CINXE.COM

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="120"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "publications.waset.org",cType: 'non-interactive',cRay: '91358a8eba1f3f4b',cH: 'mTLoG54JAF0mM1vu.fcDtp8otUiLP5uVna5rGK60.CE-1739792831-1.2.1.1-sLVWKAJ.xrG2eidpHxxjHB13y7SMtIgZlp.cyhXEOCxxGyPVK6MjihVdA1fboMDk',cUPMDTk: "\/search?q=controls&__cf_chl_tk=Tiia5XKbb.bDn.JlwD_YnHCDwkhhe.iTLU86ZvKWxwM-1739792831-1.0.1.1-esTwjINnq7gdveyuJ_TMq5y601ZhxyV0uj5Fz1WAmEs",cFPWv: 'b',cITimeS: '1739792831',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/search?q=controls&__cf_chl_f_tk=Tiia5XKbb.bDn.JlwD_YnHCDwkhhe.iTLU86ZvKWxwM-1739792831-1.0.1.1-esTwjINnq7gdveyuJ_TMq5y601ZhxyV0uj5Fz1WAmEs",md: "cVIqBGlja4EWt4YLTzkm4r4Wb9ZONQDs66sb0ZMVM7A-1739792831-1.2.1.1-HCnZfkaUq3r6f_SS0diUbkeqM04.rwKuHvH8O9dGyDU2y1SBfVuzvJu1TMGOf4f91m4HFAQ4ibvw6b04JHWj8jR1X6Qg5BmIL4w3UeNm8_s6plUhxImP.3DyRqtY6XfasBavaBfz8dCXGhZWximB9l0YPesB8iwJO0APpbhgV1D1jPuXQyfqYLMah8t4OYfp3uCdANk09paEcbgCZd7l0Qwf85thlT5fWwF.OJBBR2XVCrPLlKe4N107wE4CmT5ifOlvonnQWQk2mYyaTyovLqmDyjFGk8ltoH6n7Jp1HpwJ14tudFlF_hXTNSTyPL69aCB6_RmtVFgxf8GQK5gS8awkhG8uP5UaD5Tw8osgO4wxUvYG0D4t7W0dXcQPnSSOMEzLwnt_d6HeTzGeaQDY00Xsbt0uXSsgL_IGY4J60_T.JmgPLn8E0_wMTLmNRuvAjoA27zImiBJ7_hzUfrVHuaGCJU4eXWUv1eg9r8nhlPCNmBSy8nSNhMVyMnxQzlvvkRJtcBOn4Ie6p5FBukjuUny3WYFUhQUuY_7J4XD9x7I2GLYj6U9zXKovIzFkGu3AOqXOtgmSvThNJhYJLzvEMHALautBXv9y9CxQ4IaraaN908NVgSL5hL.1Hp9awoo8qRk6ZUlWWNKbdIbeQ.MvUwr6_eutPitiDMVAlWZIjzgWt.vJscuzPj3qvvJjjb3ckNNC35r5HrRhm4Ie1QsAuwFxoW0EaFTDzgMWShLoKoU_qB57HjCtdK65tqZJLvYosPwBqs0.jrc5BCXFPMD5xYwYA_Gyg3MbFao4pWh5RKKA0wX3dKfuRNWYWfn3TgTy5mCuCIS4x_Fr4x.B.L0ZiFeDiukPJ.d2QDfPENlaMmU_GnBFHGSMf2O2G_fZC4Eh2OMeHQ7BzGk2SyXmltb1bsihkUEhz77hyt4vLdvpT4_x9GhKJMvOoD8v4i3YfsCUJW56fqNtCIvAIJ0DO.xUQva9J1IKKmfpaA6.LBtgzq_pYxGJT84rToS.huxPZE6Kvj7Z9bWryRiQzfLJioVIB5v_je6Z9mM_eHgZCZpay8xCvR13o8niwMta8g3xb5BUhrvtMix0De7Rc7elP3GJbKypWs5PyX9qBNNxsZ9c6zHp574gIG7qPPEsNuXs1Eb717fWNLMB8Yg3Xrk8Qn9W4w5qzxMoeew_oBgEIh6xu_zVMwvVYW.Vl_68a5DkUNB8.V2IG2.1_vy1y1U3wNo5aPdUARHXHEt5_RmMeVeV9fw13TKWPbyf4LzhMJoARBzxhTdyk7hM6tgFFDDj7Mal0CZHZAANrYO7aXVYSQlqj9Wwtf3Qg7NAc2NR59n6c6JYhKNGoEGiOfd6c2GcQ92QVXq6K3TZqO2ouq9Bevw3jLxqmP5CriQq1woetSCrW4rmOVMO_9WeuA4ADyu96sLQ6353CIionFnw_ROv1pmKJIN6oSke2zbrzOmP4FxBX8hondVoCaiYYNJPuz40HzdK1NnIbw6KvmjLsIT9JeYGrAQ9k3sqfUYTIVW.heE4EVSvPgdJXGHKIeDGdjL8f7vzpEXRa5C3CP4wnvpF_eQOsHEieoNrlcJWI_Z2HOZWTmj6zJ7V.d7GWPjezwtyOZxuEDiRMabIhucAgVEeM58rLLmeD3_Xpm2xCmLL2NTiwm_YbHQ6wiJkdaLZAQmtEM2RoF11wS17wZYOzjZDFvu63_yzlBx6KLoOf8sVFCMPXjP8GZ7F6IR_ai.BQxz0Jn2v69UNYrO6dIJ8s5oWCLUTM7bxe.vrWxBNcpSrqHVjpzQinl68Qwtz2WufyCGzfnPGGnH7bruLhQdPSmq9XSEbiae5oJ41OUhoGGN3Pzs3hacNOCUJmBdOMuedPbYop4.lSJKlL1QoEe5z_EA8fnewGSanPQEuhWNDHKVtPzhLZe3K",mdrd: "w6GM73Z2oa.kxBmnrMvZtoNS7byKtAgma5E7.rLFEDA-1739792831-1.2.1.1-Cdxs..N0uZbpk1.2tYLkh8u5zKIGimxpDVrfOnfl4XefHIcoq4FYkfbKpboxBsZroYCeduiNgHW1_0qWJyQUiqj0sB1vm3vDrOshAs8Vhk.cpXU1dski30F.ILDeucv.OTF_LzCYLfOa2UrL4u87GKnt0BMXyM1sPEwH52Z1TYIaW4gkDW3J1e6bIrF_IFFHNZHH5xH6BMAhI7gwQJ6s3xE9185RQ6.Dsrn105U7HzcV8SKLtKtpruJAXaXz_lBh4hzuu6bvclla6A7Iq2q.H7Y.nYxknvsmqfez2NNVnRxG_thvBuUdQ9uAEsbj7UCgA.T5gbQ806jwq2.NkbxGi.LQ9OzUJ5eIHBaOZRqHKQ7tfvXaKJZLCuA5IS1AU1Q7ofmUIUtvIF7yJCr3LY1LcdCeo6PdwGv11SjJHkPXUIyjQSoc1emmNQ1fURnKAMyRxhmEBDj_Ii.0HYfl0izrBctYpaSefxjhg5tedA01xoMF428Nq7ynpqp37XtP9DB88bNcVxdHxlPXxfOiA6mrNeSHonVcDUqCkRyYnkBvbFJ2kURMcORribaxXnrW5htkdKK7iHJUFYZtlT4DBVxItRIQ469NspmoI3ZDt.chRmPOkxeOowy14BTTXbwniI1yZJczoZLhP8Wzp0.94_lnKKN_.rmqRlIa1.TZWUc4fNtXEVQO6mmo1cJ9HW.PvmeuC3Kav3v_A0UpvcXZB4AzJc3xPQvvImxGazlcAOk1OLKbyBlqc3o7TdPcnpiOyjCFkJoQYry.WCeoImBpnr2mAaVRBcQhdHPG0ZCGgbJrZPoxpaiLX73e2ekmU6VIctB7n05l2ImXxIUKd_LIzAqvayjD23U_keKhXVjmEy1ZcmYvluHJTYtN47xOu.8tplYLjMwNTPxDAACoXftoDsWPfJ9xOx067TLFOT6MUXT3_XB72cHpbPdei8aFkA8AdD6Dp15qQIQyw_dDaget0bEI3qMoxQLKC9XrbkOCuOoyztfHVsDtUJVUOm_XNrAyjbBhOtyF2GX8B84XfVI.V22UzN_FSsS34Za5J9uDuvAZfdst8PwbwYt1RYI6ZEnt9vfC365nGHv8Fqx_1jMNhXhbrQ8vyYcOD8sreHfiq2.d.g1s4HDU3j9yG2zkhSgQgHPZ__k4eXrvIDml8rB0mXUwgZxZhADqQFrJ9ZifkWxNDiFFn0QovNGtg.uXkbePiJRDsMMxvcGz7MGS7DB8pEQ0_7T6WoSZk0Lf_kytpEdENrkgTczkwi0xWQpWEdY_1tzsmyUOCDCkPxMdnKjlYpuwWGe7pPMdeM4.mWNY22Z4eOt.bYYNVol.84IXyPSlBR5QcE.Xx5nqAEF6iZzgtbKQfHkeEXr492j2ey7WaeKOCjnTUzAAkjY45_qKzK63IRn_I66uCmycCEmBrHui7JKfsNDa5Zq_RcNn1vkJJ3K8a5sgWuKH3A7r2ds9YgTyw.pXFyuLVdDy8KwL5dPi20bvogpHr0363cReyiN5D1F0833OYV0_rKjDBixSP4p0fSxI7uBapQqXputXG6HDoLaGyk6OxlYxsNcq.Q54tOf1.0Z12YUREt90zjjfz8S1xhOB21RRq2plTnj.Gxx0SxayMlf3IeCpBt45bVThZM3P.6RqEqclBZj41hd5gZxVzWqIRafBfiVQ1LB27hgTsDg3RPaKDRrbk.YXWEUt91jh0TCdmMK.Qo2zM38pBmS8hsedFpmUmT_z5D3B1ikXNZpzoVosXITQLd9PGx7xE_iB8AEFf5k1v4xwhA7m.8e7Y27YAz2WJsaqdFnUTAzW18qwPyEXeB5t_HwM2cMi10gLjaBgLawpU2lVM4..AAQToYzrk5fBJULsAiqd8PAHFUNaE6LJ564An7UWNcvtl9Z2Dfk2vwoZWMDcXDQcZb7i6QBKualuxfxJpqE6rFNq5PjAzi3_t8GwgI0TUNcBw1EwSA.mm0bxXuT.9MHlu9PD4Tf0YrIbN0Nfloz4KcjZb4JT0w"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=91358a8eba1f3f4b';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/search?q=controls&__cf_chl_rt_tk=Tiia5XKbb.bDn.JlwD_YnHCDwkhhe.iTLU86ZvKWxwM-1739792831-1.0.1.1-esTwjINnq7gdveyuJ_TMq5y601ZhxyV0uj5Fz1WAmEs" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>