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Results 1 - 10
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7,534
BIRCH: an efficient data clustering method for very large databases
- In Proc. of the ACM SIGMOD Intl. Conference on Management of Data (SIGMOD
, 1996
"... Finding useful patterns in large datasets has attracted considerable interest recently, and one of the most widely st,udied problems in this area is the identification of clusters, or deusel y populated regions, in a multi-dir nensional clataset. Prior work does not adequately address the problem of ..."
Abstract
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Cited by 576 (2 self)
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performance comparisons of BIR (;’H versus CLARA NS, a clustering method proposed recently for large datasets, and S11OW that BIRCH is consistently 1
An Empirical Study of Smoothing Techniques for Language Modeling
, 1998
"... We present an extensive empirical comparison of several smoothing techniques in the domain of language modeling, including those described by Jelinek and Mercer (1980), Katz (1987), and Church and Gale (1991). We investigate for the first time how factors such as training data size, corpus (e.g., Br ..."
Abstract
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Cited by 1224 (21 self)
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.g., Brown versus Wall Street Journal), and n-gram order (bigram versus trigram) affect the relative performance of these methods, which we measure through the cross-entropy of test data. In addition, we introduce two novel smoothing techniques, one a variation of Jelinek-Mercer smoothing and one a very
Suffix arrays: A new method for on-line string searches
, 1991
"... A new and conceptually simple data structure, called a suffix array, for on-line string searches is intro-duced in this paper. Constructing and querying suffix arrays is reduced to a sort and search paradigm that employs novel algorithms. The main advantage of suffix arrays over suffix trees is that ..."
Abstract
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Cited by 835 (0 self)
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in some cases slightly better than) suffix trees. The only drawback is that in those instances where the underlying alphabet is finite and small, suffix trees can be constructed in O(N) time in the worst case, versus O(N log N) time for suffix arrays. However, we give an augmented algorithm that
Improved Combinatorial Algorithms for the Facility Location and k-Median Problems
- In Proceedings of the 40th Annual IEEE Symposium on Foundations of Computer Science
, 1999
"... We present improved combinatorial approximation algorithms for the uncapacitated facility location and k-median problems. Two central ideas in most of our results are cost scaling and greedy improvement. We present a simple greedy local search algorithm which achieves an approximation ratio of 2:414 ..."
Abstract
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Cited by 225 (12 self)
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:414 + in ~ O(n 2 =) time. This also yields a bicriteria approximation tradeoff of (1 +; 1+ 2=) for facility cost versus service cost which is better than previously known tradeoffs and close to the best possible. Combining greedy improvement and cost scaling with a recent primal dual algorithm for facility
The shifting basis of life satisfaction judgments across cultures: Emotions versus norms
- Journal of Personality and Social Psychology
, 1998
"... The relative importance of emotions versus normative beliefs for life satisfaction judgments was compared among individualist and collectivist nations in 2 large sets of international data (in total, 61 nations, N = 62,446). Among nations, emotions and life satisfaction correlated significantly more ..."
Abstract
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Cited by 164 (18 self)
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The relative importance of emotions versus normative beliefs for life satisfaction judgments was compared among individualist and collectivist nations in 2 large sets of international data (in total, 61 nations, N = 62,446). Among nations, emotions and life satisfaction correlated significantly
Behavioral theories and the neurophysiology of reward,
- Annu. Rev. Psychol.
, 2006
"... ■ Abstract The functions of rewards are based primarily on their effects on behavior and are less directly governed by the physics and chemistry of input events as in sensory systems. Therefore, the investigation of neural mechanisms underlying reward functions requires behavioral theories that can ..."
Abstract
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Cited by 187 (0 self)
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the movement is being prepared, both the behavioral reaction (left versus right targets) and the kind of outcome obtained for performing the action. From 104 SCHULTZ General learning theory suggests that Pavlovian associations of reward-predicting stimuli in instrumental tasks relate either to explicit CSs
On Syntactic versus Computational Views of Approximability
, 1994
"... We attempt to reconcile the two distinct views of approximation classes: syntactic and computational. Syntactic classes such as MAX SNP permit structural results and have natural complete problems, while computational classes such as APX allow us to work with classes of problems whose approximabilit ..."
Abstract
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Cited by 126 (10 self)
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to approximate to corresponding factors. We demonstrate this technique by applying it to the classes RMAX(2) and MIN F+n2 (1) which have the clique problem and the set cover problem, respectively, as complete problems. We use the syntactic nature of MAX SNP to define a general paradigm, non-oblivious local
Higher criticism for detecting sparse heterogeneous mixtures
- Ann. Statist
, 2004
"... Higher Criticism, or second-level significance testing, is a multiple comparisons concept mentioned in passing by Tukey (1976). It concerns a situation where there are many independent tests of significance and one is interested in rejecting the joint null hypothesis. Tukey suggested to compare the ..."
Abstract
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Cited by 154 (22 self)
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, where we maximize this z-score over a range of significance levels 0 < α ≤ α0. We are able to show that the resulting Higher Criticism statistic is effective at resolving a very subtle testing problem: testing whether n normal means are all zero versus the alternative that a small fraction is nonzero
Volunteer work and well-being
- Journal of health and Social Behavior
, 2001
"... (N = 2,681), we examine the relationships between volunteer work in the com-munity and six aspects of personal well-being: happiness, life satisfaction, self-esteem, sense of control over life, physical health, and depression. Prior research has more often examined the effects of voluntary membershi ..."
Abstract
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Cited by 151 (0 self)
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(N = 2,681), we examine the relationships between volunteer work in the com-munity and six aspects of personal well-being: happiness, life satisfaction, self-esteem, sense of control over life, physical health, and depression. Prior research has more often examined the effects of voluntary
Face-to-Face Versus Computer-Mediated Communication: A Synthesis of the Empirical Literature
- Journal of Business Communication
, 1997
"... This paper synthesizes the findings of published experimental studies (n- 18) that compared face-to-face (FTF) and computer-mediated communication (CMC). The literature is pulled together hy way of ten propositions, each pre-sented with the supporting evidence. In general, discussions on CMC take lo ..."
Abstract
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Cited by 108 (1 self)
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This paper synthesizes the findings of published experimental studies (n- 18) that compared face-to-face (FTF) and computer-mediated communication (CMC). The literature is pulled together hy way of ten propositions, each pre-sented with the supporting evidence. In general, discussions on CMC take
Results 1 - 10
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7,534
