189 research outputs found

    Active Estimation of Distance in a Robotic Vision System that Replicates Human Eye Movement

    Full text link
    Many visual cues, both binocular and monocular, provide 3D information. When an agent moves with respect to a scene, an important cue is the different motion of objects located at various distances. While a motion parallax is evident for large translations of the agent, in most head/eye systems a small parallax occurs also during rotations of the cameras. A similar parallax is present also in the human eye. During a relocation of gaze, the shift in the retinal projection of an object depends not only on the amplitude of the movement, but also on the distance of the object with respect to the observer. This study proposes a method for estimating distance on the basis of the parallax that emerges from rotations of a camera. A pan/tilt system specifically designed to reproduce the oculomotor parallax present in the human eye was used to replicate the oculomotor strategy by which humans scan visual scenes. We show that the oculomotor parallax provides accurate estimation of distance during sequences of eye movements. In a system that actively scans a visual scene, challenging tasks such as image segmentation and figure/ground segregation greatly benefit from this cue.National Science Foundation (BIC-0432104, CCF-0130851

    Event-based Vision: A Survey

    Get PDF
    Event cameras are bio-inspired sensors that differ from conventional frame cameras: Instead of capturing images at a fixed rate, they asynchronously measure per-pixel brightness changes, and output a stream of events that encode the time, location and sign of the brightness changes. Event cameras offer attractive properties compared to traditional cameras: high temporal resolution (in the order of microseconds), very high dynamic range (140 dB vs. 60 dB), low power consumption, and high pixel bandwidth (on the order of kHz) resulting in reduced motion blur. Hence, event cameras have a large potential for robotics and computer vision in challenging scenarios for traditional cameras, such as low-latency, high speed, and high dynamic range. However, novel methods are required to process the unconventional output of these sensors in order to unlock their potential. This paper provides a comprehensive overview of the emerging field of event-based vision, with a focus on the applications and the algorithms developed to unlock the outstanding properties of event cameras. We present event cameras from their working principle, the actual sensors that are available and the tasks that they have been used for, from low-level vision (feature detection and tracking, optic flow, etc.) to high-level vision (reconstruction, segmentation, recognition). We also discuss the techniques developed to process events, including learning-based techniques, as well as specialized processors for these novel sensors, such as spiking neural networks. Additionally, we highlight the challenges that remain to be tackled and the opportunities that lie ahead in the search for a more efficient, bio-inspired way for machines to perceive and interact with the world

    NASA Tech Briefs, November 1999

    Get PDF
    Topics covered include: Computer-Aided Design and Engineering; Electronic Components and Circuits; Electronic Systems; Materials; Computer Programs; Mechanics; Machinery/Automation; Physical Sciences; Mathematics and Information Sciences; Books and Reports

    Design and Applications of Additive Manufacturing and 3D Printing

    Get PDF
    Additive manufacturing (AM), more commonly known as 3D printing, has grown trememdously in recent years. It has shown its potential uses in the medical, automotive, aerospace, and spare part sectors. Personal manufacturing, complex and optimized parts, short series manufacturing, and local on-demand manufacturing are just some of its current benefits. The development of new materials and equipment has opened up new application possibilities, and equipment is quicker and cheaper to use when utilizing the new materials launched by vendors and material developers. AM has become more critical for the industry but also for academics. Since AM offers more design freedom than any other manufacturing process, it provides designers with the challenge of designing better and more efficient products

    With and Without Walls: The Southern California Institute of Architecture and a New School of Los Angeles Architects in the 1970s and 1980s.

    Full text link
    The Southern California Institute of Architecture (SCI-Arc) was created with the premise that in providing freedom through self-study, it would be possible to produce both architects and architecture. Founded in 1972, after separating from the California State Polytechnic University, Pomona (Cal Poly) amidst feelings of bureaucratic and ideological oppression, SCI-Arc was self-described as a school “without walls.” From an academic context with roots in the profession, the interests of the faculty straddled social pragmatism as well as formal invention that balanced design techniques and aesthetic sensibilities. Ray Kappe, a Los Angeles-based architect and professor, proposed the formation of SCI-Arc and was the school’s first director. The style that emerged under Kappe’s directorship evoked fusion, which positioned the school with methods to develop ideas for developmental progress. Without offering tenure, SCI-Arc’s faculty, which varied consistently, created a flexible curriculum that became a tactic to promote personal directions for discourse, providing students, and the architects who taught there, a platform to respond to a postmodern architectural climate. SCI-Arc’s institutional culture adjusted over time, and it increasingly relied on the versatility of the institutional framework to forge its pedagogy. The trajectory of SCI-Arc from the early 1970s to the late 1980s revealed not only how an alternative approach to education impacted architectural production with an emerging Los Angeles architectural culture but also occurring more generally in the period, in a shift from the idealism of the 1960s to the neoliberalism of the 1990s.PhDArchitectureUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/133239/1/bnsmth_1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/133239/2/bnsmth_2.pd

    NASA Tech Briefs, June 2001

    Get PDF
    Topics covered include: Sensors; Electronic Components and Systems; Software Engineering; Materials; Manufacturing/Fabrication; physical Sciences; Information Sciences

    The Oasis retreat

    Get PDF

    Biophilic and photobiological developments of adaptive high-performance building envelopes for Northern Canada

    Get PDF
    Les configurations des enveloppes et des fenêtres des bâtiments nordiques doivent répondre aux exigences du bien-être photobiologique et psychologique des occupants par des relations positives efficaces avec la nature subarctique. Les enveloppes de bâtiments existant dans les climats (sub)arctiques du nord du Canada n'ont pas encore permis d'établir des connexions efficaces entre l'intérieur et l'extérieur afin d'aborder les relations positives entre les humains et la nature et le bien-être photobiologique et psychologique. Des connexions intérieures-extérieures efficaces indiquent une connectivité optimale de l'intérieur avec la nature subarctique extérieure répondant au bien-être des occupants et aux besoins énergétiques. Les relations positives des occupants avec la nature subarctique correspondent à des avantages maximums et des risques minimums des climats nordiques extrêmes pour le bien-être photobiologique-psychologique. L'objectif général de cette thèse est de favoriser les relations positives des occupants avec la nature subarctique au moyen de connexions efficaces entre l'intérieur et l'extérieur qui pourraient répondre aux facteurs de bien-être biophiliques et photobiologiques liés à la lumière du jour et aux photopériodes. Dans ce but, un modèle fondamental d'enveloppe de bâtiment adaptative à haute performance est développé comme une solution architecturale qui pourrait optimiser les connexions intérieur-extérieur et les principaux indicateurs biophiliques et photobiologiques. La thèse visait spécifiquement à articuler une approche photobiologique du design biophilique dans les climats nordiques extrêmes qui permet d'établir un cadre conceptuel et de design pour développer des enveloppes de bâtiments. La thèse visait également à identifier les lacunes des enveloppes de bâtiment existantes dans le Grand Nord du Canada ainsi que des systèmes d'enveloppes adaptatives existants en termes d'indicateurs biophysiques-photobiologiques. Les principaux éléments architecturaux des enveloppes adaptatives, notamment la configuration des fenêtres et les caractéristiques de surface des systèmes d'ombrage, en particulier la couleur et la réflectance, sont étudiés pour répondre aux besoins biophiles-photobiologiques des occupants du Nord. Les méthodologies de la thèse comprennent une revue de la littérature pour discuter des directives récentes de design biophilique, de l'éclairage photobiologique et des études de connectivité avec la nature par rapport aux climats subarctiques, en particulier la lumière du jour et les photopériodes. Des méthodes numériques et expérimentales ont été intégrées pour évaluer les performances biophiliques, d'éclairage photobiologique, thermiques et énergétiques des systèmes d'enveloppe pour une étude de cas d'un bureau open-plan dans le nord du Canada. Des méthodes expérimentales avec des modèles à l'échelle physique, des images à haute gamme dynamique et des techniques de post-traitement ont été utilisées pour capturer, calculer et visualiser les paramètres d'éclairage photobiologique. L'impact des caractéristiques des panneaux d'ombrage (SP) sur les performances d'éclairage photobiologique a été étudié par l'expérimentation d'environ 40 prototypes à l'échelle 1:50 et 23 prototypes à l'échelle 1:10 sous un ciel dégagé/couvert avec un éclairage naturel réel/artificiel. Des modèles numériques ont été développés pour évaluer les caractéristiques biophiques et thermiques/énergétiques des systèmes d'enveloppe. Les résultats de la thèse comprennent un cadre théorico-conceptuel du design photobiologique - biophilique qui identifie les relations positives des occupants avec la nature subarctique à travers les enveloppes. Des scénarios d'adaptation de l'éclairage photobiologique intégrés aux exigences thermiques ont été élaborés, qui permettent de répondre aux besoins photobiologiques horaires/saisonniers des occupants du Nord dans des bâtiments différents. Les lacunes des enveloppes à une peau typique du Nord du Canada et des enveloppes à plusieurs peaux avec des profondeurs d'espaces intermédiaires/cavités et des tailles de fenêtre différentes ont été spécifiquement évaluées en termes des indicateurs biophiliques, photobiologiques et thermiques. Un modèle fondamental d'enveloppes adaptatives à haute performance est proposé pour les bâtiments du Nord, qui comprend une taille de fenêtre optimale, un système d'ombrage dynamique coloré et isolé, et un système de buffer thermique constitué d'une peau extérieure en verre. Les performances d'éclairage photobiologique des configurations des SP, incluant la couleur, la réflectance, l'orientation, l'inclinaison, la densité, la taille, l'ouverture et la position à la fenêtre, ont été caractérisées. Les résultats des élévations expérimentales/numériques montrent que l'enveloppe adaptative proposée pourrait offrir des connexions intérieures-extérieures efficaces qui répondent aux besoins photobiologiques-psychologiques et aux exigences énergétiques des occupants du Nord. Les résultats de la thèse pourraient informer les architectes et les responsables politiques sur les possibilités que les enveloppes adaptatives et les cadres photobiologiques-biophiles offrent pour améliorer le bienêtre du public et l'efficacité énergétique dans les climats nordiques. Les principaux enjeux des futurs développements des bâtiments biophiliques adaptatifs dans les climats nordiques ont également été soulignés, notamment en matière d'analyses du cycle de vie et d'études socioculturelles.Sub-Arctic building envelope configurations must address occupants' photobiological-psychological wellbeing through positive relationships with the outdoor sub-Arctic nature. Existing building envelopes in Northern Canada's (sub-)Arctic climates have not, yet, enabled efficient indoor-outdoor connections to address positive human-nature relationships and photobiological-psychological wellbeing. Efficient indoor-outdoor connections indicate optimum connectivity of indoors with Northern climates in terms of occupants' wellbeing and energy factors. Positive occupants' relationships with the sub-Arctic nature refer to maximum benefits and minimum risks of the extreme cold weather and strong photoperiod of Northern climates for photo-biological and psychological wellbeing. The general objective of this dissertation is to foster positive occupants' relationships with sub-Arctic nature by enabling efficient indoor-outdoor connections which could respond to biophilic and photobiological wellbeing factors related to daylighting and photoperiods. To this end, a fundamental model of adaptive high-performance building envelopes is developed as an architectural solution which could optimize indoor-outdoor connections and main biophilic and photobiological indicators. The dissertation specifically aimed at articulating a photobiological approach to biophilic design in extreme Northern climates which enables establishing a conceptual and design framework to develop building envelopes. The thesis also focused on identifying the shortcomings of existing Canadian Northern building envelopes as well as existing adaptive envelope systems in terms of biophilicphotobiological indicators. Main architectural elements of adaptive envelopes including window configuration and surface characteristics of shading systems, in particular color and reflectance, are explored to respond to Northern occupants' biophilic-photobiological needs. The thesis methodologies include a scoping literature review to critically discuss recent biophilic design guidelines, photobiological lighting, and nature connectedness/relatedness studies in relation to sub-Arctic climates, especially daylighting and photoperiods. Numerical and experimental methods were integrated to evaluate biophilic, photobiological lighting, thermal and energy performance of envelope systems for a case study of an open-plan office in Northern Canada. Experimental methods with physical scale models, high dynamic range imagery and post-processing techniques were employed to capture, compute, and visualize photobiological lighting parameters. Impacts of shading panels' (SPs) characteristics on photobiological lighting performance were explored by experimenting approximately 40 1:50-scale prototypes and 23 1:10-scale prototypes under clear/overcast skies with actual/artificial daylighting. Numerical models were developed to evaluate biophilic and thermal/energy performance of envelope systems. Dissertation outcomes include a theoretical-conceptual framework of photobiological-biophilic design which characterizes positive occupants' relationships with the sub-Arctic nature through envelopes. Photobiological lighting adaptation scenarios integrated with thermal requirements were developed which could address hourly/seasonal photobiological needs of Northern occupants in different buildings. Deficiencies of typical single-skin envelopes in Northern Canada and multi-skin envelopes with different depths of intermediate spaces/cavities and window sizes were specifically evaluated in terms of biophilic, photobiological lighting and thermal indicators. A fundamental model of adaptive high-performance envelopes is proposed for Northern buildings which includes an optimum window size, a dynamic-colored-insulated shading system, and a thermal buffer system made of a glazing exterior skin. Photobiological lighting performance of SPs' configurations, including color, reflectance, orientation, inclination, density, size, openness, and position at the window, were characterized. Results of experimental-numerical elevations reveal that the proposed adaptive envelope could offer efficient indoor-outdoor connections which respond to Northern occupants' photobiological-psychological needs and energy requirements. Dissertation outcomes could enlighten architects and policymakers about potentials of adaptive envelopes and integrative photobiological-biophilic frameworks to improve public wellbeing and energy efficiency in Northern climates. Major issues for future developments of adaptive biophilic buildings in Northern climates were also outlined including life cycle assessments and sociocultural studies

    CMOS IMAGE SENSORS FOR LAB-ON-A-CHIP MICROSYSTEM DESIGN

    Get PDF
    The work described herein serves as a foundation for the development of CMOS imaging in lab-on-a-chip microsystems. Lab-on-a-chip (LOC) systems attempt to emulate the functionality of a cell biology lab by incorporating multiple sensing modalidites into a single microscale system. LOC are applicable to drug development, implantable sensors, cell-based bio-chemical detectors and radiation detectors. The common theme across these systems is achieving performance under severe resource constraints including noise, bandwidth, power and size. The contributions of this work are in the areas of two core lab-on-a-chip imaging functions: object detection and optical measurements

    NASA Tech Briefs, April 2002

    Get PDF
    The contents include: 1) Application Briefs; 2) Sneak Preview of Sensors Expo; 3) The Complexity of the Diagnosis Problem; 4) Design Concepts for the ISS TransHab Module; 5) Characteristics of Supercritical Transitional Mixing Layers; 6) Electrometer for Triboelectric Evaluation of Materials; 7) Infrared CO2 Sensor With Built-In Calibration Chambers; 8) Solid-State Potentiometric CO Sensor; 9) Planetary Rover Absolute Heading Detection Using a Sun Sensor; 10) Concept for Utilizing Full Areas of STJ Photodetector Arrays; 11) Development of Cognitive Sensors; 12) Enabling Higher-Voltage Operation of SOl CMOS Transistors; 13) Estimating Antenna-Pointing Errors From Beam Squints; 14) Advanced-Fatigue-Crack-Growth and Fracture- Mechanics Program; 15) Software for Sequencing Spacecraft Actions; 16) Program Distributes and Tracks Organizational Memoranda; 16) Flat Membrane Device for Dehumidification of Air; 17) Inverted Hindle Mount Reduces Sag of a Large, Precise Mirror; 18) Heart-Pump-Outlet/Cannula Coupling; 19) Externally Triggered Microcapsules Release Drugs In Situ; 20) Combinatorial Drug Design Augmented by Information Theory; 21) Multiple-Path-Length Optical Absorbance Cell; 22) Model of a Fluidized Bed Containing a Mixture of Particles; 23) Refractive Secondary Concentrators for Solar Thermal Systems; 24) Cold Flow Calorimeter; 25) Methodology for Tracking Hazards and Predicting Failures; 26) Estimating Heterodyne-Interferometer Polarization Leakage; 27) An Efficient Algorithm for Propagation of Temporal- Constraint Networks; 28) Software for Continuous Replanning During Execution; 29) Surface-Launched Explorers for Reconnaissance/Scouting; 30) Firmware for a Small Motion-Control Processor; 31) Gear Bearings and Gear-Bearing Transmissions; and 32) Linear Dynamometer With Variable Stroke and Frequency
    corecore