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Showing 1 to 20 of 58 for “"block length"”.
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Mixed block length parallel concatenated codes
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2003.
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Variable block length coding for channels with feedback and cost constraints
Variable-decoding-time/generalized block-coding schemes are investigated for discrete memoryless channels (DMC) with perfect feedback (error free, delay free, infinite capacity) under cost constraints. For a given number of messages and average error probability, upper and lower bounds are found …
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The synthesis of amphiphilic diblock copolymers: An investigation into the formation of micelles as a function of hydrophobic block length
<p>Acrylate-based amphiphilic diblock copolymers show great potential for anti-cancer drug transport due to their ability to aggregate into protective core-shell micelles. Using RAFT polymerization, copolymers containing poly(acrylic acid) and poly(methyl acrylate) blocks were made with high …
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Structure-property behavior of free radical synthesized polydimethylsiloxane-polystyrene block polymers and polytetramethyleneoxide based ionene elastomers
… (PDMS) - polystyrene and PDMS-styrene derivative block polymers have been studied. The block polymers were provided by Dr. J. V. Crivello from GE. Two different types of segmented polytetramethyleneoxide (PTMO) based ionene elastomers were also investigated. The PTMO-dihalide ionenes were obtained …
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Synthesis and Characterization of Hydrophobic-Hydrophilic Segmented and Multiblock Copolymers for Proton Exchange Membrane and Reverse Osmosis Applications
… hydrophilic-hydrophobic segmented and multiblock copolymers for application as proton exchange membranes (PEMs) in fuel cells or as reverse osmosis (RO) membranes for water desalination. The first objective was to demonstrate that synthesizing blocky copolymers using a one oligomer, two …
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On the construction of some capacity-approaching coding schemes
… methods operate in opposite regions, one has a block length of one and the other has a block length approaching infinity. The first approach is based on novel memoryless joint source-channel coding schemes. We first show some examples of sources and channels where no coding is optimal for all …
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Morphological and Structure-Property Analyses of Poly(arylene ether sulfone)-Based Random and Multiblock Copolymers for Fuel Cells
… conductivities of random copolymers. Changes in block length, however, have a pronounced effect on multiblock copolymers, affecting surface and bulk morphologies, water uptake, proton conductivity, and hydrolytic stability, suggesting that multiblock copolymer PEM properties may be optimized by …
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Locally decodable source coding
… via the mapping of consecutive source symbols (blocks) into code blocks of fixed or variable length. The fundamental limits in source coding introduces a tradeoff between the rate of compression and the fidelity of the recovery. However, in practical communication systems many issues such as …
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The optimal asset allocation for South African real return investors
… to 2017. The monthly returns are grouped in a block of rolling periods of varying block lengths in order to attempt to capture dependencies across time. These blocks of data are resampled in order to simulate the distributions of returns of portfolios with their own unique empirical …
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A Framework for Spectrally Efficient Noncoherent Communication
… is used to obtain a linear complexity (in the block length) implementation of multiple symbol demodulation of differential PSK. The degradation of this scheme from the exact, exponential complexity, implementation can be made as small as desired. (4) A block transformation is demonstrated to …
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Complexity and second moment of the mathematical theory of communication
… of an error correcting code is evaluated by its block error probability, code rate, and encoding and decoding complexity. The performance of a series of codes is evaluated by, as the block lengths approach infinity, whether their block error probabilities decay to zero, whether their code rates …
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Liquid State Theory of Equilibrium Structure and Thermodynamics of Block Copolymer Melts and Solutions
… thermodynamics and structures of fluids of multiblock polymers both with nonpolar and strongly attracting groups. The physical clustering/aggregation process is probed via the calculation of small and wide angle scattering patterns, real space intermolecular radial distribution functions, and …
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Synthesis and Characterization of Multiblock Copolymers for Proton Exchange Membrane Fuel Cells (PEMFC)
Nanophase-separated hydrophilic-hydrophobic multiblock copolymers are promising proton exchange membrane (PEM) materials due to their ability to form various morphological structures which enhance transport. Four arylene chlorides monomers (2,5-Dichlorobenzophenone and its derivatives) were first …
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Structure-property relationships of multiphase copolymers
… theoretical and phenomenalogical aspects of starblock, di- and tri-block copolymer systems with very narrow molecular weight distributions. However, in many real multiblock systems the effect of such variables as; chemical composition distribution, molecular weight distribution and block …
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Structural and morphological characterization of model elastomeric ion containing polymers
… backbone such as the telechelic ionomers, block ionomers, or the segmented ionomers where the ionene polymers serve as an example. The structure-property behavior of all these three types of ionomers have been investigated in this study. The telechelic ionomers were based on either a …
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Source-channel coding for coordination over a noisy two-node network
… vanishes exponentially fast with the sequence block length. From the general joint scheme, three special cases are constructed, one of which resembles Shannon’s separation scheme. As a surprising result, the proposed joint scheme has been found to be able to perform better than a strictly …
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Synthesis and characterization of stimuli-responsive microgels based on poly(glycidol)block copolymers
… and 4VP to give well-defined stimuli sensitive block copolymers of targeted molar ratio of blocks. The results obtained from light scattering methods showed formation of stable aggregates upon stimuli (pH or temperature) by all the obtained polymers. Additionally, photocrosslinkable block …
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Synthese und kolloidale Eigenschaften neuartiger Blockcopolymere mit beta-Dicarbonyl Einheiten = Synthesis and colloidal properties of a novel type of block copolymers bearing beta-dicarbonyl residues
… synthesis and characterisation of amphiphilic diblock copolymers bearing b-dicarbonyl (acetoacetoxy) chelating residues. Polymers were obtained by Group Transfer Polymerisation (GTP)/acetoacetylation and controlled radical polymerisation techniques (RAFT).Different micellar morphologies of …
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Structure-Property Relationships of Polyisobutylene-Block-Polyamide Thermoplastic Elastomers
… elastically-performing polymer, deemed the “soft block,” is combined with a stiffer “hard block” polymer, each of which can be selected based on their own specific properties in order to achieve desired material behavior in the final copolymer. Recently, the use of polyisobutylene as a soft block …
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Minimum distance of error correcting codes versus encoding complexity, symmetry, and pseudorandomness
… of the code cannot grow linearly with the block length when the rate is nonvanishing. * New upper bounds on the minimum distance of various types of Turbo-like codes. * The first ensemble of asymptotically good Turbo like codes. We prove that depth-three serially concatenated Turbo codes …
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