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On the mathematical relationship between expected n-call@k and the relevance vs. diversity trade-off

Kar Wai Lim, Scott Sanner, Shengbo Guo
2012 Proceedings of the 35th international ACM SIGIR conference on Research and development in information retrieval - SIGIR '12  
In this work, we explicitly derive the mathematical relationship between expected n-call@k and the relevance vs. diversity trade-off --- through fortuitous cancellations in the resulting combinatorial  ...  optimization, we show the trade-off is a simple and intuitive function of n (notably independent of the result set size k e n), where diversification increases as n approaches 1.  ...   Empirical Study of n-call@k • How does diversity of n-call@k change with n? J. Wang and J. Zhu.  ... 
doi:10.1145/2348283.2348497 dblp:conf/sigir/LimSG12 fatcat:3ify37yvnncc5o6ye6cnlbcodq

An integrative approach to understanding microbial diversity: from intracellular mechanisms to community structure

Ivana Gudelj, Joshua S. Weitz, Tom Ferenci, M. Claire Horner-Devine, Christopher J. Marx, Justin R. Meyer, Samantha E. Forde
2010 Ecology Letters  
Trade-offs have been put forward as essential to the generation and maintenance of diversity.  ...  First, we show how laboratory experiments and mathematical models have unveiled the hidden intracellular mechanisms underlying trade-offs key to microbial diversity: (i) metabolic and regulatory tradeoffs  ...  A combined theoretical and empirical study demonstrated that the relationship between resource input and diversity depended strongly on the molecular details underlying phage and host trade-offs that drive  ... 
doi:10.1111/j.1461-0248.2010.01507.x pmid:20576029 pmcid:PMC3069490 fatcat:zaaabrgm7rgorbvdlazybhzlhm

Portfolio theory of information retrieval

Jun Wang, Jianhan Zhu
2009 Proceedings of the 32nd international ACM SIGIR conference on Research and development in information retrieval - SIGIR '09  
This motivates us to quantify a ranked list of documents on the basis of its expected overall relevance (mean) and its variance; the latter serves as a measure of risk, which was rarely studied for document  ...  It is tackled in a general situation where the relevance predictions of individual documents have uncertainty, and are dependent between each other.  ...  An efficient ranking algorithm is then introduced to trade off between efficiency and accuracy, and leads to a generalization of the PRP, where both the uncertainty of the probability estimation and diversity  ... 
doi:10.1145/1571941.1571963 dblp:conf/sigir/WangZ09 fatcat:rcix3cwbbjg4rczqnqefkjr6tu

Amino acid metabolism conflicts with protein diversity [article]

Teresa Krick, David A. Shub, Nina Verstraete, Diego U. Ferreiro, Leonardo G. Alonso, Michael Shub, Ignacio E. Sanchez
2014 arXiv   pre-print
More than one hundred proteomes reach comparable solutions to the trade-off by different combinations of cost and diversity.  ...  Quantifying the interplay between proteome size and entropy shows that proteomes can get optimally large and diverse.  ...  sequence diversity, i.e, towards a better solution to the trade-off between metabolic cost and sequence diversity.  ... 
arXiv:1403.3301v2 fatcat:fqeu3itujndxpp5rtvpx6oim34

Microbial resource utilization traits and trade-offs: implications for community structure, functioning, and biogeochemical impacts at present and in the future

Elena Litchman, Kyle F. Edwards, Christopher A. Klausmeier
2015 Frontiers in Microbiology  
and in the future.  ...  Citation: Litchman E, Edwards KF and Klausmeier CA (2015) Microbial resource utilization traits and trade-offs: implications for community structure, functioning, and biogeochemical impacts at present  ...  Acknowledgments This work was in part supported by NSF grants OCE-092881 and CBET-1134215 to EL and CK, DEB-0845932 to EL, and DEB-0845825 to CK. This is W.K.  ... 
doi:10.3389/fmicb.2015.00254 pmid:25904900 pmcid:PMC4389539 fatcat:dp5xyyk3ujcslmnjy24sb5pig4

Different but equal: the implausible assumption at the heart of neutral theory

Drew W. Purves, Lindsay A. Turnbull
2010 Journal of Animal Ecology  
trade-off away from the one special form that gives equal fitness; (ii) spatial or temporal variation in performance; (iii) random species differences in performance. 3.  ...  Here we explain that perfect equalizing trade-offs are extremely unlikely to occur in reality, because equality of fitness among species is destroyed by: (i) any deviation in the functional form of the  ...  Acknowledgements We thank Greg McInerny, Andy Hector, Janneke HilleRisLambers and Bernhard Schmid for useful discussions and comments on earlier versions of this manuscript. References  ... 
doi:10.1111/j.1365-2656.2010.01738.x pmid:20726922 pmcid:PMC3025117 fatcat:lewhuksy7bfvnm4u6piyshdaem

Coverage, redundancy and size-awareness in genre diversity for recommender systems

Saúl Vargas, Linas Baltrunas, Alexandros Karatzoglou, Pablo Castells
2014 Proceedings of the 8th ACM Conference on Recommender systems - RecSys '14  
Genre information can serve as a means to measure and enhance the diversity of recommendations and is readily available in domains such as movies, music or books.  ...  Experiments with the Netflix dataset show the properties of our framework and comparison with state of the art methods.  ...  The basis for measuring this proportionality is the so-called disproportionality metric, defined as: DP = s 1 vsk R s (vsk R s ) 2 + 1 2 n 2 NR (5) where vs is the expected number of documents that  ... 
doi:10.1145/2645710.2645743 dblp:conf/recsys/VargasBKC14 fatcat:cvryyozhcngcrmpjmxqo3odgai

Accuracy-diversity trade-off in recommender systems via graph convolutions

Elvin Isufi, Matteo Pocchiari, Alan Hanjalic
2021 Information Processing & Management  
However, recommendation accuracy is tied with diversity in a delicate trade-off and the potential of graph convolutions to improve the latter is unexplored.  ...  To our knowledge, this is the first work proposing an accuracydiversity trade-off with graph convolutions and opens the doors to learning over graphs approaches for improving such trade-off. (E.  ...  B .11, we show the effect the recommendation list has on trade-off NDCG@k-AD@k, and NDCG@k-ID@k. A longer list improves diversity, but reduces accuracy.  ... 
doi:10.1016/j.ipm.2020.102459 fatcat:qsirbchbqfhrbdx3b52fgdf7nq

Optimality-based modeling of planktonic organisms

S. Lan Smith, Markus Pahlow, Agostino Merico, Kai W. Wirtz
2011 Limnology and Oceanography  
for the distinction between rates of reproduction 107 vs. growth. 108 Trade-offs 109 The choice of trade-offs (Table 1) and how to represent them is central to optimality-based 110 modeling.  ...  us to seek and identify 500 biophysical or biochemical laws or models that can explain the functional shape of relevant 501 trade-offs.  ...  The OU trade-off for growth is then: µ max = Y V 0 K app s /(V 0 /A 0 + K app s ) − ρ.  ... 
doi:10.4319/lo.2011.56.6.2080 fatcat:d7seysgqtjc3fjbnusofeyobeu

A Parametric Optimization Approach to Mitigating the Urban Heat Island Effect: A Case Study in Ancona, Italy

Roberta Cocci Grifoni, Rosalba D'Onofrio, Massimo Sargolini, Mariano Pierantozzi
2016 Sustainability  
This concept formalizes the trade-off between a given set of mutually contradicting objectives, such as high thermal comfort and low energy consumption, to identify a set of Pareto solutions.  ...  The aim of this paper is to identify a parameterization method that considers existing connections and relationships between traditional indicators of environmental sustainability as a step in combating  ...  A set of Pareto optimal solutions constitutes the Pareto frontier and movement along the frontier represents a trade-off between the objectives.  ... 
doi:10.3390/su8090896 fatcat:m2lsvrasmjb2ro3qzmjkusg2ey

Adaptive diversification of recommendation results via latent factor portfolio

Yue Shi, Xiaoxue Zhao, Jun Wang, Martha Larson, Alan Hanjalic
2012 Proceedings of the 35th international ACM SIGIR conference on Research and development in information retrieval - SIGIR '12  
It is shown that the correlations between items (and thus the item diversity) can be obtained by using the correlations between latent factors (topical diversity), which in return significantly reduce  ...  Our experiments confirm the theoretical insights and show that LFP succeeds in improving latent factor models by adaptively introducing recommendation diversity to fit the individual user's needs.  ...  Second, LFP could achieve a trade-off between the recommendation relevance and the diversity.  ... 
doi:10.1145/2348283.2348310 dblp:conf/sigir/ShiZWLH12 fatcat:tmejgfikgnc5noakothzkes2fq

The world-wide 'fast-slow' plant economics spectrum: a traits manifesto

Peter B. Reich, Hans Cornelissen
2014 Journal of Ecology  
My overarching hypothesis is that strong selection along trait trade-off axes, in tandem with biophysical constraints, results in convergence for any taxon on a uniformly fast, medium or slow strategy  ...  processes and the functioning of ecosystems.  ...  Acknowledgements I thank two anonymous referees and a large number of colleagues who shared papers, data, and ideas with me as I struggled to develop this manuscript.  ... 
doi:10.1111/1365-2745.12211 fatcat:32ropzuhtjcrlo7a7gx3w7xbde

High-dimensional coexistence based on individual variation: a synthesis of evidence

James S. Clark, David Bell, Chengjin Chu, Benoit Courbaud, Michael Dietze, Michelle Hersh, Janneke HilleRisLambers, Inés Ibáñez, Shannon LaDeau, Sean McMahon, Jessica Metcalf, Jacqueline Mohan (+7 others)
2010 Ecological Monographs  
The former show that the traditional trade-offs used to explain diversity are not present.  ...  High biodiversity of forests is not predicted by traditional models, and evidence for trade-offs those models require is limited.  ...  The relationship between trade-offs and individuals Trade-offs are needed to promote diversity in low dimensional models, by allowing competitors to share a low-dimensional niche space, partitioning it  ... 
doi:10.1890/09-1541.1 fatcat:ltbtg6x73zcjnhv5xio4x3ileq

Tag-Based Social Image Search: Toward Relevant and Diverse Results [chapter]

Kuiyuan Yang, Meng Wang, Xian-Sheng Hua, Hong-Jiang Zhang
2011 Social Media Modeling and Computing  
This chapter presents a diverse relevance ranking scheme which simultaneously takes relevance and diversity into account by exploring the content of images and their associated tags.  ...  Based on the relevance scores and the similarities, the ranking list is generated by a greedy ordering algorithm which optimizes Average Diverse Precision (ADP), a novel measure that is extended from the  ...  This shows that it is able to achieve a good trade-off between relevance and diversity. We then conduct a user study to compare the six ranking schemes.  ... 
doi:10.1007/978-0-85729-436-4_2 fatcat:rtmfjztpd5eyfhyr6on6juen7q

Adaptability of non-genetic diversity in bacterial chemotaxis

Nicholas W Frankel, William Pontius, Yann S Dufour, Junjiajia Long, Luis Hernandez-Nunez, Thierry Emonet
2014 eLife  
The resulting trade-offs show that populations facing diverse environments would ideally diversify behaviors when time for navigation is limited.  ...  Bacterial chemotaxis systems are as diverse as the environments that bacteria inhabit, but how much environmental variation can cells tolerate with a single system?  ...  Acknowledgements We thank P Cluzel, T S Shimizu, P Turner, G Wagner, and S Zucker for valuable discussion on the manuscript.  ... 
doi:10.7554/elife.03526 pmid:25279698 pmcid:PMC4210811 fatcat:asu2igr4yfbc5l7ihntbvr3sna
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