<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE article  PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "http://dtd.nlm.nih.gov/publishing/3.0/journalpublishing3.dtd"><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" dtd-version="3.0" xml:lang="en" article-type="research article"><front><journal-meta><journal-id journal-id-type="publisher-id">APM</journal-id><journal-title-group><journal-title>Advances in Pure Mathematics</journal-title></journal-title-group><issn pub-type="epub">2160-0368</issn><publisher><publisher-name>Scientific Research Publishing</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.4236/apm.2013.37081</article-id><article-id pub-id-type="publisher-id">APM-38119</article-id><article-categories><subj-group subj-group-type="heading"><subject>Articles</subject></subj-group><subj-group subj-group-type="Discipline-v2"><subject>Physics&amp;Mathematics</subject></subj-group></article-categories><title-group><article-title>
 
 
  Strong Laws of Large Numbers for Arrays of Rowwise Conditionally Negatively Dependent Random Variables
 
</article-title></title-group><contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>onald</surname><given-names>Patterson</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref><xref ref-type="corresp" rid="cor1"><sup>*</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Tamika</surname><given-names>Royal-Thomas</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Wanda</surname><given-names>Patterson</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref></contrib></contrib-group><aff id="aff1"><addr-line>Department of Mathematics, Winston-Salem State University, Winston-Salem, USA</addr-line></aff><author-notes><corresp id="cor1">* E-mail:<email>pattersonrf@wssu.edu(OP)</email>;</corresp></author-notes><pub-date pub-type="epub"><day>17</day><month>10</month><year>2013</year></pub-date><volume>03</volume><issue>07</issue><fpage>625</fpage><lpage>626</lpage><history><date date-type="received"><day>March</day>	<month>13,</month>	<year>2013</year></date><date date-type="rev-recd"><day>April</day>	<month>16,</month>	<year>2013</year>	</date><date date-type="accepted"><day>May</day>	<month>18,</month>	<year>2013</year></date></history><permissions><copyright-statement>&#169; Copyright  2014 by authors and Scientific Research Publishing Inc. </copyright-statement><copyright-year>2014</copyright-year><license><license-p>This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/</license-p></license></permissions><abstract><p><html>
 <head></head>
 
   Let {X<sub>nk</sub>} be an array of rowwise conditionally negative dependent random variables. Complete convergence of <img alt="" src="Edit_8fdc5e95-904a-489e-b7ba-459d6fff5520.bmp" width="44" height="15" /> to 0 is obtained by using various conditions on the moments and conditional means. 
 
</html></p></abstract><kwd-group><kwd>Negative Dependence; Complete Convergence</kwd></kwd-group></article-meta></front><body><sec id="s1"><title>1. Introduction and Preliminaries</title><p>Concepts of negative dependence have been useful in developing laws of large numbers (cf: Taylor, Patterson and Bozorgnia [<xref ref-type="bibr" rid="scirp.38119-ref1">1</xref>]). Chung-type laws of large numbers for arrays of independent random variables were developed by Taylor, Patterson and Bozorgnia in [<xref ref-type="bibr" rid="scirp.38119-ref2">2</xref>].</p><p>Definition 1.1 Two random variables X and Y are pairwise negatively dependent (ND) if</p><disp-formula id="scirp.38119-formula96772"><label>(1)</label><graphic position="anchor" xlink:href="4-5300451\01d2b6fe-3591-4063-9230-c2702144a924.jpg"  xlink:type="simple"/></disp-formula><p>for all<img src="4-5300451\80602f2b-86bf-47ba-9082-ea51b605bbba.jpg" />.</p><p>Let (W, F, P) denote a probability space.</p><p>Definition 1.2. The sequence of random variables <img src="4-5300451\6970fe9f-4a1f-481d-9f54-b6d5157ab375.jpg" /> is said to be conditionally negatively dependent if there exists a sub s-field z of F such that for each positive integer m</p><disp-formula id="scirp.38119-formula96773"><label>(2)</label><graphic position="anchor" xlink:href="4-5300451\48235836-71e6-4d32-9244-920b5c2d53af.jpg"  xlink:type="simple"/></disp-formula><p>where <img src="4-5300451\ebfef74d-d353-4002-93a8-cca095121828.jpg" /> denotes the conditional probability of the random variable X being in the Boral set <img src="4-5300451\79ddf15c-6616-4353-beb5-43ed38a02601.jpg" /> given the sub-s field z. Negatively dependent random variable are conditionally negatively dependent with respect to the trivial s-field<img src="4-5300451\1001255b-b8a2-49c7-8a68-65e22541e0fc.jpg" />.</p><p>Throughout this paper <img src="4-5300451\d5a614cb-73db-4d96-8a29-a6d718cb1e83.jpg" /> will denote rowwise conditionally independent random variables such that <img src="4-5300451\0245e1b3-bc9b-40fa-81c6-7f2acc29d1dd.jpg" /> for all n and k. The major result of this paper shows that</p><disp-formula id="scirp.38119-formula96774"><label>. (3)</label><graphic position="anchor" xlink:href="4-5300451\78cd33fa-fa6a-434e-a813-7a6c73018c46.jpg"  xlink:type="simple"/></disp-formula><p>where complete convergence is defined (Hsu and Robbins [<xref ref-type="bibr" rid="scirp.38119-ref3">3</xref>]) by</p><disp-formula id="scirp.38119-formula96775"><label>. (4)</label><graphic position="anchor" xlink:href="4-5300451\311eb273-3d91-45c8-b100-66466fd182c8.jpg"  xlink:type="simple"/></disp-formula><p>Here <img src="4-5300451\0794002e-1b47-4195-9d91-60d7891eff68.jpg" /> is a function on a separable Banach space toR. In the next section of this paper, strong laws of large numbers for arrays of rowwise conditionally negatively dependent random variables.</p></sec><sec id="s2"><title>2. Strong Law for Random Variables</title><p>In this section, several lemmas are used in the proof of the major result. The first lemma will be presented without proof.</p><p>Lemma 2.1. Let X and Y be pairwise negatively dependent random variables. Then</p><p><img src="4-5300451\49e9a5fc-9828-4456-8b23-c9a7926a1a43.jpg" /></p><p>Lemma 2.2. Let X and Y be pairwise negatively dependent random variables. Then</p><p><img src="4-5300451\a5ddb51a-e56f-4ee2-85b4-1b1f572f7ce9.jpg" /></p><p>Proof: For X and Y negatively dependent, we have by Lemma 2.1</p><p><img src="4-5300451\19fb85b6-1235-4bf8-9dd3-67b453790387.jpg" /></p><p>Theorem 2.1 Let <img src="4-5300451\fa83c4b0-88fe-418f-a778-476aa22f3765.jpg" /> be an array of rowwise conditionally negatively dependent random variables. If</p><p>a)<img src="4-5300451\f7350773-e8a0-40d5-85b3-9a8354d5254e.jpg" /> (5)</p><p>and for all h &gt; 0</p><p>b)<img src="4-5300451\a6065229-4f9b-4a2f-a2c2-c3cce790c011.jpg" /> (6)</p><p>where <img src="4-5300451\2cb01678-31c7-4e1c-b7ef-47e4dbdbf5e0.jpg" /> is the conditional expectation with respect to an appropriate s-field that gives conditional negative dependence. Then</p><p><img src="4-5300451\0f8a162c-3559-4c23-8a72-525c1b5f41aa.jpg" />.</p><p>Proof. Let h &gt; 0 be given. By Markov’ inequality</p><disp-formula id="scirp.38119-formula96776"><label>(7)</label><graphic position="anchor" xlink:href="4-5300451\46f4e67d-ff63-4a4f-adf4-5a271ac0b075.jpg"  xlink:type="simple"/></disp-formula><p>By Lemma 2.2, the first term in Equation (7) is bounded by</p><p><img src="4-5300451\506a88da-18cc-4a65-ac23-e5a7498c477f.jpg" />.</p><p>The second term of Equation (7) is finite by Equation (6). Thus, the result follows.</p></sec><sec id="s3"><title>3. Strong Law for Random Elements in R<sup>m</sup></title><p>Theorem 1.2 can be extended to R<sup>m</sup>. The next definition is a crucial type p inequality used to define a form of negative dependence (cf. Patterson, Taylor, and Bozorgnia [<xref ref-type="bibr" rid="scirp.38119-ref4">4</xref>]).</p><p>Definition 3.1. Random elements<img src="4-5300451\0dadcf2c-a136-4487-8b8e-247cad0f286f.jpg" />, in a type p Banach space <img src="4-5300451\ae17bcf2-567d-4ae3-bd8c-90a4effefa55.jpg" /> are said to be type p negatively dependent if <img src="4-5300451\4ad2e2a2-381a-41d4-9667-38cd8d686187.jpg" /> and if there exist a finite positive constant C such that</p><disp-formula id="scirp.38119-formula96777"><label>(8)</label><graphic position="anchor" xlink:href="4-5300451\980d3673-d0a2-4c17-9e7a-c242735710f5.jpg"  xlink:type="simple"/></disp-formula><p>for all n ≥ 1.</p><p>Coordinatewise (with respect to the standard basis) negative dependence in R<sup>m</sup> can yield type 2 negative dependence. To see this for rowwise random elements<img src="4-5300451\ba42a5e1-7843-45f5-8e90-8ba84eb26394.jpg" />, let <img src="4-5300451\9e6bbd1d-34fe-47d5-a57c-3758849efa85.jpg" /> be random elements in R<sup>m</sup> such that <img src="4-5300451\db0638e4-93cb-4d96-b605-040a62b0d9a0.jpg" /> for 1≤ i ≤ m, n, k ≥ 1. Then</p><disp-formula id="scirp.38119-formula96778"><label>(9)</label><graphic position="anchor" xlink:href="4-5300451\498f9cd1-b24a-4021-97be-9d20c65cd4c1.jpg"  xlink:type="simple"/></disp-formula><p>Theorem 3.1 Let <img src="4-5300451\9a649140-3704-434d-9b80-3d94e281404d.jpg" /> be an array of rowwise conditionally coordinatewise negatively random elements in R<sup>m</sup>. If a)<img src="4-5300451\91c3919d-e258-4a13-bbd2-f0b623af159a.jpg" />(10)</p><p>and for all h &gt; 0 b)<img src="4-5300451\10e03cdb-c6bf-4cab-8ea3-36e4bf281c67.jpg" />(11)</p><p>where <img src="4-5300451\372ebc39-6e6d-436b-ae8d-05b15e59aa19.jpg" /> is the conditional expectation with respect to an appropriate s-field that gives conditional negative dependence, then</p><p><img src="4-5300451\10274408-ebee-4a30-8897-40a9bd6a2fdf.jpg" /></p><p>Proof. The proof is similar to that of Theorem 2.1.</p></sec><sec id="s4"><title>REFERENCES</title></sec></body><back><ref-list><title>References</title><ref id="scirp.38119-ref1"><label>1</label><mixed-citation publication-type="other" xlink:type="simple">R. L. Taylor, R. Patterson and A. Bozorgnia, “A Strong Law of Large Numbers for Arrays of Rowwise Negatively Dependent Random Variables,” Stochastic Analysis and Applications, Vol. 20, No. 3, 2002, pp. 644-666.</mixed-citation></ref><ref id="scirp.38119-ref2"><label>2</label><mixed-citation publication-type="other" xlink:type="simple">R. Patterson, R. L. Taylor and A. Bozorgnia, “Chung Type Stong Laws for Arrays of Random Elements and Bootstrapping,” Stochastic Analysis and Applications, Vol. 15, No. 5, 1997, pp. 651-669.   http://dx.doi.org/10.1080/07362999708809501</mixed-citation></ref><ref id="scirp.38119-ref3"><label>3</label><mixed-citation publication-type="other" xlink:type="simple">P. L. Hu and H. Robbins, “Complete Convergence and the Law of Large Numbers,” Proceedings of the National Academy of Sciences of the United States of America, Vol. 33, No. 2, 1947, pp. 25-31.http://dx.doi.org/10.1073/pnas.33.2.25</mixed-citation></ref><ref id="scirp.38119-ref4"><label>4</label><mixed-citation publication-type="other" xlink:type="simple">R. Patterson, R. L. Taylor and A. Bozorgnia, “Strong Laws of Large Numbers for Arrays of Rowwise Conditionally Independent Random Variables,” Journal of Applied Mathematics and Stochastic Analysis, Vol. 6, No. 1, 1993, pp. 1-10.http://dx.doi.org/10.1155/S1048953393000012</mixed-citation></ref></ref-list></back></article>