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="390"></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: "scholars.cityu.edu.hk",cType: 'managed',cRay: '8eabac692b833fb3',cH: 'sbt6EWWJgYmkts42wMk3EmStuDVtDBYOphCJwR7mUyE-1732978474-1.2.1.1-MTzTBKCNoh2lNCc2YhIiHyEq5cbNpfFz4f2.TlM2vWCwe.WKBv_veJrhUdpQBOdE',cUPMDTk: "\/en\/concepts\/refinement.html?conceptIds=196540103&__cf_chl_tk=U4kiyzaMFNAA6dCz21n4PF0_dkK4jCPPvCS8d6C2n2I-1732978474-1.0.1.1-NJwaZOlUgXvEL7cYjvC7WeqM0GjyAKMHjRc3YNTW4WI",cFPWv: 'b',cITimeS: '1732978474',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/en\/concepts\/refinement.html?conceptIds=196540103&__cf_chl_f_tk=U4kiyzaMFNAA6dCz21n4PF0_dkK4jCPPvCS8d6C2n2I-1732978474-1.0.1.1-NJwaZOlUgXvEL7cYjvC7WeqM0GjyAKMHjRc3YNTW4WI",md: "W._XXaDIwKOsg8Ds54zvEs6u_E_gk9l_eY_gsEHQr.o-1732978474-1.2.1.1-icmxWA_e_NdrvfdrWZLzIB7DIRNcy80_6UPZrwz_7UFyvdSGisv6F1ZfV6NLIWU74jpdl673.6.bfM.YvwbilDclfe999Z_Kx1UC8IFZDCuUKESFMgYJ5pMd5nCJNX4g6AG4jpGVBMW2KvH_xUi60HM7qJXObdq4z.DT2K4yPdE.iRwpMHUK3WsKkFmJcEAuJrU47iz3js_GsXW_Xeg1q283wW01UojM8mHq6ShqZwXhyykHgCS3VEzIAT4Qd7gGvGksinkWkp5vgHliQNHq8uv_NM7yW2PbjOkSI0y3Lho9NpvF8b9J2s21W1_sM3YP96G0LnCBh7CTD3MQR5pyUwrfickfG5z81bvUfcojneuHy0X2Molma_6MZbnRWlgyO6RAVJpCokwc8cScccDlaUNUx7874m4hJmSe0ej79Xp5Y8N_.BOeBiTELnecU7_CxhZoZTCOMA3Qd1vNLuwgLUdHGZq5vpmQOUxH0OUzmTvPmoowGNaOMOx3ruCnWmcLqkfbGmxQJ_tvqE_wMHMC4kkv.3WUNYW79qG1JL.xstqGJ4ylygBPPH.KKH4EWS63fqUguI82hEPigQNZGfwjufnL3jmS5ldw0Bj2_vP.ofb1nO21d10Mn28M_EpTMoL758TJdaEqvIMWPAIfOCGBk93ul0U9tNL39Ylgl1BtgiycAr9SyjfEGEAQ5kMgVbeHF3Hagn_sg7rA77EVITfZdBnwE2k6wHFTea7pChs0IbjpOKOCrSh_a_09SS3QDrOM4wbXDoV3dkGoQfEPSQP9c.RiVrnxUiCJcsTr1nyz6VYScXoXXFiifsciydTV72uCFQ9d_eTScE5jFFk3vURBUWICJhierSpAYu9S5PC9FoUQqpSj9rcyIji6TOHhNUZL1h1bPeEu80jxuxapC7qGYvIrUxRvlD2tNt8mbYgxZCYbg19oYzzjRksyW4Qdrc2AKmoZtaQiMNUWQ767NjTmtzTo88xYXb5Myf4yL7IILpwJ0OJe6mGV684E6shCQhtqdkbgoVWQLRAVhMibkrwvhvCI03er.UWjARMFvVcivVGJuGNR9vf.0CEfym_x_d3swWW9GriQC2i3cQKKclW75R_hRIKOVFX4vpSYEnxkAfpPVWU8Ys51iGhfyK_J.rI0mP.fZegcRO0YhzRpmUW88kHVKokT2YUiM_8IhpAoF28eKQ8hlQ1x9C91.kUGxbHiEMPFF1oPOsVIWL3tniLJEIOP0JF07rdsxViH_rRZXUW.dtx90febSoV_3elyulSvJNh.7RcQcskdejO1lk2CiSDliWA6leMQQvHcLHG_3jUJ0BDAjnIn8_jIS3.cdXvk7.5ijDNUrK7a8lqDE.7a89vmt.XD.Dkru6Vau2Gd440EZdIHvKe.YbseWdVAJxq_tVgSvfCSENhV8RpkyG3AZu15d_5Mem_3Bzxi2wwaEICE_ikrC2vk_SOwsITTYvLujh9wVeO0g_uRfzJknRLqSFZnoYYEp6iMddxbsAvR4vfBNHX898681JA.Zpm_4Or0_1aosyT3_2XuoebgSrO27ml03CCEwtkt6puMHLn471hXD2uHFakhbd5gYyK_sMhpskajkFYMx4Cp1DV7Sg.au7yvu7WWUNDyBA55y3b3_YTPRv_T7aW7GpoDOw45PCA_48is7WbcMuaBKsf0GsT.MGhaD45OFppsTVgX_LtHktKZ_G2IYMuC5Z_KSnZBi99be80ZzVVA8cGBylWQigZJNL5L4RIG987cmF2hNvJ8LPf7bn.30ahQpA2RdQne_X6aWrJKwLkMNDbNTdJ6i9z842JyyJg3LeEigym.R8yJxq1dMs2qr4iSNjYH.jiah7YgJxEVpkAbWN93IXb65NLZ4S9P5ckQzNsev4Qghcw1PJEKeYQQsvaqGJREUxENY3lREF4ErmTpW5hSbnQU3QaO5POMepijkiW1VQQUVqNucllFU9cpBHqKEpTp27y8BZ_OC86Tt_8ufbOL3ELMC0OSn4LD0xhfMXhlSKPor_Moy6v9Miw.hdV9zEKPZAfbTEuhadbWnY0hm72HI_GkQTlN1CrQzGApKJ9HRKe_.LH6KqSUvjUZ.uGv8nezP3lcqcBEEhIko.uL6p06MIsKa1C6VDMC9l8JeNNyggCEsPruzfgBTBPzjc7F3yu54TifO7XTwNwI1HZMsoYXgdQhbjyz.uN6wphWXsv2CUY8U9nQpNfOp5dU4OkfrrcMF5.KdicsKl0FglnC.j1yZ0QDmQE1ZNTcaF7W0aNXKFeVBuT8Tduim_UiOHFVvfEc4Wn58Z2Jfqgxeojhfz9ApOFDQHhpjKQ19oZHBbXuwxkga68xwegF6DsVgyxKT.roSsIq6EvtM4j8T5xjNSF5F3geM_MdXyej7op4CdxxxUh6Qn62hblriyLRW1XqVL3qxZChEzjB5IqpU5M849jF7si0nXahE4eifGdlmiC5bKc3kapLOTA1KumJ8N1Sa5MhRkFiD3BrRcDLrVpsP5N7ICQR07WT.MrtyhIrJVDPTyFClSEod_.V9XuGKW67tWid0I1yqQ0xU6EwJUGMpGQCeJF4tsXpuqxa5jxljPdzY5VWHegXuwtuH2E_jfKV.uLrw9NdcOetQwT0SrK5HpZa.fTbWUDoLhrIRXk7CSnKCGBWSXYx4d3po3wfADFtfiq08qlc4YcXrFEbMf0peWeJETEeFdLofj8ZSgOov5R3txVbrOqQqv5nVx56qo9FrQ.Thqa41lcJktDYhMOHBIW5xuqZFgBn72K2coKNOU8rzzVGIOrY9REmNY0TWEEt4AWk7LCWpUawpsISF0vZI0uO_BjihQ0XFnGwDLIAjI1s7icZULYCveXNbXMPvk_9dIfL.N2BbQS2cAAN5mr2xPTgUjSHOTubKUBncDC88uW2HrGFQ00u4f8h5YCtACFvQOoNsaEv9yAJahiyF.82yQPekNuaDrVvf8OiH_D3Fk9ZtAkLTZyg_uS3gABC0Zvjdk2oirwbRKWXyNlItUk379dLLUZeBMzx5Ljh5tz37k3tPQb.Eziy5tK4cZ4Xi3kLqd.hYZyBhott",mdrd: "jMEn_fq1edkqF_SuXmqqXGY1CPZ2dRYc4lVHfRrHJmI-1732978474-1.2.1.1-_JdA4IAY3Kn9y0gg8uWIDszn9NpAaKZpFXYZC04jSpVhMI924Bjbswbp7vPJkZVF.agz11J7EeUz.WnsNvWl6TbuarXQdWsA8knzbRYNLUcJj5MbvxxEfCj8LJFfG__jQkD3zuFdqECqhqb8znvwOlVzm9EOmzZGljYxs0LFo20HxkZqz1Nm2fLIrXh2OW1N8CIjB.xdozWviol2Ex.PZglRf33NcC3VyC8eA9Ufgz3Ovpu3VFEgkKPS_sAqoQ_nE30Hdi4YYQT9IpeQ7WAdYMqxG1OPpXNVlPXa34qANG5RIRXIFc4V9NsjrXm59SybNaE8G4smLPm9dx_M4gsOlLg34WgNddyaUSOb66.DmicatQ6xusxqqwkxZ3yr7JFIkFrusJ8nk6ib0arqj1oU6Rqiw1ijx1BzaUsD2WcCxtrejL8sdTjvDqJXGa.v2jvhotXoRQjyq.XVCl1xMwCmAJzk78SAyuJR6BjcCCjBWOKo5Gq1C3LkNkPItxAFCCYx4AHsHtdkimgpZZ_Nau4s7ewGYutBR_M8d9TjqnLN2V50grArNrEYQIuCyl7vV9CSpIdzDRFVaWFSqtZYtXALaR8VQmuQAl5RxTutqNyFitCNS_UrbA1IXRR6_0yIhSRynrCmZaYEBlKJD77ouS35xLmAcZbRwBGpBAGJ2wnzmCNrHGXF3LLfYCUnqXaEOh.e4wh49TsIKA.6DX7OPio2FleZtHYYcA.t51KJRu59Zzr1zsvVgmGVRYraLckkxBS98X.QOCPiNzUiWIEl.K63l1Kipgzl4zOYMYMLgF1bNmYVqiZOMrH4UClEahq14AEpfs4Z3_qkA0uHD.gsgyZCNkA6HWiO.0MB69.Z.toZv0UFFW3TF507dJUuZSzqSJoQXW_6FZPoiCwHKhxWVTwZbIRf7FJU8lwQjaVp9WMv8er05W6SF7jVKL2Qi7BptNPJMBmoFePXNRzBQW6PXvb2leipAdI.7MnKMF3Ua.ZgLKJj44_wYMNilNtSEsUSuUNKXkYk0fcSeukWFJBgkPfTazcprXCVwI0JvWDId0A66BQUHof6CeulyrK9xsjfS61k_gh4Smx0.lLBO1hr7E33znmj_pzdljlKruTGcWcVTB0mZhKD9ezGt2PEMlDOK5gVhDqLxyEMzytAHjsNviyAzCcWHJZr1W6txfiDgoyNQt5nPgE4llp2y2uzHPmi_jOGVALloOcyfP.1vFf2dSXs_Wq7.yzpwI7u5KJxn.HPtYr0GDpJq5LcVON3mKgEb8wgMZkksBJZqHq_H0F_Lm_rwKHiDSP2H6ZoCu4XvRHeuJ7Iz5TneQZumRk4lh6Wf5kVQwpzFxuz0rHeXgF_k.sfv_UHg_NLjzqmUc41hp37VCtN4fyplqHlCXPqQYpaQCIvCCxFD9C.M4IDdcrfnkPlyL51qfrckKT50RKJz.1V5F1u9K1m8v2ekmMb1VLWniRz43bAoKQ4P7rL1Y2NJn8yGQADrYrJXPDGS5LlwScixzux6lFsn4EWZ7v7NubRlBz5jWT4K6fXHj8jh7ivoPu_lEM4IjY0QXuyr5QxqWLeNKn9todEmxlbII6S6LDIQ9PzDtTC1os_rL02XeVCO2RExq7NTGp6dn_SGsFn5ybAbCinWTxHCACgsDibdHtu2xeVlDDJ6dPWg6GQEZlz5rx9Y4aMUuJPFn1jTPjDzcZNwpzj3DcWWj8wsb3qM.diD42rW7BDlZaEBgGcHYY0fF.de2m90x1gZVypmVv4vI6jATS1P.xnMdL7rKSgxpL02gvKcTrXd3tAIzXnR601LbHzOl55cDyqGv.KrwIm3bujGu.6T9m78_5K6kWUbpPGHQvzJ_mqdFC7V8U8biLPot15CZO24ffe3SJXQv55PAWrapuf0hnURbWQ_phiGbqu_V85EDk35vCJpCH_8ct22d4KLjdI3PDWX_PpU_Kn2Q7OyiM"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=8eabac692b833fb3';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, "\/en\/concepts\/refinement.html?conceptIds=196540103&__cf_chl_rt_tk=U4kiyzaMFNAA6dCz21n4PF0_dkK4jCPPvCS8d6C2n2I-1732978474-1.0.1.1-NJwaZOlUgXvEL7cYjvC7WeqM0GjyAKMHjRc3YNTW4WI" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>