The objective of steganography is to hide message securely in cover objects for secret communication.How to design a secure steganographic algorithm is still major challenge in this re-search field.In this letter,deve...The objective of steganography is to hide message securely in cover objects for secret communication.How to design a secure steganographic algorithm is still major challenge in this re-search field.In this letter,developing secure steganography is formulated as solving a constrained IP(Integer Programming) problem,which takes the relative entropy of cover and stego distributions as the objective function.Furthermore,a novel method is introduced based on BPSO(Binary Particle Swarm Optimization) for achieving the optimal solution of this programming problem.Experimental results show that the proposed method can achieve excellent performance on preserving neighboring co-occurrence features for JPEG steganography.展开更多
This article is a part of a descriptive survey which aims to characterize, classify, and compare the household production in the Municipality of Itapuranga, State of Goias, Brazil, considering the access to the Nation...This article is a part of a descriptive survey which aims to characterize, classify, and compare the household production in the Municipality of Itapuranga, State of Goias, Brazil, considering the access to the National Program for Strengthening Family Agriculture （PRONAF） and its respective differentiation between beneficiary and non-beneficiary groups by the program. It applied the technique of group comparison analysis and frequency inquiry, taking into consideration several variables. Information about the origin, distribution and total income, food safety, land property, production diversification, expenditures and participation in social organizations were collected. The sample consisted of 70 producers, the calculation sample was defined by determined value at the confidence level of 90% whereas the sampling error of 7%. The results allowed describing, classifying, characterizing, and comparing the socio-economic and productive profile of farmers from that area and their access to PRONAF.展开更多
There are many business needs for implementing delegation in IT （Information Technology） systems. However, existing approaches to delegation in IT systems are limited in their usability, flexibility, and capability ...There are many business needs for implementing delegation in IT （Information Technology） systems. However, existing approaches to delegation in IT systems are limited in their usability, flexibility, and capability to implement least privilege. The result is that delegation is either not implemented or is implemented informally （e.g., by sharing credentials [passwords or hardware tokens] between users）, resulting in serious security concerns and a lack of accountability. This paper describes a methodology for delegation based on the persona concept. A persona is a special category of user that embodies only delegated privileges, and which is explicitly assumed only after the ＂real＂ human user taking on that persona explicitly chooses it, This paper describes the persona delegation framework in the context of a large enclave-based architecture currently being implemented by a major enterprise. The creation of a persona solves a lot of downstream problems by allowing the persona to be treated like any other entity in the system. That is, identity, authentication, authorization, and other security processes already know how to handle an entity of this type. Benefits of the framework include increased flexibility to handle a number of different delegation business scenarios, decreased complexity of the solution, and greater accountability with only a modest amount of additional infrastructure required.展开更多
基金Supported by the National Natural Science Foundation of China (No.60572111)
文摘The objective of steganography is to hide message securely in cover objects for secret communication.How to design a secure steganographic algorithm is still major challenge in this re-search field.In this letter,developing secure steganography is formulated as solving a constrained IP(Integer Programming) problem,which takes the relative entropy of cover and stego distributions as the objective function.Furthermore,a novel method is introduced based on BPSO(Binary Particle Swarm Optimization) for achieving the optimal solution of this programming problem.Experimental results show that the proposed method can achieve excellent performance on preserving neighboring co-occurrence features for JPEG steganography.
文摘This article is a part of a descriptive survey which aims to characterize, classify, and compare the household production in the Municipality of Itapuranga, State of Goias, Brazil, considering the access to the National Program for Strengthening Family Agriculture （PRONAF） and its respective differentiation between beneficiary and non-beneficiary groups by the program. It applied the technique of group comparison analysis and frequency inquiry, taking into consideration several variables. Information about the origin, distribution and total income, food safety, land property, production diversification, expenditures and participation in social organizations were collected. The sample consisted of 70 producers, the calculation sample was defined by determined value at the confidence level of 90% whereas the sampling error of 7%. The results allowed describing, classifying, characterizing, and comparing the socio-economic and productive profile of farmers from that area and their access to PRONAF.
文摘There are many business needs for implementing delegation in IT （Information Technology） systems. However, existing approaches to delegation in IT systems are limited in their usability, flexibility, and capability to implement least privilege. The result is that delegation is either not implemented or is implemented informally （e.g., by sharing credentials [passwords or hardware tokens] between users）, resulting in serious security concerns and a lack of accountability. This paper describes a methodology for delegation based on the persona concept. A persona is a special category of user that embodies only delegated privileges, and which is explicitly assumed only after the ＂real＂ human user taking on that persona explicitly chooses it, This paper describes the persona delegation framework in the context of a large enclave-based architecture currently being implemented by a major enterprise. The creation of a persona solves a lot of downstream problems by allowing the persona to be treated like any other entity in the system. That is, identity, authentication, authorization, and other security processes already know how to handle an entity of this type. Benefits of the framework include increased flexibility to handle a number of different delegation business scenarios, decreased complexity of the solution, and greater accountability with only a modest amount of additional infrastructure required.
