Random linear fountain codes were introduced in the last lecture as a sparse-graph codes for channels with erasure. It turned out that their encoding and decoding costs were quadratic and cubic in the number of packets encoded. We study Luby Transform (LT) codes in this lecture, pioneered by Michael Luby, that retains the good performance of random linear fountain code, while drastically reduci...

We have observed that the collisional frequency shift in primary caesium fountain clocks varies with the clock state population composition and, in particular, is zero for a given fraction of the |F=4,mF=0) atoms, depending on the initial cloud parameters. We present a theoretical model explaining our observations. The possibility of the collisional shift cancellation implies an improvement in ...

This paper proposes a universal variable-length lossless compression algorithm based on fountain codes. The compressor concatenates the Burrows-Wheeler block sorting transform (BWT) with a fountain encoder, together with the closed-loop iterative doping algorithm. The decompressor uses a Belief Propagation algorithm in conjunction with the iterative doping algorithm and the inverse BWT. Linear-...

Atomization of liquid into the air attained through submerged ultrasound irradiation will involve formation fountain, which exhibits a sequence oscillating and/or intermittent characteristics/events: its vertical/axial growth and breakup; lateral “compound swinging”; associated dynamics mist spreading. This study attempts to provide mechanistic view ultrasonic atomization (UsA) process in terms...

Field and laboratory studies were carried out to test factors expected to be relevant for the germination of fountain grass: (1) light; (2) emergence of fountain grass seedlings from depths of 0, 2.5, and 5 cm; (3) fire passing over exposed and buried seeds; (4) laboratory heat treatment mimicking exposure to grass fire. Both fire in the field and heat applied in the laboratory killed fountain ...

Background and purpose: School, as a reliable place in educating students, has an important role in training. The aim of this study was the assessment of environmental health of primary schools in Norabad Mamasani city of Fars Province. Materials and Methods: In this analytical-descriptive and cross-sectional study, all of 26 primary schools in Norabad Mamasani city were surveyed by using cens...

In the uncertainty budget of primary atomic cesium fountain clocks, evaluations of frequency-pulling shifts of the hyperfine clock transition caused by unintentional excitation of its nearby transitions (Rabi and Ramsey pulling) have been based so far on an approach developed for cesium beam clocks. We re-evaluate this type of frequency pulling in fountain clocks and pay particular attention to...

Digital fountain codes were originally packet-level forward erasure codes, but researchers have found that they are good at correcting bit errors. Modern LDPC and turbo codes have been shown to approach the Shannon limit. However, they are fixed rate codes and cannot well satisfy the Internet services that may encounter variable loss rates or asynchronous data access. For both packet and bit le...