413 research outputs found
Extending OpenVX for Model-based Design of Embedded Vision Applications
Developing computer vision applications for lowpower heterogeneous systems is increasingly gaining interest in the embedded systems community. Even more interesting is the tuning of such embedded software for the target architecture when this is driven by multiple constraints (e.g., performance, peak power, energy consumption). Indeed, developers frequently run into system-level inefficiencies and bottlenecks that can not be quickly addressed by traditional methods. In this context OpenVX has been proposed as the standard platform to develop portable, optimized and powerefficient applications for vision algorithms targeting embedded systems. Nevertheless, adopting OpenVX for rapid prototyping, early algorithm parametrization and validation of complex embedded applications is a very challenging task. This paper presents a methodology to integrate a model-based design environment to OpenVX. The methodology allows applying Matlab/Simulink for the model-based design, parametrization, and validation of computer vision applications. Then, it allows for the automatic synthesis of the application model into an OpenVX description for the hardware and constraints-aware application tuning. Experimental results have been conducted with an application for digital image stabilization developed through Simulink and, then, automatically synthesized into OpenVX-VisionWorks code for an NVIDIA Jetson TX1 boar
On number fields with nontrivial subfields
What is the probability for a number field of composite degree to have a
nontrivial subfield? As the reader might expect the answer heavily depends on
the interpretation of probability. We show that if the fields are enumerated by
the smallest height of their generators the probability is zero, at least if
. This is in contrast to what one expects when the fields are enumerated
by the discriminant. The main result of this article is an estimate for the
number of algebraic numbers of degree and bounded height which generate
a field that contains an unspecified subfield of degree . If
we get the correct asymptotics as the height tends to
infinity
Lang's Conjecture and Sharp Height Estimates for the elliptic curves
For elliptic curves given by the equation , we
establish the best-possible version of Lang's conjecture on the lower bound of
the canonical height of non-torsion points along with best-possible upper and
lower bounds for the difference between the canonical and logarithmic height.Comment: published version. Lemmas 5.1 and 6.1 now precise (with resultant
refinement to Theorem 1.2). Small corrections to
A remark on the trace-map for the Silver mean sequence
In this work we study the Silver mean sequence based on substitution rules by
means of a transfer-matrix approach. Using transfer-matrix method we find a
recurrence relation for the traces of general transfer-matrices which
characterizes electronic properties of the quasicrystal in question. We also
find an invariant of the trace-map.Comment: 5 pages, minor improvements in style and presentation of calculation
Section Extension from Hyperbolic Geometry of Punctured Disk and Holomorphic Family of Flat Bundles
The construction of sections of bundles with prescribed jet values plays a
fundamental role in problems of algebraic and complex geometry. When the jet
values are prescribed on a positive dimensional subvariety, it is handled by
theorems of Ohsawa-Takegoshi type which give extension of line bundle valued
square-integrable top-degree holomorphic forms from the fiber at the origin of
a family of complex manifolds over the open unit 1-disk when the curvature of
the metric of line bundle is semipositive. We prove here an extension result
when the curvature of the line bundle is only semipositive on each fiber with
negativity on the total space assumed bounded from below and the connection of
the metric locally bounded, if a square-integrable extension is known to be
possible over a double point at the origin. It is a Hensel-lemma-type result
analogous to Artin's application of the generalized implicit function theorem
to the theory of obstruction in deformation theory. The motivation is the need
in the abundance conjecture to construct pluricanonical sections from flatly
twisted pluricanonical sections. We also give here a new approach to the
original theorem of Ohsawa-Takegoshi by using the hyperbolic geometry of the
punctured open unit 1-disk to reduce the original theorem of Ohsawa-Takegoshi
to a simple application of the standard method of constructing holomorphic
functions by solving the d-bar equation with cut-off functions and additional
blowup weight functions
Assessment of Axial Postural Abnormalities in Parkinsonism: Automatic Picture Analysis Software
BackgroundSoftware-based measurements of axial postural abnormalities in Parkinson's disease (PD) are the gold standard but may be time-consuming and not always feasible in clinical practice. An automatic and reliable software to accurately obtain real-time spine flexion angles according to the recently proposed consensus-based criteria would be a useful tool for both research and clinical practice. ObjectiveWe aimed to develop and validate a new software based on Deep Neural Networks to perform automatic measures of PD axial postural abnormalities. MethodsA total of 76 pictures from 55 PD patients with different degrees of anterior and lateral trunk flexion were used for the development and pilot validation of a new software called AutoPosturePD (APP); postural abnormalities were measured in lateral and posterior view using the freeware NeuroPostureApp (gold standard) and compared with the automatic measurement provided by the APP. Sensitivity and specificity for the diagnosis of camptocormia and Pisa syndrome were assessed. ResultsWe found an excellent agreement between the new APP and the gold standard for lateral trunk flexion (intraclass correlation coefficient [ICC] 0.960, IC95% 0.913-0.982, P < 0.001), anterior trunk flexion with thoracic fulcrum (ICC 0.929, IC95% 0.846-0.968, P < 0.001) and anterior trunk flexion with lumbar fulcrum (ICC 0.991, IC95% 0.962-0.997, P < 0.001). Sensitivity and specificity were 100% and 100% for detecting Pisa syndrome, 100% and 95.5% for camptocormia with thoracic fulcrum, 100% and 80.9% for camptocormia with lumbar fulcrum. ConclusionsAutoPosturePD is a valid tool for spine flexion measurement in PD, accurately supporting the diagnosis of Pisa syndrome and camptocormia
A Cross-level Verification Methodology for Digital IPs Augmented with Embedded Timing Monitors
Smart systems implement the leading technology advances in the context of embedded devices. Current design methodologies are not suitable to deal with tightly interacting subsystems of different technological domains, namely analog, digital, discrete and power devices, MEMS and power sources. The interaction effects between the components and between the environment and the system must be modeled and simulated at system level to achieve high performance. Focusing on digital subsystem, additional design constraints have to be considered as a result of the integration of multi-domain subsystems in a single device. The main digital design challenges combined with those emerging from the heterogeneous nature of the whole system directly impact on performance, hence propagation delay, of the digital component. In this paper we propose a design approach to enhance the RTL model of a given digital component for the integration in smart systems, and a methodology to verify the added features at system-level. The design approach consists of ``augmenting'' the RTL model through the automatic insertion of delay sensors, which are capable of detecting and correcting timing failures. The verification methodology consists of an automatic flow of two steps. Firstly the augmented model is abstracted to system-level (i.e., SystemC TLM); secondly mutants, which are code mutations to emulate timing failures, are automatically injected into the abstracted model. Experimental results demonstrate the applicability of the proposed design and verification methodology and the effectiveness of the simulation performance
Addressing the Smart Systems Design Challenge: The SMAC Platform
This article presents the concepts, the organization, and the preliminary application results of SMAC, a smart systems co-design platform. The SMAC platform, which has been developed as Integrated Project (IP) of the 7th ICT Call under the Objective 3.2 \u201cSmart components and Smart Systems integration\u201d addresses the challenges of the integration of heterogeneous and conflicting domains that emerge in the design of smart systems. SMAC includes methodologies and EDA tools enabling multi-disciplinary and multi-scale modelling and design, simulation of multidomain systems, subsystems and components at different levels of abstraction, system integration and exploration for optimization of functional and non-functional metrics. The article presents the preliminary results obtained by adopting the SMAC platform for the design of a limb tracking smart system
On certain infinite extensions of the rationals with Northcott property
A set of algebraic numbers has the Northcott property if each of its subsets
of bounded Weil height is finite. Northcott's Theorem, which has many
Diophantine applications, states that sets of bounded degree have the Northcott
property. Bombieri, Dvornicich and Zannier raised the problem of finding fields
of infinite degree with this property. Bombieri and Zannier have shown that
\IQ_{ab}^{(d)}, the maximal abelian subfield of the field generated by all
algebraic numbers of degree at most , is such a field. In this note we give
a simple criterion for the Northcott property and, as an application, we deduce
several new examples, e.g.
\IQ(2^{1/d_1},3^{1/d_2},5^{1/d_3},7^{1/d_4},11^{1/d_5},...) has the Northcott
property if and only if
tends to infinity
On some notions of good reduction for endomorphisms of the projective line
Let be an endomorphism of \SR(\bar{\Q}), the projective line over
the algebraic closure of \Q, of degree defined over a number field
. Let be a non-archimedean valuation of . We say that has
critically good reduction at if any pair of distinct ramification points of
do not collide under reduction modulo and the same holds for any
pair of branch points. We say that has simple good reduction at if
the map , the reduction of modulo , has the same degree of
. We prove that if has critically good reduction at and the
reduction map is separable, then has simple good reduction at
.Comment: 15 page
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