The need for access control in a hierarchy arises in several different contexts. One such context is managing the information of an organization where the users are divided into different security classes depending on who has access to what. Several cryptographic solutions have been proposed to address this problem --- the solutions are based on generating cryptographic keys for each security class such that the key for a lower level security class depends on the key for the security class that is higher up in the hierarchy. Most solutions use complex cryptographic techniques: integrating these into existing systems may not be trivial. Others have impractical requirement: if a user at a security level wants to access data at lower levels, then all intermediate nodes must be traversed. Moreover, if there is an access control policy that does not conform to the hierarchical structure, such policy cannot be handled by existing solutions. We propose a new solution that overcomes the above mentioned shortcomings. Our solution not only addresses the problem of access control in a hierarchy but also can be used for general cases. It is a scheme similar to the RSA cryptosystem and can be easily incorporated in existing systems.

In this paper, a technique for extracting the distortion parameters in filled-in forms is presented. The technique determines the transformations that is required to convert a filled-in form to match a known master and then extracts filled-in information. The method involves determining corresponding lines and keypoints between the master and the filled-in form and using the correspondence to determine the appropriate transformation. The correspondence problem is solved using results from geometric hashing voting scheme.

In this paper, a technique for extracting the distortion parameters in filled-in forms is presented. The technique determines the transformations that are required to convert a filled-in form to match a known master and then extracts filled-in information. The method involves determining corresponding lines and key points between the master and the filled-in form and using the correspondence to determine the appropriate transformation. The correspondence problem is solved using results from affine geometry.

A technique for extracting filled-in information in form documents is presented. The transformation that is required to convert a filled-in form to match the master (blank form) is derived using results from projective geometry. Experimental studies with several forms indicate the proposed technique to be accurate and robust.

Article Automatic linking of thesauri Share on Authors: S. Amba Information Area, Central Leather Research Institute, Adyar, Madras 600 020 Information Area, Central Leather Research Institute, Adyar, Madras 600 020View Profile , N. Narasimhamurthi Dept. of Electrical and Computer Engineering, University of Michigan-Dearborn, Dearborn, Michigan Dept. of Electrical and Computer Engineering, University of Michigan-Dearborn, Dearborn, MichiganView Profile , Kevin C. O'Kane Dept. of Computer Science, University of Northern Iowa, Iowa Dept. of Computer Science, University of Northern Iowa, IowaView Profile , Philip M. Turner School of Library and Information Studies, University of Alabama, AL School of Library and Information Studies, University of Alabama, ALView Profile Authors Info & Claims SIGIR '96: Proceedings of the 19th annual international ACM SIGIR conference on Research and development in information retrievalAugust 1996 Pages 181–186https://doi.org/10.1145/243199.243265Published:18 August 1996 8citation347DownloadsMetricsTotal Citations8Total Downloads347Last 12 Months1Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

In this paper, a technique for registering filled-in forms is presented. The technique determines the transformations that is required to convert a filled-in form to match a known master and then extracts filled-in information. This method involves determining corresponding points between the master and the filled-in form and using this correspondence to determine the appropriate transformation. The correspondence problem is solved using results from projective geometry.

A novel algorithm for the determination of surface shapes from intensity measurements is presented. The proposed model allows the estimation of the normals at any point on the surface and of the depth at any point in the image plane along the viewer (camera) direction. Simple shape descriptors for characterizing most developable surfaces are derived. It is shown that the principal curvatures of the surface are simply eigenvalues of the restriction of the shape matrix to the tangent space. The proposed algorithm allows incorporation of prior information obtained from stereopsis and other vision processes. Tests with intensity images have shown the algorithm to be convergent, robust, and accurate.>