Data Delivery Method Based on Neighbor Nodes’ Information in a Mobile Ad Hoc Network

This paper proposes a data delivery method based on neighbor nodes’ information to achieve reliable communication in a mobile ad hoc network (MANET). In a MANET, it is difficult to deliver data reliably due to instabilities in network topology and wireless network condition which result from node movement. To overcome such unstable communication, opportunistic routing and network coding schemes have lately attracted considerable attention. Although an existing method that employs such schemes, MAC-independent opportunistic routing and encoding (MORE), Chachulski et al. (2007), improves the efficiency of data delivery in an unstable wireless mesh network, it does not address node movement. To efficiently deliver data in a MANET, the method proposed in this paper thus first employs the same opportunistic routing and network coding used in MORE and also uses the location information and transmission probabilities of neighbor nodes to adapt to changeable network topology and wireless network condition. The simulation experiments showed that the proposed method can achieve efficient data delivery with low network load when the movement speed is relatively slow

Design and Implementation of an Inter-Device Authentication Framework Guaranteeing Explicit Ownership

Future networks everywhere will be connected to innumerable Internet-ready home appliances. A device accepting connections over a network must be able to verify the identity of a connecting device in order to prevent device spoofing and other malicious actions. In this paper, we propose a security mechanism for an inter-device communication. We state the importance of a distingushing and binding mechanism between a devices identity and its ownership information to realize practical inter-device authentication. In many conventional authentication systems, the relationship between the devices identity and the ownership information is not considered. Therefore, we propose a novel inter-device authentication framework guaranteeing this relationship. Our prototype implementation employs a smart card to maintain the devices identity, the ownership information and the access control rules securely. Our framework efficiently achieves secure inter-device authentication based on the devices identity, and authorization based on the ownership information related to the device. We also show how to apply our smart card system for inter-device authentication to the existing standard security protocols

The Deep-Sea Tube Worm Hemoglobin : Subunit Structure and Phylogenetic Relationship with Annelid Hemoglobin : Biochemistry

Volume: 6Start Page: 915End Page: 92

Regulated Assembly of the Transenvelope Protein Complex Required for Lipopolysaccharide Export

Gram-negative bacteria are impervious to many drugs and environmental stresses because they possess an outer membrane (OM) containing lipopolysaccharide (LPS). LPS is biosynthesized at the cytoplasmic (inner) membrane and is transported to the OM by an unknown mechanism involving the LPS transport proteins, LptA–G. These proteins have been proposed to form a bridge between the two membranes; however, it is not known how this bridge is assembled to prevent mistargeting of LPS. We use in vivo photo-cross-linking to reveal the specific protein–protein interaction sites that give rise to the Lpt bridge. We also show that the formation of this transenvelope bridge cannot proceed before the correct assembly of the LPS translocon in the OM. This ordered sequence of events may ensure that LPS is never transported to the OM if it cannot be translocated across it to the cell surface