7,816 research outputs found
Computing the Ball Size of Frequency Permutations under Chebyshev Distance
Let be the set of all permutations over the multiset
where
. A frequency permutation array (FPA) of minimum distance is a
subset of in which every two elements have distance at least .
FPAs have many applications related to error correcting codes. In coding
theory, the Gilbert-Varshamov bound and the sphere-packing bound are derived
from the size of balls of certain radii. We propose two efficient algorithms
that compute the ball size of frequency permutations under Chebyshev distance.
Both methods extend previous known results. The first one runs in time and space. The second one runs in time and
space. For small constants and ,
both are efficient in time and use constant storage space.Comment: Submitted to ISIT 201
Weighted Shift Matrices: Unitary Equivalence, Reducibility and Numerical Ranges
An -by- () weighted shift matrix is one of the form
[{array}{cccc}0 & a_1 & & & 0 & \ddots & & & \ddots & a_{n-1} a_n & & &
0{array}], where the 's, called the weights of , are complex numbers.
Assume that all 's are nonzero and is an -by- weighted shift
matrix with weights . We show that is unitarily equivalent to
if and only if and, for some fixed , , () for all . Next, we show that
is reducible if and only if has periodic weights, that is, for some
fixed , , is divisible by , and
for all . Finally, we prove that and
have the same numerical range if and only if and
for all , where 's are the circularly symmetric functions.Comment: 27 page
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Multimodal News Summarization, Tracking and Annotation Incorporating Tensor Analysis of Memes
We demonstrate four novel multimodal methods for efficient video summarization and comprehensive cross-cultural news video understanding.
First, For video quick browsing, we demonstrate a multimedia event recounting system. Based on nine people-oriented design principles, it summarizes YouTube-like videos into short visual segments (812sec) and textual words (less than 10 terms). In the 2013 Trecvid Multimedia Event Recounting competition, this system placed first in recognition time efficiency, while remaining above average in description accuracy.
Secondly, we demonstrate the summarization of large amounts of online international news videos. In order to understand an international event such as Ebola virus, AirAsia Flight 8501 and Zika virus comprehensively, we present a novel and efficient constrained tensor factorization algorithm that first represents a video archive of multimedia news stories concerning a news event as a sparse tensor of order 4. The dimensions correspond to extracted visual memes, verbal tags, time periods, and cultures. The iterative algorithm approximately but accurately extracts coherent quad-clusters, each of which represents a significant summary of an important independent aspect of the news event. We give examples of quad-clusters extracted from tensors with at least 108 entries derived from international news coverage. We show the method is fast, can be tuned to give preferences to any subset of its four dimensions, and exceeds three existing methods in performance.
Thirdly, noting that the co-occurrence of visual memes and tags in our summarization result is sparse, we show how to model cross-cultural visual meme influence based on normalized PageRank, which more accurately captures the rates at which visual memes are reposted in a specified time period in a specified culture.
Lastly, we establish the correspondences of videos and text descriptions in different cultures by reliable visual cues, detect culture-specific tags for visual memes and then annotate videos in a cultural settings. Starting with any video with less text or no text in one culture (say, US), we select candidate annotations in the text of another culture (say, China) to annotate US video. Through analyzing the similarity of images annotated by those candidates, we can derive a set of proper tags from the viewpoints of another culture (China). We illustrate cultural-based annotation examples by segments of international news. We evaluate the generated tags by cross-cultural tag frequency, tag precision, and user studies
Influence of migration policy risk on international market segmentation: analysis of housing and rental markets in the euro area
This paper aims to discuss the influence of migration policy risk
on market segmentation of housing and rental markets in the
Euro Area. Policy risk is represented by the Migration Policy
Uncertainty Index (MPUI) and Migration Fear Index (MFI) of
Germany and the United Kingdom; in this study, whether these
indexes influence the interaction between the housing and rental
markets of the two countries and euro-area countries was examined.
The empirical results showed that the influence of the
United Kingdom’s migration policy risk on the euro-area countries
is higher than that of Germany. The United Kingdom’s MPUI and
MFI significantly contribute to the influence of the United
Kingdom’s housing market on other markets except for Belgium
and Spain. Compared with housing market connectedness, the
rental market connectedness is less influenced by migration policy
risk and migration fear. This may be because variables related
to short-term residence policies influence the rental market. The
high policy risk is more likely to influence decisions related to
long-term house purchase, but not those related to short-term
residence. Finally, this study found that the higher the uncertainty
of the migration policies of the United Kingdom and Germany is,
the higher the house market segmentation is
Biodegradation of phenol and 2-chlorophenol using a fill-and-draw-reactor
The biological degradation of phenol and 2-chlorophenol was studied at room temperature in a microprocesser controlled fill-and-draw reactor using activated sludge from the Passaic Valley Sewerage Commissioners wastewater treatment plant (Newark, New Jersey). The reactor was cycled through four unit processes: fill, react, settle, and draw. Different cycle times were tested, and the system response was characterized by dissolved oxygen measurements and substrate analysis (by gas chromatography).
With inhibitory substrates, such as those tested, this reactor had much more flexibility, and was therefore much easier to operate, than a standard continuous flow reactor
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