Personalized Navigation Instruments for Map User Interfaces

A map is a big multi-scale information space. The size of a computer display, however, is limited. Users of digital maps often need to repeatedly resize and reposition the map to seek information. These repeated and excess interactions mar the user experience, and create bottlenecks for efficient information processing. We introduce personalized navigation instruments, a class of navigation instruments that leverage personal important spatial entities (e.g., landmarks and routes) to tackle navigation challenges in map user interfaces. Specifically, we contribute the following three instruments, each of which embodies a novel research idea: 1) Personalized Compass (P-Compass) is a multi-needle compass that extends the concept of a conventional compass to help users establish a reference frame. P-Compass localizes an unknown reference point by visualizing its relationship with respect to landmarks. P-Compass leverages what a user knows to help them figure out what they do not know. 2) SpaceTokens are interactive map widgets that represent locations, and help users see and link locations rapidly. With SpaceTokens, users can use locations directly as controls to manipulate a map, or building blocks to link with other locations. SpaceTokens make locations first-class citizens of map interaction. 3) SpaceBar associates a simple linear scrollbar with a complex nonlinear route, thus facilitates efficient route comprehension and interaction. SpaceBar is akin to a scrollbar for a route. We prototyped these three instruments in a custom smartphone application, used the application regularly in daily life, and validated our design in two formal studies. While maps are the focus in this dissertation, our ideas need not be limited to maps. For example, we have prototyped P-Compass with Google Street View and a 3D virtual earth tour application. We conclude this dissertation with several directions for future work, such as AR/VR and personalized spatial information user interfaces involving sound, gestures, and speech

Focal Sweep Camera for Space-Time Refocusing

A conventional camera has a limited depth of field (DOF), which often results in defocus blur and loss of image detail. The technique of image refocusing allows a user to interactively change the plane of focus and DOF of an image after it is captured. One way to achieve refocusing is to capture the entire light field. But this requires a significant compromise of spatial resolution. This is because of the dimensionality gap - the captured information (a light field) is 4-D, while the information required for refocusing (a focal stack) is only 3-D. In this paper, we present an imaging system that directly captures a focal stack by physically sweeping the focal plane. We first describe how to sweep the focal plane so that the aggregate DOF of the focal stack covers the entire desired depth range without gaps or overlaps. Since the focal stack is captured in a duration of time when scene objects can move, we refer to the captured focal stack as a duration focal stack. We then propose an algorithm for computing a space-time in-focus index map from the focal stack, which represents the time at which each pixel is best focused. The algorithm is designed to enable a seamless refocusing experience, even for textureless regions and at depth discontinuities. We have implemented two prototype focal-sweep cameras and captured several duration focal stacks. Results obtained using our method can be viewed at www.focalsweep.com

Prognostic Values of Tumor Necrosis Factor/Cachectin, Interleukin-l, Interferon-α, and Interferon-γ in the Serum of Patients with Septic Shock

Serum concentrations of immunoreactive tumor necrosis factor/cachectin (TNF), interleukin-1β (IL-1β), interferon-γ (IFNγ, and interferon-α (IFNα) were prospectively measured in 70 patients with septic shock to determine their evolution and prognostic values. In a univariate analysis, levels of TNF (P = .002) and IL-1β (P = .05) were associated with the patient's outcome, but not IFNα (P = .15) and IFNγ (P = .26). In contrast, in a stepwise logistic regression analysis, the severity of the underlying disease (P = .01), the age of the patient (P = .02), the documentation of infection (nonbacteremic infections vs. bacteremias, P = .03), the urine output (P = .04), and the arterial pH (P = .05) contributed more significantly to prediction of patient outcome than the serum levels of TNF (P = .07). After 10 days, the median concentration of TNF was undetectable <100 pg/ml) in the survivors, whereas it remained elevated (305 pg/ml, P = .002) in the nonsurvivors. Thus, in patients with septic shock due to various gram-negative bacteria, other parameters than the absolute serum concentration of immunoreactive TNF contributed significantly to the prediction of outcom

Learning Lens Blur Fields

Optical blur is an inherent property of any lens system and is challenging to model in modern cameras because of their complex optical elements. To tackle this challenge, we introduce a high-dimensional neural representation of blur$-$$\textit{the lens blur field}$$-$and a practical method for acquiring it. The lens blur field is a multilayer perceptron (MLP) designed to (1) accurately capture variations of the lens 2D point spread function over image plane location, focus setting and, optionally, depth and (2) represent these variations parametrically as a single, sensor-specific function. The representation models the combined effects of defocus, diffraction, aberration, and accounts for sensor features such as pixel color filters and pixel-specific micro-lenses. To learn the real-world blur field of a given device, we formulate a generalized non-blind deconvolution problem that directly optimizes the MLP weights using a small set of focal stacks as the only input. We also provide a first-of-its-kind dataset of 5D blur fields$-$for smartphone cameras, camera bodies equipped with a variety of lenses, etc. Lastly, we show that acquired 5D blur fields are expressive and accurate enough to reveal, for the first time, differences in optical behavior of smartphone devices of the same make and model

Focal Sweep Videography with Deformable Optics

A number of cameras have been introduced that sweep the focal plane using mechanical motion. However, mechanical motion makes video capture impractical and is unsuitable for long focal length cameras. In this paper, we present a focal sweep telephoto camera that uses a variable focus lens to sweep the focal plane. Our camera requires no mechanical motion and is capable of sweeping the focal plane periodically at high speeds. We use our prototype camera to capture EDOF videos at 20fps, and demonstrate space-time refocusing for scenes with a wide depth range. In addition, we capture periodic focal stacks, and show how they can be used for several interesting applications such as video refocusing and trajectory estimation of moving objects. 1

Gigapixel Computational Imaging

Today, consumer cameras produce photographs with tens of millions of pixels. The recent trend in image sensor resolution seems to suggest that we will soon have cameras with billions of pixels. However, the resolution of any camera is fundamentally limited by geometric aberrations. We derive a scaling law that shows that, by using computations to correct for aberrations, we can create cameras with unprecedented resolution that have low lens complexity and compact form factor. In this paper, we present an architecture for gigapixel imaging that is compact and utilizes a simple optical design. The architecture consists of a ball lens shared by several small planar sensors, and a post-capture image processing stage. Several variants of this architecture are shown for capturing a contiguous hemispherical field of view as well as a complete spherical field of view. We demonstrate the effectiveness of our architecture by showing example images captured with two proof-of-concept gigapixel cameras. 1

BIRDY - Interplanetary CubeSat for planetary geodesy of Small Solar System Bodies (SSSB).

International audienceWe are developing the Birdy concept of a scientific interplanetary CubeSat, for cruise, or proximity operations around a Small body of the Solar System (asteroid, comet, irregular satellite). The scientific aim is to characterise the body's shape, gravity field, and internal structure through imaging and radio-science techniques. Radio-science is now of common use in planetary science (flybys or orbiters) to derive the mass of the scientific target and possibly higher order terms of its gravity field. Its application to a nano-satellite brings the advantage of enabling low orbits that can get closer to the body's surface, hence increasing the SNR for precise orbit determination (POD), with a fully dedicated instrument. Additionally, it can be applied to two or more satellites, on a leading-trailing trajectory, to improve the gravity field determination. However, the application of this technique to CubeSats in deep space, and inter-satellite link has to be proven. Interplanetary CubeSats need to overcome a few challenges before reaching successfully their deep-space objectives: link to ground-segment, energy supply, protection against radiation, etc. Besides, the Birdy CubeSat --- as our basis concept --- is designed to be accompanying a mothercraft, and relies partly on the main mission for reaching the target, as well as on data-link with the Earth. However, constraints to the mothercraft needs to be reduced, by having the CubeSat as autonomous as possible. In this respect, propulsion and auto-navigation are key aspects, that we are studying in a Birdy-T engineering model. We envisage a 3U size CubeSat with radio link, object-tracker and imaging function, and autonomous ionic propulsion system. We are considering two case studies for autonomous guidance, navigation and control, with autonomous propulsion: in cruise and in proximity, necessitating DeltaV up to 2m/s for a total budget of about 50m/s. In addition to the propulsion, in-flight orbit determination (IFOD) and maintenance are studied, through analysis of images by an object-tracker and astrometry of solar system objects in front of background stars. Before going to deep-space, our project will start with BIRDY-1 orbiting the Earth, to validate the concepts of adopted propulsion, IFOD and orbit maintenance, as well as the radio-science and POD

BIRDY - Interplanetary CubeSat for planetary geodesy of Small Solar System Bodies (SSSB).

International audienceWe are developing the Birdy concept of a scientific interplanetary CubeSat, for cruise, or proximity operations around a Small body of the Solar System (asteroid, comet, irregular satellite). The scientific aim is to characterise the body's shape, gravity field, and internal structure through imaging and radio-science techniques. Radio-science is now of common use in planetary science (flybys or orbiters) to derive the mass of the scientific target and possibly higher order terms of its gravity field. Its application to a nano-satellite brings the advantage of enabling low orbits that can get closer to the body's surface, hence increasing the SNR for precise orbit determination (POD), with a fully dedicated instrument. Additionally, it can be applied to two or more satellites, on a leading-trailing trajectory, to improve the gravity field determination. However, the application of this technique to CubeSats in deep space, and inter-satellite link has to be proven. Interplanetary CubeSats need to overcome a few challenges before reaching successfully their deep-space objectives: link to ground-segment, energy supply, protection against radiation, etc. Besides, the Birdy CubeSat --- as our basis concept --- is designed to be accompanying a mothercraft, and relies partly on the main mission for reaching the target, as well as on data-link with the Earth. However, constraints to the mothercraft needs to be reduced, by having the CubeSat as autonomous as possible. In this respect, propulsion and auto-navigation are key aspects, that we are studying in a Birdy-T engineering model. We envisage a 3U size CubeSat with radio link, object-tracker and imaging function, and autonomous ionic propulsion system. We are considering two case studies for autonomous guidance, navigation and control, with autonomous propulsion: in cruise and in proximity, necessitating DeltaV up to 2m/s for a total budget of about 50m/s. In addition to the propulsion, in-flight orbit determination (IFOD) and maintenance are studied, through analysis of images by an object-tracker and astrometry of solar system objects in front of background stars. Before going to deep-space, our project will start with BIRDY-1 orbiting the Earth, to validate the concepts of adopted propulsion, IFOD and orbit maintenance, as well as the radio-science and POD

BIRDY - Planetary Geodesy of Small Bodies _through CubeSats in Autonomous Navigation

International audienceBringing a CubeSat that could autonomously navigate in the vicinity of small bodies would be an ideal platform to perform radio-science from multiple locations at low altitudes that are too risky for a mothercraft. The perturbations due to the asteroid during the orbit or multiple flybys of the CubeSat allow the reconstruction of its detailed gravitational field by planetary geodesy and, eventually, the identification of its internal structure. To this purpose, we are developing the BIRDY concept of interplanetary CubeSat, accompanying a mothercraft for planetary geodesy of small bodies (asteroids, comets, satellites). Besides, classical radio tracking can be coupled to other techniques such as space astrometry and VLBI [1]. Interplanetary CubeSats need to overcome a few challenges before reaching successfully their deep-space objectives: link to ground-segment, energy supply, protection against radiation, etc. Besides, the Birdy CubeSat - as our basis concept - is designed to be accompanying a mothercraft, and relies partly on the main mission for reaching the target, as well as on data-link with the Earth. Autonomous navigation could then provide a way to perform a new kind of planetary geodesy, particularly well adapted to small bodies..Future mission for space exploration or sample return could hence take profit of having accompanying nano-orbiters, as complementary or deported instruments with increased autonomy. Furthermore, in the current context of more and more small satellites being launched in solo or in network/swarms missions, the operational cost of such projects is booming; especially because of the required ground segment. This kind of technology could greatly increase the feasibility of such projects (by moving the decision making to the satellite), for example high frequency imaging of the Earth, Radio Interferometry from space, simultaneous multi-point in situ study of the solar wind, etc. A performant autonomous navigation function for small satellite could hence unlock new scientific missions and commercial applications.This autonomous attitude and orbit determination and control function (a.k.a autonomous navigation) for small satellites, in addition to radio science fro planetary missions, is currently being developed by a Consortium made of laboratories LESIA and IMCCE from Observatory of Paris in France, and the National Cheng Kung University and ODYSSEUS Space Co., Ltd in Taiwan. Before going to deep-space, and performing planetary science, our project will start with BIRDY-1 orbiting the Earth, to validate the concepts of adopted propulsion, IFOD and orbit maintenance, as well as the radio-science.[1] Gurvits, L. et al. 2013. Planetary Radio Interferometry and Doppler Experiment (PRIDE) for the JUICE mission. EPSC 8, 357.This work has been supported by Labex ESEP (ANR N&deg; 2011-LABX-030

BIRDY - Planetary Geodesy of Small Bodies _through CubeSats in Autonomous Navigation

International audienceBringing a CubeSat that could autonomously navigate in the vicinity of small bodies would be an ideal platform to perform radio-science from multiple locations at low altitudes that are too risky for a mothercraft. The perturbations due to the asteroid during the orbit or multiple flybys of the CubeSat allow the reconstruction of its detailed gravitational field by planetary geodesy and, eventually, the identification of its internal structure. To this purpose, we are developing the BIRDY concept of interplanetary CubeSat, accompanying a mothercraft for planetary geodesy of small bodies (asteroids, comets, satellites). Besides, classical radio tracking can be coupled to other techniques such as space astrometry and VLBI [1]. Interplanetary CubeSats need to overcome a few challenges before reaching successfully their deep-space objectives: link to ground-segment, energy supply, protection against radiation, etc. Besides, the Birdy CubeSat - as our basis concept - is designed to be accompanying a mothercraft, and relies partly on the main mission for reaching the target, as well as on data-link with the Earth. Autonomous navigation could then provide a way to perform a new kind of planetary geodesy, particularly well adapted to small bodies..Future mission for space exploration or sample return could hence take profit of having accompanying nano-orbiters, as complementary or deported instruments with increased autonomy. Furthermore, in the current context of more and more small satellites being launched in solo or in network/swarms missions, the operational cost of such projects is booming; especially because of the required ground segment. This kind of technology could greatly increase the feasibility of such projects (by moving the decision making to the satellite), for example high frequency imaging of the Earth, Radio Interferometry from space, simultaneous multi-point in situ study of the solar wind, etc. A performant autonomous navigation function for small satellite could hence unlock new scientific missions and commercial applications.This autonomous attitude and orbit determination and control function (a.k.a autonomous navigation) for small satellites, in addition to radio science fro planetary missions, is currently being developed by a Consortium made of laboratories LESIA and IMCCE from Observatory of Paris in France, and the National Cheng Kung University and ODYSSEUS Space Co., Ltd in Taiwan. Before going to deep-space, and performing planetary science, our project will start with BIRDY-1 orbiting the Earth, to validate the concepts of adopted propulsion, IFOD and orbit maintenance, as well as the radio-science.[1] Gurvits, L. et al. 2013. Planetary Radio Interferometry and Doppler Experiment (PRIDE) for the JUICE mission. EPSC 8, 357.This work has been supported by Labex ESEP (ANR N&deg; 2011-LABX-030