórica. Esta evaluación consiste en el análisis comparativo experimental entre el elemento innovador y un elemento estándar; para llevar a cabo este análisis se han diseñado dos espacios iguales, que denominamos módulos de experimentación, en los que se han incorporado los dos sistemas; estos espacios se han monitorizado, obteniéndose datos de consumo, temperatura, iluminancia y humedad relativa. Se ha realizado una medición durante un periodo de nueve meses y se han analizado y comparado los resultados, obteniendo así el comportamiento real del sistema. Tras el análisis teórico y el experimental, y como consecuencia de esa necesidad de integrar el conocimiento existente se propone una herramienta de evaluación integral del elemento acristalado. El desarrollo de esta herramienta se realiza en base al procedimiento de diagnóstico de calidad ambiental interior (CAI) de acuerdo con la norma UNE 171330 “Calidad ambiental en interiores”, incorporando el factor de eficiencia energética. De la primera parte del proceso, la parte teórica y el estado del arte, se obtendrán los parámetros que son determinantes y los valores de referencia de dichos parámetros. En base a los parámetros relevantes obtenidos se da forma a la herramienta, que consiste en un indicador de producto para ventanas que integra todos los factores analizados y que se desarrolla según la Norma UNE 21929 “Sostenibilidad en construcción de edificios. Indicadores de sostenibilidad”. ABSTRACT The hypothesis of this thesis is: "The optimization of windows considering energy and indoor environmental quality issues simultaneously (hydrothermal comfort, lighting comfort, and acoustic comfort) is compatible, provided that the synergies between these issues are known and considered from the early stages of design ". The implications of many of the decisions made on this item are currently unclear. So that savings can be made, an effective tool is needed to provide more information during the design process than the currently available, thus enabling optimization of the system according to the specific circumstances of each project. The initial phase deals with the study from an energy efficiency point of view, performing a qualitative and quantitative analysis of commercial, innovative and experimental windows. It is observed that sometimes, high-energy efficiency requirements may mean a reduction in the system's performance in relation to user comfort and health, that's why there is an interest in performing an integrated analysis of indoor environment aspects and energy efficiency. At this point a need for a comprehensive study incorporating the different aspects is detected, to evaluate the synergies that exist between the various benefits that meet the window. Moreover, from the analysis of experimental and innovative windows, a difficulty in establishing to what extent these solutions are efficient is observed; therefore, there is a need to generate a methodology for performing the analysis of the efficiency of the systems. Therefore, a second need arises, to generate an experimental methodology to perform characterization and analysis of the efficiency of innovative systems. To address this dual need, the optimization of windows by an integrated evaluation arises, considering energy efficiency and indoor environmental quality, combining theoretical and experimental research. In the theoretical field, simulations and calculations are performed; also information about the different aspects of indoor environment (acoustics, lighting, ventilation) is gathered independently. Despite having started with an integrative approach, this integration is difficult detecting lack available tools. In the experimental field, a methodology for evaluating energy efficiency and indoor environment quality is developed, to be implemented in innovative elements which are difficult to evaluate using a theoretical methodology This evaluation is an experimental comparative analysis between an innovative element and a standard element. To carry out this analysis, two equal spaces, called experimental cells, have been designed. These cells have been monitored, obtaining consumption, temperature, luminance and relative humidity data. Measurement has been performed during nine months and results have been analyzed and compared, obtaining results of actual system behavior. To advance this optimization, windows have been studied from the point of view of energy performance and performance in relation to user comfort and health: thermal comfort, acoustic comfort, lighting comfort and air quality; proposing the development of a methodology for an integrated analysis including energy efficiency and indoor environment quality. After theoretical and experimental analysis and as a result of the need to integrate existing knowledge, a comprehensive evaluation procedure for windows is proposed. This evaluation procedure is developed according to the UNE 171330 "Indoor Environmental Quality", also incorporating energy efficiency and cost as factors to evaluate. From the first part of the research process, outstanding parameters are chosen and reference values of these parameters are set. Finally, based on the parameters obtained, an indicator is proposed as windows product indicator. The indicator integrates all factors analyzed and is developed according to ISO 21929-1:2011"Sustainability in building construction. Sustainability indicators. Part 1: Framework for the development of indicators and a core set of indicators for buildings".