<?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">OALibJ</journal-id><journal-title-group><journal-title>Open Access Library Journal</journal-title></journal-title-group><issn pub-type="epub">2333-9705</issn><publisher><publisher-name>Scientific Research Publishing</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.4236/oalib.1102247</article-id><article-id pub-id-type="publisher-id">OALibJ-68222</article-id><article-categories><subj-group subj-group-type="heading"><subject>Articles</subject></subj-group><subj-group subj-group-type="Discipline-v2"><subject>Biomedical&amp;Life Sciences</subject><subject> Business&amp;Economics</subject><subject> Chemistry&amp;Materials Science</subject><subject> Computer Science&amp;Communications</subject><subject> Earth&amp;Environmental Sciences</subject><subject> Engineering</subject><subject> Medicine&amp;Healthcare</subject><subject> Physics&amp;Mathematics</subject><subject> Social Sciences&amp;Humanities</subject></subj-group></article-categories><title-group><article-title>
 
 
  On One-Step Method of Euler-Maruyama Type for Solution of Stochastic Differential Equations Using Varying Stepsizes
 
</article-title></title-group><contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Sunday</surname><given-names>Jacob Kayode</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>Akeem</surname><given-names>Adebayo Ganiyu</given-names></name><xref ref-type="aff" rid="aff2"><sup>2</sup></xref><xref ref-type="corresp" rid="cor1"><sup>*</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Adegoke</surname><given-names>Sule Ajiboye</given-names></name><xref ref-type="aff" rid="aff3"><sup>3</sup></xref></contrib></contrib-group><aff id="aff1"><addr-line>Department of Mathematical Sciences, Federal University of Technology, Akure, Nigeria</addr-line></aff><aff id="aff2"><addr-line>Mathematics Department, Adeyemi College of Education, Ondo, Nigeria</addr-line></aff><aff id="aff3"><addr-line>Department of Statistics, Federal University of Technology, Akure, Nigeria</addr-line></aff><author-notes><corresp id="cor1">* E-mail:<email>ganiyuiwajowa@gmail.com(AAG)</email>;</corresp></author-notes><pub-date pub-type="epub"><day>29</day><month>01</month><year>2016</year></pub-date><volume>03</volume><issue>01</issue><fpage>1</fpage><lpage>15</lpage><history><date date-type="received"><day>9</day>	<month>January</month>	<year>2016</year></date><date date-type="rev-recd"><day>accepted</day>	<month>24</month>	<year>January</year>	</date><date date-type="accepted"><day>29</day>	<month>January</month>	<year>2016</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>
 
 
   
   In this work, a one-step method of Euler-Maruyama (EMM) type has been developed for the solution of general first order stochastic differential equations (SDEs) using Ito integral equation as basis tool. The effect of varying stepsizes on the numerical solution is also examined for the SDEs. Two problems of first order SDEs are solved. Absolute errors for the problems are obtained from which the mean absolute errors (MAEs) are calculated. Comparison of variation in stepsizes is achieved using the MAEs. The results show that the MAEs decrease as the stepsize decreases. The strong orders of convergence and the residuals for the problem for the theoretical are respectively obtained using Least Square Fit. This work produces numerical values for the solution to the problems which differ from the existing methods of EMM type in which results are always obtained by simulation. 
  
 
</p></abstract><kwd-group><kwd>One-Step Method</kwd><kwd> Ito Integral</kwd><kwd> Stochastic State Model</kwd><kwd> Gaussian White Noise</kwd><kwd> Wiener Process</kwd><kwd> Wiener Increment</kwd></kwd-group></article-meta></front><body><sec id="s1"><title>1. Introduction</title><p>Modeling of physical systems by ordinary differential equations (ODEs) ignores stochastic effects. Addition of random elements into the differential equations leads to what is called stochastic differential equations (SDEs), and the term stochastic is called noise [<xref ref-type="bibr" rid="scirp.68222-ref1">1</xref>] . Many researchers have worked extensively on a first and higher order ordinary differential equations of the form</p><disp-formula id="scirp.68222-formula198"><label>(1)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x6.png"  xlink:type="simple"/></disp-formula><p>where<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x7.png" xlink:type="simple"/></inline-formula>. These researchers include [<xref ref-type="bibr" rid="scirp.68222-ref2">2</xref>] - [<xref ref-type="bibr" rid="scirp.68222-ref19">19</xref>] .</p><p>Equation (1) is a deterministic state model which can be turned to a stochastic state model by including noise term. For one dimensional noise term, consider a general first order stochastic differential Equation (SDE) of the form</p><disp-formula id="scirp.68222-formula199"><label>(2)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x8.png"  xlink:type="simple"/></disp-formula><p>where <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x9.png" xlink:type="simple"/></inline-formula> and <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x10.png" xlink:type="simple"/></inline-formula> drift function and diffusion function respectively. The noise <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x11.png" xlink:type="simple"/></inline-formula> in Equation (2) is generally called Gaussian white noise. It is expressed as<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x12.png" xlink:type="simple"/></inline-formula>, where <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x13.png" xlink:type="simple"/></inline-formula> is the Wiener process.</p><p>Equation (2) can be written as</p><disp-formula id="scirp.68222-formula200"><label>(3)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x14.png"  xlink:type="simple"/></disp-formula><p>Integrating (3) from 0 to t, we have It&#244; integral equation</p><disp-formula id="scirp.68222-formula201"><label>(4)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x15.png"  xlink:type="simple"/></disp-formula><p>The first integral at the right hand side of Equation (4) is called Riemman integral while the second integral is called It&#244; or stochastic integral. Many researchers have also worked on SDEs of the form (3). Amongst these are [<xref ref-type="bibr" rid="scirp.68222-ref20">20</xref>] - [<xref ref-type="bibr" rid="scirp.68222-ref29">29</xref>] .</p><p>The aim of this paper is to develop numerical method for solution of first order stochastic differential Equation (3). Our objectives are to develop one-step Euler-Maruyama method (EMM) for solution of SDE (3) and apply it to solve two problems in the form of first order SDEs. Absolute errors (AEs) will be determined at various point in the interval<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x16.png" xlink:type="simple"/></inline-formula>, where<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x17.png" xlink:type="simple"/></inline-formula>. The AEs will be determined by finding the absolute value of the difference between the exact solution and numerical solution of Equation (3) for various values of <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x18.png" xlink:type="simple"/></inline-formula> using one-step Euler-Maruyama method. These values will allow us to obtain mean absolute error (MAE).</p><p>The strong order of convergence (SOC) of the method will be determined from the results of the mean absolute errors obtained. [<xref ref-type="bibr" rid="scirp.68222-ref25">25</xref>] considered the effect of using single stepsize for solution of SDE (3). The first section of this paper introduces the content of the paper. The second section discusses the research methodology. Under this section, It&#244; integral form of stochastic differential Equation (3) stated in Equation (4) is used as the basis for the derivation of one-step Euler-Maruyama method. The method is implemented with two problems in the form of SDE in Equation (3). In section three, the effect of varying the stepsizes in determining the solution of SDE in Equation (3) is considered. The stepsizes used are<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x19.png" xlink:type="simple"/></inline-formula>. Numerical solution and absolute error are then obtained using each of the stepsize. Using ten values of<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x20.png" xlink:type="simple"/></inline-formula>, mean absolute errors are determined for each of the stepsizes. The SOC is calculated for each problem using the least square fit in [<xref ref-type="bibr" rid="scirp.68222-ref26">26</xref>] . MATLAB program is used as a supporting tool.</p></sec><sec id="s2"><title>2. Research Methodology</title><p>There are many methods for determining the solution of SDE (3), they include, Euler-Maruyama method, Euler-Maruyama method, Runge-Kutta method, Heun method and so on. For more information about the list of methods or schemes for solution of first order SDEs (see [<xref ref-type="bibr" rid="scirp.68222-ref30">30</xref>] ). To determine the solution of SDE (3), one-step method of Euler-Maruyama type will be used. Euler-Maruyama method was used by [<xref ref-type="bibr" rid="scirp.68222-ref26">26</xref>] for considering an autonomous system of stochastic differential equations. Here, we shall consider the derivation of the method using It&#244; integral Equation (4) obtained from a general form of the SDE stated in Equation (3).</p><sec id="s2_1"><title>2.1. Derivation of One Step Euler-Maruyama Method</title><p>One-step Euler-Maruyama method will be derived by setting <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x21.png" xlink:type="simple"/></inline-formula> in the integral</p><disp-formula id="scirp.68222-formula202"><label>(4)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x22.png"  xlink:type="simple"/></disp-formula><p>This gives</p><disp-formula id="scirp.68222-formula203"><label>(5)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x23.png"  xlink:type="simple"/></disp-formula><disp-formula id="scirp.68222-formula204"><label>(6)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x24.png"  xlink:type="simple"/></disp-formula><disp-formula id="scirp.68222-formula205"><label>(6) - (5)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x25.png"  xlink:type="simple"/></disp-formula><disp-formula id="scirp.68222-formula206"><label>(7)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x26.png"  xlink:type="simple"/></disp-formula><p>Using a conventional deterministic quadrature, the two integral terms at the right hand side can be approximated as follows:</p><disp-formula id="scirp.68222-formula207"><label>(8)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x27.png"  xlink:type="simple"/></disp-formula><disp-formula id="scirp.68222-formula208"><label>(9)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x28.png"  xlink:type="simple"/></disp-formula><p>Substituting (8) and (9) in (7), we have</p><disp-formula id="scirp.68222-formula209"><label>(10)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x29.png"  xlink:type="simple"/></disp-formula><p>Define<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x30.png" xlink:type="simple"/></inline-formula>,<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x30.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x31.png" xlink:type="simple"/></inline-formula>;<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x30.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x31.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x32.png" xlink:type="simple"/></inline-formula>,<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x30.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x31.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x32.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x33.png" xlink:type="simple"/></inline-formula>.</p><p>Equation (10) becomes</p><disp-formula id="scirp.68222-formula210"><label>(11)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x34.png"  xlink:type="simple"/></disp-formula></sec><sec id="s2_2"><title>2.2. Implementation of the Method</title><p>The method in Equation (11) was considered by [<xref ref-type="bibr" rid="scirp.68222-ref26">26</xref>] using backward difference. In this paper, we shall apply this method to the SDE (3) using discritised interval <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x35.png" xlink:type="simple"/></inline-formula> as<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x35.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x36.png" xlink:type="simple"/></inline-formula>. Let <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x35.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x36.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x37.png" xlink:type="simple"/></inline-formula> be the stepsize defined as<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x35.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x36.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x37.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x38.png" xlink:type="simple"/></inline-formula>, where N are some integer and<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x35.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x36.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x37.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x38.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x39.png" xlink:type="simple"/></inline-formula>. The <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x35.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x36.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x37.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x38.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x39.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x40.png" xlink:type="simple"/></inline-formula>-space path increment <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x35.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x36.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x37.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x38.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x39.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x40.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x41.png" xlink:type="simple"/></inline-formula> will be approximated by summing the underlying <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x35.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x36.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x37.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x38.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x39.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x40.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x41.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x42.png" xlink:type="simple"/></inline-formula>-space increments as established by [<xref ref-type="bibr" rid="scirp.68222-ref26">26</xref>] using</p><disp-formula id="scirp.68222-formula211"><label>(12)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x43.png"  xlink:type="simple"/></disp-formula><p>Wiener increment <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x44.png" xlink:type="simple"/></inline-formula> will be generated in MATLAB over the space intervals by using <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x44.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x45.png" xlink:type="simple"/></inline-formula>. For computational purpose, we shall assume that<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x44.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x45.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x46.png" xlink:type="simple"/></inline-formula>, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x44.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x45.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x46.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x47.png" xlink:type="simple"/></inline-formula>and<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x44.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x45.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x46.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x47.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x48.png" xlink:type="simple"/></inline-formula>. In this paper, we shall investigate the effect of varying stepsizes in determining the numerical solution of SDE (3) using one-step method of EMM type in Equation (11). This is provided in section 3.0. The absolute errors will be obtained. From this, the mean absolute errors will be determined. Strong order of convergence and the residual for one-step method of EMM type will be determined from mean absolute error by making least square fit using the MALAB commands.</p></sec></sec><sec id="s3"><title>3. Effect of Varying Stepsizes in Determining Numerical Solution of Stochastic Differential Equations Using One-Step Euler-Maruyama Method</title><p>In this section, we will consider two problems in the form of first order stochastic differential Equation (3) to investigate the effect of varying stepsizes when finding the solution of SDEs using one step method of EMM type in Equation (11).</p><p>Problem 1.</p><disp-formula id="scirp.68222-formula212"><label>(13)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x49.png"  xlink:type="simple"/></disp-formula><p>where <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x50.png" xlink:type="simple"/></inline-formula> and <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x50.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x51.png" xlink:type="simple"/></inline-formula> are arbitrary values.</p><p>The exact solution of the SDE (13) is</p><disp-formula id="scirp.68222-formula213"><label>(14)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x52.png"  xlink:type="simple"/></disp-formula><p>Problem 1 is the Black Scholes option price model with a drift function<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x53.png" xlink:type="simple"/></inline-formula>, drift coefficient<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x53.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x54.png" xlink:type="simple"/></inline-formula>, diffusion function <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x53.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x54.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x55.png" xlink:type="simple"/></inline-formula> and diffusion coefficient<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x53.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x54.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x55.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x56.png" xlink:type="simple"/></inline-formula>. The model was also used by [<xref ref-type="bibr" rid="scirp.68222-ref26">26</xref>] and [<xref ref-type="bibr" rid="scirp.68222-ref29">29</xref>] .</p><p>The following stepsizes will be used to carry out our investigation,<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x57.png" xlink:type="simple"/></inline-formula>.</p><sec id="s3_1"><title>3.1. Results Showing the Effect of Using Varying Stepsizes When Euler-Maruyama Method Is Applied to Problem 1</title><p>See <xref ref-type="fig" rid="fig1">Figure 1</xref> for the graph of the result on <xref ref-type="table" rid="table1">Table 1</xref>.</p><fig id="fig1"  position="float"><label><xref ref-type="fig" rid="fig1">Figure 1</xref></label><caption><title> Shows the graph of the result on <xref ref-type="table" rid="table1">Table 1</xref></title></caption><graphic mimetype="image"   position="float"  xlink:type="simple"  xlink:href="http://html.scirp.org/file/68222x58.png"/></fig><table-wrap id="table1" ><label><xref ref-type="table" rid="table1">Table 1</xref></label><caption><title> Result of Problem 1 showing the effect of using stepsize 2<sup>−4</sup></title></caption><table><tbody><thead><tr><th align="center" valign="middle" >t-value Error</th><th align="center" valign="middle" >Exact Solution</th><th align="center" valign="middle" >Numerical Solution</th><th align="center" valign="middle" >Absolute</th></tr></thead><tr><td align="center" valign="middle" >0.062500</td><td align="center" valign="middle" >1.000035213412162</td><td align="center" valign="middle" >1.000035213104684</td><td align="center" valign="middle" >3.07477599e−10</td></tr><tr><td align="center" valign="middle" >0.125000</td><td align="center" valign="middle" >0.999992194240297</td><td align="center" valign="middle" >0.999992193320025</td><td align="center" valign="middle" >9.20271970e−10</td></tr><tr><td align="center" valign="middle" >0.187500</td><td align="center" valign="middle" >0.999998717493128</td><td align="center" valign="middle" >0.999998716864071</td><td align="center" valign="middle" >6.29056918e−10</td></tr><tr><td align="center" valign="middle" >0.250000</td><td align="center" valign="middle" >1.000012935644641</td><td align="center" valign="middle" >1.000012935226998</td><td align="center" valign="middle" >4.17643475e−10</td></tr><tr><td align="center" valign="middle" >0.312500</td><td align="center" valign="middle" >0.999974930990167</td><td align="center" valign="middle" >0.999974930162858</td><td align="center" valign="middle" >8.27309221e−10</td></tr><tr><td align="center" valign="middle" >0.375000</td><td align="center" valign="middle" >0.999978328502518</td><td align="center" valign="middle" >0.999978327981927</td><td align="center" valign="middle" >5.20591348e−10</td></tr><tr><td align="center" valign="middle" >0.437500</td><td align="center" valign="middle" >0.999988796767910</td><td align="center" valign="middle" >0.999988796505013</td><td align="center" valign="middle" >2.62896704e−10</td></tr><tr><td align="center" valign="middle" >0.500000</td><td align="center" valign="middle" >0.999951804297058</td><td align="center" valign="middle" >0.999951803662421</td><td align="center" valign="middle" >6.34636454e−10</td></tr><tr><td align="center" valign="middle" >0.562500</td><td align="center" valign="middle" >0.999984007130832</td><td align="center" valign="middle" >0.999984006290135</td><td align="center" valign="middle" >8.40697068e−10</td></tr><tr><td align="center" valign="middle" >0.625000</td><td align="center" valign="middle" >1.000014922754158</td><td align="center" valign="middle" >1.000014921748044</td><td align="center" valign="middle" >1.00611364e−9</td></tr></tbody></table></table-wrap><p>The mean absolute error is 6.366694393911132e−10.</p><p><xref ref-type="table" rid="table1">Table 1</xref> shows the exact solution, numerical solution and absolute error for the effect of using stepsize 2<sup>−4</sup>.</p><p>See <xref ref-type="fig" rid="fig2">Figure 2</xref> for the graph of the result on <xref ref-type="table" rid="table2">Table 2</xref>.</p><fig id="fig2"  position="float"><label><xref ref-type="fig" rid="fig2">Figure 2</xref></label><caption><title> Shows the graph of the result on <xref ref-type="table" rid="table2">Table 2</xref></title></caption><graphic mimetype="image"   position="float"  xlink:type="simple"  xlink:href="http://html.scirp.org/file/68222x59.png"/></fig><table-wrap id="table2" ><label><xref ref-type="table" rid="table2">Table 2</xref></label><caption><title> Result of Problem 1 showing the effect of using stepsize 2<sup>−5</sup></title></caption><table><tbody><thead><tr><th align="center" valign="middle" >t-value Error</th><th align="center" valign="middle" >Exact Solution</th><th align="center" valign="middle" >Numerical Solution</th><th align="center" valign="middle" >Absolute</th></tr></thead><tr><td align="center" valign="middle" >0.062500</td><td align="center" valign="middle" >0.999989302989965</td><td align="center" valign="middle" >0.999989302508838</td><td align="center" valign="middle" >4.81126805e−10</td></tr><tr><td align="center" valign="middle" >0.125000</td><td align="center" valign="middle" >0.999998791743439</td><td align="center" valign="middle" >0.999998791544895</td><td align="center" valign="middle" >1.98543737e−10</td></tr><tr><td align="center" valign="middle" >0.187500</td><td align="center" valign="middle" >0.999969143626926</td><td align="center" valign="middle" >0.999969143306858</td><td align="center" valign="middle" >3.20068305e−10</td></tr><tr><td align="center" valign="middle" >0.250000</td><td align="center" valign="middle" >0.999945211010976</td><td align="center" valign="middle" >0.999945210578632</td><td align="center" valign="middle" >4.32343716e−10</td></tr><tr><td align="center" valign="middle" >0.312500</td><td align="center" valign="middle" >0.999984664319081</td><td align="center" valign="middle" >0.999984663809844</td><td align="center" valign="middle" >5.09236209e−10</td></tr><tr><td align="center" valign="middle" >0.375000</td><td align="center" valign="middle" >1.000048162051462</td><td align="center" valign="middle" >1.000048160772574</td><td align="center" valign="middle" >1.27888855e−9</td></tr><tr><td align="center" valign="middle" >0.437500</td><td align="center" valign="middle" >1.000031603910325</td><td align="center" valign="middle" >1.000031602873598</td><td align="center" valign="middle" >1.03672670e−9</td></tr><tr><td align="center" valign="middle" >0.500000</td><td align="center" valign="middle" >0.999985898306111</td><td align="center" valign="middle" >0.999985896243317</td><td align="center" valign="middle" >2.06279349e−9</td></tr><tr><td align="center" valign="middle" >0.562500</td><td align="center" valign="middle" >1.000027707908093</td><td align="center" valign="middle" >1.000027705706180</td><td align="center" valign="middle" >2.20191265e−9</td></tr><tr><td align="center" valign="middle" >0.625000</td><td align="center" valign="middle" >1.000029576187069</td><td align="center" valign="middle" >1.000029574216571</td><td align="center" valign="middle" >1.97049865e−9</td></tr></tbody></table></table-wrap><p>The mean absolute error is 1.049213882442501e−9.</p><p><xref ref-type="table" rid="table2">Table 2</xref> shows the exact solution, numerical solution and absolute error for the effect of using stepsize 2<sup>−5</sup>.</p><p>See <xref ref-type="fig" rid="fig3">Figure 3</xref> for the graph of the result on <xref ref-type="table" rid="table3">Table 3</xref>.</p><fig id="fig3"  position="float"><label><xref ref-type="fig" rid="fig3">Figure 3</xref></label><caption><title> Shows the graph of the result on <xref ref-type="table" rid="table3">Table 3</xref></title></caption><graphic mimetype="image"   position="float"  xlink:type="simple"  xlink:href="http://html.scirp.org/file/68222x60.png"/></fig><table-wrap id="table3" ><label><xref ref-type="table" rid="table3">Table 3</xref></label><caption><title> Result of Problem 1 showing the effect of using stepsize 2<sup>−6</sup></title></caption><table><tbody><thead><tr><th align="center" valign="middle" >t-value</th><th align="center" valign="middle" >Exact Solution</th><th align="center" valign="middle" >Numerical Solution</th><th align="center" valign="middle" >Absolute Error</th></tr></thead><tr><td align="center" valign="middle" >0.062500</td><td align="center" valign="middle" >0.999993968111180</td><td align="center" valign="middle" >0.999993968007453</td><td align="center" valign="middle" >1.03727471e−10</td></tr><tr><td align="center" valign="middle" >0.125000</td><td align="center" valign="middle" >0.999950903398081</td><td align="center" valign="middle" >0.999950903125062</td><td align="center" valign="middle" >2.73019052e−10</td></tr><tr><td align="center" valign="middle" >0.187500</td><td align="center" valign="middle" >1.000018522444389</td><td align="center" valign="middle" >1.000018521838989</td><td align="center" valign="middle" >6.05399730e−10</td></tr><tr><td align="center" valign="middle" >0.250000</td><td align="center" valign="middle" >0.999969318836642</td><td align="center" valign="middle" >0.999969317778954</td><td align="center" valign="middle" >1.05768760e−9</td></tr><tr><td align="center" valign="middle" >0.312500</td><td align="center" valign="middle" >0.999995025525107</td><td align="center" valign="middle" >0.999995024550208</td><td align="center" valign="middle" >9.74898495e−10</td></tr><tr><td align="center" valign="middle" >0.375000</td><td align="center" valign="middle" >0.999971494315777</td><td align="center" valign="middle" >0.999971493473134</td><td align="center" valign="middle" >8.42642955e−10</td></tr><tr><td align="center" valign="middle" >0.437500</td><td align="center" valign="middle" >1.000023470014742</td><td align="center" valign="middle" >1.000023468767193</td><td align="center" valign="middle" >1.24754895e−9</td></tr><tr><td align="center" valign="middle" >0.500000</td><td align="center" valign="middle" >1.000006560271671</td><td align="center" valign="middle" >1.000006558980626</td><td align="center" valign="middle" >1.29104549e−9</td></tr><tr><td align="center" valign="middle" >0.562500</td><td align="center" valign="middle" >1.000016550151243</td><td align="center" valign="middle" >1.000016548430911</td><td align="center" valign="middle" >1.72033232e−9</td></tr><tr><td align="center" valign="middle" >0.625000</td><td align="center" valign="middle" >1.000050801848815</td><td align="center" valign="middle" >1.000050800269305</td><td align="center" valign="middle" >1.57950941e−9</td></tr></tbody></table></table-wrap><p>The mean absolute error is 9.695811487020478e−10.</p><p><xref ref-type="table" rid="table3">Table 3</xref> shows the exact solution, numerical solution and absolute error for the effect of using stepsize 2<sup>−6</sup>.</p><p>See <xref ref-type="fig" rid="fig4">Figure 4</xref> for the graph of the result on <xref ref-type="table" rid="table4">Table 4</xref>.</p><fig id="fig4"  position="float"><label><xref ref-type="fig" rid="fig4">Figure 4</xref></label><caption><title> Shows the graph of the result on <xref ref-type="table" rid="table4">Table 4</xref></title></caption><graphic mimetype="image"   position="float"  xlink:type="simple"  xlink:href="http://html.scirp.org/file/68222x61.png"/></fig><table-wrap id="table4" ><label><xref ref-type="table" rid="table4">Table 4</xref></label><caption><title> Result of Problem 1 showing the effect of using stepsize 2<sup>−7</sup></title></caption><table><tbody><thead><tr><th align="center" valign="middle" >t-value</th><th align="center" valign="middle" >Exact Solution</th><th align="center" valign="middle" >Numerical Solution</th><th align="center" valign="middle" >Absolute Error</th></tr></thead><tr><td align="center" valign="middle" >0.062500</td><td align="center" valign="middle" >0.999960105863295</td><td align="center" valign="middle" >0.999960105702641</td><td align="center" valign="middle" >1.60653491e−10</td></tr><tr><td align="center" valign="middle" >0.125000</td><td align="center" valign="middle" >0.999967950241945</td><td align="center" valign="middle" >0.999967949695712</td><td align="center" valign="middle" >5.46233170e−10</td></tr><tr><td align="center" valign="middle" >0.187500</td><td align="center" valign="middle" >0.999964311166688</td><td align="center" valign="middle" >0.999964310727299</td><td align="center" valign="middle" >4.39388304e−10</td></tr><tr><td align="center" valign="middle" >0.250000</td><td align="center" valign="middle" >0.999983928766161</td><td align="center" valign="middle" >0.999983928116954</td><td align="center" valign="middle" >6.49207244e−10</td></tr><tr><td align="center" valign="middle" >0.312500</td><td align="center" valign="middle" >1.000010033769263</td><td align="center" valign="middle" >1.000010032994412</td><td align="center" valign="middle" >7.74851072e−10</td></tr><tr><td align="center" valign="middle" >0.375000</td><td align="center" valign="middle" >1.000060677640722</td><td align="center" valign="middle" >1.000060676842953</td><td align="center" valign="middle" >7.97768518e−10</td></tr><tr><td align="center" valign="middle" >0.437500</td><td align="center" valign="middle" >1.000067288106194</td><td align="center" valign="middle" >1.000067287456036</td><td align="center" valign="middle" >6.50158150e−10</td></tr><tr><td align="center" valign="middle" >0.500000</td><td align="center" valign="middle" >1.000122399331946</td><td align="center" valign="middle" >1.000122398556290</td><td align="center" valign="middle" >7.75655762e−10</td></tr><tr><td align="center" valign="middle" >0.562500</td><td align="center" valign="middle" >1.000162783152388</td><td align="center" valign="middle" >1.000162782441429</td><td align="center" valign="middle" >7.10958847e−10</td></tr><tr><td align="center" valign="middle" >0.625000</td><td align="center" valign="middle" >1.000180536086851</td><td align="center" valign="middle" >1.000180535284656</td><td align="center" valign="middle" >8.02195865e−10</td></tr></tbody></table></table-wrap><p>The mean absolute error is 6.307070421485150e−10.</p><p><xref ref-type="table" rid="table4">Table 4</xref> shows the exact solution, numerical solution and absolute error for the effect of using stepsize 2<sup>−7</sup>.</p><p>See <xref ref-type="fig" rid="fig5">Figure 5</xref> for the graph of the result on <xref ref-type="table" rid="table5">Table 5</xref>.</p><fig id="fig5"  position="float"><label><xref ref-type="fig" rid="fig5">Figure 5</xref></label><caption><title> Shows the graph of the result on <xref ref-type="table" rid="table5">Table 5</xref></title></caption><graphic mimetype="image"   position="float"  xlink:type="simple"  xlink:href="http://html.scirp.org/file/68222x62.png"/></fig><table-wrap id="table5" ><label><xref ref-type="table" rid="table5">Table 5</xref></label><caption><title> Result of Problem 1 showing the effect of using stepsize 2<sup>−8</sup></title></caption><table><tbody><thead><tr><th align="center" valign="middle" >t-value</th><th align="center" valign="middle" >Exact Solution</th><th align="center" valign="middle" >Numerical Solution</th><th align="center" valign="middle" >Absolute Error</th></tr></thead><tr><td align="center" valign="middle" >0.062500</td><td align="center" valign="middle" >0.999972159883026</td><td align="center" valign="middle" >0.999972159601738</td><td align="center" valign="middle" >2.81287882e−10</td></tr><tr><td align="center" valign="middle" >0.125000</td><td align="center" valign="middle" >0.999978280985938</td><td align="center" valign="middle" >0.999978280655984</td><td align="center" valign="middle" >3.29953620e−10</td></tr><tr><td align="center" valign="middle" >0.187500</td><td align="center" valign="middle" >1.000027372023912</td><td align="center" valign="middle" >1.000027371636413</td><td align="center" valign="middle" >3.87499366e−10</td></tr><tr><td align="center" valign="middle" >0.250000</td><td align="center" valign="middle" >1.000065836108020</td><td align="center" valign="middle" >1.000065835744871</td><td align="center" valign="middle" >3.63149066e−10</td></tr><tr><td align="center" valign="middle" >0.312500</td><td align="center" valign="middle" >1.000101764246374</td><td align="center" valign="middle" >1.000101763882430</td><td align="center" valign="middle" >3.63944430e−10</td></tr><tr><td align="center" valign="middle" >0.375000</td><td align="center" valign="middle" >1.000108726423491</td><td align="center" valign="middle" >1.000108726193473</td><td align="center" valign="middle" >2.30018227e−10</td></tr><tr><td align="center" valign="middle" >0.437500</td><td align="center" valign="middle" >1.000148957998176</td><td align="center" valign="middle" >1.000148957704878</td><td align="center" valign="middle" >2.93298275e−10</td></tr><tr><td align="center" valign="middle" >0.500000</td><td align="center" valign="middle" >1.000172569073211</td><td align="center" valign="middle" >1.000172568980299</td><td align="center" valign="middle" >9.29125665e−11</td></tr><tr><td align="center" valign="middle" >0.562500</td><td align="center" valign="middle" >1.000206392121796</td><td align="center" valign="middle" >1.000206391996795</td><td align="center" valign="middle" >1.25001121e−10</td></tr><tr><td align="center" valign="middle" >0.625000</td><td align="center" valign="middle" >1.000193604241676</td><td align="center" valign="middle" >1.000193604296249</td><td align="center" valign="middle" >5.45721246e−11</td></tr></tbody></table></table-wrap><p>The mean absolute error is 2.521636677244032e−10.</p><p><xref ref-type="table" rid="table5">Table 5</xref> shows the exact solution, numerical solution and absolute error for the effect of using stepsize 2<sup>−8</sup>.</p><p>See <xref ref-type="fig" rid="fig6">Figure 6</xref> for the graph of the result on <xref ref-type="table" rid="table6">Table 6</xref>.</p><fig id="fig6"  position="float"><label><xref ref-type="fig" rid="fig6">Figure 6</xref></label><caption><title> Shows the graph of the result on <xref ref-type="table" rid="table6">Table 6</xref></title></caption><graphic mimetype="image"   position="float"  xlink:type="simple"  xlink:href="http://html.scirp.org/file/68222x63.png"/></fig><table-wrap id="table6" ><label><xref ref-type="table" rid="table6">Table 6</xref></label><caption><title> Result of Problem 1 showing the effect of using stepsize 2<sup>−9</sup></title></caption><table><tbody><thead><tr><th align="center" valign="middle" >t-value</th><th align="center" valign="middle" >Exact Solution</th><th align="center" valign="middle" >Numerical Solution</th><th align="center" valign="middle" >Absolute Error</th></tr></thead><tr><td align="center" valign="middle" >0.062500</td><td align="center" valign="middle" >0.999979464841858</td><td align="center" valign="middle" >0.999979464673978</td><td align="center" valign="middle" >1.67880376e−10</td></tr><tr><td align="center" valign="middle" >0.125000</td><td align="center" valign="middle" >1.000036197200983</td><td align="center" valign="middle" >1.000036197026108</td><td align="center" valign="middle" >1.74874559e−10</td></tr><tr><td align="center" valign="middle" >0.187500</td><td align="center" valign="middle" >1.000061346273481</td><td align="center" valign="middle" >1.000061346169660</td><td align="center" valign="middle" >1.03820508e−10</td></tr><tr><td align="center" valign="middle" >0.250000</td><td align="center" valign="middle" >1.000101309205331</td><td align="center" valign="middle" >1.000101309176948</td><td align="center" valign="middle" >2.83835178e−11</td></tr><tr><td align="center" valign="middle" >0.312500</td><td align="center" valign="middle" >1.000111004081822</td><td align="center" valign="middle" >1.000111004129163</td><td align="center" valign="middle" >4.73403539e−11</td></tr><tr><td align="center" valign="middle" >0.375000</td><td align="center" valign="middle" >1.000054041052400</td><td align="center" valign="middle" >1.000054040994347</td><td align="center" valign="middle" >5.80526738e−11</td></tr><tr><td align="center" valign="middle" >0.437500</td><td align="center" valign="middle" >1.000068042560500</td><td align="center" valign="middle" >1.000068042466253</td><td align="center" valign="middle" >9.42474987e−11</td></tr><tr><td align="center" valign="middle" >0.500000</td><td align="center" valign="middle" >1.000067650976551</td><td align="center" valign="middle" >1.000067650858876</td><td align="center" valign="middle" >1.17674315e−10</td></tr><tr><td align="center" valign="middle" >0.562500</td><td align="center" valign="middle" >1.000133899286137</td><td align="center" valign="middle" >1.000133899093955</td><td align="center" valign="middle" >1.92182270e−10</td></tr><tr><td align="center" valign="middle" >0.625000</td><td align="center" valign="middle" >1.000143970608418</td><td align="center" valign="middle" >1.000143970444947</td><td align="center" valign="middle" >1.63471015e−10</td></tr></tbody></table></table-wrap><p>The mean absolute error is 1.147927086719847e−10.</p><p><xref ref-type="table" rid="table6">Table 6</xref> shows the exact solution, numerical solution and absolute error for the effect of using stepsize 2<sup>−9</sup>.</p><p>Problem 2.</p><disp-formula id="scirp.68222-formula214"><label>(15)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x64.png"  xlink:type="simple"/></disp-formula><p>where <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x65.png" xlink:type="simple"/></inline-formula> and <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x65.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x66.png" xlink:type="simple"/></inline-formula> are arbitrary values. They are used for better accuracy.</p><p>The true solution is</p><disp-formula id="scirp.68222-formula215"><label>(16)</label><graphic position="anchor" xlink:href="http://html.scirp.org/file/68222x67.png"  xlink:type="simple"/></disp-formula><p>Problem 2 was used by [<xref ref-type="bibr" rid="scirp.68222-ref25">25</xref>] with constants<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x68.png" xlink:type="simple"/></inline-formula>, <inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x68.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x69.png" xlink:type="simple"/></inline-formula>and<inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x68.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x69.png" xlink:type="simple"/></inline-formula><inline-formula><inline-graphic xlink:href="http://html.scirp.org/file/68222x70.png" xlink:type="simple"/></inline-formula>.</p></sec><sec id="s3_2"><title>3.2. Results Showing the Effect of Using Varying Stepsizes When Euler-Maruyama Method Is Applied to Problem 2</title><p>See <xref ref-type="fig" rid="fig7">Figure 7</xref> for the graph of the result on <xref ref-type="table" rid="table7">Table 7</xref>.</p><fig id="fig7"  position="float"><label><xref ref-type="fig" rid="fig7">Figure 7</xref></label><caption><title> Shows the graph of the result on <xref ref-type="table" rid="table7">Table 7</xref></title></caption><graphic mimetype="image"   position="float"  xlink:type="simple"  xlink:href="http://html.scirp.org/file/68222x71.png"/></fig><table-wrap id="table7" ><label><xref ref-type="table" rid="table7">Table 7</xref></label><caption><title> Result of Problem 2 showing the effect of using stepsize 2<sup>−4</sup></title></caption><table><tbody><thead><tr><th align="center" valign="middle" >t-value</th><th align="center" valign="middle" >Exact Solution</th><th align="center" valign="middle" >Numerical Solution</th><th align="center" valign="middle" >Absolute Error</th></tr></thead><tr><td align="center" valign="middle" >0.062500</td><td align="center" valign="middle" >−2.000030639939910</td><td align="center" valign="middle" >−2.000030643064053</td><td align="center" valign="middle" >3.12414317e−9</td></tr><tr><td align="center" valign="middle" >0.125000</td><td align="center" valign="middle" >−1.999826604550993</td><td align="center" valign="middle" >−1.999826583667489</td><td align="center" valign="middle" >2.08835040e−8</td></tr><tr><td align="center" valign="middle" >0.187500</td><td align="center" valign="middle" >−1.999771190197802</td><td align="center" valign="middle" >−1.999771171017104</td><td align="center" valign="middle" >1.91806975e−8</td></tr><tr><td align="center" valign="middle" >0.250000</td><td align="center" valign="middle" >−1.999738855905664</td><td align="center" valign="middle" >−1.999738839777066</td><td align="center" valign="middle" >1.61285976e−8</td></tr><tr><td align="center" valign="middle" >0.312500</td><td align="center" valign="middle" >−1.999549931800135</td><td align="center" valign="middle" >−1.999549895620500</td><td align="center" valign="middle" >3.61796346e−8</td></tr><tr><td align="center" valign="middle" >0.375000</td><td align="center" valign="middle" >−1.999485167195670</td><td align="center" valign="middle" >−1.999485131968585</td><td align="center" valign="middle" >3.52270857e−8</td></tr><tr><td align="center" valign="middle" >0.437500</td><td align="center" valign="middle" >−1.999441604632085</td><td align="center" valign="middle" >−1.999441571887793</td><td align="center" valign="middle" >3.27442917e−8</td></tr><tr><td align="center" valign="middle" >0.500000</td><td align="center" valign="middle" >−1.999255786341376</td><td align="center" valign="middle" >−1.999255734318596</td><td align="center" valign="middle" >5.20227794e−8</td></tr><tr><td align="center" valign="middle" >0.562500</td><td align="center" valign="middle" >−1.999277377750062</td><td align="center" valign="middle" >−1.999277329159688</td><td align="center" valign="middle" >4.85903735e−8</td></tr><tr><td align="center" valign="middle" >0.625000</td><td align="center" valign="middle" >−1.999295108719981</td><td align="center" valign="middle" >−1.999295063663776</td><td align="center" valign="middle" >4.50562045e−8</td></tr></tbody></table></table-wrap><p>The mean absolute error is 3.091373117491969e−8.</p><p><xref ref-type="table" rid="table7">Table 7</xref> shows the exact solution, numerical solution and absolute error for the effect of using stepsize 2<sup>−4</sup>.</p><p>See <xref ref-type="fig" rid="fig8">Figure 8</xref> for the graph of the result on <xref ref-type="table" rid="table8">Table 8</xref>.</p><fig id="fig8"  position="float"><label><xref ref-type="fig" rid="fig8">Figure 8</xref></label><caption><title> Shows the graph of the result on <xref ref-type="table" rid="table8">Table 8</xref></title></caption><graphic mimetype="image"   position="float"  xlink:type="simple"  xlink:href="http://html.scirp.org/file/68222x72.png"/></fig><table-wrap id="table8" ><label><xref ref-type="table" rid="table8">Table 8</xref></label><caption><title> Result of Problem 2 showing the effect of using stepsize 2<sup>−5</sup></title></caption><table><tbody><thead><tr><th align="center" valign="middle" >t-value</th><th align="center" valign="middle" >Exact Solution</th><th align="center" valign="middle" >Numerical Solution</th><th align="center" valign="middle" >Absolute Error</th></tr></thead><tr><td align="center" valign="middle" >0.062500</td><td align="center" valign="middle" >−1.999892917380804</td><td align="center" valign="middle" >−1.999892908128028</td><td align="center" valign="middle" >9.25277566e−9</td></tr><tr><td align="center" valign="middle" >0.125000</td><td align="center" valign="middle" >−1.999846392834979</td><td align="center" valign="middle" >−1.999846386521514</td><td align="center" valign="middle" >6.31346508e−9</td></tr><tr><td align="center" valign="middle" >0.187500</td><td align="center" valign="middle" >−1.999682499484875</td><td align="center" valign="middle" >−1.999682485395495</td><td align="center" valign="middle" >1.40893797e−8</td></tr><tr><td align="center" valign="middle" >0.250000</td><td align="center" valign="middle" >−1.999535775997482</td><td align="center" valign="middle" >−1.999535755103327</td><td align="center" valign="middle" >2.08941555e−8</td></tr><tr><td align="center" valign="middle" >0.312500</td><td align="center" valign="middle" >−1.999579115423757</td><td align="center" valign="middle" >−1.999579097646508</td><td align="center" valign="middle" >1.77772492e−8</td></tr><tr><td align="center" valign="middle" >0.375000</td><td align="center" valign="middle" >−1.999694550513440</td><td align="center" valign="middle" >−1.999694531148642</td><td align="center" valign="middle" >1.93647987e−8</td></tr><tr><td align="center" valign="middle" >0.437500</td><td align="center" valign="middle" >−1.999569940134597</td><td align="center" valign="middle" >−1.999569919321205</td><td align="center" valign="middle" >2.08133912e−8</td></tr><tr><td align="center" valign="middle" >0.500000</td><td align="center" valign="middle" >−1.999357977043176</td><td align="center" valign="middle" >−1.999357935211449</td><td align="center" valign="middle" >4.18317270e−8</td></tr><tr><td align="center" valign="middle" >0.562500</td><td align="center" valign="middle" >−1.999408364465035</td><td align="center" valign="middle" >−1.999408325355391</td><td align="center" valign="middle" >3.91096437e−8</td></tr><tr><td align="center" valign="middle" >0.625000</td><td align="center" valign="middle" >−1.999339028019188</td><td align="center" valign="middle" >−1.999338990093991</td><td align="center" valign="middle" >3.79251974e−8</td></tr></tbody></table></table-wrap><p>The mean absolute error is 2.273717831791089e−8.</p><p><xref ref-type="table" rid="table8">Table 8</xref> shows the exact solution, numerical solution and absolute error for the effect of using stepsize 2<sup>−5</sup>.</p><p>See <xref ref-type="fig" rid="fig9">Figure 9</xref> for the graph of the result on <xref ref-type="table" rid="table9">Table 9</xref>.</p><fig id="fig9"  position="float"><label><xref ref-type="fig" rid="fig9">Figure 9</xref></label><caption><title> Shows the graph of the result on <xref ref-type="table" rid="table9">Table 9</xref></title></caption><graphic mimetype="image"   position="float"  xlink:type="simple"  xlink:href="http://html.scirp.org/file/68222x73.png"/></fig><table-wrap id="table9" ><label><xref ref-type="table" rid="table9">Table 9</xref></label><caption><title> Result of Problem 2 showing the effect of using stepsize 2<sup>−6</sup></title></caption><table><tbody><thead><tr><th align="center" valign="middle" >t-value</th><th align="center" valign="middle" >Exact Solution</th><th align="center" valign="middle" >Numerical Solution</th><th align="center" valign="middle" >Absolute Error</th></tr></thead><tr><td align="center" valign="middle" >0.062500</td><td align="center" valign="middle" >−1.999906910993895</td><td align="center" valign="middle" >−1.999906908359276</td><td align="center" valign="middle" >2.63461808e−9</td></tr><tr><td align="center" valign="middle" >0.125000</td><td align="center" valign="middle" >−1.999702767364218</td><td align="center" valign="middle" >−1.999702758533899</td><td align="center" valign="middle" >8.83031892e−9</td></tr><tr><td align="center" valign="middle" >0.187500</td><td align="center" valign="middle" >−1.999830588766838</td><td align="center" valign="middle" >−1.999830580080542</td><td align="center" valign="middle" >8.68629546e−9</td></tr><tr><td align="center" valign="middle" >0.250000</td><td align="center" valign="middle" >−1.999608061287530</td><td align="center" valign="middle" >−1.999608042553839</td><td align="center" valign="middle" >1.87336919e−8</td></tr><tr><td align="center" valign="middle" >0.312500</td><td align="center" valign="middle" >−1.999610182559322</td><td align="center" valign="middle" >−1.999610165808479</td><td align="center" valign="middle" >1.67508436e−8</td></tr><tr><td align="center" valign="middle" >0.375000</td><td align="center" valign="middle" >−1.999464678473431</td><td align="center" valign="middle" >−1.999464660611312</td><td align="center" valign="middle" >1.78621189e−8</td></tr><tr><td align="center" valign="middle" >0.437500</td><td align="center" valign="middle" >−1.999545553506756</td><td align="center" valign="middle" >−1.999545533746613</td><td align="center" valign="middle" >1.97601426e−8</td></tr><tr><td align="center" valign="middle" >0.500000</td><td align="center" valign="middle" >−1.999419912678686</td><td align="center" valign="middle" >−1.999419890196399</td><td align="center" valign="middle" >2.24822863e−8</td></tr><tr><td align="center" valign="middle" >0.562500</td><td align="center" valign="middle" >−1.999374919082127</td><td align="center" valign="middle" >−1.999374891267540</td><td align="center" valign="middle" >2.78145871e−8</td></tr><tr><td align="center" valign="middle" >0.625000</td><td align="center" valign="middle" >−1.999402649038457</td><td align="center" valign="middle" >−1.999402624540933</td><td align="center" valign="middle" >2.44975247e−8</td></tr></tbody></table></table-wrap><p>The mean absolute error is 1.680524275293749e−8.</p><p><xref ref-type="table" rid="table9">Table 9</xref> shows the exact solution, numerical solution and absolute error for the effect of using stepsize 2<sup>−6</sup>.</p><p>See <xref ref-type="fig" rid="fig1">Figure 1</xref>0 for the graph of the result on <xref ref-type="table" rid="table1">Table 1</xref>0.</p><fig id="fig10"  position="float"><label><xref ref-type="fig" rid="fig1">Figure 1</xref>0</label><caption><title> Shows the graph of the result on <xref ref-type="table" rid="table1">Table 1</xref>0</title></caption><graphic mimetype="image"   position="float"  xlink:type="simple"  xlink:href="http://html.scirp.org/file/68222x74.png"/></fig><table-wrap id="table10" ><label><xref ref-type="table" rid="table1">Table 1</xref>0</label><caption><title> Result of Problem 2 showing the effect of using stepsize 2<sup>−7</sup></title></caption><table><tbody><thead><tr><th align="center" valign="middle" >t-value</th><th align="center" valign="middle" >Exact Solution</th><th align="center" valign="middle" >Numerical Solution</th><th align="center" valign="middle" >Absolute Error</th></tr></thead><tr><td align="center" valign="middle" >0.062500</td><td align="center" valign="middle" >−1.999805341404871</td><td align="center" valign="middle" >−1.999805337513111</td><td align="center" valign="middle" >3.89176003e−9</td></tr><tr><td align="center" valign="middle" >0.125000</td><td align="center" valign="middle" >−1.999753891446814</td><td align="center" valign="middle" >−1.999753882755321</td><td align="center" valign="middle" >8.69149241e−9</td></tr><tr><td align="center" valign="middle" >0.187500</td><td align="center" valign="middle" >−1.999668007898771</td><td align="center" valign="middle" >−1.999667999884824</td><td align="center" valign="middle" >8.01394706e−9</td></tr><tr><td align="center" valign="middle" >0.250000</td><td align="center" valign="middle" >−1.999651870477482</td><td align="center" valign="middle" >−1.999651860214105</td><td align="center" valign="middle" >1.02633777e−8</td></tr><tr><td align="center" valign="middle" >0.312500</td><td align="center" valign="middle" >−1.999655185128882</td><td align="center" valign="middle" >−1.999655173868698</td><td align="center" valign="middle" >1.12601839e−8</td></tr><tr><td align="center" valign="middle" >0.375000</td><td align="center" valign="middle" >−1.999732080887753</td><td align="center" valign="middle" >−1.999732070781591</td><td align="center" valign="middle" >1.01061621e−8</td></tr><tr><td align="center" valign="middle" >0.437500</td><td align="center" valign="middle" >−1.999676933687320</td><td align="center" valign="middle" >−1.999676925131407</td><td align="center" valign="middle" >8.55591287e−9</td></tr><tr><td align="center" valign="middle" >0.500000</td><td align="center" valign="middle" >−1.999767219155966</td><td align="center" valign="middle" >−1.999767210691419</td><td align="center" valign="middle" >8.46454751e−9</td></tr><tr><td align="center" valign="middle" >0.562500</td><td align="center" valign="middle" >−1.999813341382202</td><td align="center" valign="middle" >−1.999813334738500</td><td align="center" valign="middle" >6.64370181e−9</td></tr><tr><td align="center" valign="middle" >0.625000</td><td align="center" valign="middle" >−1.999791597710221</td><td align="center" valign="middle" >−1.999791590169479</td><td align="center" valign="middle" >7.54074203e−9</td></tr></tbody></table></table-wrap><p>The mean absolute error is 8.343182744674494e−9.</p><p><xref ref-type="table" rid="table1">Table 1</xref>0 shows the exact solution, numerical solution and absolute error for the effect of using stepsize 2<sup>−7</sup>.</p><p>See <xref ref-type="fig" rid="fig1">Figure 1</xref>1 for the graph of the result on <xref ref-type="table" rid="table1">Table 1</xref>1.</p><fig id="fig11"  position="float"><label><xref ref-type="fig" rid="fig1">Figure 1</xref>1</label><caption><title> Shows the graph of the result on <xref ref-type="table" rid="table1">Table 1</xref>1</title></caption><graphic mimetype="image"   position="float"  xlink:type="simple"  xlink:href="http://html.scirp.org/file/68222x75.png"/></fig><table-wrap id="table11" ><label><xref ref-type="table" rid="table1">Table 1</xref>1</label><caption><title> Result of Problem 2 showing the effect of using stepsize 2<sup>−8</sup></title></caption><table><tbody><thead><tr><th align="center" valign="middle" >t-value</th><th align="center" valign="middle" >Exact Solution</th><th align="center" valign="middle" >Numerical Solution</th><th align="center" valign="middle" >Absolute Error</th></tr></thead><tr><td align="center" valign="middle" >0.062500</td><td align="center" valign="middle" >−1.999841496174841</td><td align="center" valign="middle" >−1.999841492043785</td><td align="center" valign="middle" >4.13105594e−9</td></tr><tr><td align="center" valign="middle" >0.125000</td><td align="center" valign="middle" >−1.999784874982539</td><td align="center" valign="middle" >−1.999784870148436</td><td align="center" valign="middle" >4.83410290e−9</td></tr><tr><td align="center" valign="middle" >0.187500</td><td align="center" valign="middle" >−1.999857131369450</td><td align="center" valign="middle" >−1.999857126530599</td><td align="center" valign="middle" >4.83885132e−9</td></tr><tr><td align="center" valign="middle" >0.250000</td><td align="center" valign="middle" >−1.999897512575721</td><td align="center" valign="middle" >−1.999897508515622</td><td align="center" valign="middle" >4.06009937e−9</td></tr><tr><td align="center" valign="middle" >0.312500</td><td align="center" valign="middle" >−1.999930285134005</td><td align="center" valign="middle" >−1.999930281503511</td><td align="center" valign="middle" >3.63049413e−9</td></tr><tr><td align="center" valign="middle" >0.375000</td><td align="center" valign="middle" >−1.999876177386879</td><td align="center" valign="middle" >−1.999876175259421</td><td align="center" valign="middle" >2.12745799e−9</td></tr><tr><td align="center" valign="middle" >0.437500</td><td align="center" valign="middle" >−1.999921851349309</td><td align="center" valign="middle" >−1.999921848982462</td><td align="center" valign="middle" >2.36684672e−9</td></tr><tr><td align="center" valign="middle" >0.500000</td><td align="center" valign="middle" >−1.999917674573231</td><td align="center" valign="middle" >−1.999917674818573</td><td align="center" valign="middle" >2.45341969e−10</td></tr><tr><td align="center" valign="middle" >0.562500</td><td align="center" valign="middle" >−1.999944122996693</td><td align="center" valign="middle" >−1.999944123256830</td><td align="center" valign="middle" >2.60136801e−10</td></tr><tr><td align="center" valign="middle" >0.625000</td><td align="center" valign="middle" >−1.999830784974864</td><td align="center" valign="middle" >−1.999830786914828</td><td align="center" valign="middle" >1.93996397e−9</td></tr></tbody></table></table-wrap><p>The mean absolute error is 2.843435109589621e−9.</p><p><xref ref-type="table" rid="table1">Table 1</xref>1 shows the exact solution, numerical solution and absolute error for the effect of using stepsize 2<sup>−7</sup>.</p><p>See <xref ref-type="fig" rid="fig1">Figure 1</xref>2 for the graph of the result on <xref ref-type="table" rid="table1">Table 1</xref>2.</p><fig id="fig12"  position="float"><label><xref ref-type="fig" rid="fig1">Figure 1</xref>2</label><caption><title> shows the graph of the result on <xref ref-type="table" rid="table1">Table 1</xref>2</title></caption><graphic mimetype="image"   position="float"  xlink:type="simple"  xlink:href="http://html.scirp.org/file/68222x76.png"/></fig><table-wrap id="table12" ><label><xref ref-type="table" rid="table1">Table 1</xref>2</label><caption><title> Result of problem 2 showing the effect of using stepsize 2<sup>−9</sup></title></caption><table><tbody><thead><tr><th align="center" valign="middle" >t-value</th><th align="center" valign="middle" >Exact Solution</th><th align="center" valign="middle" >Numerical Solution</th><th align="center" valign="middle" >Absolute Error</th></tr></thead><tr><td align="center" valign="middle" >0.062500</td><td align="center" valign="middle" >−1.999863407270136</td><td align="center" valign="middle" >−1.999863404946251</td><td align="center" valign="middle" >2.32388553e−9</td></tr><tr><td align="center" valign="middle" >0.125000</td><td align="center" valign="middle" >−1.999958592655718</td><td align="center" valign="middle" >−1.999958590662368</td><td align="center" valign="middle" >1.99335082e−9</td></tr><tr><td align="center" valign="middle" >0.187500</td><td align="center" valign="middle" >−1.999959037106798</td><td align="center" valign="middle" >−1.999959036084589</td><td align="center" valign="middle" >1.02220876e−9</td></tr><tr><td align="center" valign="middle" >0.250000</td><td align="center" valign="middle" >−2.000003915981924</td><td align="center" valign="middle" >−2.000003916122282</td><td align="center" valign="middle" >1.40357947e−10</td></tr><tr><td align="center" valign="middle" >0.312500</td><td align="center" valign="middle" >−1.999957999627532</td><td align="center" valign="middle" >−1.999958000650131</td><td align="center" valign="middle" >1.02259934e−9</td></tr><tr><td align="center" valign="middle" >0.375000</td><td align="center" valign="middle" >−1.999712179640226</td><td align="center" valign="middle" >−1.999712178747598</td><td align="center" valign="middle" >8.92628638e−10</td></tr><tr><td align="center" valign="middle" >0.437500</td><td align="center" valign="middle" >−1.999679195925699</td><td align="center" valign="middle" >−1.999679194613133</td><td align="center" valign="middle" >1.31256606e−9</td></tr><tr><td align="center" valign="middle" >0.500000</td><td align="center" valign="middle" >−1.999603058636733</td><td align="center" valign="middle" >−1.999603056922618</td><td align="center" valign="middle" >1.71411507e−9</td></tr><tr><td align="center" valign="middle" >0.562500</td><td align="center" valign="middle" >−1.999726729199231</td><td align="center" valign="middle" >−1.999726727095061</td><td align="center" valign="middle" >2.10416973e−9</td></tr><tr><td align="center" valign="middle" >0.625000</td><td align="center" valign="middle" >−1.999681957561421</td><td align="center" valign="middle" >−1.999681955778895</td><td align="center" valign="middle" >1.78252613e−9</td></tr></tbody></table></table-wrap><p>The mean absolute error is 1.430840801397437e−9.</p><p><xref ref-type="table" rid="table1">Table 1</xref>2 shows the exact solution, numerical solution and absolute error for the effect of using stepsize 2<sup>−9</sup>.</p></sec></sec><sec id="s4"><title>4. Determination of Strong Order of Convergence of the Method</title><p>In this section, it will be wise to determine the strong order of convergence (SOC) and the residual of the method as this property is important to examine how good or how accurate our approximations are. SOC is a property of solution that is indispensable in examining the accuracy of any numerical method for solution of SDEs.</p><p>The issues of convergence and SOC of SDEs have also been examined by [<xref ref-type="bibr" rid="scirp.68222-ref20">20</xref>] [<xref ref-type="bibr" rid="scirp.68222-ref23">23</xref>] [<xref ref-type="bibr" rid="scirp.68222-ref25">25</xref>] - [<xref ref-type="bibr" rid="scirp.68222-ref27">27</xref>] [<xref ref-type="bibr" rid="scirp.68222-ref29">29</xref>] [<xref ref-type="bibr" rid="scirp.68222-ref31">31</xref>] for one step Method. The papers and book gives the theoretical background of SDEs and SOC. [<xref ref-type="bibr" rid="scirp.68222-ref27">27</xref>] examined the SOC for one step method of Milstein (MLSTM) type. The vital tool in the determination of SOC is the mean absolute error (MAE) or strong error. MAE is the mean of the absolute value of difference between the exact solution and numerical solution of a given stochastic differential equation. It serves as a tool for assessing the effect of varying step sizes. MAE will be determined for one-step method of EMM type just developed using varying stepsizes. The SOC of the method will be obtained using the MAE.</p><table-wrap id="table13" ><label><xref ref-type="table" rid="table1">Table 1</xref>3</label><caption><title> Results of the MAE of one step method of EMM type for Problem 1</title></caption><table><tbody><thead><tr><th align="center" valign="middle"  rowspan="2"  >Stepsize</th><th align="center" valign="middle" >Problem 1</th></tr></thead><tr><td align="center" valign="middle" >MAE of One Step Method EMM Type</td></tr><tr><td align="center" valign="middle" >2<sup>−4</sup></td><td align="center" valign="middle" >6.36669439e−10</td></tr><tr><td align="center" valign="middle" >2<sup>−5</sup></td><td align="center" valign="middle" >1.04921388e−9</td></tr><tr><td align="center" valign="middle" >2<sup>−6</sup></td><td align="center" valign="middle" >9.69581149e−10</td></tr><tr><td align="center" valign="middle" >2<sup>−7</sup></td><td align="center" valign="middle" >6.30707042e−10</td></tr><tr><td align="center" valign="middle" >2<sup>−8</sup></td><td align="center" valign="middle" >2.52163668e−10</td></tr><tr><td align="center" valign="middle" >2<sup>−9</sup></td><td align="center" valign="middle" >1.14792709e−10</td></tr></tbody></table></table-wrap><p><xref ref-type="table" rid="table1">Table 1</xref>3 shows the results of mean absolute error of one-step method of EMM type applied to Problem 1 with varying stepsizes.</p><table-wrap id="table14" ><label><xref ref-type="table" rid="table1">Table 1</xref>4</label><caption><title> Results of the MAE of one-step method of EMM type for Problem 2</title></caption><table><tbody><thead><tr><th align="center" valign="middle"  rowspan="2"  >Stepsize</th><th align="center" valign="middle" >Problem 2</th></tr></thead><tr><td align="center" valign="middle" >MAE of One Step Method EMM Type</td></tr><tr><td align="center" valign="middle" >2<sup>−4</sup></td><td align="center" valign="middle" >3.09137312e−8</td></tr><tr><td align="center" valign="middle" >2<sup>−5</sup></td><td align="center" valign="middle" >2.27371783e−8</td></tr><tr><td align="center" valign="middle" >2<sup>−6</sup></td><td align="center" valign="middle" >1.68052428e−8</td></tr><tr><td align="center" valign="middle" >2<sup>−7</sup></td><td align="center" valign="middle" >8.34318274e−9</td></tr><tr><td align="center" valign="middle" >2<sup>−8</sup></td><td align="center" valign="middle" >2.84343511e−9</td></tr><tr><td align="center" valign="middle" >2<sup>−9</sup></td><td align="center" valign="middle" >1.43084080e−9</td></tr></tbody></table></table-wrap><p><xref ref-type="table" rid="table1">Table 1</xref>4 shows the results of mean absolute error of one-step method of EMM type applied to Problem 2 with varying stepsizes.</p><table-wrap id="table15" ><label><xref ref-type="table" rid="table1">Table 1</xref>5</label><caption><title> Results of the strong order of convergence of one-step method of Euler-Maruyama type for Problems 1 and 2</title></caption><table><tbody><thead><tr><th align="center" valign="middle"  colspan="3"  >One-step Method of EMM Type</th></tr></thead><tr><td align="center" valign="middle" ></td><td align="center" valign="middle" >Problem 1</td><td align="center" valign="middle" >Problem 2</td></tr><tr><td align="center" valign="middle" >SOC</td><td align="center" valign="middle" >0.5471</td><td align="center" valign="middle" >0.9193</td></tr><tr><td align="center" valign="middle" >RESIDUAL</td><td align="center" valign="middle" >1.0975</td><td align="center" valign="middle" >0.6067</td></tr></tbody></table></table-wrap><p><xref ref-type="table" rid="table1">Table 1</xref>5 shows the strong order of convergence of one-step method of EMM type for Problems 1 and 2.</p></sec><sec id="s5"><title>5. Discussion</title><p>In this paper effort has been made to discuss the derivation of one-step method of Euler-Maruyama type. This method was applied to two problems in the form of first order SDEs. The method was used to determine the numerical solution of the two problems. Absolute errors were calculated using the numerical approximation and the corresponding exact solution. Mean absolute errors were also determined. To determine the accuracy of the method, strong order of convergence and residuals were obtained for each problem.</p></sec><sec id="s6"><title>6. Conclusion</title><p>In this paper, two problems in the form of first order SDEs have been considered. One-step method of Euler- Maruyama type for solution of general first order SDEs has been derived. The absolute errors between the exact solution and numerical solution can be observed. The mean absolute error for varying stepsizes has been determined. The result shows that the mean absolute error generally decreases as the stepsizes decreases. The accuracy of the method is determined by finding the strong order of convergence of the method. The result shows that the strong order of convergence is 0.5471 and the residual is 1.0975 for Problem 1 while the strong</p><p>order of convergence is 0.9193 and the residual is 0.6067 for Problem 2. The effect of the varying stepsizes can also be seen by observing the behaviour of the exact solution and numerical solution using graphical method as indicated in Figures 1-12. The results are obtained using MATLAB as supporting tool.</p></sec><sec id="s7"><title>Cite this paper</title><p>Sunday Jacob Kayode,Akeem Adebayo Ganiyu,Adegoke Sule Ajiboye, (2016) On One-Step Method of Euler-Maruyama Type for Solution of Stochastic Differential Equations Using Varying Stepsizes. 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