The Online Computer Library Center's Open WorldCat Program

This article describes the Online Computer Library Center???s (OCLC) Open WorldCat program. WorldCat is a worldwide union catalog created and maintained collectively by more than 9,000 member institutions. Open WorldCat seeks to make library collections and services visible and available through popular search engines such as Yahoo! and Google and other heavily used sites on the open Web. In this capacity, Open WorldCat provides an important central connection between the shared information of the library network and the Web. The article describes the history and rationale of the project; explains how Open WorldCat works for information seekers, participating libraries, and partners; and reports on what OCLC has learned from the program to date.published or submitted for publicatio

Weakening the Isolation Assumption of Tamper-proof Hardware Tokens

Recent results have shown the usefulness of tamper-proof hardware tokens as a setup assumption for building UC-secure two-party computation protocols, thus providing broad security guarantees and allowing the use of such protocols as buildings blocks in the modular design of complex cryptography protocols. All these works have in common that they assume the tokens to be completely isolated from their creator, but this is a strong assumption. In this work we investigate the feasibility of cryptographic protocols in the setting where the isolation of the hardware token is weakened. We consider two cases: (1) the token can relay messages to its creator, or (2) the creator can send messages to the token after it is sent to the receiver. We provide a detailed characterization for both settings, presenting both impossibilities and information-theoretically secure solutions

Shelling the Voronoi interface of protein-protein complexes predicts residue activity and conservation

The accurate description of protein-protein interfaces remains a challenging task. Traditional criteria, based on atomic contacts or changes in solvent accessibility, tend to over or underpredict the interface itself and cannot discriminate active from less relevant parts. A recent simulation study by Mihalek and co-authors (2007, JMB 369, 584-95) concluded that active residues tend to be `dry', that is, insulated from water fluctuations. We show that patterns of `dry' residues can, to a large extent, be predicted by a fast, parameter-free and purely geometric analysis of protein interfaces. We introduce the shelling order of Voronoi facets as a straightforward quantitative measure of an atom's depth inside an interface. We analyze the correlation between Voronoi shelling order, dryness, and conservation on a set of 54 protein-protein complexes. Residues with high shelling order tend to be dry; evolutionary conservation also correlates with dryness and shelling order but, perhaps not surprisingly, is a much less accurate predictor of either property. Voronoi shelling order thus seems a meaningful and efficient descriptor of protein interfaces. Moreover, the strong correlation with dryness suggests that water dynamics within protein interfaces may, in first approximation, be described by simple diffusion models

The Cryptographic Strength of Tamper-Proof Hardware

Tamper-proof hardware has found its way into our everyday life in various forms, be it SIM cards, credit cards or passports. Usually, a cryptographic key is embedded in these hardware tokens that allows the execution of simple cryptographic operations, such as encryption or digital signing. The inherent security guarantees of tamper-proof hardware, however, allow more complex and diverse applications

Blitzeinschlagsanalyse für rückwärtige Überschläge einer Hybridleitung

A new method to transfer energy over short and long distances is to use hybrid lines. In this paper a lightning surge analysis for backflashovers on overhead transmission lines with one DC and three AC systems on the same tower is considered. Lightning strikes are the most common source of failures on transmission systems and are not considered for hybrid lines. The main aim is to get essential information about the behavior of the HVDC system due to a backflashover. We simulate a lightning stroke into a hybrid line using EMTP-ATP. The results clearly show that the 110-kV AC systems provide protective effects for the HVDC system. Therefore, it is concluded that the backflashover performance of HVDC systems is better on AC/DC hybrid lines, compared to identically constructed towers with just one HVDC system installed