Shelter: Smartphone Bridged Socialized Body Networks for Epidemic Control

We propose using information, computing and networking innovations to tackle epidemic control challenges

PAS: Predicate-Based Authentication Services Against Powerful Passive Adversaries

Securely authenticating a human user without assistance from any auxiliary device in the presence of powerful passive adversaries is an important and challenging problem. Passive adversaries are those that can passively monitor, intercept, and analyze every part of the authentication procedure, except for an initial secret shared between the user and the server. In this paper, we propose a new secure authentication scheme called predicate-based authentication service (PAS). In this scheme, for the first time, the concept of a predicate is introduced for authentication. We conduct analysis on the proposed scheme and implement its prototype system. Our analytical data and experimental data illustrate that the PAS scheme can simultaneously achieve a desired level of security and user friendliness

Tutkimus IP-verkon moniluokkareititysalgoritmeista

Multi-Class Routing (MCR) is to route different traffic classes using different routing metrics or routing algorithms, while Single-Class Routing (SCR) routes different traffic classes using the same routing metric or algorithm. The optimal MCR scheme in fixed IP networks and relative analyses are investigated in this thesis. We investigate and analyze the cost function based optimal capacity allocation in MCR when source routing is used. A novel cost function is proposed for low-level traffic optimization when the capacities of links for each traffic class are fixed. Further more, a heuristic way is introduced for allocating capacity dynamically. Simulations are made and we investigate the results from our heuristic method. Then, the BE class optimization problem (BECOP) is defined in MCR and a novel MCR scheme is introduced when hop-by-hop routing is considered. A simplified traffic model for SCR and MCR is introduced here and some analyses are made based on it. We furthermore explore the proper routing algorithms by simulations to find the best combination of routing algorithms used for different traffic classes. According to our analysis and simulations, MCR performs better than Single Class Routing (SCR) on most conditions

The Decomposition of the Matrix

Macierz jest ważnym pojęciem z algebry, którego pojawienie się spowodowało szybki rozwój tego działu matematyki. Rozkład macierzy jest to przedstawienie macierzy w postaci iloczynu (lub sumy) kilku macierzy o określonych własnościach, będący ważnym sposobem rozwiązy- wanie niektórych problemów liniowych. W tej pracy, wprowadzono dwa rozkłady macierzy, takie jak rozkład LU oraz rozkład QR. Przedstawiono definicje tych rozkładów i twierdzenia z nimi związane, a następnie podano dokładne metody rozkładów. Na końcu pracy pokazano przykłady zastosowania rozkładów macierzy.Matrix is one of the most important concepts in algebra, whose appearance promotes the development of algebra．While as a significant part of the theory of matrix, the decomposition of matrix aims at decomposing a matrix into the product (or sum) of several specific kinds of matrices. The decomposition of matrix not only concludes rich contents and forms, but also works as one of the significant methods in dealing with some linear algebra problems. In this paper, the decomposition of matrix is mainly introduced from the aspects mentioned below, such as QR decomposition, LU decomposition and so on. Firstly, the definitions and related properties of these forms of decomposition are given. And then, specific decomposition ways of theirs are illustrated. Finally, these decomposition methods are clearly presented by the forms of some examples

Network decoupling for secure communications in wireless sensor networks

Abstract — Secure communications are highly demanded by many wireless sensor network (WSN) applications. The random key pre-distribution (¢¤£¦ ¥ ) scheme has become well accepted to achieve secure communications in WSNs. However, due to its randomness in key distribution and strong constraint in key path construction, the ¢¤£¦ ¥ scheme can only be applied in highly dense networks, which are not always feasible in practice. In this paper, we propose a methodology called network decoupling to solve this problem. With this methodology, a wireless sensor network is decoupled into a logical key-sharing network and a physical neighborhood network, which significantly releases the constraint in key path construction of ¢¤£¦ ¥ scheme. We design a secure neighbor establishment protocol ¢¤£¦ ¥ (called §©¨) as well as a set of link and path dependency elimination rules in decoupled wireless sensor networks. Our analytical and simulation data demonstrate the performance enhancement of our solution and its applicability in non-highly dense wireless sensor networks. I