This paper proposed a watermarking algorithm for tamper-proof of web pages. For a web page, it generates a watermark consisting of a sequence of Space and Tab. The wa termark is then embedded into the web page after e...This paper proposed a watermarking algorithm for tamper-proof of web pages. For a web page, it generates a watermark consisting of a sequence of Space and Tab. The wa termark is then embedded into the web page after each word and each line. When a watermarked web page is tampered, the extracted watermark can detect and locate the modifications to the web page. Besides, the framework of watermarked Web Server system was given. Compared with traditional digital signature methods, this watermarking method is more transparent in that there is no necessary to detach the watermark before displaying web pages. The e xperimental results show that the proposed scheme is an effective tool for tamper-proof of web pages.展开更多
The Southern Annular Mode(SAM)is the leading mode of atmospheric variability in the mid–high latitudes of the Southern Hemisphere,representing large-scale variations in pressure and the polar front jet(PFJ).In SAM ev...The Southern Annular Mode(SAM)is the leading mode of atmospheric variability in the mid–high latitudes of the Southern Hemisphere,representing large-scale variations in pressure and the polar front jet(PFJ).In SAM events,the combination of the SAM and other modes may result in different atmospheric patterns.In this study,a neural-network-based cluster technique,the self-organizing map,was applied to extract the distinct patterns of SAM events on the monthly time scale based on geopotential height anomalies at 500 hPa.Four pairs of distinguishable patterns of positive and negative SAM events were identified,representing the diversity in spatial distribution,especially the zonal symmetry of the center of action at high latitudes—that is,symmetric patterns,split-center patterns,West Antarctica patterns,and a tripole pattern.Although the SAM is well known to be beltshaped,within the selected SAM events,the occurrence frequency of symmetric patterns is only 23.8%—less than that of West Antarctica patterns.Diverse PFJ variations were found in the symmetric and asymmetric patterns of SAM events.The more asymmetric the spatial distribution of the pressure anomaly,the more localized the adjusted zonal wind anomaly.The adjusted PFJ varied in meridional displacement and strength in different patterns of SAM events.In addition,the entrance and exit of the jet changed in most of the patterns,especially in the asymmetric patterns,which might result in different climate impacts of the SAM.展开更多
邦瀚斯继续扩大欧洲阵地今年以来不断扩大世界业务版图的国际拍卖行邦瀚斯又出手了——日前,其宣布成功收购巴黎Cornette de Saint Cyr拍卖行,同时将Cornette de Saint Cyr更名为Bonhams Cornette de Saint Cyr。邦瀚斯于2021年进驻法...邦瀚斯继续扩大欧洲阵地今年以来不断扩大世界业务版图的国际拍卖行邦瀚斯又出手了——日前,其宣布成功收购巴黎Cornette de Saint Cyr拍卖行,同时将Cornette de Saint Cyr更名为Bonhams Cornette de Saint Cyr。邦瀚斯于2021年进驻法国巴黎,此次收购目标为进一步扩大其法国版图,壮大其欧洲业务规模,并有效发展其欧洲以至环球网络。展开更多
文摘This paper proposed a watermarking algorithm for tamper-proof of web pages. For a web page, it generates a watermark consisting of a sequence of Space and Tab. The wa termark is then embedded into the web page after each word and each line. When a watermarked web page is tampered, the extracted watermark can detect and locate the modifications to the web page. Besides, the framework of watermarked Web Server system was given. Compared with traditional digital signature methods, this watermarking method is more transparent in that there is no necessary to detach the watermark before displaying web pages. The e xperimental results show that the proposed scheme is an effective tool for tamper-proof of web pages.
基金This work was jointly supported by the National Natural Science Foundation of China[grant numbers 42088101 and 42175019]Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies[grant number 2020B1212060025].
文摘The Southern Annular Mode(SAM)is the leading mode of atmospheric variability in the mid–high latitudes of the Southern Hemisphere,representing large-scale variations in pressure and the polar front jet(PFJ).In SAM events,the combination of the SAM and other modes may result in different atmospheric patterns.In this study,a neural-network-based cluster technique,the self-organizing map,was applied to extract the distinct patterns of SAM events on the monthly time scale based on geopotential height anomalies at 500 hPa.Four pairs of distinguishable patterns of positive and negative SAM events were identified,representing the diversity in spatial distribution,especially the zonal symmetry of the center of action at high latitudes—that is,symmetric patterns,split-center patterns,West Antarctica patterns,and a tripole pattern.Although the SAM is well known to be beltshaped,within the selected SAM events,the occurrence frequency of symmetric patterns is only 23.8%—less than that of West Antarctica patterns.Diverse PFJ variations were found in the symmetric and asymmetric patterns of SAM events.The more asymmetric the spatial distribution of the pressure anomaly,the more localized the adjusted zonal wind anomaly.The adjusted PFJ varied in meridional displacement and strength in different patterns of SAM events.In addition,the entrance and exit of the jet changed in most of the patterns,especially in the asymmetric patterns,which might result in different climate impacts of the SAM.
文摘邦瀚斯继续扩大欧洲阵地今年以来不断扩大世界业务版图的国际拍卖行邦瀚斯又出手了——日前,其宣布成功收购巴黎Cornette de Saint Cyr拍卖行,同时将Cornette de Saint Cyr更名为Bonhams Cornette de Saint Cyr。邦瀚斯于2021年进驻法国巴黎,此次收购目标为进一步扩大其法国版图,壮大其欧洲业务规模,并有效发展其欧洲以至环球网络。
