Up to now,detailedstrategies and algorithms of automaticchange detection for road networksbased on GIS have not been discussed.This paper discusses two differentstrategies of automatic change detec-tion for images wit...Up to now,detailedstrategies and algorithms of automaticchange detection for road networksbased on GIS have not been discussed.This paper discusses two differentstrategies of automatic change detec-tion for images with low resolution andhigh resolution using old GIS data,and presents a buffer detection andtracing algorithm for detecting roadfrom low-resolution images and a newprofile tracing algorithm for detectingroad from high-resolution images.Forfeature-level change detection(FL-CD),a so-called buffer detection algo-rithm is proposed to detect changes offeatures.Some ideas and algorithms ofusing GIS prior information and somecontext information such as substructures of road in high-resolution imagesto assist road detection and extractionare described in detail.展开更多
Buffer overflow is the most dangerous attack method that can be exploited. According to the statistics of Computer Emergency Readiness Team （ CERT ）, buffer overflow accounts for 50% of the current software vulnerab...Buffer overflow is the most dangerous attack method that can be exploited. According to the statistics of Computer Emergency Readiness Team （ CERT ）, buffer overflow accounts for 50% of the current software vulnerabilities, and this ratio is going up. Considering a subset of C language, Mini C, this paper presents an abstract machine model that can realire buffer overflow detection, which is based on operation semantic. Thus the research on buffer overflow detection can be built on strict descriptions of operation semantic. Not only the correctness can be assured, but also the system can be realized and extended easily.展开更多
基金the Open Research Fund Program of LIESMARS of Wuhan University(No.(01)0304).
文摘Up to now,detailedstrategies and algorithms of automaticchange detection for road networksbased on GIS have not been discussed.This paper discusses two differentstrategies of automatic change detec-tion for images with low resolution andhigh resolution using old GIS data,and presents a buffer detection andtracing algorithm for detecting roadfrom low-resolution images and a newprofile tracing algorithm for detectingroad from high-resolution images.Forfeature-level change detection(FL-CD),a so-called buffer detection algo-rithm is proposed to detect changes offeatures.Some ideas and algorithms ofusing GIS prior information and somecontext information such as substructures of road in high-resolution imagesto assist road detection and extractionare described in detail.
文摘Buffer overflow is the most dangerous attack method that can be exploited. According to the statistics of Computer Emergency Readiness Team （ CERT ）, buffer overflow accounts for 50% of the current software vulnerabilities, and this ratio is going up. Considering a subset of C language, Mini C, this paper presents an abstract machine model that can realire buffer overflow detection, which is based on operation semantic. Thus the research on buffer overflow detection can be built on strict descriptions of operation semantic. Not only the correctness can be assured, but also the system can be realized and extended easily.
