CINXE.COM

Just a moment...

<!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: '9134acbe2c748986',cH: '3vIzRwMEmWtHR7vc5rq66sQeKbrxoQJPAjN9CcRyM7I-1739783746-1.2.1.1-apth02RCR3tCkaNSjxGCH62KCcb49I.DZf5_QB3Mw5VLv50Eo.PxWxaGttPVpsu4',cUPMDTk: "\/search?q=Y.%20S.%20Oh&__cf_chl_tk=sMMKyO7WU8kBD2H6qJt3uuoORw.i4zDn3GwMz1CS7YU-1739783746-1.0.1.1-.amIp3wKsau19f5uca9BLGlEyOIbX0QOUhHDy_EW5vM",cFPWv: 'b',cITimeS: '1739783746',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/search?q=Y.%20S.%20Oh&__cf_chl_f_tk=sMMKyO7WU8kBD2H6qJt3uuoORw.i4zDn3GwMz1CS7YU-1739783746-1.0.1.1-.amIp3wKsau19f5uca9BLGlEyOIbX0QOUhHDy_EW5vM",md: "ohQzOCGGMlEkY3kTLb9I9lX7rxYLxqGaQfSd1cHuiKQ-1739783746-1.2.1.1-VPBBNJd6ktnPiWKDghKaVNblOv4PROGKOGX.enYgovKGwENZzj7S.rRqZ3RqYmgs1.bBD3lixo2JtqAN74TL7vr2JBkb9TUCMPrIit6OWh9b5YV1wnAtVQsiruzAHQJpGAKAq7bpcfilcRdwqbVGf0gUu0g..nV11XfCaM6CGHD.CfBAHGHt0u0ZZdAjNysdJc3UzTbuPNqD51IrqUXUYwn17YO57rcROWn6uJ8.U1gS.QUH8vZBJz6yNVpzC_OXqMA2RUsKD5_6Hx1Vf_AiPkNLqfhPm7ylE.QqTiqpzJIM9CbtseO_GB1NzBoVdNNDXJj.SLgFpcX._FLrRdeYRP3mLY3xmZ8cqrGCiU1M2G4a5IxD8RhAFbRwYjkdcxD0Q7JkrqVF2aHYcswLkbzGkBCBH6rXjWNs1SitRMujjpgxKE1kZgTKp5bpMPyhJxcWFHPFMiDWVZ9tUrW36GtR_TiZfjJU3cZAo46OBsW4Xc0u.nE3FaRZrHK3ElLMW1eixrZZetApNmO5I3iI6ph3vhNYqf2Qr8eZ43OQIhnJlKKeTO8.UOaKexMdKbpZocJ9NC3nSyvkb94xDbVz_3uSeTZuVwLd_rmYXbwuBuS0HaP.AuKAuuhFIY8CVmx.4V_gWBbuWE7HV6unZdZpzRadrs2wpMX6ROqHw6dDHnyEM7wufHhEVK_ZcS6rQ_EZ_vsPWlcATLGI8Gs3FVa23ZfFmQ2scmHU5hCtFthCrMNDUc81jnvRPTc8WTjOo8nC6A.mHtxOnSLmk0eUT9FIP1iuy7Z4WgvuJaN3kvUgTnxdzCxRzmB5Dtz8YJUrHQeVr6c.k0lU9z9wX4nJF5IzlkmEC4qwmGReOuc.mAV.L4TNfJnABQIF69bL7bGBU74AaBRqUyd5JaTFyLoUWcMN68UUM0k5bmXlgHnbKb2WqIKrlwblDZAC2u5uGuPG9gj2puWhVKaMLxArf5qag7SLwrRVmOh.AxxsH_DsJyN6z83Q70tmo4rKOl60gE9S.NwFDScQP81WNnzPcJrR7RdJEQ5OTycecThpkZ_AXi_TrhDI2Vt_GDuyfUgnSS3slV9J38DRlB53wZXSILUqv9iY70qCaol9a.5DlBcPSldY46VUKyX5Uc3GMbI3umwuUnkU0ukkprHUv5N9uE__bnr0v5itoPk2V6O6umr1NfuzpDACVgKlsF6f.TZVwFq1dEV_VNqqH2haQKLM_YatFbjgLpKM82rsIoDrDPlCVDth.3GajeG3_baUMiSW1jp9SPmd3l4hw3Og.ktn_KIshkPncIpKOxZwy_G48frle0PoKBHgGWgB.W3UHL9iIRqCuSucpssyudvqvlYgPcAxKIEHfiTr_APN_VyvWLt9X4z.MsujpzemV4Hgqcs96XWAjDsnHcKrktfKR0Oaphd7XSI9C8yBw57eyYp3lQsboYvu_Sgtlx9LqOl.BO_D5OGvA_3Krp5tdkMlb28ILZuqQhaEB28dAovAc9cToG7kjwodiHHCQz9eQoGvta9JCIEPWKWdEpQU6xJctJQmJPecIPn4Zo.A1hVCit44NZdVQtTDa9j7duTU3NpugvaBJ39tdkkIi9_.j7toCoh4pWbivufmVKg4aKh7QvmXoz1CqW.IBsmVjwvdY9vqdoKS3T_9H7AIt3nGmdongBXdZNT0Pi7bDfmkyzycP_TfU4ef70HMA4l1x2RTIhrbZkD2klCAplhO6HFWdnppfX6yqdpSVuxq7Ney2hnzwvmeUrrTbV3ylPDaESb6EFNJQ0oXWq0Gs8PQxDxi8F4vhj2oisZNNW8.Oe8qdf_9XF82uziyZBU1qmOIgIe1ThZ5LzKowT4h1lwuH9TyyBWZnFOLf6l61UONb6K4iCtlc9hT46GeLOyf3KTp_WzFUyaT7EizCnPzYYskdjj4",mdrd: "tN2NLFIY5RWmlc6z6kalTMcTLGrtLiXQH5MkbQHOsGg-1739783746-1.2.1.1-Ck8c5BMVKYVKBddEiJAlMX2dbCLGJUQf0x4k35UIUStbA5p6UsHh.7Iu9Qp5IZy0lbHQmu5rO_jvEkW0aCIr4z2xAyPnsLiUowsRVB3Yl5PDJC0USHpGwJQlvvUvm0A4IoFjpeIARCQW.J7BQyoz3h3R16w2bQESXN28fijlKgUvk5G46o8LjJAbtbDDniH8vgr6yiC2elHF8A5.Z0KH7T5QgZkVCNp1mBxnk3rR04x.9BV_LgHHy7A.cqh2z9r_BMf6AIgjzJm5KSuUX7VFJ0SCONy0FQrp1ySq_FNXE6_sTyIG1UTy6vXOOW_nniBLWTOhJpF7YVjrof1QApZ6tFAikTpys8q5QCne16OvG4PMOamoWrzXNpZrHOFzSwL5hn3AqNdJmm.O86AYzTVC5b2RD1qnHH9j2bat0DFoJBYryvJ0BtnEtBk95XeKSyfutZeclw0.m3VTLdKtWKSWhR39qn0NamO0.DLWaAAKdF_6.SqwesDaGN1zEzpKHyLw8ljkBNRjeYRYevdekKy0y9fDa2u5Y7fTW_lQYCNCCYUFBoXWe888GyxnVjeEQZH4_.IMG8XRcjtMHVlK94Ay559qb5997MDVHGHgOdytB.COkvitW0TZyo4oH63OVkhM7hv_KBLcqNdH6jVl3Joqyrym490i3L0bZusB1diwio2Wq.Pgn9yoMnh4FMyTmge22inG70WXXgG2uHDDUk_gCYI7nFNXlhyQR7Vr6PdH.ku4fhy_fuNluXPkkmboEAMkXNnm_ZPbPk5epW1GQnXIwDRFKpQs80nu3WdmYri9h_T2nIGl4SbQgagMii3dUHxryD_FvRWvlPUGU_K2xifnIq25U4taaGGaf._zFc2vE53q4BxqRgU0koyJq0nrvvfKHtlR8xDeBiOOFwumdg9USevAQDHuwHCyW75BDbqGI4nW_Hk9wMR18CY3WSOPtRGOP6nxJuCpD3mvEfaN7cLzNWqecxoAr.h7Zb.K4oYhhn4PwdwuJ.L4X17L5upFEXwceUdKgpVpheK4lAXMOSvFhreE4v8tzveUptyvML.qzhoGcw6i187rCvmDF0nAsawC9fOKEY3NMIxUAohOup4Gy4l8W3JLzCWo0yS70HQwZPvGX59PpGNoFXVgd7.AqeCEbL7csJIVH19tgIXOZZduomr_pY1j7zM8oj8aCkkPuPLQ7wgOHszq9yOsIjepmDFjZh.AzJOlE3cOX9xNW7cFyw9iTXxpY39RvGP6AVrNWXBNsO4V6WgIJEAeWkTTwHoZSSdSZwkkxOLN2YOiXMeZ0EUt4dqmzdWuQ5RpsKzJb_5d4z7WAcFGSaw7ng1pLCanSlHiieu0czdZ2EbGV2Jm3HgdCFOB4pAtRmawn70SDUtYEWYaQV2LBI4In.6LrRl.YTq8.5mPLCiKGpqilpgkkafPsODJRWf3tuYsj5jWUh3eOU53yjQET_ggvwaQmOk8eTUi1lcAcvNzERpooAzKihih78g3HOh8CNyPz6rlfMgaMnH5j3ntAkmuHBL5tPlU89XKCS_c4UjGC4JtDt1mVgUOqDmWxyrdq8IU24zTX992ruWeCbvWN7_tpFBKsmUKCgHXPCnkhuVLHpMLh.IFxmWVUdR48Rwb5Glyt8V7PSJjqmfsT5HI2Yd94uxMDrqxS40vYj3Wop4I4c52_KwslgWxMCIAYyyGCWL8PidWV9j6LouGkR5fqnRH0T8y7CUoWvt5FxnN2YIJ0kuztIrnk1UvxXlY92oi02dXJkAzHB6MrsCrbcnsvY2Kotleo3VGKW7Am4t_ah_nP6p.OGBG4Dw6YyI3yNI9xCzKap8G4LUem_BbNmKsOcKmoBl4MQp1FUxdMfMXJu.xIdwINlmEUiiNpcY78cQ5zuwdeKjJZ4g_ZlK8JDCF2eVzeFB4Etlo6wjaubuV4sC1JBEh_80uM4ssWVmh6atge5Zj9JGgG7lGv4ntgtv90S4UlJI1gJok"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9134acbe2c748986';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=Y.%20S.%20Oh&__cf_chl_rt_tk=sMMKyO7WU8kBD2H6qJt3uuoORw.i4zDn3GwMz1CS7YU-1739783746-1.0.1.1-.amIp3wKsau19f5uca9BLGlEyOIbX0QOUhHDy_EW5vM" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>