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,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIzMiIgaGVpZ2h0PSIzMiIgZmlsbD0ibm9uZSI+PHBhdGggZmlsbD0iI0IyMEYwMyIgZD0iTTE2IDNhMTMgMTMgMCAxIDAgMTMgMTNBMTMuMDE1IDEzLjAxNSAwIDAgMCAxNiAzbTAgMjRhMTEgMTEgMCAxIDEgMTEtMTEgMTEuMDEgMTEuMDEgMCAwIDEtMTEgMTEiLz48cGF0aCBmaWxsPSIjQjIwRjAzIiBkPSJNMTcuMDM4IDE4LjYxNUgxNC44N0wxNC41NjMgOS41aDIuNzgzem0tMS4wODQgMS40MjdxLjY2IDAgMS4wNTcuMzg4LjQwNy4zODkuNDA3Ljk5NCAwIC41OTYtLjQwNy45ODQtLjM5Ny4zOS0xLjA1Ny4zODktLjY1IDAtMS4wNTYtLjM4OS0uMzk4LS4zODktLjM5OC0uOTg0IDAtLjU5Ny4zOTgtLjk4NS40MDYtLjM5NyAxLjA1Ni0uMzk3Ii8+PC9zdmc+);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: '9135995a38f540c1',cH: '9A2ICj8XLCq4ojYlh4qS_tYOrjZcU3GiG3ERYXCQzVU-1739793437-1.2.1.1-gAThfHEKDvZmIT64W7vWuSOpy5NIOnzKbTBo3G0LR3tNHqOjSmzBC.NbR5fZvsl6',cUPMDTk: "\/search?q=Zhihan%20Yang&__cf_chl_tk=ftt4fQD3uJMu3WF6PvTq03ORveEXdOZ7nlFC1Ru3bYc-1739793437-1.0.1.1-s5FuvS.N3caJ_eMoWfGLZrYITbcjdMUjsyGFSUcCpl8",cFPWv: 'b',cITimeS: '1739793437',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/search?q=Zhihan%20Yang&__cf_chl_f_tk=ftt4fQD3uJMu3WF6PvTq03ORveEXdOZ7nlFC1Ru3bYc-1739793437-1.0.1.1-s5FuvS.N3caJ_eMoWfGLZrYITbcjdMUjsyGFSUcCpl8",md: "gclBhjo51Uo6W5FPuK8NhAtiXCiuXeZPplxxl8QebAw-1739793437-1.2.1.1-c2bNbTR14QUeiY5EAN79sCKwFOPV5wTw0bHK7tRAGxFwdRUHto.9TiBwvgJQujv7VKKWYQM8_syeEsQ_vIb1eK2BjL8qsJLl_hGiJRjb3_gcJq3DwFFXtQ2GC_Tmw5tc2n5vHoSbsVX8ynkyV5Vqr_YM_NeJwDiOD0z8.A2zsniYRv56I5MeEDPyBfo2xGc4V4dbGSy554aH3HKhcEtvBAzgqkNhiTstBcsmfrlKELpTk5PppYLRgv9Cz6x6mIjjPDeNJkOkW4RREM9IrJ7NSJ4KaEaIl9ETrzojsGPEkYtXu.f8u8nAqGMsOlZYWGMZj06NhcqDR8h2ha567ix1QEEQPxEVoiQogE6CD6JhhuPmIf79jmrNVBbyyjL6iLj3_.FlSHBumNtMjYtP4IUANF5JArIQZOj9K81S0RQhMfpIHxJ5GgU9jhKuqWOh5R2gJC6OfEMlOzI.dI.1c5_Znb9GcuZG77OPTNLBp8vgBHZ4XeOQ9QjclTY1kq_DOdyS6hDPJQJEQZq2BhO05v8tXUCtte7dnixKNe060Lx2kiyP2mSccsEXtdepI5sTJJMy9LauiHrIfYPq_AFK0tuM5fVKnZswmCCOhb1b7pASTPuioMxKC9G0rvG5VIR11rjKrIa3D8Rvg9h83CfunJ.5fGNAjsg8SN2OVx7W59BT3OXFXkawlZ8suUhuhR3mQRWAWg8NBtNjJDpzmIuEvrpP8lRQtAeEbKm.LjadeZopRkBXePXfYfesp6ycubnUcOEs9.3M.1p9_NxmwOZky8aCQdL4aWudSPA_PDVsY5Key0yWqCw7KFp29NKH3MCM4wDuMN_5nLCRULgZgmb23ggHbBDISCDN5tkl.S7CLr3uRUl47P66K0sppZM7gJAD269kVJAw21A4MdJE0wl1IB14RzhxXeZq2SFbdhMY8YL6I5L.CEOASl_7i.zFjpjAM6JnQnMfmGW5W2VNvYMRtsqfSn15e8mA7UbkZ0GqJTI564InI6zvSfx5hWEOEtwFUCbX1mfvpPlNF5236VLJJfJ2Lm0bcMAxPzNg8PzDLWbjVpHehe7BmiSoXOJZ_KNCy3h5R7CLcgZgubLIKaE8HuXL8h7k4wnN8LVvVmP2yDomGzfZkOapGEi1X.em8AZshwMSSZIqRB0e6fcu8pl7NiEBZpQ8bnCVU96JZ2T.gbi7lCAr2.AMQk4MlbBA6FRBiIoBoUjn6PXnhteBm6BGxc_Z7YV1aeI8WNY8_u2OM6T6utTNUH2IRCzGOfmO00q4zdIEa3eDkeVulHDc.7IIV80OF5BUX3pwR2TjvRGOTG.BzuJrNCE2MfwXCgXczqbKNjOfdykUhqBJ5nAJRTbiamGEAZfYMUlKKVFdF3FuvK58wdsyMKeqmQknr.X945Bb_EB.EM9liRV7zZhhI5cxHOlpJnRlUibIp8aLWldksUhodqtr4kPLKs5u1FLoWdHj5h4UamXext9R_AfecA0AgYJDelqmLf3jeoiQcfnpu1VLh05UKzjPUNXPKnoG2yzAaZo2asXUCbipq5Hs3WRuwpSYVJSfQWMw7ablBzbPC.Ira4yHhVnXDjRYcMrCOP6ElZ_4NSuByuXCdi6v1nupOxYnGFj5fVS1pQJRUYmOeIGEsjx5Yy6KxTXdijXtm6HnhNOtfwbdKOfzrjYfStouAvak7kjHP38sqwLNtAduNOSx76JILAIfnAOoDQHgSu49NtxdBGuSphACuVMsErAL1KytVx5YiWlXCmXwEHosgqJPycMjH9yfXco5EkcREqQHuc1QId.j1m1lFvJ7XHJm1ykWqb_Aufw5oVrsRsjfTJNkjXr2mPs_RMH_HnoLXRlNzLWYDzQVN9R6EVHdOhEIZYGh.mKC0MEBq3VIUP.npsGKG8b7Ijl8HYyNmzPRQGCrtY3o",mdrd: "D2PUl5woeYX5iIgxQwEwEfCVLY6gKI2D2kwsUNFXGh8-1739793437-1.2.1.1-eqgrPSjDYapcZZX7Kk9YqIipAyo6b0Vu9tzOskPacYK9V_jEEGXbdM9RRUiwaO0U5UUYgVwdberXJNAu9bkNiZlxON2D6y_6WOF0qH_xV7zI8_pMAePf4al2WGA9Dh5IcpUy4flX0WuZjebI1otVkLq5ovSKESfwUdMfb4Y7_yVKvb3ejO1rjg0O1TCEG9gelUq1BaDynurcHd.k8S4WJ5Z5geoXGzh0oRWblaL_4vq9Nr.OFJIkXFe7zRpw7.FcoTZvO405LR31ucWjtia4JqplJYsbnRoKJXsX9ZEsS_QCbOA2yuZ.DIz.W1d1BS5lJrUFSBmuj7fATI0LEdA5PrY2ZeZ.AvCiaWRpE2C5Q5QuCC4LuoiIi5w9DUBEXPg2uNK40i1NyoEd9nY6MroFvWyALIHNOrZtQxX9NDDcP0sDEPVSvSw.ysvDNRwrTsf4omGkI9otwOljtN8DHEhmTG9e8sXiU0H0iVlGZjKN66kKZ8rfZq1Kx7LDpA.P1VkGGnGrqvuX3EqZnJ1M2NyuzLzHgl_Q9M8FbdN.tA0MxoqLFfqefnC8VeB8VXEf72ItEkI3a_ej_PGh6nqea2i.cQoG56Alp2IVnnHeivTFXx3dPxHSDfhtSVvhHMQr9PoJIKqRjSBWTMKgOom6fk7OW3aypUd9YpVthZaF6B_3WQzG.ZSJUt.sdxVd2pF34SJbW6KLjPl2_Gm5Z2qJ3FK.cYBxNPdD_vtNWj9hYLJT04fO7xCwi8QK8PHdXYkTqXrqtz2_qLZ7Q0WYpdcUV2G.rpwBTx6_S4yf8jhdFEM3SHvL9Ak5Y1wmznbSz71ZEo5dsiDVT6Z1pOSDBgKjeEKNaceG1dCPht2ZmRPaFIPBOA6Oc73y9z.WRxCa2BkZWzlfXQnkvV9ib.9ReInVhH_HjQn98.AHWKZMaCT3.CUsQQf0CJOVS8HsUjlDagSnojDOsqIyiWrlgp63kkcd32FwJBsH8hukd3HX6L5fQeAIww1CfxJPctAnT7P2quZeTpe2rXlBnZFx2SDgkKZo2FnP4PNfhct8PJzQnkGw9KieOnLwoeMIcEtDIAX5JxrQa21w4yURFpGpYhxpNdGs3VmVgVNVKpVMHW1Mq7UMoEBMVl215FTR5.7f5xW50HtLI0zoS7j5HgsYa2O9u3uqsqXFj8fSlxJQQ5pZq6yN8VAcKICSd_wGoULlXghxk67uXeN6WqSHcZqRyor5mmyLOg295GMqE9eiuk.2hgok7qYb5pZ.3nWkZDYHZyKpeWvW82keTxnkzhO_5146FWbIRjFHynHYtSQVhzUV3CSs0HNFfZ5GU3IKhqZM7JB59xr0aDM.shoLxDPc75dplAS0QYrEO0.mrWUmAK2qBoiGWVs_FMLAsKtBjGzZvkoshwHJ5FtkisRqtU4uHw0OSaQvpz1J85FY4dWPmhhNLmGWlUZlcLucQRdm4sVogfYrJQ8Qxjh1TgsORce.oAbNMB1DWnaa1ek4zNoaEzmMHQQDgH4.fnKj7_G_r7G3RjmOrlLfnVJLEayxT80dyQ1RGy4T99qIkEB6qQXkySHqhkv_TY_TwY6zVw6lQfvWd_gS_Si8m4skWyprowxSGBExF8MHMyO5aZejvszXmdSt8tye3XW75J92t2AgV2882emL2gQ_P4oli_d5LId8PBChPyT_A5NRc5SsQsfwtfmkO3PmTrEaXrPG.LPuzCHqZV1K3KwUHvwzv53sqLVnZGfcVo9W.R7_Md_uP2iBjHUnnGMmCfzwAUnZvRurdMtnmedFN1Rd3b51SsfygzMrdYXd4ihOOq2GeP91Oy6MsS9PcyEem33uDgj.d_mLH5RlF6Nn_LGvILDwdaklMXCH6XqNIu6wfS1BGGfNitoKuAa7XkWIyYynpsm6fg5Mh5g8fVb1ZEEtRFzFfaI9eV91bwXlktGt3M6r1L6mZOLJc.TJDWdrb1TJm9Zc2s4LPPlso5FWR7EeAXqo"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=9135995a38f540c1';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=Zhihan%20Yang&__cf_chl_rt_tk=ftt4fQD3uJMu3WF6PvTq03ORveEXdOZ7nlFC1Ru3bYc-1739793437-1.0.1.1-s5FuvS.N3caJ_eMoWfGLZrYITbcjdMUjsyGFSUcCpl8" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>