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<front>
<journal-meta>
<journal-id journal-id-type="pmc">CMC</journal-id>
<journal-id journal-id-type="nlm-ta">CMC</journal-id>
<journal-id journal-id-type="publisher-id">CMC</journal-id>
<journal-title-group>
<journal-title>Computers, Materials &#x0026; Continua</journal-title>
</journal-title-group>
<issn pub-type="epub">1546-2226</issn>
<issn pub-type="ppub">1546-2218</issn>
<publisher>
<publisher-name>Tech Science Press</publisher-name>
<publisher-loc>USA</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="publisher-id">22203</article-id>
<article-id pub-id-type="doi">10.32604/cmc.2022.022203</article-id>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Article</subject>
</subj-group>
</article-categories>
<title-group>
<article-title>An Improved Sparrow Search Algorithm for Node Localization in WSN</article-title>
<alt-title alt-title-type="left-running-head">An Improved Sparrow Search Algorithm for Node Localization in WSN</alt-title>
<alt-title alt-title-type="right-running-head">An Improved Sparrow Search Algorithm for Node Localization in WSN</alt-title>
</title-group>
<contrib-group content-type="authors">
<contrib id="author-1" contrib-type="author"><name name-style="western"><surname>Thenmozhi</surname><given-names>R.</given-names></name><xref ref-type="aff" rid="aff-1">1</xref>
</contrib>
<contrib id="author-2" contrib-type="author"><name name-style="western"><surname>Nasir</surname><given-names>Abdul Wahid</given-names></name><xref ref-type="aff" rid="aff-2">2</xref>
</contrib>
<contrib id="author-3" contrib-type="author"><name name-style="western"><surname>Sonthi</surname><given-names>Vijaya Krishna</given-names></name><xref ref-type="aff" rid="aff-3">3</xref>
</contrib>
<contrib id="author-4" contrib-type="author"><name name-style="western"><surname>Avudaiappan</surname><given-names>T.</given-names></name><xref ref-type="aff" rid="aff-4">4</xref>
</contrib>
<contrib id="author-5" contrib-type="author"><name name-style="western"><surname>Kadry</surname><given-names>Seifedine</given-names></name><xref ref-type="aff" rid="aff-5">5</xref>
</contrib>
<contrib id="author-6" contrib-type="author"><name name-style="western"><surname>Pin</surname><given-names>Kuntha</given-names></name><xref ref-type="aff" rid="aff-6">6</xref>
</contrib>
<contrib id="author-7" contrib-type="author" corresp="yes"><name name-style="western"><surname>Nam</surname><given-names>Yunyoung</given-names></name><xref ref-type="aff" rid="aff-7">7</xref><email>ynam@sch.ac.kr</email>
</contrib>
<aff id="aff-1"><label>1</label><institution>Department of Computer Science and Engineering, College of Engineering and Technology, SRM Institute of Science and Technology</institution>, <addr-line>Kattankulathur, 603203</addr-line>, <country>India</country></aff>
<aff id="aff-2"><label>2</label><institution>Department of Electronics Communication and Engineering, CMR Institute of Technology</institution>, <addr-line>Bengaluru, 560037</addr-line>, <country>India</country></aff>
<aff id="aff-3"><label>3</label><institution>Department of Computer Science and Engineering, Koneru Lakshmaiah Education Foundation</institution>, <addr-line>Vaddeswaram, 522502, Andhra Pradesh</addr-line>, <country>India</country></aff>
<aff id="aff-4"><label>4</label><institution>Department of Computer Science and Engineering, K. Ramakrishnan College of engineering</institution>, <addr-line>Tiruchirappalli, 621112</addr-line>, <country>India</country></aff>
<aff id="aff-5"><label>5</label><institution>Department of Applied Data Science, Noroff University College</institution>, <addr-line>Kristiansand</addr-line>, <country>Norway</country></aff>
<aff id="aff-6"><label>6</label><institution>Department of ICT Convergence, Soonchunhyang University</institution>, <country>Korea</country></aff>
<aff id="aff-7"><label>7</label><institution>Department of Computer Science and Engineering, Soonchunhyang University</institution>, <country>Korea</country></aff>
</contrib-group>
<author-notes>
<corresp id="cor1">Corresponding Author: Yunyoung Nam. Email: <email>ynam@sch.ac.kr</email></corresp>
</author-notes>
<pub-date pub-type="epub" date-type="pub" iso-8601-date="2021-10-18">
<day>18</day>
<month>10</month>
<year>2021</year>
</pub-date>
<volume>71</volume>
<issue>1</issue>
<fpage>2037</fpage>
<lpage>2051</lpage>
<history>
<date date-type="received">
<day>30</day>
<month>7</month>
<year>2021</year>
</date>
<date date-type="accepted">
<day>30</day>
<month>9</month>
<year>2021</year>
</date>
</history>
<permissions>
<copyright-statement>&#x00A9; 2022 Thenmozhi et al.</copyright-statement>
<copyright-year>2022</copyright-year>
<copyright-holder>Thenmozhi et al.</copyright-holder>
<license xlink:href="https://creativecommons.org/licenses/by/4.0/">
<license-p>This work is licensed under a <ext-link ext-link-type="uri" xlink:type="simple" xlink:href="https://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution 4.0 International License</ext-link>, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.</license-p>
</license>
</permissions>
<self-uri content-type="pdf" xlink:href="TSP_CMC_22203.pdf"></self-uri>
<abstract>
<p>Wireless sensor networks (WSN) comprise a set of numerous cheap sensors placed in the target region. A primary function of the WSN is to avail the location details of the event occurrences or the node. A major challenge in WSN is node localization which plays an important role in data gathering applications. Since GPS is expensive and inaccurate in indoor regions, effective node localization techniques are needed. The major intention of localization is for determining the place of node in short period with minimum computation. To achieve this, bio-inspired algorithms are used and node localization is assumed as an optimization problem in a multidimensional space. This paper introduces a new Sparrow Search Algorithm with Doppler Effect (SSA-DE) for Node Localization in Wireless Networks. The SSA is generally stimulated by the group wisdom, foraging, and anti-predation behaviors of sparrows. Besides, the Doppler Effect is incorporated into the SSA to further improve the node localization performance. In addition, the SSA-DE model defines the position of node in an iterative manner using Euclidian distance as the fitness function. The presented SSA-DE model is implanted in MATLAB R2014. An extensive set of experimentation is carried out and the results are examined under a varying number of anchor nodes and ranging error. The attained experimental outcome ensured the superior efficiency of the SSA-DE technique over the existing techniques.</p>
</abstract>
<kwd-group kwd-group-type="author">
<kwd>Localization</kwd>
<kwd>wireless networks</kwd>
<kwd>sparrow search algorithm</kwd>
<kwd>machine learning</kwd>
<kwd>bio-inspired algorithm</kwd>
</kwd-group>
<counts>
<page-count count="0"/>
</counts>
</article-meta>
</front>
<body>
<sec id="s1">
<label>1</label>
<title>Introduction</title>
<p>Wireless sensor networks (WSNs) are related closely to the physical phenomena in its environments. The collected data must be related to the location of sensors for providing a precise overview of the analyzed sensory regions. The positioning is significant in many applications, like geographical routing and tracking and environment rescue, sensing, and search; the location of all the nodes need to be recognized [<xref ref-type="bibr" rid="ref-1">1</xref>]. This requirement stimulates the development of effective localizing algorithm for WSN. In previous years, there have been a huge amount of studies on localization for WSN [<xref ref-type="bibr" rid="ref-2">2</xref>]. They share similar concept that nodes with unknown coordinates are used for more than one GPS armed nodes with known coordinates for estimating their position. Almost all of this work considers the static beacon. Initially, GPS accessible for WSN is highly expensive, exceed the cost of sensors. Furthermore, GPS process has a higher power consumption profile that might enforce further limitations on the WSN lifetime. Moreover, WSN is generally static, and localizing algorithm might be needed for running only at the time of network initialization. Subsequently, GPS process mayn&#x2019;t be inexpensive for various WSN realizations [<xref ref-type="bibr" rid="ref-3">3</xref>]. Hence, for obtaining position data, they require a method that incurs less cost and provides a more precise position. With the known location of anchor nodes, localizing algorithm could be applied for estimating the position of unknown nodes. There exist 2 types of non GPS based localizing processes, such as range-based algorithm and rang-free algorithm [<xref ref-type="bibr" rid="ref-4">4</xref>]. Point-to-point or Angle based distance estimations amongst the sensors are utilized for rang based localizing algorithm. In this algorithm, the position of sensors is estimated using anchors trilateration [<xref ref-type="bibr" rid="ref-5">5</xref>]. Different from range based localizing algorithms, range-free localizing algorithms don&#x2019;t require range data for estimating the position of unknown nodes. Only it is based on the topological data. <?A3B2 "fig1",5,"anchor"?><xref ref-type="fig" rid="fig-1">Fig. 1</xref> shows the overview of WSN.</p>
<fig id="fig-1">
<label>Figure 1</label>
<caption>
<title>Overview of WSN</title>
</caption>
<graphic mimetype="image" mime-subtype="png" xlink:href="CMC_22203-fig-1.png"/>
</fig>
<p>In recent times, NL in WSNs is dealing with a multidimensional and multimodal optimization problem which could be resolved by population based stochastic methods. In the study, several Meta heuristic approaches were applied for solving the localization problems in WSN. This algorithm has achieved in decreasing the localization error drastically [<xref ref-type="bibr" rid="ref-6">6</xref>]. This algorithm attempts to resolve optimization problems using error and trial where the possible solution is treated, and the near optimum solution is recognized [<xref ref-type="bibr" rid="ref-7">7</xref>]. Now, several optimization approaches like particle swarm optimization (PSO), cuckoo search (CS), genetic algorithm (GA), artificial bee colony (ABC), gravitational search algorithm (GSA), butterfly optimization algorithm (BOA), and so on, were applied efficiently in representing the position of unknown nodes in WSN.</p>
<p>Kanoosh et al. [<xref ref-type="bibr" rid="ref-8">8</xref>], proposed an NL algorithm that depends on a novel bio-inspired approach named SSA deals with the NL problems as an optimization problem. The presented method was validated and implemented in distinct WSN placements with distinct numbers of anchor and target nodes. Amri et al. [<xref ref-type="bibr" rid="ref-9">9</xref>] implement and propose a novel method for geographic routing. Hence, the presented methods are depending upon a weighted centroid localizing method, in which the positions of unknown node is evaluated by FL approach. In this regard, they proposed a fuzzy localization algorithm which utilizes flow measurement via wireless network for computing the distance splitting the sensor node and anchor node. Consequently, this study is depending upon the centroid algorithms which estimate the positions of unknown nodes by Sugeno inference and fuzzy Mamdani methods for increasing the precision of calculated positions.</p>
<p>Mihoubi et al. [<xref ref-type="bibr" rid="ref-10">10</xref>] proposed an efficient BA approach for the NL problems, the efficacy is depending on the adaption of velocity of Bat using hybridization, using Doppler effects to improve the efficiency, appropriately called Dopeffbat. Therefore, Dopeffbat calculates (via development) the node position iteratively by the Euclidian distance as fitness. Positioning these algorithms on a huge WSN with hundreds of sensor nodes shows better efficiency based on NL. Furthermore, the Dopeffbat parameter is interpreted and simulated in various situations. Miloud et al. [<xref ref-type="bibr" rid="ref-11">11</xref>] proposed a technique for NL, i.e., MFOA. Node is positioned with Euclidean distance, hence it is set as a FF in the optimization method. Positioning these algorithms on a huge WSN with hundreds of sensor nodes demonstrates better efficiency based on NL. Computer simulation shows that MFOA converges quickly to an optimum nodes location.</p>
<p>Wang et al. [<xref ref-type="bibr" rid="ref-12">12</xref>], proposed a new NL approach called KELM-HQ. The presented method applies the real number of hop counts among anchors and unknown nodes as the training input and the location of anchor as the training target to train KELM. Also, the presented technique applies the real number of hop-counts among unknown nodes as the test sample to estimate the positions of unknown nodes to train KELM. Santhosh et al. [<xref ref-type="bibr" rid="ref-13">13</xref>] present a new NMGOA method for NL in WSN. The Nelder&#x2013;Mead simplex search technique is applied for improving the efficacy of GOA due to its ability of fast convergence. Initially, the node in WSN are arbitrarily located in the target area and later the nodes are initialized. Then, the node performs the NMGOA method to evaluate the places of unknown node and becomes localizing node. Subsequently, the localizing node would be added to the group of anchor nodes for performing the localization procedure. In Li et al. [<xref ref-type="bibr" rid="ref-14">14</xref>], a novel heuristic approach called PCCSO using 3 distinct transmission approaches and the idea of compacts is introduced in this study. The advantages of PCCSO are reflected in improving the capability of local search, as well as storing in the computer memory.</p>
<p>Qi et al. [<xref ref-type="bibr" rid="ref-15">15</xref>] proposed an NWS2CNS for solving the optimization of several bumps in a huge three dimension WSNs. NWS2CNS is presented for improving the position accuracy attained by node inertia weight to precisely estimate the acceleration factors. The suboptimal network segmentation is achieved by precisely recognizing concave nodes which breakdown the three dimension WSNs into various roughly convex subnets. Sekhar et al. [<xref ref-type="bibr" rid="ref-16">16</xref>] designed an efficient Meta heuristic based GTOA NL method for WSN. The aim is to define the positions of unknown nodes using anchors node in the WSN with the help of maximal localizing accuracy and minimal localizing error. The proposed method is inspired by the group teaching approach and it could be utilized to process optimization without losing generalization.</p>
<p>Phoemphon et al. [<xref ref-type="bibr" rid="ref-17">17</xref>] presented a new method, NS-IPSO which separated SNs as to segments for improving the accuracy of calculated distances among pairs of unknown node and anchor node. Firstly, they define candidate nodes which can be possibly utilized for segmenting anchor node in the areas. This sensor node (STs) on the shortest paths among anchor nodes appears frequently compared to the average appearance of each sensor. Later, segmented nodes (SM, sensors to segment the anchor node) is elected from each ST depending on specific condition. Dao et al. [<xref ref-type="bibr" rid="ref-18">18</xref>] proposed an NL recognition in WSN depending upon the integrated ALO with a general method of positioning. The FF is modelled arithmetically depends on evaluating the distance of WSN sensor node. The upgrading solution of populations is designed for correcting positions to enhance the node localization accuracy. The effect of parameters such as transmitting range and node density is tested in the experiment for evaluating the efficiency of this presented technique based on the success ratio and average positioning error.</p>
<p>This paper introduces a new Sparrow Search Algorithm with Doppler Effect (SSA-DE) for Node Localization in Wireless Network. The SSA is generally stimulated by the group wisdom, foraging, and anti-predation behaviors of sparrows. Besides, the Doppler effect is incorporated into the SSA to further improve the node localization performance. In addition, the SSA-DE model defines the position of the nodes in an iterative manner using Euclidian distance as the fitness function. The presented SSA-DE model is implanted in MATLAB R2014. An extensive set of experimentation is carried out and the results are examined under a varying number of anchor nodes and ranging error.</p>
</sec>
<sec id="s2">
<label>2</label>
<title>The Proposed Model</title>
<p>The proposed SSA-DE technique incorporates the concepts of the SSA and DE in order to proficiently localize the nodes in WSN. The working process of the SSA-DE technique is discussed in the following.</p>
<sec id="s2_1">
<label>2.1</label>
<title>Overview of SSA</title>
<p>Generally, the sparrows are social in nature and have different types. They are circulating all over the world and attracted to survive in regions near humans. Likewise, they are omnivorous species and mainly eat grain and seeds. It is generally termed as resident in nature. Compared to other birds, it is robust in creativity and memory power. Most importantly they have 2 various kinds of captive house sparrows <italic>i.e</italic>., producer and scrounger. The producer energetically tries to find the source of food, whereas the scroungers acquire food from the producers. Depending upon the above description of sparrow, a mathematical technique could be evolved as SSA. The virtual sparrows are applied for identifying the improved food source. The place of sparrows are given in the following equation:</p>
<p><disp-formula id="eqn-1">
<label>(1)</label>
<mml:math id="mml-eqn-1" display="block"><mml:mi>X</mml:mi><mml:mo>=</mml:mo><mml:mrow><mml:mo>[</mml:mo><mml:mtable columnalign="center center" rowspacing="4pt" columnspacing="1em"><mml:mtr><mml:mtd><mml:msub><mml:mi>&#x03C7;</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mn>1</mml:mn><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:mtd><mml:mtd><mml:msub><mml:mi>&#x03C7;</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mn>1</mml:mn><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:msub><mml:mi>&#x03C7;</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mn>2</mml:mn><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:mtd><mml:mtd><mml:msub><mml:mi>&#x03C7;</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mn>2</mml:mn><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mtable rowspacing="4pt" columnspacing="1em"><mml:mtr><mml:mtd><mml:mo>&#x22EE;</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:msub><mml:mi>x</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mi>n</mml:mi><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:mtd><mml:mtd><mml:mtable rowspacing="4pt" columnspacing="1em"><mml:mtr><mml:mtd><mml:mo>&#x22EE;</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:msub><mml:mi>x</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mi>n</mml:mi><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:mtd></mml:mtr></mml:mtable><mml:mtable columnalign="center center center" rowspacing="4pt" columnspacing="1em"><mml:mtr><mml:mtd><mml:mo>&#x22EF;</mml:mo></mml:mtd><mml:mtd><mml:mo>&#x22EF;</mml:mo></mml:mtd><mml:mtd><mml:msub><mml:mi>&#x03C7;</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mn>1</mml:mn><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mi>d</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mo>&#x22EF;</mml:mo></mml:mtd><mml:mtd><mml:mo>&#x22EF;</mml:mo></mml:mtd><mml:mtd><mml:msub><mml:mi>&#x03C7;</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mn>2</mml:mn><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mi>d</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mtable rowspacing="4pt" columnspacing="1em"><mml:mtr><mml:mtd><mml:mo>&#x22EE;</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mo>&#x22EF;</mml:mo></mml:mtd></mml:mtr></mml:mtable></mml:mtd><mml:mtd><mml:mtable rowspacing="4pt" columnspacing="1em"><mml:mtr><mml:mtd><mml:mo>&#x22EE;</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mo>&#x22EF;</mml:mo></mml:mtd></mml:mtr></mml:mtable></mml:mtd><mml:mtd><mml:mtable rowspacing="4pt" columnspacing="1em"><mml:mtr><mml:mtd><mml:mo>&#x22EE;</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:msub><mml:mi>x</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mi>n</mml:mi><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mi>d</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:mtd></mml:mtr></mml:mtable><mml:mo>]</mml:mo></mml:mrow></mml:math></disp-formula>whereas <inline-formula id="ieqn-1"><mml:math id="mml-ieqn-1"><mml:mi>n</mml:mi></mml:math></inline-formula> depicts the amount of sparrows and <inline-formula id="ieqn-2"><mml:math id="mml-ieqn-2"><mml:mi>d</mml:mi></mml:math></inline-formula> denotes the direction of variables that has to be optimized. Hence, the fitness score of each sparrow is given as follows:</p>
<p><disp-formula id="eqn-2">
<label>(2)</label>
<mml:math id="mml-eqn-2" display="block"><mml:msub><mml:mi>F</mml:mi><mml:mrow><mml:mi>X</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mrow><mml:mo>[</mml:mo><mml:mtable columnalign="center center center" rowspacing="4pt" columnspacing="1em"><mml:mtr><mml:mtd><mml:mi>f</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mo stretchy="false">[</mml:mo><mml:msub><mml:mi>x</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mn>1</mml:mn><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:mtd><mml:mtd><mml:msub><mml:mi>&#x03C7;</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mn>1</mml:mn><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mtd><mml:mtd><mml:mo>&#x22EF;</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mi>f</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mo stretchy="false">[</mml:mo><mml:msub><mml:mi>x</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mn>2</mml:mn><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:mtd><mml:mtd><mml:msub><mml:mi>&#x03C7;</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mn>2</mml:mn><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mtd><mml:mtd><mml:mo>&#x22EF;</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mtable rowspacing="4pt" columnspacing="1em"><mml:mtr><mml:mtd><mml:mo>&#x22EE;</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mi>f</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mo stretchy="false">[</mml:mo><mml:msub><mml:mi>x</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mi>n</mml:mi><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:mtd><mml:mtd><mml:mtable rowspacing="4pt" columnspacing="1em"><mml:mtr><mml:mtd><mml:mo>&#x22EE;</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:msub><mml:mi>x</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mi>n</mml:mi><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable></mml:mtd><mml:mtd><mml:mtable rowspacing="4pt" columnspacing="1em"><mml:mtr><mml:mtd><mml:mo>&#x22EE;</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mo>&#x22EF;</mml:mo></mml:mtd></mml:mtr></mml:mtable></mml:mtd></mml:mtr></mml:mtable><mml:mtable columnalign="center center" rowspacing="4pt" columnspacing="1em"><mml:mtr><mml:mtd><mml:mo>&#x22EF;</mml:mo></mml:mtd><mml:mtd><mml:msub><mml:mi>&#x03C7;</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mn>1</mml:mn><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mi>d</mml:mi></mml:mrow></mml:msub><mml:mo stretchy="false">]</mml:mo><mml:mo stretchy="false">)</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mo>&#x22EF;</mml:mo></mml:mtd><mml:mtd><mml:msub><mml:mi>&#x03C7;</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mn>2</mml:mn><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mi>d</mml:mi></mml:mrow></mml:msub><mml:mo stretchy="false">]</mml:mo><mml:mo stretchy="false">)</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mtable rowspacing="4pt" columnspacing="1em"><mml:mtr><mml:mtd><mml:mo>&#x22EE;</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:mo>&#x22EF;</mml:mo></mml:mtd></mml:mtr></mml:mtable></mml:mtd><mml:mtd><mml:mtable rowspacing="4pt" columnspacing="1em"><mml:mtr><mml:mtd><mml:mo>&#x22EE;</mml:mo></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:msub><mml:mi>x</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mi>n</mml:mi><mml:mo>,</mml:mo></mml:msub></mml:mrow><mml:mi>d</mml:mi></mml:mrow></mml:msub><mml:mo stretchy="false">]</mml:mo><mml:mo stretchy="false">)</mml:mo></mml:mtd></mml:mtr></mml:mtable></mml:mtd></mml:mtr></mml:mtable><mml:mo>]</mml:mo></mml:mrow></mml:math></disp-formula></p>
<p>In which <inline-formula id="ieqn-3"><mml:math id="mml-ieqn-3"><mml:mi>n</mml:mi></mml:math></inline-formula> defines the count of sparrows, and measure of all rows in <inline-formula id="ieqn-4"><mml:math id="mml-ieqn-4"><mml:msub><mml:mi>F</mml:mi><mml:mrow><mml:mi>X</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> refers the fitness score. In SSA, the producers have maximum fitness measures to accomplish optimal food in searching process. As well, the producers are in-charge to explore food and help the action of whole population. Therefore, the producers are capable of finding food in wider ranges than scroungers. Depending upon the rules <xref ref-type="disp-formula" rid="eqn-1">(1)</xref> &#x0026; <xref ref-type="disp-formula" rid="eqn-2">(2)</xref>, the location of producers are enlarged by the given equation:</p>
<p><disp-formula id="eqn-3">
<label>(3)</label>
<mml:math id="mml-eqn-3" display="block"><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>j</mml:mi><mml:mo>,</mml:mo><mml:mi>j</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>+</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msubsup><mml:mo>=</mml:mo><mml:mrow><mml:mo>{</mml:mo><mml:mtable columnalign="left left" rowspacing=".2em" columnspacing="1em" displaystyle="false"><mml:mtr><mml:mtd><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>i</mml:mi><mml:mo>,</mml:mo><mml:mi>j</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msubsup><mml:mo>&#x22C5;</mml:mo><mml:mi>exp</mml:mi><mml:mo>&#x2061;</mml:mo><mml:mstyle scriptlevel="0"><mml:mrow><mml:mo maxsize="2.047em" minsize="2.047em">(</mml:mo></mml:mrow></mml:mstyle><mml:mstyle displaystyle="true" scriptlevel="0"><mml:mfrac><mml:mrow><mml:mo>&#x2212;</mml:mo><mml:mi>i</mml:mi></mml:mrow><mml:mrow><mml:mi>&#x03B1;</mml:mi><mml:mo>&#x22C5;</mml:mo><mml:mi>i</mml:mi><mml:mi>t</mml:mi><mml:mi>e</mml:mi><mml:msub><mml:mi>r</mml:mi><mml:mrow><mml:mo movablelimits="true" form="prefix">max</mml:mo></mml:mrow></mml:msub></mml:mrow></mml:mfrac><mml:mstyle scriptlevel="0"><mml:mrow><mml:mo maxsize="2.047em" minsize="2.047em">)</mml:mo></mml:mrow></mml:mstyle></mml:mstyle></mml:mtd><mml:mtd><mml:mrow><mml:mtext mathvariant="italic">if&#xA0;</mml:mtext></mml:mrow><mml:msub><mml:mi>R</mml:mi><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>&#x003C;</mml:mo><mml:mi>S</mml:mi><mml:mi>T</mml:mi></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>i</mml:mi><mml:mo>,</mml:mo><mml:mi>j</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msubsup><mml:mo>+</mml:mo><mml:mi>O</mml:mi><mml:mo>&#x22C5;</mml:mo><mml:mi>L</mml:mi></mml:mtd><mml:mtd><mml:mrow><mml:mtext mathvariant="italic">if&#xA0;</mml:mtext></mml:mrow><mml:msub><mml:mi>R</mml:mi><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>&#x2265;</mml:mo><mml:mi>S</mml:mi><mml:mi>T</mml:mi></mml:mtd></mml:mtr></mml:mtable><mml:mo fence="true" stretchy="true" symmetric="true"></mml:mo></mml:mrow></mml:math></disp-formula>whereas <inline-formula id="ieqn-5"><mml:math id="mml-ieqn-5"><mml:mi>t</mml:mi></mml:math></inline-formula> denotes the recent iteration, <inline-formula id="ieqn-6"><mml:math id="mml-ieqn-6"><mml:mi>j</mml:mi><mml:mo>=</mml:mo><mml:mn>1</mml:mn><mml:mo>,</mml:mo><mml:mn>2</mml:mn><mml:mo>,</mml:mo><mml:mo>&#x2026;</mml:mo><mml:mo>,</mml:mo><mml:mi>d</mml:mi><mml:mo>.</mml:mo><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>j</mml:mi><mml:mo>,</mml:mo><mml:mi>j</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msubsup></mml:math></inline-formula> indicates the rate of <inline-formula id="ieqn-7"><mml:math id="mml-ieqn-7"><mml:mi>j</mml:mi><mml:mi>t</mml:mi><mml:mi>h</mml:mi></mml:math></inline-formula> dimension of <inline-formula id="ieqn-8"><mml:math id="mml-ieqn-8"><mml:mi>i</mml:mi><mml:mi>t</mml:mi><mml:mi>h</mml:mi></mml:math></inline-formula> sparrows at iteration <inline-formula id="ieqn-9"><mml:math id="mml-ieqn-9"><mml:mi>t</mml:mi><mml:mo>.</mml:mo><mml:mi>i</mml:mi><mml:mi>t</mml:mi><mml:mi>e</mml:mi><mml:msub><mml:mi>r</mml:mi><mml:mrow><mml:mo movablelimits="true" form="prefix">max</mml:mo></mml:mrow></mml:msub></mml:math></inline-formula> indicates a constant with maximum iteration. <inline-formula id="ieqn-10"><mml:math id="mml-ieqn-10"><mml:mi>&#x03B1;</mml:mi><mml:mo>&#x2208;</mml:mo><mml:mo stretchy="false">(</mml:mo><mml:mn>0</mml:mn><mml:mo>,</mml:mo><mml:mn>1</mml:mn></mml:math></inline-formula>] demonstrates an arbitrary value. <inline-formula id="ieqn-11"><mml:math id="mml-ieqn-11"><mml:msub><mml:mi>R</mml:mi><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:msub><mml:mi>R</mml:mi><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>&#x2208;</mml:mo><mml:mo stretchy="false">[</mml:mo><mml:mn>0</mml:mn><mml:mo>,</mml:mo><mml:mn>1</mml:mn><mml:mo stretchy="false">]</mml:mo><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> and <inline-formula id="ieqn-12"><mml:math id="mml-ieqn-12"><mml:mi>S</mml:mi><mml:mi>T</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>S</mml:mi><mml:mi>T</mml:mi><mml:mo>&#x2208;</mml:mo><mml:mo stretchy="false">[</mml:mo><mml:mn>0.5</mml:mn><mml:mo>,</mml:mo><mml:mn>1.0</mml:mn><mml:mo stretchy="false">]</mml:mo><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> show an alarm value and safety threshold correspondingly. <inline-formula id="ieqn-13"><mml:math id="mml-ieqn-13"><mml:mi>Q</mml:mi></mml:math></inline-formula> signifies a random value which applies simple distribution and <inline-formula id="ieqn-14"><mml:math id="mml-ieqn-14"><mml:mi>L</mml:mi></mml:math></inline-formula> signifies a matrix of <inline-formula id="ieqn-15"><mml:math id="mml-ieqn-15"><mml:mn>1</mml:mn><mml:mo>&#x00D7;</mml:mo><mml:mi>d</mml:mi></mml:math></inline-formula> for each element within one. <?A3B2 "fig2",5,"anchor"?><xref ref-type="fig" rid="fig-2">Fig. 2</xref> illustrates the process flow of SSA.</p>
<p>If <inline-formula id="ieqn-16"><mml:math id="mml-ieqn-16"><mml:msub><mml:mi>R</mml:mi><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>&#x003C;</mml:mo><mml:mi>S</mml:mi><mml:mi>T</mml:mi></mml:math></inline-formula>, represents that no predators exist, and producer gets into extensive search mode. If <inline-formula id="ieqn-17"><mml:math id="mml-ieqn-17"><mml:msub><mml:mi>R</mml:mi><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>&#x2265;</mml:mo><mml:mi>S</mml:mi><mml:mi>T</mml:mi></mml:math></inline-formula>, few sparrows have established the predators, and it is necessary to safeguard them by flying to safer areas. For scroungers, it employs rules <xref ref-type="disp-formula" rid="eqn-4">(4)</xref> &#x0026; <xref ref-type="disp-formula" rid="eqn-5">(5)</xref>. Few scroungers only follow the producer significantly [<xref ref-type="bibr" rid="ref-19">19</xref>]. If the producers detect the best food, it leaves the place to compete for food. If the competition is accomplished, it can obtain the food of producers, otherwise, rules <xref ref-type="disp-formula" rid="eqn-7">(7)</xref> are implemented. The location updating expressions for scroungers are determined below:</p>
<p><disp-formula id="eqn-4">
<label>(4)</label>
<mml:math id="mml-eqn-4" display="block"><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>i</mml:mi><mml:mo>,</mml:mo><mml:mi>j</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>+</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msubsup><mml:mo>=</mml:mo><mml:mrow><mml:mo>{</mml:mo><mml:mtable columnalign="left left" rowspacing=".2em" columnspacing="1em" displaystyle="false"><mml:mtr><mml:mtd><mml:mn>0.</mml:mn><mml:mi>exp</mml:mi><mml:mo>&#x2061;</mml:mo><mml:mstyle scriptlevel="0"><mml:mrow><mml:mo maxsize="2.047em" minsize="2.047em">(</mml:mo></mml:mrow></mml:mstyle><mml:mstyle displaystyle="true" scriptlevel="0"><mml:mfrac><mml:mrow><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mrow><mml:mi mathvariant="italic">w</mml:mi><mml:mi mathvariant="italic">o</mml:mi><mml:mi mathvariant="italic">r</mml:mi><mml:mi mathvariant="italic">s</mml:mi><mml:mi mathvariant="italic">t</mml:mi></mml:mrow></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msubsup><mml:mo>&#x2212;</mml:mo><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow><mml:mrow><mml:msub><mml:mi>t</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:msubsup></mml:mrow><mml:msup><mml:mi>j</mml:mi><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:mfrac><mml:mstyle scriptlevel="0"><mml:mrow><mml:mo maxsize="2.047em" minsize="2.047em">)</mml:mo></mml:mrow></mml:mstyle></mml:mstyle></mml:mtd><mml:mtd><mml:mrow><mml:mtext mathvariant="italic">if&#xA0;</mml:mtext></mml:mrow><mml:mi>i</mml:mi><mml:mo>&#x003E;</mml:mo><mml:mi>n</mml:mi><mml:mrow><mml:mo>/</mml:mo></mml:mrow><mml:mn>2</mml:mn></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>P</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>+</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msubsup><mml:mo>+</mml:mo><mml:mrow><mml:mo stretchy="false">|</mml:mo></mml:mrow><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>j</mml:mi><mml:mo>,</mml:mo><mml:mi>j</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msubsup><mml:mo>&#x2212;</mml:mo><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>P</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>+</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msubsup><mml:mrow><mml:mo stretchy="false">|</mml:mo></mml:mrow><mml:mo>&#x22C5;</mml:mo><mml:msup><mml:mi>A</mml:mi><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup><mml:mo>&#x22C5;</mml:mo><mml:mi>L</mml:mi></mml:mtd><mml:mtd><mml:mrow><mml:mi mathvariant="italic">o</mml:mi><mml:mi mathvariant="italic">t</mml:mi><mml:mi mathvariant="italic">h</mml:mi><mml:mi mathvariant="italic">e</mml:mi><mml:mi mathvariant="italic">r</mml:mi><mml:mi mathvariant="italic">w</mml:mi><mml:mi mathvariant="italic">i</mml:mi><mml:mi mathvariant="italic">s</mml:mi><mml:mi mathvariant="italic">e</mml:mi></mml:mrow></mml:mtd></mml:mtr></mml:mtable><mml:mo fence="true" stretchy="true" symmetric="true"></mml:mo></mml:mrow></mml:math></disp-formula>whereas <inline-formula id="ieqn-18"><mml:math id="mml-ieqn-18"><mml:msub><mml:mi>X</mml:mi><mml:mrow><mml:mi>P</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> implies the optimal position applied by a producer, <inline-formula id="ieqn-19"><mml:math id="mml-ieqn-19"><mml:msub><mml:mi>X</mml:mi><mml:mrow><mml:mrow><mml:mi mathvariant="italic">w</mml:mi><mml:mi mathvariant="italic">o</mml:mi><mml:mi mathvariant="italic">r</mml:mi><mml:mi mathvariant="italic">s</mml:mi><mml:mi mathvariant="italic">t</mml:mi></mml:mrow></mml:mrow></mml:msub></mml:math></inline-formula> refers the recent global worst position, <inline-formula id="ieqn-20"><mml:math id="mml-ieqn-20"><mml:mi>A</mml:mi></mml:math></inline-formula> showcases a matrix of <inline-formula id="ieqn-21"><mml:math id="mml-ieqn-21"><mml:mn>1</mml:mn><mml:mo>&#x00D7;</mml:mo><mml:mi>d</mml:mi></mml:math></inline-formula> for elements within 1, and <inline-formula id="ieqn-22"><mml:math id="mml-ieqn-22"><mml:msup><mml:mi>A</mml:mi><mml:mrow><mml:mo>+</mml:mo></mml:mrow></mml:msup><mml:mo>=</mml:mo><mml:msup><mml:mi>A</mml:mi><mml:mrow><mml:mi>T</mml:mi></mml:mrow></mml:msup><mml:mo stretchy="false">(</mml:mo><mml:mi>A</mml:mi><mml:msup><mml:mi>A</mml:mi><mml:mrow><mml:mi>T</mml:mi></mml:mrow></mml:msup><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mrow><mml:mo>&#x2212;</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math></inline-formula>. When <inline-formula id="ieqn-23"><mml:math id="mml-ieqn-23"><mml:mi>i</mml:mi><mml:mo>&#x003E;</mml:mo><mml:mi>n</mml:mi><mml:mrow><mml:mo>/</mml:mo></mml:mrow><mml:mn>2</mml:mn></mml:math></inline-formula>, it recommends that <inline-formula id="ieqn-24"><mml:math id="mml-ieqn-24"><mml:mi>i</mml:mi><mml:mi>t</mml:mi><mml:mi>h</mml:mi></mml:math></inline-formula> scroungers with ineffective fitness are more starving.</p>
<p>As a result, the sparrow <italic>i.e</italic>., far from risk will have additional lifetime. The primary location of sparrows is generated randomly in the population. Depends on, the mathematical approach is provided in the following:</p>
<p><disp-formula id="eqn-5">
<label>(5)</label>
<mml:math id="mml-eqn-5" display="block"><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>i</mml:mi><mml:mo>,</mml:mo><mml:mi>j</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>+</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msubsup><mml:mo>=</mml:mo><mml:mrow><mml:mo>{</mml:mo><mml:mtable columnalign="left left" rowspacing=".2em" columnspacing="1em" displaystyle="false"><mml:mtr><mml:mtd><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>b</mml:mi><mml:mi>e</mml:mi><mml:mi>s</mml:mi><mml:mi>t</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msubsup><mml:mo>+</mml:mo><mml:mi>&#x03B2;</mml:mi><mml:mo>&#x22C5;</mml:mo><mml:mrow><mml:mo stretchy="false">|</mml:mo></mml:mrow><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>i</mml:mi><mml:mo>,</mml:mo><mml:mi>j</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msubsup><mml:mo>&#x2212;</mml:mo><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>b</mml:mi><mml:mi>e</mml:mi><mml:mi>s</mml:mi><mml:mi>t</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msubsup><mml:mrow><mml:mo stretchy="false">|</mml:mo></mml:mrow></mml:mtd><mml:mtd><mml:mrow><mml:mtext mathvariant="italic">if&#xA0;</mml:mtext></mml:mrow><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>&#x003E;</mml:mo><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>g</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr><mml:mtr><mml:mtd><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>i</mml:mi><mml:mo>,</mml:mo><mml:mi>j</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msubsup><mml:mo>+</mml:mo><mml:mi>K</mml:mi><mml:mo>&#x22C5;</mml:mo><mml:mrow><mml:mo>(</mml:mo><mml:mstyle displaystyle="true" scriptlevel="0"><mml:mfrac><mml:mrow><mml:mo>|</mml:mo><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mi>i</mml:mi><mml:mo>,</mml:mo><mml:mi>j</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msubsup><mml:mo>&#x2212;</mml:mo><mml:msubsup><mml:mi>X</mml:mi><mml:mrow><mml:mrow><mml:mi mathvariant="italic">w</mml:mi><mml:mi mathvariant="italic">o</mml:mi><mml:mi mathvariant="italic">r</mml:mi><mml:mi mathvariant="italic">s</mml:mi><mml:mi mathvariant="italic">t</mml:mi></mml:mrow></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msubsup><mml:mo>|</mml:mo></mml:mrow><mml:mrow><mml:mrow><mml:mo>(</mml:mo><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>j</mml:mi></mml:mrow></mml:msub><mml:mo>&#x2212;</mml:mo><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>w</mml:mi></mml:mrow></mml:msub><mml:mo>)</mml:mo></mml:mrow><mml:mo>+</mml:mo><mml:mi>&#x03B5;</mml:mi></mml:mrow></mml:mfrac></mml:mstyle><mml:mo>)</mml:mo></mml:mrow></mml:mtd><mml:mtd><mml:mrow><mml:mtext mathvariant="italic">if&#xA0;</mml:mtext></mml:mrow><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>g</mml:mi></mml:mrow></mml:msub></mml:mtd></mml:mtr></mml:mtable><mml:mo fence="true" stretchy="true" symmetric="true"></mml:mo></mml:mrow></mml:math></disp-formula>where <inline-formula id="ieqn-25"><mml:math id="mml-ieqn-25"><mml:msub><mml:mi>X</mml:mi><mml:mrow><mml:mi>b</mml:mi><mml:mi>e</mml:mi><mml:mi>s</mml:mi><mml:mi>t</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> represents recent global best location.<inline-formula id="ieqn-26"><mml:math id="mml-ieqn-26"><mml:mi>&#x03B2;</mml:mi></mml:math></inline-formula>, indicates a step size control variable, <italic>i.e</italic>., a normal distribution of arbitrary values with mean value of <inline-formula id="ieqn-27"><mml:math id="mml-ieqn-27"><mml:mi>z</mml:mi><mml:mi>e</mml:mi><mml:mi>r</mml:mi><mml:mi>o</mml:mi></mml:math></inline-formula> and a variance of 1. <inline-formula id="ieqn-28"><mml:math id="mml-ieqn-28"><mml:mi>K</mml:mi><mml:mo>&#x2208;</mml:mo><mml:mo stretchy="false">[</mml:mo><mml:mo>&#x2212;</mml:mo><mml:mn>1</mml:mn><mml:mo>,</mml:mo><mml:mn>1</mml:mn><mml:mo stretchy="false">]</mml:mo></mml:math></inline-formula> represents a random measure. In this method, <inline-formula id="ieqn-29"><mml:math id="mml-ieqn-29"><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> refers fitness value of recent sparrow. <inline-formula id="ieqn-30"><mml:math id="mml-ieqn-30"><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>g</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> and <inline-formula id="ieqn-31"><mml:math id="mml-ieqn-31"><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>w</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> signifies recent global best and worst fitness measures. <inline-formula id="ieqn-32"><mml:math id="mml-ieqn-32"><mml:mi>&#x03B5;</mml:mi></mml:math></inline-formula> depicts a minimum constant and eliminates zero-division-error.</p>
<p>When <inline-formula id="ieqn-33"><mml:math id="mml-ieqn-33"><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>&#x003E;</mml:mo><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>g</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula>, the sparrows are at border of a group. <inline-formula id="ieqn-34"><mml:math id="mml-ieqn-34"><mml:msub><mml:mi>X</mml:mi><mml:mrow><mml:mi>e</mml:mi><mml:mi>s</mml:mi><mml:mi>t</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> represents a position of a centre of population <italic>i.e</italic>., safer. Here, <inline-formula id="ieqn-35"><mml:math id="mml-ieqn-35"><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>j</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>g</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> denotes that the sparrow, is in between a population <italic>i.e</italic>., aware of a threat and migrate close to the edge. <inline-formula id="ieqn-36"><mml:math id="mml-ieqn-36"><mml:mi>K</mml:mi></mml:math></inline-formula> is a direction where sparrows move and a step-size control coefficient.</p>
<fig id="fig-2">
<label>Figure 2</label>
<caption>
<title>Process flow of SSA</title>
</caption>
<graphic mimetype="image" mime-subtype="png" xlink:href="CMC_22203-fig-2.png"/>
</fig>
</sec>
<sec id="s2_2">
<label>2.2</label>
<title>Design of SSA-DE Technique</title>
<p>The SSA-DE algorithm is defined depending upon the change in frequency of steady events when the viewer moves in related sources. This particular variation is called DE and is represented as the variation in wavelength of a source between two points [<xref ref-type="bibr" rid="ref-20">20</xref>]. The associated development affects the observed frequency which is a growth in the line of sight (LOS) amongst two points. The sparrows encompass improved vision over humans and they can be embedded to a high frequency which results in moving and reaching the food as a chain. The sparrow directs the remaining ones to move in the direction of the food source and the leader sparrow has the ability to determine the distance and place of the source.</p>
<p>The leader sparrow travels arbitrarily and raises the frequency Doppler to be kept in a controlled frequency measuring area. It contains better hearing competence and due to the Doppler shift recompense. The benefit of Doppler shift is employed in the design of the SSA. Totally, two Doppler shifts are used to estimate the place of the sparrows. It is considered that <inline-formula id="ieqn-37"><mml:math id="mml-ieqn-37"><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msub><mml:mrow><mml:mo>/</mml:mo></mml:mrow><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> and <inline-formula id="ieqn-38"><mml:math id="mml-ieqn-38"><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>r</mml:mi></mml:mrow></mml:msub><mml:mrow><mml:mo>/</mml:mo></mml:mrow><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi>r</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> are frequencies of two ends. An original frequency comprises a relationship by the use of a wavelength, where <inline-formula id="ieqn-39"><mml:math id="mml-ieqn-39"><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mi>C</mml:mi><mml:mrow><mml:mo>/</mml:mo></mml:mrow><mml:msub><mml:mi>&#x03BB;</mml:mi><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msub><mml:mo>,</mml:mo></mml:math></inline-formula> <inline-formula id="ieqn-40"><mml:math id="mml-ieqn-40"><mml:msub><mml:mi>&#x03BB;</mml:mi><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msub></mml:math></inline-formula> signifies the wavelength of a source, and <inline-formula id="ieqn-41"><mml:math id="mml-ieqn-41"><mml:mi>C</mml:mi></mml:math></inline-formula> outlines the wave frequency. If the source is kept from the observer, then the sparrow leader position update tends to be negative and therefore</p>
<p><disp-formula id="eqn-6">
<label>(6)</label>
<mml:math id="mml-eqn-6" display="block"><mml:mi>f</mml:mi><mml:mi mathvariant="normal">&#x2032;</mml:mi><mml:mo>=</mml:mo><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msub><mml:mrow><mml:mo>[</mml:mo><mml:mfrac><mml:mrow><mml:mi>C</mml:mi><mml:mo>+</mml:mo><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi>r</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mi>C</mml:mi></mml:mfrac><mml:mo>]</mml:mo></mml:mrow><mml:mo>.</mml:mo></mml:math></disp-formula>when the source is moving the distance away from observer, the place of the sparrow leader resulted to positive; and thereby:</p>
<p><disp-formula id="eqn-7">
<label>(7)</label>
<mml:math id="mml-eqn-7" display="block"><mml:mi>f</mml:mi><mml:mi mathvariant="normal">&#x2032;</mml:mi><mml:mo>=</mml:mo><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msub><mml:mrow><mml:mo>[</mml:mo><mml:mfrac><mml:mrow><mml:mi>C</mml:mi><mml:mo>&#x2212;</mml:mo><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi>r</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mi>C</mml:mi></mml:mfrac><mml:mo>]</mml:mo></mml:mrow><mml:mo>.</mml:mo></mml:math></disp-formula></p>
<p><disp-formula id="eqn-8">
<label>(8)</label>
<mml:math id="mml-eqn-8" display="block"><mml:mi>f</mml:mi><mml:mi mathvariant="normal">&#x2032;</mml:mi><mml:mo>=</mml:mo><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msub><mml:mrow><mml:mo>[</mml:mo><mml:mfrac><mml:mrow><mml:mi>C</mml:mi><mml:mo>&#x00B1;</mml:mo><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi>r</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mi>C</mml:mi></mml:mfrac><mml:mo>]</mml:mo></mml:mrow><mml:mo>.</mml:mo></mml:math></disp-formula>when the source is moved towards the direction of the receiver, the function can be rewritten as follows:</p>
<p><disp-formula id="eqn-9">
<label>(9)</label>
<mml:math id="mml-eqn-9" display="block"><mml:mi>f</mml:mi><mml:mi mathvariant="normal">&#x2032;</mml:mi><mml:mo>=</mml:mo><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msub><mml:mrow><mml:mo>[</mml:mo><mml:mfrac><mml:mi>C</mml:mi><mml:mrow><mml:mi>C</mml:mi><mml:mo>&#x2212;</mml:mo><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi>s</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mfrac><mml:mo>]</mml:mo></mml:mrow><mml:mo>.</mml:mo></mml:math></disp-formula></p>
<p>In case, the source is developed, the maximization of actual frequency take place using <xref ref-type="disp-formula" rid="eqn-10">Eq. (10)</xref>:</p>
<p><disp-formula id="eqn-10">
<label>(10)</label>
<mml:math id="mml-eqn-10" display="block"><mml:mi>f</mml:mi><mml:mi mathvariant="normal">&#x2032;</mml:mi><mml:mo>=</mml:mo><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msub><mml:mrow><mml:mo>[</mml:mo><mml:mfrac><mml:mi>C</mml:mi><mml:mrow><mml:mi>C</mml:mi><mml:mo>+</mml:mo><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi>s</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mfrac><mml:mo>]</mml:mo></mml:mrow><mml:mo>.</mml:mo></mml:math></disp-formula></p>
<p>Finally, the new frequency can be represented as follows:</p>
<p><disp-formula id="eqn-11">
<label>(11)</label>
<mml:math id="mml-eqn-11" display="block"><mml:mi>f</mml:mi><mml:mi mathvariant="normal">&#x2032;</mml:mi><mml:mo>=</mml:mo><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mn>0</mml:mn></mml:mrow></mml:msub><mml:mrow><mml:mo>[</mml:mo><mml:mfrac><mml:mi>C</mml:mi><mml:mrow><mml:mi>C</mml:mi><mml:mo>&#x2213;</mml:mo><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi>s</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mfrac><mml:mo>]</mml:mo></mml:mrow><mml:mo>.</mml:mo></mml:math></disp-formula></p>
<p>The &#x002B;/&#x2212; signs are overturned as the sign on top can be employed to the relative movement between two points. The estimated DE function can be defined by:</p>
<p><disp-formula id="eqn-12">
<label>(12)</label>
<mml:math id="mml-eqn-12" display="block"><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>r</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:msub><mml:mi>f</mml:mi><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msub><mml:mrow><mml:mo>[</mml:mo><mml:mfrac><mml:mrow><mml:mi>C</mml:mi><mml:mo>&#x00B1;</mml:mo><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi>r</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:mi>C</mml:mi><mml:mo>&#x2213;</mml:mo><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi>r</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mfrac><mml:mo>]</mml:mo></mml:mrow></mml:math></disp-formula></p>
<p>The actual frequency function is integrated into the SSA algorithm as given below.</p>
<p><disp-formula id="eqn-13">
<label>(13)</label>
<mml:math id="mml-eqn-13" display="block"><mml:msubsup><mml:mi>f</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>+</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msubsup><mml:mo>=</mml:mo><mml:msubsup><mml:mi>f</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msubsup><mml:mrow><mml:mo>[</mml:mo><mml:mfrac><mml:mrow><mml:mi>C</mml:mi><mml:mo>&#x00B1;</mml:mo><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:mi>C</mml:mi><mml:mo>&#x2213;</mml:mo><mml:msub><mml:mi>v</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mfrac><mml:mo>]</mml:mo></mml:mrow></mml:math></disp-formula></p>
<p>Likewise, the actual variables <inline-formula id="ieqn-42"><mml:math id="mml-ieqn-42"><mml:mo stretchy="false">(</mml:mo><mml:mi>w</mml:mi><mml:mn>1</mml:mn><mml:mo>,</mml:mo><mml:mi>w</mml:mi><mml:mn>2</mml:mn><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> are employed for improving the operation and performance of the method. They are applied for controlling the proportional link between the global and local convergence abilities <inline-formula id="ieqn-43"><mml:math id="mml-ieqn-43"><mml:mo stretchy="false">(</mml:mo><mml:mi>w</mml:mi><mml:mn>1</mml:mn><mml:mo>,</mml:mo><mml:mi>w</mml:mi><mml:mn>2</mml:mn><mml:mo stretchy="false">)</mml:mo><mml:mo>&#x2208;</mml:mo><mml:mi>C</mml:mi><mml:mo stretchy="false">[</mml:mo><mml:mn>0.7</mml:mn><mml:mo>,</mml:mo><mml:mn>1</mml:mn><mml:mo stretchy="false">]</mml:mo><mml:mo>.</mml:mo></mml:math></inline-formula></p>
<p><disp-formula id="eqn-14">
<label>(14)</label>
<mml:math id="mml-eqn-14" display="block"><mml:msubsup><mml:mi>v</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>+</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msubsup><mml:mo>=</mml:mo><mml:msub><mml:mi>w</mml:mi><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub><mml:mo>&#x2217;</mml:mo><mml:msubsup><mml:mi>v</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msubsup><mml:mo>+</mml:mo><mml:mrow><mml:mo>(</mml:mo><mml:msubsup><mml:mi>x</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>+</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msubsup><mml:mo>&#x2212;</mml:mo><mml:msub><mml:mi>x</mml:mi><mml:mrow><mml:mo>&#x2217;</mml:mo></mml:mrow></mml:msub><mml:mo>)</mml:mo></mml:mrow><mml:mo>&#x00D7;</mml:mo><mml:msubsup><mml:mi>f</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>+</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msubsup></mml:math></disp-formula></p>
<p><disp-formula id="eqn-15">
<label>(15)</label>
<mml:math id="mml-eqn-15" display="block"><mml:msubsup><mml:mi>x</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>+</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msubsup><mml:mo>=</mml:mo><mml:msub><mml:mi>w</mml:mi><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>&#x2217;</mml:mo><mml:msubsup><mml:mi>x</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi></mml:mrow></mml:msubsup><mml:mo>+</mml:mo><mml:msubsup><mml:mi>v</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow><mml:mrow><mml:mi>t</mml:mi><mml:mo>+</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msubsup></mml:math></disp-formula></p>
</sec>
<sec id="s2_3">
<label>2.3</label>
<title>Steps Involved in the SSA-DE Technique for Localization Process</title>
<p>The SSA-DE localization approach was mostly utilized for estimating the coordinate points of sensor in WSN. The goal is for determining the coordinate point of target node with minimization of objective function. The procedures contained in the SSA-DE manner are provided in the succeeding:
<list list-type="roman-lower">
<list-item>
<p>Initialized of <inline-formula id="ieqn-44"><mml:math id="mml-ieqn-44"><mml:mi>N</mml:mi></mml:math></inline-formula> unidentified node and <inline-formula id="ieqn-45"><mml:math id="mml-ieqn-45"><mml:mi>M</mml:mi></mml:math></inline-formula> anchor node arbitrarily in the sensing field with broadcast radius <inline-formula id="ieqn-46"><mml:math id="mml-ieqn-46"><mml:mi>R</mml:mi></mml:math></inline-formula>. All anchor nodes define the locating and sending the coordinate point to adjacent nodes. To all iterations, the node which settles down at the end is recognized as reference nodes and its roles as anchor nodes in the succeeding iteration.</p></list-item>
<list-item>
<p>The group of 3 or superior to 3 anchor nodes occur in the broadcast radius of node was defined as localized node.</p></list-item>
<list-item>
<p>The distance among the target as well as anchor nodes is defined and obtains altered using additive Gaussian noises. The target node calculates the distance with <inline-formula id="ieqn-47"><mml:math id="mml-ieqn-47"><mml:msub><mml:mrow><mml:mover><mml:mi>d</mml:mi><mml:mo stretchy="false">&#x005E;</mml:mo></mml:mover></mml:mrow><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:msub><mml:mi>d</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>+</mml:mo><mml:msub><mml:mi>n</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> where <inline-formula id="ieqn-48"><mml:math id="mml-ieqn-48"><mml:msub><mml:mi>d</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> refers the actual distance that is defined amongst the places of target nodes <inline-formula id="ieqn-49"><mml:math id="mml-ieqn-49"><mml:mo stretchy="false">(</mml:mo><mml:mi>x</mml:mi><mml:mo>,</mml:mo><mml:mi>y</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> and place of beacon <inline-formula id="ieqn-50"><mml:math id="mml-ieqn-50"><mml:mo stretchy="false">(</mml:mo><mml:msub><mml:mi>x</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:msub><mml:mi>y</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> utilizing in <xref ref-type="disp-formula" rid="eqn-16">Eq. (16)</xref>:
<disp-formula id="eqn-16">
<label>(16)</label>
<mml:math id="mml-eqn-16" display="block"><mml:msub><mml:mi>d</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:msqrt><mml:mo stretchy="false">(</mml:mo><mml:mi>x</mml:mi><mml:mo>&#x2212;</mml:mo><mml:msub><mml:mi>x</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:mo>+</mml:mo><mml:mo stretchy="false">(</mml:mo><mml:mi>y</mml:mi><mml:mo>&#x2212;</mml:mo><mml:msub><mml:mi>y</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:msqrt></mml:math></disp-formula>where <inline-formula id="ieqn-51"><mml:math id="mml-ieqn-51"><mml:msub><mml:mi>n</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> implies the noise affect the defined distance from <inline-formula id="ieqn-52"><mml:math id="mml-ieqn-52"><mml:msub><mml:mi>d</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>&#x00B1;</mml:mo><mml:msub><mml:mi>d</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:mfrac><mml:msub><mml:mi>P</mml:mi><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:msub><mml:mn>100</mml:mn></mml:mfrac><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> where <inline-formula id="ieqn-53"><mml:math id="mml-ieqn-53"><mml:msub><mml:mi>P</mml:mi><mml:mrow><mml:mi>n</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula> represents the ratio of noise in presented distance.</p></list-item>
<list-item>
<p>The target node is named a localizable node when it contains 3 anchor nodes within broadcast range of target nodes. According to employed trigonometric law of sine/cosine, the coordinate points of target nodes are estimated.</p></list-item>
<list-item>
<p>The SSA-DE manner was utilized to define the coordinate points <inline-formula id="ieqn-54"><mml:math id="mml-ieqn-54"><mml:mo stretchy="false">(</mml:mo><mml:mi>x</mml:mi><mml:mo>,</mml:mo><mml:mi>y</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> of target nodes which minimizes the localization errors. The primitive employed in localization problem was average square distance among the target as well as anchor nodes that are minimized utilizing <xref ref-type="disp-formula" rid="eqn-17">Eq. (17)</xref>:
<disp-formula id="eqn-17">
<label>(17)</label>
<mml:math id="mml-eqn-17" display="block"><mml:mi>f</mml:mi><mml:mrow><mml:mo>(</mml:mo><mml:mi>x</mml:mi><mml:mo>,</mml:mo><mml:mi>y</mml:mi><mml:mo>)</mml:mo></mml:mrow><mml:mo>=</mml:mo><mml:mfrac><mml:mn>1</mml:mn><mml:mi>N</mml:mi></mml:mfrac><mml:msup><mml:mrow><mml:mo>(</mml:mo><mml:msubsup><mml:mo movablelimits="false">&#x2211;</mml:mo><mml:mrow><mml:mi>i</mml:mi><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow><mml:mrow><mml:mi>N</mml:mi></mml:mrow></mml:msubsup><mml:msqrt><mml:mo stretchy="false">(</mml:mo><mml:mi>x</mml:mi><mml:mo>&#x2212;</mml:mo><mml:msub><mml:mi>x</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:mo>+</mml:mo><mml:mo stretchy="false">(</mml:mo><mml:mi>y</mml:mi><mml:mo>&#x2212;</mml:mo><mml:msub><mml:mi>y</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:msqrt><mml:mo>&#x2212;</mml:mo><mml:mrow><mml:mover><mml:mi>d</mml:mi><mml:mo stretchy="false">&#x005E;</mml:mo></mml:mover></mml:mrow><mml:mo>)</mml:mo></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:math></disp-formula>where <inline-formula id="ieqn-55"><mml:math id="mml-ieqn-55"><mml:mi>N</mml:mi><mml:mo>&#x2265;</mml:mo><mml:mn>3</mml:mn></mml:math></inline-formula> signifies the anchor node count to be broadcast range.</p></list-item>
<list-item><p>The optimal measure <inline-formula id="ieqn-56"><mml:math id="mml-ieqn-56"><mml:mo stretchy="false">(</mml:mo><mml:mi>x</mml:mi><mml:mo>,</mml:mo><mml:mi>y</mml:mi><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> was calculated by utilizing of SSA-DE manner at the end of iteration.</p></list-item>
<list-item>
<p>The entire localization error was estimated next to estimate of localizable target nodes <inline-formula id="ieqn-57"><mml:math id="mml-ieqn-57"><mml:msub><mml:mi>N</mml:mi><mml:mrow><mml:mi>L</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula>. It can be validated estimated as average square of distance from defined node coordinate points <inline-formula id="ieqn-58"><mml:math id="mml-ieqn-58"><mml:mo stretchy="false">(</mml:mo><mml:msub><mml:mi>X</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:msub><mml:mi>Y</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> but the original node coordinate points <inline-formula id="ieqn-59"><mml:math id="mml-ieqn-59"><mml:mo stretchy="false">(</mml:mo><mml:msub><mml:mi>x</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>,</mml:mo><mml:msub><mml:mi>y</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo stretchy="false">)</mml:mo></mml:math></inline-formula> are determined as:
<disp-formula id="eqn-18">
<label>(18)</label>
<mml:math id="mml-eqn-18" display="block"><mml:msub><mml:mi>E</mml:mi><mml:mrow><mml:mi>L</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mfrac><mml:mn>1</mml:mn><mml:msub><mml:mi>N</mml:mi><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:mfrac><mml:msubsup><mml:mo movablelimits="false">&#x2211;</mml:mo><mml:mrow><mml:mi>i</mml:mi><mml:mo>=</mml:mo><mml:mn>1</mml:mn></mml:mrow><mml:mrow><mml:mi>N</mml:mi></mml:mrow></mml:msubsup><mml:msqrt><mml:mo stretchy="false">(</mml:mo><mml:msub><mml:mi>x</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>&#x2212;</mml:mo><mml:msub><mml:mi>X</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup><mml:mo>+</mml:mo><mml:mo stretchy="false">(</mml:mo><mml:msub><mml:mi>y</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:mo>&#x2212;</mml:mo><mml:msub><mml:mi>Y</mml:mi><mml:mrow><mml:mi>i</mml:mi></mml:mrow></mml:msub><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msup></mml:msqrt></mml:math></disp-formula></p></list-item>
<list-item>
<p>Steps 2&#x2013;5 develop iterated still the place of target node was recognized. The localization method was dependent upon maximum localization error <inline-formula id="ieqn-60"><mml:math id="mml-ieqn-60"><mml:msub><mml:mi>E</mml:mi><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:math></inline-formula> and unlocalized node count <inline-formula id="ieqn-61"><mml:math id="mml-ieqn-61"><mml:msub><mml:mi>N</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mi>N</mml:mi><mml:mrow><mml:mi>L</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mrow></mml:msub></mml:math></inline-formula> that was estimated by the utilize of <inline-formula id="ieqn-62"><mml:math id="mml-ieqn-62"><mml:msub><mml:mi>N</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mi>N</mml:mi><mml:mrow><mml:mi>L</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mi>M</mml:mi><mml:mo>&#x2212;</mml:mo><mml:msub><mml:mi>N</mml:mi><mml:mrow><mml:mi>L</mml:mi></mml:mrow></mml:msub></mml:math></inline-formula>. The minimum score of <inline-formula id="ieqn-63"><mml:math id="mml-ieqn-63"><mml:msub><mml:mi>E</mml:mi><mml:mrow><mml:mn>1</mml:mn></mml:mrow></mml:msub></mml:math></inline-formula> and <inline-formula id="ieqn-64"><mml:math id="mml-ieqn-64"><mml:msub><mml:mi>N</mml:mi><mml:mrow><mml:mrow><mml:msub><mml:mi>N</mml:mi><mml:mrow><mml:mi>L</mml:mi></mml:mrow></mml:msub></mml:mrow></mml:mrow></mml:msub></mml:math></inline-formula> outcomes in proficient localization efficiency.</p></list-item>
</list></p>
</sec>
</sec>
<sec id="s3">
<label>3</label>
<title>Performance Validation</title>
<p>The proposed SSA-DE technique is simulated using MATLAB tool. The results of the SSA-DE technique are inspected interms of different measures under varying anchors, error, and transmission ranges.</p>
<p>A brief analysis of node localization performance of the SSA-DE approach is observed with respect to NLLN under distinct numbers of anchor nodes in <?A3B2 "tbl1",5,"anchor"?><xref ref-type="table" rid="table-1">Tab. 1</xref> and <?A3B2 "fig3",5,"anchor"?><xref ref-type="fig" rid="fig-3">Fig. 3</xref>. The experimental outcomes exhibited that the SSA-DE approach has resulted in an increased NLLN under all anchor counts. For sample, with 10 anchors, the SSA-DE manner has obtainable an improved NLLN of 134 whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL manners have reached a lesser PDR of 120, 118, 111, and 108 correspondingly. Followed by, with 30 anchors, the SSA-DE algorithm has accessible an enhanced NLLN of 168 whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL techniques have attained a minimal PDR of 148, 144, 127, and 118 respectively. Eventually, with 50 anchors, the SSA-DE technique has offered an enhanced NLLN of 193 whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL methodologies have gained a lower PDR of 173, 160, 148, and 137 correspondingly.</p>
<table-wrap id="table-1">
<label>Table 1</label>
<caption>
<title>Analysis of number of localized nodes (NLLN) under varying number of anchors</title>
</caption>
<table frame="hsides">
<colgroup>
<col align="left"/>
<col align="left"/>
<col align="left"/>
<col align="left"/>
<col align="left"/>
<col align="left"/>
</colgroup>
<thead>
<tr>
<th>No. of anchors</th>
<th>SSA-DE</th>
<th>SSA-NL</th>
<th>CSA-NL</th>
<th>GWO-NL</th>
<th>PSO-NL</th>
</tr>
</thead>
<tbody>
<tr>
<td>10</td>
<td>134</td>
<td>120</td>
<td>118</td>
<td>111</td>
<td>108</td>
</tr>
<tr>
<td>20</td>
<td>146</td>
<td>133</td>
<td>126</td>
<td>123</td>
<td>111</td>
</tr>
<tr>
<td>30</td>
<td>168</td>
<td>148</td>
<td>144</td>
<td>127</td>
<td>118</td>
</tr>
<tr>
<td>40</td>
<td>173</td>
<td>159</td>
<td>147</td>
<td>141</td>
<td>125</td>
</tr>
<tr>
<td>50</td>
<td>193</td>
<td>173</td>
<td>160</td>
<td>148</td>
<td>137</td>
</tr>
</tbody>
</table>
</table-wrap>
<fig id="fig-3">
<label>Figure 3</label>
<caption>
<title>NLLN analysis of SSA-DE model under different anchors</title>
</caption>
<graphic mimetype="image" mime-subtype="png" xlink:href="CMC_22203-fig-3.png"/>
</fig>
<table-wrap id="table-2">
<label>Table 2</label>
<caption>
<title>Analysis of localization errors (LLE) <italic>vs</italic>. the number of anchors</title>
</caption>
<table frame="hsides">
<colgroup>
<col align="left"/>
<col align="left"/>
<col align="left"/>
<col align="left"/>
<col align="left"/>
<col align="left"/>
</colgroup>
<thead>
<tr>
<th>No. of anchors</th>
<th>SSA-DE</th>
<th>SSA-NL</th>
<th>CSA-NL</th>
<th>GWO-NL</th>
<th>PSO-NL</th>
</tr>
</thead>
<tbody>
<tr>
<td>10</td>
<td>0.30</td>
<td>0.37</td>
<td>0.47</td>
<td>0.63</td>
<td>0.64</td>
</tr>
<tr>
<td>20</td>
<td>0.24</td>
<td>0.33</td>
<td>0.42</td>
<td>0.61</td>
<td>0.63</td>
</tr>
<tr>
<td>30</td>
<td>0.18</td>
<td>0.31</td>
<td>0.40</td>
<td>0.47</td>
<td>0.48</td>
</tr>
<tr>
<td>40</td>
<td>0.14</td>
<td>0.28</td>
<td>0.35</td>
<td>0.43</td>
<td>0.45</td>
</tr>
<tr>
<td>50</td>
<td>0.10</td>
<td>0.23</td>
<td>0.32</td>
<td>0.38</td>
<td>0.42</td>
</tr>
</tbody>
</table>
</table-wrap>
<p><?A3B2 "tbl2",5,"anchor"?><xref ref-type="table" rid="table-2">Tab. 2</xref> and <?A3B2 "fig4",5,"anchor"?><xref ref-type="fig" rid="fig-4">Fig. 4</xref> investigates the performance of the SSA-DE technique interms of LLE under varying numbers of anchors. The results showcased the effective localization outcome of the SSA-DE technique with the least LLE value. For instance, with 10 anchors, the SSA-DE technique has offered a minimal LLE of 0.30 whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL techniques have attained a maximum LLE of 0.37, 0.47, 0.63, and 0.64 respectively. In line with, with 30 anchors, the SSA-DE approach has offered a lesser LLE of 0.18 whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL algorithms have obtained a superior LLE of 0.31, 0.40, 0.47, and 0.48 correspondingly. At the same time, with 50 anchors, the SSA-DE manner has existed a reduced LLE of 0.10 whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL techniques have obtained a higher LLE of 0.23, 0.32, 0.38, and 0.42 correspondingly.</p>
<fig id="fig-4">
<label>Figure 4</label>
<caption>
<title>LLE analysis of SSA-DE model under different anchors</title>
</caption>
<graphic mimetype="image" mime-subtype="png" xlink:href="CMC_22203-fig-4.png"/>
</fig>
<p><?A3B2 "tbl3",5,"anchor"?><xref ref-type="table" rid="table-3">Tab. 3</xref> examines the performance of the SSA-DE technique with respect to LLE under different error and transmission ranges. <?A3B2 "fig5",5,"anchor"?><xref ref-type="fig" rid="fig-5">Fig. 5</xref> illustrates the LLE analysis of SSA-DE method under different errors. The outcomes showcased the effectual localization outcome of the SSA-DE manner with the minimal LLE value. For sample, with 10% error, the SSA-DE approach has accessible a lesser LLE of 0.23 whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL algorithms have reached a maximal LLE of 0.34, 0.39, 0.59, and 0.60 correspondingly. Similarly, with 20% error, the SSA-DE algorithm has existed a minimal LLE of 0.11 whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL manners have gained a superior LLE of 0.29, 0.35, 0.47, and 0.50 correspondingly. Simultaneously, with 30% error, the SSA-DE method has offered a reduced LLE of 0.08 whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL techniques have attained an enhanced LLE of 0.25, 0.27, 0.38, and 0.42 correspondingly.</p>
<table-wrap id="table-3">
<label>Table 3</label>
<caption>
<title>Analysis of LLE under varying error and transmission range</title>
</caption>
<table frame="hsides">
<colgroup>
<col align="left"/>
<col align="left"/>
<col align="left"/>
<col align="left"/>
<col align="left"/>
<col align="left"/>
</colgroup>
<thead>
<tr>
<th>Error (%)</th>
<th>SSA-DE</th>
<th>SSA-NL</th>
<th>CSA-NL</th>
<th>GWO-NL</th>
<th>PSO-NL</th>
</tr>
</thead>
<tbody>
<tr>
<td>10</td>
<td>0.23</td>
<td>0.34</td>
<td>0.39</td>
<td>0.59</td>
<td>0.60</td>
</tr>
<tr>
<td>15</td>
<td>0.17</td>
<td>0.31</td>
<td>0.36</td>
<td>0.51</td>
<td>0.58</td>
</tr>
<tr>
<td>20</td>
<td>0.11</td>
<td>0.29</td>
<td>0.35</td>
<td>0.47</td>
<td>0.50</td>
</tr>
<tr>
<td>25</td>
<td>0.09</td>
<td>0.28</td>
<td>0.31</td>
<td>0.41</td>
<td>0.46</td>
</tr>
<tr>
<td>30</td>
<td>0.08</td>
<td>0.25</td>
<td>0.27</td>
<td>0.38</td>
<td>0.42</td>
</tr>
<tr>
<td>Transmission range</td>
<td>SSA-DE</td>
<td>SSA-NL</td>
<td>CSA-NL</td>
<td>GWO-NL</td>
<td>PSO-NL</td>
</tr>
<tr>
<td>10</td>
<td>0.16</td>
<td>0.29</td>
<td>0.31</td>
<td>0.46</td>
<td>0.49</td>
</tr>
<tr>
<td>15</td>
<td>0.13</td>
<td>0.19</td>
<td>0.26</td>
<td>0.42</td>
<td>0.43</td>
</tr>
<tr>
<td>20</td>
<td>0.10</td>
<td>0.16</td>
<td>0.26</td>
<td>0.41</td>
<td>0.46</td>
</tr>
<tr>
<td>25</td>
<td>0.07</td>
<td>0.07</td>
<td>0.20</td>
<td>0.33</td>
<td>0.35</td>
</tr>
<tr>
<td>30</td>
<td>0.05</td>
<td>0.09</td>
<td>0.18</td>
<td>0.31</td>
<td>0.37</td>
</tr>
</tbody>
</table>
</table-wrap>
<fig id="fig-5">
<label>Figure 5</label>
<caption>
<title>LLE analysis of SSA-DE model under different error</title>
</caption>
<graphic mimetype="image" mime-subtype="png" xlink:href="CMC_22203-fig-5.png"/>
</fig>
<p><?A3B2 "fig6",5,"anchor"?><xref ref-type="fig" rid="fig-6">Fig. 6</xref> depicts the LLE analysis of SSA-DE approach under varying transmission ranges. The outcomes demonstrated the effectual localization outcome of the SSA-DE approach with the minimal LLE value. For sample, with 10 transmission range, the SSA-DE approach has obtainable the least LLE of 0.16 whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL techniques have reached a higher LLE of 0.29, 0.31, 0.46, and 0.49 correspondingly. Similarly, with 20 transmission range, the SSA-DE method has offered a lower LLE of 0.10 whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL methods have achieved a maximal LLE of 0.16, 0.26, 0.41, and 0.46 correspondingly. Eventually, with 30 transmission range, the SSA-DE methodology has existed a lesser LLE of 0.05 whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL algorithms have reached an improved LLE of 0.09, 0.18, 0.31, and 0.37 correspondingly.</p>
<fig id="fig-6">
<label>Figure 6</label>
<caption>
<title>NLLN analysis of SSA-DE model under different transmission range</title>
</caption>
<graphic mimetype="image" mime-subtype="png" xlink:href="CMC_22203-fig-6.png"/>
</fig>
<p>Finally, the node localization performance of the SSA-DE technique is examined interms of PDR under distinct number of anchor nodes in <?A3B2 "tbl4",5,"anchor"?><xref ref-type="table" rid="table-4">Tab. 4</xref> and <?A3B2 "fig7",5,"anchor"?><xref ref-type="fig" rid="fig-7">Fig. 7</xref>. The experimental outcomes exhibited that the SSA-DE technique has resulted in a minimum PDR under all anchor counts. For instance, with 10 anchors, the SSA-DE technique has offered a lower PDR of 94.15% whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL techniques have attained a higher PDR of 96.47%, 97.37%, 98.25%, and 98.67% respectively. In line with, 30 anchors, the SSA-DE manner has existed at least PDR of 90.37% whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL approaches have gained an increased PDR of 93.28%, 94.30%, 96.35%, and 97.04% correspondingly. At last, with 50 anchors, the SSA-DE technique has presented a minimum PDR of 86.06% whereas the SSA-NL, CSA-NL, GWO-NL, and PSO-NL algorithms have achieved an improved PDR of 89.55%, 92.41%, 94.26%, and 95.14% correspondingly.</p>
<table-wrap id="table-4">
<label>Table 4</label>
<caption>
<title>Result analysis of proposed SSA-DE method with existing methods in terms PDR (%)</title>
</caption>
<table frame="hsides">
<colgroup>
<col align="left"/>
<col align="left"/>
<col align="left"/>
<col align="left"/>
<col align="left"/>
<col align="left"/>
</colgroup>
<thead>
<tr>
<th colspan="6">Packet delivery ratio (%)</th>
</tr>
<tr>
<th>No. of anchors</th>
<th>SSA-DE</th>
<th>SSA-NL</th>
<th>CSA-NL</th>
<th>GWO-NL</th>
<th>PSO-NL</th>
</tr>
</thead>
<tbody>
<tr>
<td>10</td>
<td>94.15</td>
<td>96.47</td>
<td>97.37</td>
<td>98.25</td>
<td>98.67</td>
</tr>
<tr>
<td>20</td>
<td>92.46</td>
<td>95.36</td>
<td>96.39</td>
<td>97.27</td>
<td>98.21</td>
</tr>
<tr>
<td>30</td>
<td>90.37</td>
<td>93.28</td>
<td>94.30</td>
<td>96.35</td>
<td>97.04</td>
</tr>
<tr>
<td>40</td>
<td>88.41</td>
<td>91.19</td>
<td>93.39</td>
<td>95.24</td>
<td>96.19</td>
</tr>
<tr>
<td>50</td>
<td>86.06</td>
<td>89.55</td>
<td>92.41</td>
<td>94.26</td>
<td>95.14</td>
</tr>
</tbody>
</table>
</table-wrap>
<fig id="fig-7">
<label>Figure 7</label>
<caption>
<title>PDR analysis of SSA-DE model with existing techniques</title>
</caption>
<graphic mimetype="image" mime-subtype="png" xlink:href="CMC_22203-fig-7.png"/>
</fig>
<p>From the above-mentioned results analysis, it is demonstrated that the SSA-DE technique has resulted in an effectual approach for node localization process in WSN. The improved performance is due to the Doppler Effect which is incorporated into the SSA.</p>
</sec>
<sec id="s4">
<label>4</label>
<title>Conclusion</title>
<p>This paper has developed an SSD-DE technique for WSN. The proposed SSA-DE technique incorporates the concepts of the SSA and DE for proficiently localize the node in WSN. Besides, the Doppler Effect is incorporated into the SSA to further improve the node localization performance. In addition, the SSA-DE model defines the position of node in an iterative manner using Euclidian distance as the fitness function. An extensive set of experimentation is carried out and the outcomes are examined under a different number of anchor nodes and ranging error. The SSA-DE technique has presented a minimum PDR of 86.06% under the presence of 50 anchors. The attained experimental outcome make sure that higher efficiency of the SSA-DE algorithm over the existing algorithms. In future, time synchronization approaches are designed for enhancing the overall performance of the network.</p>
</sec>
</body>
<back>
<fn-group>
<fn fn-type="other">
<p><bold>Funding Statement:</bold> This research was supported by Korea Institute for Advancement of Technology (KIAT) grant funded by the Korea Government (MOTIE) (P0012724, The Competency Development Program for Industry Specialist) and the Soonchunhyang University Research Fund.</p>
</fn>
<fn fn-type="conflict">
<p><bold>Conflicts of Interest:</bold> The authors declare that they have no conflicts of interest to report regarding the present study.</p>
</fn>
</fn-group>
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