56,352 research outputs found
Personal Papers (MS 80-0002)
No full textLetter from H. J. Ettlinger to I. H. Kempner apologizing for missing the check for the University of Texas Hillel Building Fund that Kempner sent
Personal Papers (MS 80-0002)
No full textLetter from H. J. Ettlinger to I. H. Kempner discussing a letter and check for the University of Texas Hillel Building Fund that Kempner promised
Letter from J. H. Dickens to S. B. Simmons
No full textLetter from J. H. Dickens to S. B. Simmons, concerning check
Letter from J. H. Rumph to S. B. Simmons
No full textLetter from J. H. Rumph to S. B. Simmons, sending in monthly report and check for camp fund drive
The Fed's entry into check clearing reconsidered
No full textCheck collection systems ; Federal Reserve System
Letter from J. H. Rumph to S. B. Simmons
No full textLetter from J. H. Rumph to S. B. Simmons, sending in check for camp fund drive and list of businesses that had assisted him with fundraising
Multilevel Generalised Low-Density Parity-Check Codes
No full textMultilevel coding invoking generalised low-density parity-check component codes is proposed, which is capable of outperforming the classic low-density parity check component codes at a reduced decoding latency
Personal Papers (MS 80-0002)
No full textLetter from Isaac H. Kempner to J. H. Bowling offering a donation check for $100 to the Sam Rayburn Foundation
A 2 h periodic variation in the low-mass X-ray binary Ser X-1
No full textSpectroscopy of the low-mass X-ray binary Ser X-1 using the Gran Telescopio Canarias have revealed a ?2 h periodic variability that is present in the three strongest emission lines. We tentatively interpret this variability as due to orbital motion, making it the first indication of the orbital period of Ser X-1. Together with the fact that the emission lines are remarkably narrow, but still resolved, we show that a main-sequence K dwarf together with a canonical 1.4 M? neutron star gives a good description of the system. In this scenario, the most likely place for the emission lines to arise is the accretion disc, instead of a localized region in the binary (such as the irradiated surface or the stream-impact point), and their narrowness is due instead to the low inclination (?10°) of Ser X-1
Multilevel structured low-density parity-check codes
No full textLow-Density Parity-Check (LDPC) codes are typically characterized by a relatively high-complexity description, since a considerable amount of memory is required in order to store their code description, which can be represented either by the connections of the edges in their Tanner graph or by the non-zero entries in their parity-check matrix (PCM). This problem becomes more pronounced for pseudo-random LDPC codes, where literally each non-zero entry of their PCM has to be enumerated, and stored in a look-up table. Therefore, they become inadequate for employment in memoryconstrainedtransceivers. Motivated by this, we are proposing a novel family of structured LDPC codes, termed as Multilevel Structured (MLS) LDPC codes, which benefit from reduced storage requirements, hardware-friendly implementations as well as from low-complexity encoding and decoding. Our simulation results demonstrate that these advantages accrue without any compromise in their attainable Bit Error Ratio (BER) performance, when compared to their previously proposed more complex counterparts of the same code-length. In particular, wecharacterize a half-rate quasi-cyclic (QC) MLS LDPC code having a block length of 8064 that can be uniquely and unambiguously described by as few as 144 edges, despite exhibiting an identical BER performance over both Additive White Gaussian Noise (AWGN) and uncorrelated Rayleigh (UR) channels, when compared to a pseudorandom construction, which requires the enumeration of a significantly higher number of 24,192 edges
- …
