5 research outputs found
Real-Time Mapping Using Stereoscopic Vision Optimization
This research focuses on efficient methods of generating 2D maps from stereo vision in real-time. Instead of attempting to locate edges between objects, we make the assumption that the representative surfaces of objects in a view provide enough information to generate a map while taking less time to locate during processing. Since all real-time vision processing endeavors are extremely computationally intensive, numerous optimization techniques are applied to allow for a real-time application: horizontal spike smoothing for post-disparity noise, masks to focus on close-proximity objects, melding for object synthesis, and rectangular fitting for object extraction under a planar assumption. Additionally, traditional image transformation mechanisms such as rotation, translation, and scaling are integrated. Results from our research are an encouraging 10Hz with no vision post processing and accuracy up to 11 feet. Finally, vision mapping results are compared to simultaneously collected sonar data in three unique experimental settings
Fusion-layer-based machine vision for intelligent transportation systems/
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 307-317).Environment understanding technology is very vital for intelligent vehicles that are expected to automatically respond to fast changing environment and dangerous situations. To obtain perception abilities, we should automatically detect static and dynamic obstacles, and obtain their related information, such as, locations, speed, collision/occlusion possibility, and other dynamic current/historic information. Conventional methods independently detect individual information, which is normally noisy and not very reliable. Instead we propose fusion-based and layered-based information-retrieval methodology to systematically detect obstacles and obtain their location/timing information for visible and infrared sequences. The proposed obstacle detection methodologies take advantage of connection between different information and increase the computational accuracy of obstacle information estimation, thus improving environment understanding abilities, and driving safety.by Yajun Fang.Ph.D
On the relationship between neuronal codes and mental models
Das ĂŒbergeordnete Ziel meiner Arbeit an dieser Dissertation
war ein besseres VerstÀndnis des Zusammenhangs
von mentalen Modellen
und den zugrundeliegenden Prinzipien,
die zur Selbstorganisation neuronaler Verschaltung fĂŒhren.
Die Dissertation besteht aus vier individuellen Publikationen,
die dieses Ziel aus unterschiedlichen Perspektiven angehen.
WÀhrend die Selbstorganisation von Sparse-Coding-ReprÀsentationen
in neuronalem Substrat
bereits ausgiebig untersucht worden ist,
sind viele Forschungsfragen dazu,
wie Sparse-Coding fĂŒr höhere, kognitive Prozesse genutzt werden könnte
noch offen.
Die ersten zwei Studien,
die in Kapitel 2 und Kapitel 3 enthalten sind,
behandeln die Frage,
inwieweit ReprÀsentationen, die mit Sparse-Coding entstehen,
mentalen Modellen entsprechen.
Wir haben folgende SelektivitÀten
in Sparse-Coding-ReprÀsentationen identifiziert:
mit Stereo-Bildern als Eingangsdaten
war die ReprĂ€sentation selektiv fĂŒr die DisparitĂ€ten von Bildstrukturen,
welche fĂŒr das AbschĂ€tzen der Entfernung der Strukturen zum Beobachter genutzt werden können.
AuĂerdem war die ReprĂ€sentation selektiv fĂŒr die die vorherrschende Orientierung in Texturen,
was fĂŒr das AbschĂ€tzen der Neigung von OberflĂ€chen genutzt werden kann.
Mit optischem Fluss von Eigenbewegung als Eingangsdaten
war die ReprĂ€sentation selektiv fĂŒr die Richtung der Eigenbewegung
in den sechs Freiheitsgraden.
Wegen des direkten Zusammenhangs der SelektivitÀten mit physikalischen Eigenschaften
können ReprÀsentationen, die mit Sparse-Coding entstehen,
als frĂŒhe sensorische Modelle der Umgebung dienen.
Die kognitiven Prozesse hinter rÀumlichem Wissen
ruhen auf mentalen Modellen, welche die Umgebung representieren.
Wir haben in der dritten Studie,
welche in Kapitel 4 enthalten ist,
ein topologisches Modell zur Navigation prÀsentiert,
Es beschreibt einen dualen Populations-Code,
bei dem der erste Populations-Code Orte anhand von Orts-Feldern (Place-Fields) kodiert
und der zweite Populations-Code Bewegungs-Instruktionen,
basierend auf der VerknĂŒpfung von Orts-Feldern, kodiert.
Der Fokus lag nicht auf der Implementation in biologischem Substrat
oder auf einer exakten Modellierung physiologischer Ergebnisse.
Das Modell ist eine biologisch plausible, einfache Methode zur Navigation,
welche sich an einen Zwischenschritt emergenter Navigations-FĂ€higkeiten
in einer evolutiven Navigations-Hierarchie annÀhert.
Unser automatisierter Test der Sehleistungen von MĂ€usen,
welcher in Kapitel 5 beschrieben wird,
ist ein Beispiel von Verhaltens-Tests
im Wahrnehmungs-Handlungs-Zyklus (Perception-Action-Cycle).
Das Ziel dieser Studie war die Quantifizierung des optokinetischen Reflexes.
Wegen des reichhaltigen Verhaltensrepertoires von MĂ€usen
sind fĂŒr die Quantifizierung viele umfangreiche Analyseschritte erforderlich.
Tiere und Menschen sind verkörperte (embodied) lebende Systeme
und daher aus stark miteinander verwobenen Modulen oder EntitÀten zusammengesetzt,
welche auĂerdem auch mit der Umgebung verwoben sind.
Um lebende Systeme als Ganzes zu studieren
ist es notwendig Hypothesen,
zum Beispiel zur Natur mentaler Modelle,
im Wahrnehmungs-Handlungs-Zyklus zu testen.
Zusammengefasst erweitern die Studien dieser Dissertation
unser VerstĂ€ndnis des Charakters frĂŒher sensorischer ReprĂ€sentationen als mentale Modelle,
sowie unser VerstĂ€ndnis höherer, mentalen Modellen fĂŒr die rĂ€umliche Navigation.
DarĂŒber hinaus enthĂ€lt es ein Beispiel
fĂŒr das Evaluieren von Hypothesn im Wahr\-neh\-mungs-Handlungs-Zyklus.The superordinate aim of my work towards this thesis
was a better understanding
of the relationship between mental models
and the underlying principles that lead to the self-organization
of neuronal circuitry.
The thesis consists of four individual publications,
which approach this goal from differing perspectives.
While the formation of sparse coding representations in neuronal substrate
has been investigated extensively,
many research questions
on how sparse coding may be exploited for higher cognitive processing
are still open.
The first two studies,
included as chapter 2 and chapter 3,
asked to what extend representations obtained with sparse coding
match mental models.
We identified the following selectivities in sparse coding representations:
with stereo images as input,
the representation was selective for the disparity of image structures,
which can be used to infer the distance of structures to the observer.
Furthermore, it was selective to the predominant orientation in textures,
which can be used to infer the orientation of surfaces.
With optic flow from egomotion as input,
the representation was selective to the direction of egomotion
in 6 degrees of freedom.
Due to the direct relation between selectivity and physical properties,
these representations, obtained with sparse coding,
can serve as early sensory models of the environment.
The cognitive processes behind spatial knowledge
rest on mental models that represent the environment.
We presented a topological model for wayfinding
in the third study,
included as chapter 4.
It describes a dual population code,
where the first population code encodes places
by means of place fields,
and the second population code encodes motion instructions
based on links between place fields.
We did not focus on an implementation in biological substrate
or on an exact fit to physiological findings.
The model is a biologically plausible, parsimonious method for wayfinding,
which may be close to an intermediate step
of emergent skills in an evolutionary navigational hierarchy.
Our automated testing for visual performance in mice,
included in chapter 5,
is an example of behavioral testing in the perception-action cycle.
The goal of this study was to quantify the optokinetic reflex.
Due to the rich behavioral repertoire of mice,
quantification required many elaborate steps of computational analyses.
Animals and humans are embodied living systems,
and therefore composed of strongly enmeshed modules or entities,
which are also enmeshed with the environment.
In order to study living systems as a whole,
it is necessary to test hypothesis,
for example on the nature of mental models,
in the perception-action cycle.
In summary,
the studies included in this thesis
extend our view on the character of early sensory representations
as mental models,
as well as on high-level mental models
for spatial navigation.
Additionally it contains an example
for the evaluation of hypotheses in the perception-action cycle
Forum Bildverarbeitung 2016
Bildverarbeitung spielt in vielen Bereichen der Technik zur schnellen und berĂŒhrungslosen Datenerfassung eine SchlĂŒsselrolle. Der vorliegende Tagungsband des âForums Bildverarbeitungâ, das am 1. und 2. Dezember 2016 in Karlsruhe als Veranstaltung des Karlsruher Instituts fĂŒr Technologie und des Fraunhofer-Instituts fĂŒr Optronik, Systemtechnik und Bildauswertung stattfand, enthĂ€lt die AufsĂ€tze der eingegangenen BeitrĂ€ge. Darin wird ĂŒber aktuelle Trends und Lösungen der Bildverarbeitung berichtet
Craniofacial anomalies in children: diagnosis, management, outcomes
The causes of facial anomalies in children may be congenital, traumatic, oncologic (or in some cases) remain unknown. Many of these craniofacial conditions warrant further elucidation of the clinical features, to allow accurate diagnosis and targeted management. Long term outcome studies of children with craniofacial anomalies, are essential to evaluate treatment protocols and to aid those who treat affected children to improve and advance their standards of care. These objectives require clinicians, along with their scientific colleagues to strive to increase their recognition of morphological anomalies and understanding of the underlying disease processes, so as to develop specific management strategies. The aim is to find new answers to improve the quality of life of affected children throughout the world. This collection of papers has been prompted by a desire to contribute towards that goal