Steganography has been used to prevent unauthorized access to private information during transmission.It is the scheme of securing sensitive information by concealing it within carriers such as digital images,videos,a...Steganography has been used to prevent unauthorized access to private information during transmission.It is the scheme of securing sensitive information by concealing it within carriers such as digital images,videos,audio,or text.Current steganography methods are working by assigning a cover le then embed the payload within it by making some modications,creating the stego-le.However,the left traces that are caused by these modications will make steganalysis algorithms easily detect the hidden payload.Aiming to solve this issue,a novel,highly robust steganography method based on hacking anti-shoplifting systems has proposed to hide data within clothes.The anti-Shoplifting system is an anti-theft security system that protects goods and products,leaving the store in an illegal way(i.e.,without paying for them).The proposed method works by modifying the default anti-shoplifting system by changing its built-in soft RFID(radio-frequency identication)tags sewn in clothes into NFC(Near Field Communication)tags.These NFC tags are smart tags that can communicate with NFC-Enabled smart-phones using NDEF(NFC Data Exchange Format).NDEF is one of the advancements added to RFID technology by NFC,which allows the data exchange.Every NDEF message has one/more NDEF records that contain record type,a unique ID,a length,and a payload of data that contains the secret message content that can be any type of data that ts in a byte stream.Based on NDEF and NFC-enabled smart-phones,the proposed method will take the secret message from the sender,make use of his NFC-enabled smart-phone to communicate with the NFC tag,then hide the secret message within the NDEF’s payload of the NFC tag stuck in clothes.Finally,to evaluate the proposed method,it has been compared with default(digital)steganography weak points.Such as time,lockable,robustness,attacks,capacity,and a few more points.The results and comparisons showed that the proposed method is more efcient than default(digital)steganography and has many advantages.展开更多
Near-field strong ground motions are useful for engineering seismology studies and seismic design, but dense observation networks of damaging earthquakes are still rare. In this study, based on the strong-motion data ...Near-field strong ground motions are useful for engineering seismology studies and seismic design, but dense observation networks of damaging earthquakes are still rare. In this study, based on the strong-motion data from the M w 6.6 Lushan earthquake, the ground motion parameters in different spatial regions are systematically analyzed, and the contributions from different effects, like the hanging-wall effect, directivity effect, and attenuation effect are separated to the extent possible. Different engineering parameters from the observed ground motions are compared with the local design response spectra and a new attenuation relation of Western China. General results indicate that the high frequency ground motion, like the peak ground acceleration, on two sides of the fault plane is sensitive to the hanging-wall effect, whereas the low frequency ground motion, like the long period spectral acceleration, in the rupture propagation direction is affected by the directivity effect. Moreover, although the M w 6.6 Lushan earthquake is not a large magnitude event, the spatial difference of ground motion is still obvious; thus, for a thrust faulting earthquake, in addition to the hanging effect, the directivity effect should also be considered.展开更多
文摘Steganography has been used to prevent unauthorized access to private information during transmission.It is the scheme of securing sensitive information by concealing it within carriers such as digital images,videos,audio,or text.Current steganography methods are working by assigning a cover le then embed the payload within it by making some modications,creating the stego-le.However,the left traces that are caused by these modications will make steganalysis algorithms easily detect the hidden payload.Aiming to solve this issue,a novel,highly robust steganography method based on hacking anti-shoplifting systems has proposed to hide data within clothes.The anti-Shoplifting system is an anti-theft security system that protects goods and products,leaving the store in an illegal way(i.e.,without paying for them).The proposed method works by modifying the default anti-shoplifting system by changing its built-in soft RFID(radio-frequency identication)tags sewn in clothes into NFC(Near Field Communication)tags.These NFC tags are smart tags that can communicate with NFC-Enabled smart-phones using NDEF(NFC Data Exchange Format).NDEF is one of the advancements added to RFID technology by NFC,which allows the data exchange.Every NDEF message has one/more NDEF records that contain record type,a unique ID,a length,and a payload of data that contains the secret message content that can be any type of data that ts in a byte stream.Based on NDEF and NFC-enabled smart-phones,the proposed method will take the secret message from the sender,make use of his NFC-enabled smart-phone to communicate with the NFC tag,then hide the secret message within the NDEF’s payload of the NFC tag stuck in clothes.Finally,to evaluate the proposed method,it has been compared with default(digital)steganography weak points.Such as time,lockable,robustness,attacks,capacity,and a few more points.The results and comparisons showed that the proposed method is more efcient than default(digital)steganography and has many advantages.
基金The Basic Science Research Foundation of Institute of Engineering Mechanics,CEA under Grant No.2011B02as part of the National Natural Science Foundation of China under Grant Nos.51238012,91215301,973+1 种基金Program under Grant No.2011CB013601International Science&Technology Cooperation Program of China under Grant No.2012DFA70810
文摘Near-field strong ground motions are useful for engineering seismology studies and seismic design, but dense observation networks of damaging earthquakes are still rare. In this study, based on the strong-motion data from the M w 6.6 Lushan earthquake, the ground motion parameters in different spatial regions are systematically analyzed, and the contributions from different effects, like the hanging-wall effect, directivity effect, and attenuation effect are separated to the extent possible. Different engineering parameters from the observed ground motions are compared with the local design response spectra and a new attenuation relation of Western China. General results indicate that the high frequency ground motion, like the peak ground acceleration, on two sides of the fault plane is sensitive to the hanging-wall effect, whereas the low frequency ground motion, like the long period spectral acceleration, in the rupture propagation direction is affected by the directivity effect. Moreover, although the M w 6.6 Lushan earthquake is not a large magnitude event, the spatial difference of ground motion is still obvious; thus, for a thrust faulting earthquake, in addition to the hanging effect, the directivity effect should also be considered.
