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46,801
Termweighting approaches in automatic text retrieval
 INFORMATION PROCESSING AND MANAGEMENT
, 1988
"... The experimental evidence accumulated over the past 20 years indicates that text indexing systems based on the assignment of appropriately weighted single terms produce retrieval results that are superior to those obtainable with other more elaborate text representations. These results depend crucia ..."
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Cited by 2159 (10 self)
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The experimental evidence accumulated over the past 20 years indicates that text indexing systems based on the assignment of appropriately weighted single terms produce retrieval results that are superior to those obtainable with other more elaborate text representations. These results depend
Iterative decoding of binary block and convolutional codes
 IEEE Trans. Inform. Theory
, 1996
"... Abstract Iterative decoding of twodimensional systematic convolutional codes has been termed “turbo ” (de)coding. Using loglikelihood algebra, we show that any decoder can he used which accepts soft inputsincluding a priori valuesand delivers soft outputs that can he split into three terms: the ..."
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Cited by 600 (43 self)
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/convolutional component codes, interleaver sizes less than 1000 and for three to six iterations. Index Terms Concatenated codes, product codes, iterative decoding, “softinlsoftout ” decoder, “turbo ” (de)coding.
An iterative thresholding algorithm for linear inverse problems with a sparsity constraint
, 2008
"... ..."
A model of growth through creative destruction
, 1990
"... This paper develops a model based on Schumpeter's process of creative destruction. It departs from existing models of endogeneous growth in emphasizing obsolescence of old technologies induced by the accumulation of knowledge and the resulting process or industrial innovations. This has both ..."
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Cited by 1923 (29 self)
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This paper develops a model based on Schumpeter's process of creative destruction. It departs from existing models of endogeneous growth in emphasizing obsolescence of old technologies induced by the accumulation of knowledge and the resulting process or industrial innovations. This has both positive and normative implications for growth. In positive terms, the prospect of a high level of research in the future can deter research today by threatening the fruits of that research with rapid obsolescence. In normative terms, obsolescence creates a negative externality from innovations, and hence a tendency for laissezfaire economies to generate too many innovations, i.e too much growth. This "businessstealing" effect is partly compensated by the fact that innovations tend to be too small under laissezfaire. The model possesses a unique balanced growth equilibrium in which the log of GNP follows a random walk with drift. The size of the drift is the average growth rate of the economy and it is endogeneous to the model; in particular it depends on the size and likilihood of innovations resulting from research and also on the degree of market power available to an innovator.
Interior Point Methods in Semidefinite Programming with Applications to Combinatorial Optimization
 SIAM Journal on Optimization
, 1993
"... We study the semidefinite programming problem (SDP), i.e the problem of optimization of a linear function of a symmetric matrix subject to linear equality constraints and the additional condition that the matrix be positive semidefinite. First we review the classical cone duality as specialized to S ..."
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Cited by 557 (12 self)
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We study the semidefinite programming problem (SDP), i.e the problem of optimization of a linear function of a symmetric matrix subject to linear equality constraints and the additional condition that the matrix be positive semidefinite. First we review the classical cone duality as specialized to SDP. Next we present an interior point algorithm which converges to the optimal solution in polynomial time. The approach is a direct extension of Ye's projective method for linear programming. We also argue that most known interior point methods for linear programs can be transformed in a mechanical way to algorithms for SDP with proofs of convergence and polynomial time complexity also carrying over in a similar fashion. Finally we study the significance of these results in a variety of combinatorial optimization problems including the general 01 integer programs, the maximum clique and maximum stable set problems in perfect graphs, the maximum k partite subgraph problem in graphs, and va...
Do investmentcash flow sensitivities provide useful measures of financing constraints?
 QUARTERLY JOURNAL OF ECONOMICS
, 1997
"... No. This paper investigates the relationship between financing constraints and investmentcash flow sensitivities by analyzing the firms identified by Fazzari, Hubbard, and Petersen as having unusually high investmentcash flow sensitivities. We Quarterlynd that firms that appear less Quarterlynanci ..."
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Cited by 656 (8 self)
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No. This paper investigates the relationship between financing constraints and investmentcash flow sensitivities by analyzing the firms identified by Fazzari, Hubbard, and Petersen as having unusually high investmentcash flow sensitivities. We Quarterlynd that firms that appear less Quarterlynancially constrained exhibit significantly greater sensitivities than firms that appear more financially constrained. We find this pattern for the entire sample period, subperiods, and individual years. These results (and simple theoretical arguments) suggest that higher sensitivities cannot be interpreted as evidence that firms are more financially constrained. These findings call into question the interpretation of most previous research that uses this methodology. “Our financial position is sound... Most of the company’s funds are generated by operations and these funds grew at an average annual rate of 29 % [over the past 3 years]. Throughout the company’s history this selffinancing concept has not been a constraint on the company’s growth. With recent growth restrained by depressed economic
Hierarchies from Fluxes in String Compactifications
, 2002
"... Warped compactifications with significant warping provide one of the few known mechanisms for naturally generating large hierarchies of physical scales. We demonstrate that this mechanism is realizable in string theory, and give examples involving orientifold compactifications of IIB string theory a ..."
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Cited by 724 (33 self)
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Warped compactifications with significant warping provide one of the few known mechanisms for naturally generating large hierarchies of physical scales. We demonstrate that this mechanism is realizable in string theory, and give examples involving orientifold compactifications of IIB string theory and Ftheory compactifications on CalabiYau fourfolds. In each case, the hierarchy of scales is fixed by a choice of RR and NS fluxes in the compact manifold. Our solutions involve compactifications of the KlebanovStrassler gravity dual to a confining N = 1 supersymmetric gauge theory, and the hierarchy reflects the small scale of chiral symmetry breaking in the dual gauge theory.
Superconformal field theory on threebranes at a CalabiYau singularity
 Nucl. Phys. B
, 1998
"... Just as parallel threebranes on a smooth manifold are related to string theory on AdS5 × S 5, parallel threebranes near a conical singularity are related to string theory on AdS5 × X5, for a suitable X5. For the example of the conifold singularity, for which X5 = (SU(2) × SU(2))/U(1), we argue that ..."
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Cited by 690 (37 self)
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Just as parallel threebranes on a smooth manifold are related to string theory on AdS5 × S 5, parallel threebranes near a conical singularity are related to string theory on AdS5 × X5, for a suitable X5. For the example of the conifold singularity, for which X5 = (SU(2) × SU(2))/U(1), we argue that string theory on AdS5 × X5 can be described by a certain N = 1 supersymmetric gauge theory which we describe in detail.
Results 1  10
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