Henry M. Gladney

Access control for large collections

Efforts to place vast information resources at the fingertips of each individual in large user populations must be balanced by commensurate attention to information protection. For distributed systems with less-structured tasks, more-diversified information, and a heterogeneous user set, the computing system must administer enterprise-chosen access control policies. One kind of resource is a digital library that emulates massive collections of paper and other physical media for clerical, engineering, and cultural applications. This article considers the security requirements for such libraries and proposes an access control method that mimics organizational practice by combining a subject tree with ad hoc role granting that controls privileges for many operations independently, that treats (all but one) privileged roles (e.g., auditor, security officer) like every other individual authorization, and that binds access control information to objects indirectly for scaling, flexibility, and reflexive protection. We sketch a realization and show that it will perform well, generalizes many deployed proposed access control policies, and permits individual data centers to implement other models economically and without disruption.

Toward online, worldwide access to Vatican Library materials

The Vatican Library is an extraordinary repository of rare books and manuscripts. Among its 150,000 manuscripts are early copies of works by Aristotle, Dante, Euclid, Homer, and Virgil. Yet today access to the Library is limited. Because of the time and cost required to travel to Rome, only some 2000 scholars can afford to visit the Library each year. Through the Vatican Library Project, we are exploring the practicality of providing digital library services that extend access to portions of the Librarys collections to scholars worldwide, as an early example of providing digital library services that extend and complement traditional library services. A core goal of the project is to provide access via the Internet to some of the Librarys most valuable manuscripts, printed books, and other sources to a scholarly community around the world. A multinational, multidisciplinary team is addressing the technical challenges raised by that goal, including • Development of a multiserver system suitable for providing information to scholars worldwide. • Capture of images of the materials with faithful color and sufficient detail to support scholarly study. Protection of the on-line materials, especially images, from misappropriation. • Development of tools to enable scholars to locate desired materials. • Development of tools to enable scholars to scrutinize images of manuscripts. • In this paper, we provide an overview of the project, a description of the system being developed to satisfy its needs, and a discussion of how the technical challenges are being addressed.

Computer analysis of electron paramagnetic resonance spectra

Algebraic methods that are useful in the reduction of EPR spectra to the magnetic parameters in the phenomenological Hamiltonian are summarized and programs presently available to accomplish the necessary computations are described. Among the topics discussed are (i) the calculation of the spectrum of the complete spin Hamiltonian for single-crystal experiments, with the principal axis system; (ii) the transformation of the Hamiltonian to the magnetic quantization axes, which is convenient for perturbation theory; (iii) the use of iteration methods to determine the parameters by a least-squares technique; (iv) the detailed fitting of EPR spectra of polycrystalline or glassy-state magnetic sites; (v) the correlation methods in the analysis of solution spectra; (vi) a novel integral transformation to improve the resolution; and (vii) the calculation of the dipolar sum for line width studies.

Covalency and Electronic Structure of Cu2+ in ZnF2 by EPR

With the aid of computer techniques, including a laboratory automation system, accurate computer simulation, and an accurate calculation method, the EPR spectrum of copper doped in zinc fluoride has been analyzed. The observed g values led by a new method to a determination of the coefficients of the Kramers doublet. Copper hyperfine structure verified these values and fluorine transferred hyperfine structure gave a measure of covalency. The fractional orbital occupation showed predominantly σ bonding which is similar to other reported transition metal ions in ionic insulating crystals. Orbital reduction, though no doubt present, makes only an insignificant and undetectable contribution.

Trustworthy 100-year digital objects: Evidence after every witness is dead

In ancient times, wax seals impressed with signet rings were affixed to documents as evidence of their authenticity. A digital counterpart is a message authentication code fixed firmly to each important document. If a digital object is sealed together with its own audit trail, each user can examine this evidence to decide whether to trust the content---no matter how distant this user is in time, space, and social affiliation from the documents source.We propose an architecture and design that accomplish this: encapsulation of digital object content with metadata describing its origins, cryptographic sealing, webs of trust for public keys rooted in a forest of respected institutions, and a certain way of managing information identifiers. These means will satisfy emerging needs in civilian and military record management, including medical patient records, regulatory records for aircraft and pharmaceuticals, business records for financial audit, legislative and legal briefs, and scholarly works.This is true for any kind of digital object, independent of its purposes and of most data type and representation details, and provides every kind of user---information authors and editors, librarians and collection managers, and information consumers---with autonomy for implied tasks. Our prototype will conform to applicable standards, will be interoperable over most computing bases, and will be compatible with existing digital library software.The proposed architecture integrates software that is mostly available and widely accepted.

Trustworthy 100-year digital objects: durable encoding for when it's too late to ask

How can an author store digital information so that it will be reliably intelligible, even years later when he or she is no longer available to answer questions? Methods that might work are not good enough; what is preserved today should be reliably intelligible whenever someone wants it. Prior proposals fail because they generally confound saved data with irrelevant details of todays information technology---details that are difficult to define, extract, and save completely and accurately.We use a virtual machine to represent and eventually to render any data whatsoever. We focus on a case of intermediate difficulty---an executable procedure---and identify a variant for every other data type.This solution might be more elaborate than needed to render some text, image, audio, or video data. Simple data can be preserved as representations using well-known standards. We sketch practical methods for files ranging from simple structures to those containing computer programs, treating simple cases here and deferring complex cases for future work. Enough of the complete solution is known to enable practical aggressive preservation programs today.

A storage subsystem for image and records management

Digital storage and communications are becoming cost effective for massive collections of document images with access not only for nearby users but also for those who are hundreds of miles from their libraries. The Document Storage Subsystem (DocSS) provides generic library services such as searching, storage, and retrieval of document pages and sharing of objects with appropriate data security and integrity safeguards. A library session has three components: a manager of remote catalogs, a set of managers of large-object stores, and a manager of cache services. DocSS supports all kinds of page data--text, pictures, spreadsheets, graphics, programs--and can be extended to audio and video data. Document models can be built as DocSS applications; the paper describes a folder manager as an example. What differentiates DocSS among digital library projects is its approach to data distribution over wide area networks, its client-server approach to the heterogeneous environment, and its synergism with other components of evolving open systems.

A theory of the hard sphere solid. II

A ’’self‐consistent field’’ theory based on the Bethe approximation previously estimated the entropy and single‐particle distribution function in good agreement with computer simulations for the three‐dimensional hard‐sphere solid. In this paper we carry through the theory for the hard disk system, finding results closely similar to those for hard spheres, and numerically in good agreement with asymptotic high‐density numerical simulations. Cluster corrections through third‐order interactions are calculated and found small. The asymptotic high‐density approximation fails, correctly, to lead to a solution for the one‐dimensional system of rods in cells. In this case, an exact analytic solution is possible. For this solution, the one‐particle distribution function retains finite width in the high‐density limit, in contrast to the two‐ and three‐dimensional solutions. At high densities, the free energy of this ’’self‐consistent’’ cell model solution corresponds to the known correct result.

Authorization management for digital libraries

COMMUNICATIONS OF THE ACM May 2001/Vol. 44, No. 5 63 Safe Dealing (SD) is an authorization mechanism motivated by information delivery that has many other potential applications among popular services. Some prior approaches to protecting the valuable resources in such applications have had too much administrative overhead to be widely practical. Others, such as sniffing IP addresses, have such well-known weaknesses that their use is typically introduced with apologies. That information serving is similar to other transactions that deliver valuable benefits to individual users suggests that library controls would be economical if they used the same mechanisms as e-commerce. Each of us executes many transactions for valuable goods or services with people we know only slightly or not at all. Some of these transactions are for cash, others are with a debit or credit card, and some occur only when a service agent believes we are entitled by virtue of being enrolled in a privileged group. Notwithstanding much investigation of digital payments and other business controls, and immense interest in e-commerce and control of sensitive resources, the widely deployed mechanisms are either limited to small populations within single enterprises or are merely semiautomated replacements for what H.M. Gladney and Arthur Cantu { {

LABS/7: a distributed real-time operating system

A hierarchical distributed real-time computing system, LABS/7, provides facilities for attaching multiple IBM System/7s to a host System/360 or System/370. LABS/7 consists of a multiprogramming and multitasking supervisor for the System/7, a host communication facility that supports multiple satellite System/7s, and a high-level real-time language for user application development. LABS/7 is operational in a variety of environments, including research, development, manufacturing, and clinical. The functional characteristics of the system are reviewed, performance is stated for well-defined situations, and experience with the system is reviewed with reference to some typical applications.