8,622 research outputs found
Adaptive thresholding in dynamic scene analysis for extraction of fine line
This paper presents an adaptive threshold method whereby a fine thin line of one-pixel width lines could be detected in a gray level images. The proposed method uses the percentage difference between the mean of the pixels within a window and the center pixel. The minimum threshold value however is heuristically set to 32. If the percentage difference is greater than 40% then the threshold value will be set to the difference value. This method has been applied in detecting moving objects with fine lines and the results showed that the method was able to pickup straight thin edges that belong to the moving objec
On the Capacity of the Finite Field Counterparts of Wireless Interference Networks
This work explores how degrees of freedom (DoF) results from wireless
networks can be translated into capacity results for their finite field
counterparts that arise in network coding applications. The main insight is
that scalar (SISO) finite field channels over are analogous
to n x n vector (MIMO) channels in the wireless setting, but with an important
distinction -- there is additional structure due to finite field arithmetic
which enforces commutativity of matrix multiplication and limits the channel
diversity to n, making these channels similar to diagonal channels in the
wireless setting. Within the limits imposed by the channel structure, the DoF
optimal precoding solutions for wireless networks can be translated into
capacity optimal solutions for their finite field counterparts. This is shown
through the study of the 2-user X channel and the 3-user interference channel.
Besides bringing the insights from wireless networks into network coding
applications, the study of finite field networks over also
touches upon important open problems in wireless networks (finite SNR, finite
diversity scenarios) through interesting parallels between p and SNR, and n and
diversity.Comment: Full version of paper accepted for presentation at ISIT 201
Coolant side heat transfer with rotation: User manual for 3D-TEACH with rotation
This program solves the governing transport equations in Reynolds average form for the flow of a 3-D, steady state, viscous, heat conducting, multiple species, single phase, Newtonian fluid with combustion. The governing partial differential equations are solved in physical variables in either a Cartesian or cylindrical coordinate system. The effects of rotation on the momentum and enthalpy calculations modeled in Cartesian coordinates are examined. The flow of the fluid should be confined and subsonic with a maximum Mach number no larger than 0.5. This manual describes the operating procedures and input details for executing a 3D-TEACH computation
Distributed Data Storage with Minimum Storage Regenerating Codes - Exact and Functional Repair are Asymptotically Equally Efficient
We consider a set up where a file of size M is stored in n distributed
storage nodes, using an (n,k) minimum storage regenerating (MSR) code, i.e., a
maximum distance separable (MDS) code that also allows efficient exact-repair
of any failed node. The problem of interest in this paper is to minimize the
repair bandwidth B for exact regeneration of a single failed node, i.e., the
minimum data to be downloaded by a new node to replace the failed node by its
exact replica. Previous work has shown that a bandwidth of B=[M(n-1)]/[k(n-k)]
is necessary and sufficient for functional (not exact) regeneration. It has
also been shown that if k < = max(n/2, 3), then there is no extra cost of exact
regeneration over functional regeneration. The practically relevant setting of
low-redundancy, i.e., k/n>1/2 remains open for k>3 and it has been shown that
there is an extra bandwidth cost for exact repair over functional repair in
this case. In this work, we adopt into the distributed storage context an
asymptotically optimal interference alignment scheme previously proposed by
Cadambe and Jafar for large wireless interference networks. With this scheme we
solve the problem of repair bandwidth minimization for (n,k) exact-MSR codes
for all (n,k) values including the previously open case of k > \max(n/2,3). Our
main result is that, for any (n,k), and sufficiently large file sizes, there is
no extra cost of exact regeneration over functional regeneration in terms of
the repair bandwidth per bit of regenerated data. More precisely, we show that
in the limit as M approaches infinity, the ratio B/M = (n-1)/(k(n-k))$
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