796 research outputs found
A turbo-decoding message-passing algorithm for sparse parity-check matrix codes
No full textA turbo-decoding message-passing (TDMP) algorithm for sparse parity-check matrix (SPCM) codes such as low-density parity-check, repeat-accumulate, and turbo-like codes is presented. The main advantages of the proposed algorithm over the standard decoding algorithm are 1) its faster convergence speed by a factor of two in terms of decoding iterations, 2) improvement in coding gain by an order of magnitude at high signal-to-noise ratio (SNR), 3) reduced memory requirements, and 4) reduced decoder complexity. In addition, an efficient algorithm for message computation using simple max operations is also presented. Analysis using EXIT charts shows that the TDMP algorithm offers a better performance-complexity tradeoff when the number of decoding iterations is small, which is attractive for high-speed applications. A parallel version of the TDMP algorithm in conjunction with architecture-aware (AA) SPCM codes, which have embedded structure that enables efficient high-throughput decoder implementation, are presented. Design examples of AA-SPCM codes based on graphs with large girth demonstrate that AA-SPCM codes have very good error-correcting capability using the TDMP algorithm. © 2006 IEEE.BAHL LR, 1974, IEEE T INFORM THEORY, V20, P284, DOI 10.1109-TIT.1974.1055186; Bangerter B., 2003, INTEL TECHNOL J, V7; BENES VE, 1964, ATandT TECH J, V43, P1641; BERROU C, 1993, IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS 93 : TECHNICAL PROGRAM, CONFERENCE RECORD, VOLS 1-3, P1064, DOI 10.1109-ICC.1993.397441; Blanksby AJ, 2002, IEEE J SOLID-ST CIRC, V37, P404, DOI 10.1109-4.987093; Brink S. T., 2001, IEEE T COMMUN, V49, P1727; Divsalar D., 1998, Proceedings. Thiry-Sixth Annual Allerton Conference on Communication, Control, and Computing; FAN J, LDPC EFFICIENT ALTER; Gallager R., 1963, LOW DENSITY PARITY C; Gross WJ, 2001, IEEE T CIRCUITS-II, V48, P904, DOI 10.1109-82.974777; GUILLOUD F, 2004, THESIS ENST PARIS; Hocevar D. E., 2003, P IEEE INT C COMM, P2708; HU XY, 2001, P IEEE GLOB TEL C IE, pE1036; Jin H., 2001, THESIS CALTECH PASAD; Jin H., 2000, P 2 INT S TURB COD R, P1; Kschischang FR, 1998, IEEE J SEL AREA COMM, V16, P219, DOI 10.1109-49.661110; Lan CF, 2004, IEEE T COMMUN, V52, P1092, DOI 10.1109-TCOMM.2004.831406; Lin S., 2004, ERROR CONTROL CODING; LUBOTZKY A, 1988, COMBINATORICA, V8, P261, DOI 10.1007-BF02126799; Mansour M. M., 2002, P INT S LOW POW EL D, P284; MANSOUR MM, 2002, P IEEE GLOB TEL C 20, P1383; Mansor M, 2003, PASOH: ECOLOGY OF A LOWLAND RAIN FOREST IN SOUTHEAST ASIA, P215; MANSOUR MM, 2005, 39 ANN C INF SCI SYS; Mansour MM, 2003, IEEE T VLSI SYST, V11, P976, DOI 10.1109-TVLSI.2003.817545; MANSOUR MM, 2003, P IEEE INT S CIRC SY, V2, P57; MANSOUR MM, 2002, ANN C INF SCI SYST C; MARGULIS GA, 1982, COMBINATORICA, V2, P71, DOI 10.1007-BF02579283; MCLIECE RJ, 1998, IEEE J SEL AREA COMM, V16, P140; Pearl J., 1988, PROBABILISTIC REASON; RASHI Y, EFFICIENT ALTERNATIV; Richardson TJ, 2001, IEEE T INFORM THEORY, V47, P619, DOI 10.1109-18.910578; Rosenthal J., 2000, P 38 ALL C COMM CONT, P248; Roumy A, 2004, IEEE T INFORM THEORY, V50, P1711, DOI 10.1109-TIT.2004.831778; Royle G., CUBIC CAGES; SONG H, 2002, JPN J APPL PHYS, P1749; TANNER RM, 1981, IEEE T INFORM THEORY, V27, P533, DOI 10.1109-TIT.1981.1056404; Tanner R. M., 1999, P 37 ALL C COMM CONT; TANNER RM, 2001, P INT S COMM THEOR A, P1; Tanner RM, 2004, IEEE T INFORM THEORY, V50, P2966, DOI 10.1109-TIT.2004.838370; TUCHLER M, 2002, C INF SCI SYST PRINC; Vasic B, 2003, J LIGHTWAVE TECHNOL, V21, P438, DOI 10.1109-JLT.2003.808769; Yang M, 2004, IEEE T COMMUN, V52, P564, DOI 10.1109-TCOMM.2004.826367; YEO E, 2001, P IEEE GLOBECOM, P3019; Zhang JT, 2005, IEEE T COMMUN, V53, P209, DOI 10.1109-TCOMM.2004.84198252453
Interview with Anis Mansour
No full textلقاء مع الكاتب المصري أنيس منصور حول اعجابه بإذاعة "صوت أمريكا" واعجابه بالمذيعين بها. أجرت هذاا اللقاء إيمان رافع.An interview with Egyptian journalist and author Anis Mansour about his admiration for the Voice of America radio station and its broadcasters. Interview conducted by Iman Rafi
Interview with Anis Mansour
No full textلقاء مع الكاتب المصري أنيس منصور حول أبعاد تأثر المنطقة العربية برحلة الرئيس المصري أنور السادات إلى القدس منذ 15 عامًا مضت. أجرت هذاا اللقاء إيمان رافع.An interview with Egyptian journalist and author Anis Mansour about the impact of President Anwar Sadat's 1977 visit to Jerusalem on the Arab region. Interview conducted by Iman Rafi
A novel design methodology for high-performance programmable decoder cores for AA-LDPC codes
No full textA new parameterized-core-based design methodology targeted for programmable decoders for low-density parity-check (LDPC) codes is proposed. The methodology solves the two major drawbacks of excessive memory overhead and complex on-chip interconnect typical of existing decoder implementations which limit the scalability, degrade the error-correction capability, and restrict the domain of application of LDPC codes. Diverse memory and interconnect optimizations are performed at the code-design, decoding algorithm, decoder architecture, and physical layout levels, with the following features: (1) Architecture-aware (AA)-LDPC code design with embedded structural features that significantly reduce interconnect complexity, (2) faster and memory-efficient turbo-decoding algorithm for LDPC codes, (3) programmable architecture having distributed memory, parallel message processing units, and dynamic-scalable transport networks for routing messages, and (4) a parameterized macro-cell layout library implementing the main components of the architecture with scaling parameters that enable low-level transistor sizing and power-rail scaling for power-delay-area optimization. A 14.3 mm 2 programmable decoder core for a rate-1-2, length 2048 AA-LDPC code generated using the proposed methodology is presented, which delivers a throughput of 6.4 Gbps at 125 MHz and consumes 787 mW of power. © 2005 Springer Science + Business Media, Inc.BAHL LR, 1974, IEEE T INFORM THEORY, V20, P284, DOI 10.1109-TIT.1974.1055186; BERROU C, 1993, IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS 93 : TECHNICAL PROGRAM, CONFERENCE RECORD, VOLS 1-3, P1064, DOI 10.1109-ICC.1993.397441; Gallager R., 1963, LOW DENSITY PARITY C; HU XY, 2001, GLOBECOM 2001, V2, P1036; Mansour M. M., 2002, IEEE Workshop on Signal Processing Systems (SPIS'02) (Cat. No.02TH8638), DOI 10.1109-SIPS.2002.1049702; Mansour M. M., 2002, P INT S LOW POW EL D, P284; MANSOUR MM, 2002, P IEEE GLOB TEL C 20, P1383; MANSOUR MM, 2003, THESIS U ILLINOIS UR; Mansour MM, 2003, IEEE T VLSI SYST, V11, P976, DOI 10.1109-TVLSI.2003.817545; Mansour MM, 2003, IEEE COMP SOC ANN, P62, DOI 10.1109-ISVLSI.2003.1183354; MANSOUR MM, 2002, C INF SCI SYST PRINC; ROWLAND C, 2001, P 2001 IEEE INT C CI, P742; Wiberg N., 1996, THESIS LINKOPING U S; Yeo E, 2001, IEEE T MAGN, V37, P7480
Kernel method and system of functional equations
No full textAbstractIntroduced by Knuth and subsequently developed by Banderier et al., Prodinger, and others, the kernel method is a powerful tool for solving power series equations in the form of F(z,t)=A(z,t)F(z0,t)+B(z,t) and several variations. Recently, Hou and Mansour [Q.-H. Hou, T. Mansour, Kernel Method and Linear Recurrence System, J. Comput. Appl. Math. (2007), (in press).] presented a systematic method to solve equation systems of two variables F(z,t)=A(z,t)F(z0,t)+B(z,t), where A is a matrix, and F and B are vectors of rational functions in z and t. In this paper we generalize this method to another type of rational function matrices, i.e., systems of functional equations. Since the types of equation systems we are interested in arise frequently in various enumeration questions via generating functions, our tool is quite useful in solving enumeration problems. To illustrate this, we provide several applications, namely the recurrence relations with two indices, and counting descents in signed permutations
A reconfigurable TDMP decoder for raptor codes
No full textA Raptor code is a concatenation of a fixed rate precode and a Luby-Transform (LT) code that can be used as a rateless error-correcting code over communication channels. By definition, Raptor codes are characterized by irregularity features such as dynamic rate, check-degree variability, and joint coding, which make the design of hardware-efficient decoders a challenging task. In this paper, serial turbo decoding of architecture-aware Raptor codes is mapped into sequential row processing of a regular matrix by using a combination of code enhancements and architectural optimizations. The proposed mapping approach is based on three basic steps: (1) applying systematic permutations on the source matrix of the Raptor code, (2) confining LT random encoding to pseudo-random permutation of messages and periodic selection of rowsplitting scenarios, and (3) developing a reconfigurable parallel check-node processor that attains a constant throughput while processing LT- and LDPC-nodes of varying degrees and count. The decoder scheduling is, thus, made simple and uniform across both LDPC and LT decoding. A serial decoder implementing the proposed approach was synthesized in 65 nm, 1.2 V CMOS technology. Hardware simulations show that the decoder, decoding a rate-0.4 code instance, achieves a throughput of 36 Mb-s at SNR of 1.5 dB, dissipates an average power of 27 mW and occupies an area of 0.55 mm 2. © Springer Science+Business Media, LLC 2012.Elias P, 1955, 3 LOND S, P61; Etesami O, 2006, IEEE T INFORM THEORY, V52, P2033, DOI 10.1109-TIT.2006.872855; Fossorier MPC, 1999, IEEE T COMMUN, V47, P673, DOI 10.1109-26.768759; Gallager R., 1963, LOW DENSITY PARITY C; Kai Zhang X. H., 2009, IEEE T VERY LARGE SC, V27, P985; Luby M, 2002, ANN IEEE SYMP FOUND, P271; Mansour MA, 2006, IEEE T SIGNAL PROCES, V54, P4376, DOI 10.1109-TSP.2006.880240; Mansour MM, 2003, IEEE T VLSI SYST, V11, P976, DOI 10.1109-TVLSI.2003.817545; Palanki R., 2004, Proceedings. 2004 IEEE International Symposium on Information Theory (IEEE Cat. No.04CH37522); Shokrollahi A, 2006, IEEE T INFORM THEORY, V52, P2551, DOI 10.1109-TIT.2006.874390; TANNER RM, 1981, IEEE T INFORM THEORY, V27, P533, DOI 10.1109-TIT.1981.1056404; Xiang B, 2010, IEEE T VLSI SYST, V18, P1447, DOI 10.1109-TVLSI.2009.2025169; Zeineddine H, 2011, IEEE T SIGNAL PROCES, V59, P2943, DOI 10.1109-TSP.2011.21146550
Îles flottantes : où ils et elle parlent. Un récit de Joyce Mansour.
No full textIles flottantes : where men and she speak. A tale by Joyce Mansour.
Mansour's only first person narration, whose title also calls a childhood sweet and the masculine plural subject pronoun « ils », develops a relationship between the female author/reader and male texts (Pierre-Jean Jouve), while inscribing the failure of feminine mastery.Dumas Marie-Claire. Îles flottantes : où ils et elle parlent. Un récit de Joyce Mansour.. In: Littérature, n°97, 1995. Le récit médusé. pp. 60-72
Corrigendum: Anemia detection through non-invasive analysis of lip mucosa images
No full textIn the published article, there was an error in the author list. The new requested author order is: Shekhar Mahmud1, Turker Berk Donmez2, Mohammed Mansour3*, Mustafa Kutlu3 and Chris Freeman41 Department of Systems Engineering, Military Technological College, Muscat, Oman 2 Department of Biomedical Engineering, Sakarya University of Applied Sciences, Serdivan, Sakarya, Türkiye 3 Department of Mechatronics Engineering, Sakarya University of Applied Sciences, Serdivan, Sakarya, Türkiye 4 Electronics and Computer Sciences, University of Southampton, Southampton, United Kingdom The authors apologize for this error and state that this does not change the scientific conclusions of the article in any way. The original article has been updated. Copyright © 2023 Mahmud, Donmez, Mansour, Kutlu and Freeman
Pruned bit-reversal permutations: Mathematical characterization, fast algorithms and architectures
No full textA mathematical characterization of serially pruned permutations (SPPs) employed in variable-length permuters and their associated fast pruning algorithms and architectures are proposed. Permuters are used in many signal processing systems for shuffling data and in communication systems as an adjunct to coding for error correction. Typically, only a small set of discrete permuter lengths are supported. Serial pruning is a simple technique to alter the length of a permutation to support a wider range of lengths, but results in a serial processing bottleneck. In this paper, parallelizing SPPs is formulated in terms of recursively computing sums involving integer floor functions using integer operations, in a fashion analogous to evaluating Dedekind sums. A mathematical treatment for bit-reversal permutations (BRPs) is presented, and closed-form expressions for BRP statistics including descents-ascents, major index, excedances-descedances, inversions, and serial correlations are derived. It is shown that BRP sequences have weak correlation properties. Moreover, a new statistic called permutation inliers that characterizes the pruning gap of pruned interleavers is proposed. Using this statistic, a recursive algorithm that computes the minimum inliers count of a pruned BR interleaver (PBRI) in logarithmic time is presented. This algorithm enables parallelizing a serial PBRI algorithm by any desired parallelism factor by computing the pruning gap in lookahead rather than a serial fashion, resulting in significant reduction in interleaving latency and memory overhead. Extensions to 2-D block and stream interleavers, as well as applications to pruned fast Fourier transforms and LTE turbo interleavers, are also presented. Moreover, hardware-efficient architectures for the proposed algorithms are developed. Simulation results of interleavers employed in modern communication standards demonstrate three to four orders of magnitude improvement in interleaving time compared to existing approaches. © 1991-2012 IEEE.3GPP, 2008, 36212 3GPP TS; [Anonymous], 2008, 80220 IEEE; [Anonymous], 2009, 80216 IEEE; [Anonymous], 2011, 302755 ETSI EN; [Anonymous], 2009, 80211N IEEE; BERROU C, 2004, P IEEE INT C COMM IC, V1, P341; Berrou C., 1993, P IEEE INT C COMM IC, V2, P1064, DOI 10.1109-ICC.1993.397441; BINGHAM JAC, 1990, IEEE COMMUN MAG, V28, P5, DOI 10.1109-35.54342; BISWAS A, 1991, IEEE T SIGNAL PROCES, V39, P1415, DOI 10.1109-78.136547; BURRUS CS, 1988, IEEE T ACOUST SPEECH, V36, P1086, DOI 10.1109-29.1631; Chang GJ, 1999, NETWORKS, V33, P261, DOI 10.1002-(SICI)1097-0037(199907)33:4261::AID-NET33.0.CO;2-Q; Clarke RJ, 1997, ADV APPL MATH, V18, P237, DOI 10.1006-aama.1996.0506; COOLEY JW, 1965, MATH COMPUT, V19, P297, DOI 10.2307-2003354; Crozier S, 2001, IEEE VTS VEH TECHNOL, P2394, DOI 10.1109-VTC.2001.957178; DIETER U, 1971, NUMER MATH, V17, P101, DOI 10.1007-BF01406000; Dinoi L, 2005, IEEE T WIREL COMMUN, V4, P2540, DOI 10.1109-TWC.2005.853836; Divsalar D, 1995, MILCOM 95 - CONFERENCE RECORD, VOLS 1-3, P279, DOI 10.1109-MILCOM.1995.483313; Dolinar S., 1995, 42122 JPL TDA; Drouiche K, 2001, IEEE T SIGNAL PROCES, V49, P251, DOI 10.1109-78.890370; Elster A., 1989, P IEEE C AC SPEECH S, V2, P1099; Eroz M, 1999, IEEE VTS VEH TECHNOL, P1669, DOI 10.1109-VETEC.1999.780687; EVANS DMW, 1987, IEEE T ACOUST SPEECH, V35, P1120, DOI 10.1109-TASSP.1987.1165252; Ferrari M, 2002, 2002 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS, VOLS 1-5, CONFERENCE PROCEEDINGS, P1711, DOI 10.1109-ICC.2002.997141; FORNEY GD, 1971, IEEE T COMMUN TECHN, VCO19, P772, DOI 10.1109-TCOM.1971.1090719; Gallager R., 1963, LOW DENSITY PARITY C; Garello R, 2001, IEEE T COMMUN, V49, P793, DOI 10.1109-26.923803; He SS, 1996, IEEE SIGNAL PROC LET, V3, P173; HOLM S, 1987, IEEE T ACOUST SPEECH, V35, P1776, DOI 10.1109-TASSP.1987.1165102; Hu Z, 2005, IEEE T SIGNAL PROCES, V53, P274, DOI 10.1109-TSP.2004.838925; JEONG JC, 1992, IEEE T SIGNAL PROCES, V40, P1091, DOI 10.1109-78.134472; Kim K, 1999, IPPS PROC, P268; Knuth D.E., 1998, ART COMPUTER PROGRAM, VII; Lee R., 2004, P INT C INF TECHN CO, V2, P569; MacMahon P. A., 1913, AM J MATH, V35, P281, DOI 10.2307-2370312; MacMahon P. A., 1915, COMBINATORY ANAL, VI; Mansour MM, 2009, IEEE T COMMUN, V57, P3188, DOI 10.1109-TCOMM.2009.11.070661; Mansour MM, 2009, IEEE T VLSI SYST, V17, P1147, DOI 10.1109-TVLSI.2008.2008831; MARKEL JD, 1971, IEEE T ACOUST SPEECH, VAU19, P305, DOI 10.1109-TAU.1971.1162205; Nimbalker A, 2008, IEEE T COMMUN, V56, P1258, DOI 10.1109-TCOMM.2008.050502; Nimbalker A, 2008, IEEE WCNC, P1032; ORCHARD M, 1992, IEEE T SIGNAL PROCES, V40, P1004, DOI 10.1109-78.127979; Parsons A, 2009, IEEE SIGNAL PROC LET, V16, P477, DOI 10.1109-LSP.2009.2016836; Pei SC, 2007, IEEE T SIGNAL PROCES, V55, P1173, DOI 10.1109-TSP.2006.887567; POLGE RJ, 1974, IEEE T COMPUT, VC 23, P1, DOI 10.1109-T-C.1974.223771; Portnoff MR, 1999, IEEE T IMAGE PROCESS, V8, P1265, DOI 10.1109-83.784438; Prado J, 2004, IEEE SIGNAL PROC LET, V11, P933, DOI 10.1109-LSP.2004.838211; RAMSEY JL, 1970, IEEE T INFORM THEORY, V16, P338, DOI 10.1109-TIT.1970.1054443; RIUS JM, 1995, IEEE T SIGNAL PROCES, V43, P991, DOI 10.1109-78.376852; Rodriguez J., 1988, P INT C AC SPEECH SI, V3, P1407; SKODRAS AN, 1991, ELECTRON LETT, V27, P1973, DOI 10.1049-el:19911222; SORENSEN HV, 1993, IEEE T SIGNAL PROCES, V41, P1184, DOI 10.1109-78.205723; SREENIVAS TV, 1980, IEEE T ACOUST SPEECH, V28, P254, DOI 10.1109-TASSP.1980.1163376; SREENIVAS TV, 1979, IEEE T ACOUST SPEECH, V27, P291, DOI 10.1109-TASSP.1979.1163246; Sun J, 2005, IEEE T INFORM THEORY, V51, P101, DOI 10.1109-TIT.2004.839478; Takeshita OY, 2007, IEEE T INFORM THEORY, V53, P2116, DOI 10.1109-TIT.2007.896870; Takeshita OY, 2006, IEEE T INFORM THEORY, V52, P1249, DOI 10.1109-TIT.2005.864450; TANNER RM, 1981, IEEE T INFORM THEORY, V27, P533, DOI 10.1109-TIT.1981.1056404; Verbauwhede I., 1991, Journal of VLSI Signal Processing, V3, DOI 10.1007-BF00925830; Wang LK, 2012, IEEE SIGNAL PROC LET, V19, P167, DOI 10.1109-LSP.2012.2184283; YONG AA, 1991, IEEE T SIGNAL PROCES, V39, P2365, DOI 10.1109-78.91199; ZEHAVI E, 1992, IEEE T COMMUN, V40, P873, DOI 10.1109-26.1414530
Insight into 8 patients with nonarteritic anterior ischemic optic neuropathy following anti-VEGF injections
No full text[No abstract available]Mansour AM, 2012, CLIN OPHTHALMOL, P343; Prescott CR, 2012, J NEURO-OPHTHALMOL, V13, P5130
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