Leibniz University of Hanover

About: Leibniz University of Hanover is a education organization based out in Hanover, Niedersachsen, Germany. It is known for research contribution in the topics: Finite element method & Population. The organization has 14283 authors who have published 29845 publications receiving 682152 citations.

PeerTrust: Automated Trust Negotiation for Peers on the Semantic Web

Abstract: Researchers have recently begun to develop and investigate policy languages to describe trust and security requirements on the Semantic Web. Such policies will be one component of a run-time system that can negotiate to establish trust on the Semantic Web. In this paper, we show how to express different kinds of access control policies and control their use at run time using PeerTrust, a new approach to trust establishment. We show how to use distributed logic programs as the basis for PeerTrust’s simple yet expressive policy and trust negotiation language, built upon the rule layer of the Semantic Web layer cake. We describe the PeerTrust language based upon distributed logic programs, and compare it to other approaches to implementing policies and trust negotiation. Through examples, we show how PeerTrust can be used to support delegation, policy protection and negotiation strategies in the ELENA distributed eLearning environment. Finally, we discuss related work and identify areas for further research.

One- or two-plate fixation of mandibular angle fractures?

Abstract: Standard treatment of mandibular angle fractures with miniplates, according to the recommendations of Champy et al. (1976), consists of fixation with one plate at the superior border of the mandible ventral to the external oblique line. In certain constellations, a second miniplate at the lower mandibular margin may provide additional stability. In contrast, extremely high complication rates following two-plate fixation of mandibular angle fractures were reported by Ellis and Walker (1994). In a prospective randomized study, 31 consecutive patients were treated with 2.0 mm (mini) plates (Synthes Co., Switzerland). One group was treated with one plate, the other one with two plates. In none of the patients was intermaxillary immobilization used. Follow-up was performed 6 months postoperatively, consisting of clinical and radiographic examination. No significant differences (P = 0.74 for infection, and P = 1.0 for occlusal and postoperative sensory disturbance) in postoperative short- or long-term complications were found between the two groups. The results are compared with our experimental investigations presented at the annual congress of the Germany Society of Oral and Maxillofacial Surgery, 1995. Two-plate fixation may not offer advantages over single-plate fixation in general. However, individual fracture constellations may benefit from variation in plate(s) localization. Factors contributing to complications in mandibular angle fractures are discussed.