294,685 research outputs found
Census and ear-notching of black rhinos (Diceros bicornis michaeli) in Tsavo East National Park, Kenya
This paper updates the status of the black rhino population in Tsavo East National Park (NP). Data were acquired through aerial counts of the black rhino between 3 and 9 October 2010 using three fixed-wing husky aircrafts and a Bell 206L helicopter in an area of about 3,300 km2. Based on previous sightings of rhinos, the area was divided into 14 blocks, with each block subdivided into 400 m transects. An aircraft flying at about 500 m above the ground was assigned to carry out the aerial survey following these transects within each block. Observers scanned for rhinos about 200 m on either sides of the flight paths. Intensive searches in areas with dense vegetation, especially along the Galana and Voi Rivers and other known rhino range areas was also carried out by both the huskies and the helicopter. The count resulted in sighting of 11 black rhinos. Seven of these individuals were ear notched and fitted with radio transmitters and the horns were tipped off to discourage poaching. Three of the seven captured rhinos were among the 49 animals translocated to Tsavo East between 1993 and 1999. The other four animals were born in Tsavo East. Two female rhinos and their calves were not ear-notched or fitted with transmitters. It is recommended that another count be carried out immediately after the wet season as the rhinos spend more time in the open areas while the vegetation is still green. The repeat aerail count is to include blocks north of River Galana
Cannon-Thurston Maps,i-bounded Geometry and a theorem of McMullen
The notion of i-bounded geometry generalises simultaneously bounded geometry
and the geometry of punctured torus Kleinian groups. We show that the limit set
of a surface Kleinian group of i-bounded geometry is locally connected by
constructing a natural Cannon-Thurston map. This is an exposition of a special
case of the main result of arXiv:math/0607509.Comment: v3: 32 pages 3 figure
Walks and Paths in Trees
Recently Csikv\'ari \cite{csik} proved a conjecture of Nikiforov concerning
the number of closed walks on trees. Our aim is to extend his theorem to all
walks. In addition, we give a simpler proof of Csikv\'ari's result and answer
one of his questions in the negative. Finally we consider an analogous question
for paths rather than walks
An Implementation of List Successive Cancellation Decoder with Large List Size for Polar Codes
Polar codes are the first class of forward error correction (FEC) codes with
a provably capacity-achieving capability. Using list successive cancellation
decoding (LSCD) with a large list size, the error correction performance of
polar codes exceeds other well-known FEC codes. However, the hardware
complexity of LSCD rapidly increases with the list size, which incurs high
usage of the resources on the field programmable gate array (FPGA) and
significantly impedes the practical deployment of polar codes. To alleviate the
high complexity, in this paper, two low-complexity decoding schemes and the
corresponding architectures for LSCD targeting FPGA implementation are
proposed. The architecture is implemented in an Altera Stratix V FPGA.
Measurement results show that, even with a list size of 32, the architecture is
able to decode a codeword of 4096-bit polar code within 150 us, achieving a
throughput of 27MbpsComment: 4 pages, 4 figures, 4 tables, Published in 27th International
Conference on Field Programmable Logic and Applications (FPL), 201
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