10 research outputs found
Planning Visual Inspection Tours for a 3D Dubins Airplane Model in an Urban Environment
This paper investigates the problem of planning a minimum-length tour for a
three-dimensional Dubins airplane model to visually inspect a series of targets
located on the ground or exterior surface of objects in an urban environment.
Objects are 2.5D extruded polygons representing buildings or other structures.
A visibility volume defines the set of admissible (occlusion-free) viewing
locations for each target that satisfy feasible airspace and imaging
constraints. The Dubins traveling salesperson problem with neighborhoods
(DTSPN) is extended to three dimensions with visibility volumes that are
approximated by triangular meshes. Four sampling algorithms are proposed for
sampling vehicle configurations within each visibility volume to define
vertices of the underlying DTSPN. Additionally, a heuristic approach is
proposed to improve computation time by approximating edge costs of the 3D
Dubins airplane with a lower bound that is used to solve for a sequence of
viewing locations. The viewing locations are then assigned pitch and heading
angles based on their relative geometry. The proposed sampling methods and
heuristics are compared through a Monte-Carlo experiment that simulates view
planning tours over a realistic urban environment.Comment: 18 pages, 10 figures, Presented at 2023 SciTech Intelligent Systems
in Guidance Navigation and Control conferenc
Design and Flight Demonstration of a Quadrotor for Urban Mapping and Target Tracking Research
This paper describes the hardware design and flight demonstration of a small
quadrotor with imaging sensors for urban mapping, hazard avoidance, and target
tracking research. The vehicle is equipped with five cameras, including two
pairs of fisheye stereo cameras that enable a nearly omnidirectional view and a
two-axis gimbaled camera. An onboard NVIDIA Jetson Orin Nano computer running
the Robot Operating System software is used for data collection. An autonomous
tracking behavior was implemented to coordinate the motion of the quadrotor and
gimbaled camera to track a moving GPS coordinate. The data collection system
was demonstrated through a flight test that tracked a moving GPS-tagged vehicle
through a series of roads and parking lots. A map of the environment was
reconstructed from the collected images using the Direct Sparse Odometry (DSO)
algorithm. The performance of the quadrotor was also characterized by acoustic
noise, communication range, battery voltage in hover, and maximum speed tests.Comment: 7 pages, 10 figures, To be presented at IEEE SoutheastCon 202
Differential IRF8 Transcription Factor Requirement Defines Two Pathways of Dendritic Cell Development in Humans
The formation of mammalian dendritic cells (DCs) is controlled by multiple hematopoietic transcription factors, including IRF8. Loss of IRF8 exerts a differential effect on DC subsets, including plasmacytoid DCs (pDCs) and the classical DC lineages cDC1 and cDC2. In humans, cDC2-related subsets have been described including AXL+ SIGLEC6+ pre-DC, DC2 and DC3. The origin of this heterogeneity is unknown. Using highdimensional analysis, in vitro differentiation, and an allelic series of human IRF8 deficiency, we demonstrated that cDC2 (CD1c+ DC) heterogeneity originates from two distinct pathways of development. The lymphoidprimed IRF8hi pathway, marked by CD123 and BTLA, carried pDC, cDC1, and DC2 trajectories, while the common myeloid IRF8lo pathway, expressing SIRPA, formed DC3s and monocytes. We traced distinct trajectories through the granulocyte-macrophage progenitor (GMP) compartment showing that AXL+ SIGLEC6+ pre-DCs mapped exclusively to the DC2 pathway. In keeping with their lower requirement for IRF8, DC3s expand to replace DC2s in human partial IRF8 deficiency
The α1-adrenergic receptors: diversity of signaling networks and regulation
The α1-adrenergic receptor (AR) subtypes (α1a, α1b, and α1d) mediate several physiological effects of epinephrineand norepinephrine. Despite several studies in recombinant systems and insightfrom genetically modified mice, our understanding of the physiological relevance and specificity of the α1-AR subtypes is still limited. Constitutive activity and receptor oligomerization have emerged as potential features regulating receptor function. Another recent paradigm is that βarrestins and G protein-coupled receptors themselves can act as scaffolds binding a variety of proteins and this can result in growing complexity of the receptor-mediated cellular effects. The aim of this review is to summarize our current knowledge on some recently identified functional paradigms and signaling networks that might help to elucidate the functional diversity of the α1-AR subtypes in various organs
IMPLICATION DE LA CAMK II ET DU METABOLISME DES PHOSPHOINOSITIDES DANS LA REGULATION DE L'HOMEOSTARIE CALCIQUE INTRACELLULAIRE
AMIENS-BU Sciences (800212103) / SudocSudocFranceF