Mathematical Sciences Dept
Lewis & Clark College
0615 SW Palatine Hill Rd
Portland, OR 97219
Office: 5037687565
Email: nelsen(at)lclark[dot]edu
Charming Proofs
(with Claudi Alsina) 
Proofs Without Words


The Calculus Collection
(with Caren L. Diefenderfer) 
Proofs Without Words II


When Less is More
(with Claudi Alsina) 
An Introduction to Copulas, 2nd Edition


Math Made Visual
(with Claudi Alsina) 
Icons of Mathematics
(with Claudi Alsina) 
Some recent publications:
2013
1. "A new index to measure positive dependence in trivariate distributions" (with J. E. García and V. A. GonzálezLópez), Journal of Multivariate Analysis, 115 (2013), pp. 481495. PDF
2012
1. "Directional dependence in multivariate distributions" (with M. Úbeda
Flores), Annals of the Institute of Statistical Mathematics, 64
(2012), pp. 677685. PDF
2011
1. "Proof without words: Inequalities for two numbers whose sum is
one" (with C. Alsina), Mathematics Magazine, 84 (2011), p.
228. PDF
2010
1. "An invitation to proofs without words" (with C. Alsina), European
Journal of Pure and Applied Mathematics, 3 (2010), pp. 118127. PDF
2. "Teaching Tip: The limit of (sin t)/t" (with C.
Alsina), The College Mathematics Journal, 41 (2010), p. 192 PDF
3. "Quasicopulas and signed measures" (with with J. J. Quesada
Molina, J. A. Rodríguez Lallena, and M. Úbeda Flores), Fuzzy Sets and
Systems, 161 (2010), pp. 23282336. PDF
4. "Proof without words: New Pythagoreanlike theorems" (with C.
Alsina), The College Mathematics Journal, 41 (2010), p. 370. PDF
2009
1. "Kendall distribution functions and associative copulas" (with
with J. J. Quesada Molina, J. A. Rodríguez Lallena, and M. Úbeda Flores), Fuzzy
Sets and Systems, 160 (2009), pp. 5257. PDF
2. "Letter to the editor: Isosceles dissections", Mathematics
Magazine, 82 (2009), p. 77. PDF
3. "Worst VaR scenarios with given marginals and measures of
association" (with R. Kaas and R. J. A. Laeven), Insurance; Mathematics
and Economics, 44 (2009), pp. 146158. PDF
4. "Proof without words: Steiner's problem on the number e", Mathematics
Magazine, 82 (2009), p. 102. PDF
5. "Teaching tip: Partial sums of geometric series", The College
Mathematics Journal, 40 (2009), p. 278. PDF
6. "Proof without words: Squares in Circles and Semicircles," Mathematics
Magazine, 82 (2009), p. 359. PDF
7. "Proof without words: A reciprocal Pythagorean theorem," Mathematics
Magazine, 82 (2009), p. 370.PDF
2008
1. "Euler's triangle inequality via proofs without words," Mathematics
Magazine, 81 (2008), pp. 5861. PDF
2. "On the construction of copulas and quasicopulas with given diagonal
sections" (with J. J. Quesada Molina, J. A. Rodríguez Lallena, and M.
Úbeda Flores), Insurance: Mathematics and Economics, 42 (2008)
pp. 473483. PDF
3. "A sampler of visual proofs in firstyear calculus," available at
the AP
Central website (http://apcentral.collegeboard.com).
4. "Visual gems of number theory." Math Horizons, February
2008, pp. 79, 31. PDF
5. "Geometric proofs of the Weitzenböck and HadwigerFinsler
inequalities" (with C. Alsina), Mathematics Magazine, 81
(2008), pp. 216219. PDF
6. "Proof without words: Carnot's theorem for acute triangles" (with
C. Alsina), The College Mathematics Journal, 39 (2008), p. 111. PDF
7. "Symmetries of random discrete copulas" (with A. Erdely and J. M.
GonzálezBarrios), Kybernetika, 44 (2008), pp. 846863. PDF
2007
1. "Extremes of nonexchangeability," Statistical Papers, 48
(2007) pp. 329336. PDF
2. "Proof without words: The area of a right triangle," Mathematics
Magazine, 80 (2007), p. 45. PDF
3. "On the relationship between Spearman's rho and Kendall's tau for pairs
of continuous random variables" (with G. A. Fredricks), Journal of
Statistical Planning and Inference, 137 (2007), pp. 21432150. PDF
4. "A visual proof of the ErdösMordell inequality" (with C. Alsina),
Forum Geometricorum, 7 (2007), pp. 99102. PDF
5. "On Candido's identity" (with C. Alsina), Mathematics Magazine,
80 (2007), pp. 226228. PDF
6. "On the diagonals of a cyclic quadrilateral" (with C. Alsina), Forum
Geometricorum, 7 (2007) pp. 147149. PDF
7. "Robust fits for copula models" (with B. V. M. Mendes and E. F. L.
de Melo), Communication in StatisticsSimulation and Computation, 36
(2007), pp. 9971017. Website
2006
1. "Proof without words: Every fourth power greater than one is sum of two
nonconsecutive triangular numbers," Mathematics Magazine, 79
(2006) p. 44. PDF
2. "Proof without words: Padoa's inequality," Mathematics Magazine,
79 (2006) p. 53. PDF
3. "Proof without words: Right triangles and geometric series," Mathematics
Magazine, 79 (2006) p. 60. PDF
4. "Proof without words: Inclusionexclusion for triangular numbers,"
Mathematics Magazine, 79 (2006) p. 65. PDF
5. "Proof without words: A weighted sum of triangular numbers," Mathematics
Magazine, 79 (2006) p. 317. PDF
2005
1. "Proof without words: Candido's identity," Mathematics
Magazine, 78 (2005), p. 131. PDF
2. "Proof without words: Sums of triangular numbers," Mathematics
Magazine, 78 (2005), p. 231. PDF
3. "Dependence modeling with Archimedean copulas," Proceedings of
the Second Brazilian Conference on Statistical Modelling in Insurance and
Finance, (N. Kolev and P. Morettin, editors), Institute of Mathematics and
Statistics, University of São Paulo (2005), pp 45  54. PDF
4. "Copulas with fractal supports" (with G. A. Fredricks and J. A.
Rodríguez Lallena), Insurance: Mathematics and Economics, 37 (2005),
pp. 4248. PDF
5. "The latticetheoretic structure of sets of bivariate copulas and
quasicopulas" (with M. Úbeda Flores), C. R. Acad. Sci. Paris, Ser I, 341
(2005) pp. 583586. PDF
6. "Proof without words: A triangular sum," Mathematics Magazine,
78 (2005), p. 395. PDF
7. "Some properties of Schurconstant survival models and their
copulas," Brazilian Journal of Probability and Statistics, 19
(2005) pp. 179190. PDF
2004
1. "Bestpossible bounds on sets of bivariate distribution functions"
(with J. J. Quesada Molina, J. A. Rodríguez Lallena, and M. Úbeda Flores), Journal
of Multivariate Analysis, 90 (2004), pp. 348356. PDF
2. "The symmetric footrule is Gini's rank association coefficient"
(with M. Úbeda Flores), Communications in Statistics  Theory & Methods,
33 (2004), pp. 19596. PDF
3. "Proof without words: Four squares with constant area," Mathematics
Magazine, 77 (2004), p. 135. PDF
4. "Proof without words: Every octagonal number is the difference of two
squares," Mathematics Magazine, 77 (2004), p. 200. PDF
5. "A comparison of bounds on sets of joint distribution functions derived
from various measures of association" (with M. Úbeda Flores),
Communications in Statistics  Theory & Methods, 33 (2004), pp.
22992305. PDF
6. "Proof without words: A triangular identity," Mathematics
Magazine, 77 (2004), p. 395. PDF
2003
1. "Kendall distribution functions" (with J. J. Quesada Molina, J. A.
Rodríguez Lallena, and M. Úbeda Flores), Statistics & Probability
Letters, 65 (2003), pp. 263268. PDF
2. "Paintings, plane tilings, and proofs," Math Horizons, November
2003, pp. 5  8. PDF
3. "An improved remainder estimate for use with the integral test," The
College Mathematics Journal, 34 (2003), pp. 397399. PDF
4. "Properties and applications of copulas: A brief survey," Proceedings
of the First Brazilian Conference on Statistical Modelling in Insurance and
Finance (J. Dhaene, N. Kolev, and P. Morettin, eds.), Institute of
Mathematics and Statistics, University of São Paulo (2003), pp. 10  28. PDF
5. "Proof without words: The cube as an arithmetic sum," Mathematics
Magazine, 76 (2003), p. 136. PDF
2002
1. "Concordance and copulas: A survey," Distributions with Given
Marginals and Statistical Modelling (C. M. Cuadras, J. Fortiana, and J. A.
Rodríguez Lallena eds.), Kluwer Academic Publishers, Dordrecht (2002), pp.
169178. PDF
2. "The Bertino family of copulas" (with G. A. Fredricks), Distributions
with Given Marginals and Statistical Modelling (C. M. Cuadras, J. Fortiana,
and J. A. Rodríguez Lallena eds.), Kluwer Academic Publishers, Dordrecht
(2002), pp. 8192. PDF
3. "Some new properties of quasicopulas" (with J. J. Quesada Molina,
J. A. Rodríguez Lallena, and M. Úbeda Flores), Distributions with Given
Marginals and Statistical Modelling (C. M. Cuadras, J. Fortiana, and J. A.
Rodríguez Lallena eds.), Kluwer Academic Publishers, Dordrecht (2002), pp.
187194. PDF
4. "Multivariate Archimedian quasicopulas" (with J. J. Quesada
Molina, J. A. Rodríguez Lallena, and M. Úbeda Flores), Distributions with
Given Marginals and Statistical Modelling (C. M. Cuadras, J. Fortiana, and
J. A. Rodríguez Lallena eds.), Kluwer Academic Publishers, Dordrecht (2002),
pp. 179186. PDF
5. "Proof without words: The area of a salinon," Mathematics Magazine,
75 (2002), p. 130. PDF
6. "Proof without words: The area of an arbelos," Mathematics
Magazine, 75 (2002), p. 144. PDF
7. "Proof without words: Lunes and the regular hexagon," Mathematics
Magazine, 75 (2002), p. 316. PDF
Updated: February 2012
By: Anne Boal