Problem-based learning as an effective tool for teaching computer network design

This paper addresses the challenge of developing techniques for the effective teaching of computer network design. It reports on the experience of using the technique of problem-based learning as a key pedagogical method for teaching practical network design within the context of a Master's program module in data telecommunications and networks at the University of Salford, Salford, Greater Manchester, U.K. A two-threaded approach was adopted that comprised a problem-based learning thread and a conventional lecture thread. The problem-based learning thread within the module comprised sessions designed to place the students in the position of network design consultants who are introduced to scenarios that have a high degree of realism in which a client has specific business requirements that can be met through the adoption of a network solution. In this way, the problem-based learning thread allows the students to develop their design skills, while the lecture thread uses traditional teaching methods to allow students to develop their understanding of key network components and architectures. A formal evaluation of this approach has been carried out and demonstrated a very effective and realistic learning experience for the students. Therefore, the authors propose that problem-based learning is an ideal pedagogical tool for the teaching of computer network design

Pulsatile spiral blood flow through arterial stenosis

Pulsatile spiral blood flow in a modelled three-dimensional arterial stenosis, with a 75% cross-sectional area reduction, is investigated by using numerical fluid dynamics. Two-equation k-ω model is used for the simulation of the transitional flow with Reynolds numbers 500 and 1000. It is found that the spiral component increases the static pressure in the vessel during the deceleration phase of the flow pulse. In addition, the spiral component reduces the turbulence intensity and wall shear stress found in the post-stenosis region of the vessel in the early stages of the flow pulse. Hence, the findings agree with the results of Stonebridge et al. (2004). In addition, the results of the effects of a spiral component on time-varying flow are presented and discussed along with the relevant pathological issues

Active router approach to defeating denial-of-service attacks in networks

Denial-of-service attacks represent a major threat to modern organisations who are increasingly dependent on the integrity of their computer networks. A new approach to combating such threats introduces active routers into the network architecture. These active routers offer the combined benefits of intrusion detection, firewall functionality and data encryption and work collaboratively to provide a distributed defence mechanism. The paper provides a detailed description of the design and operation of the algorithms used by the active routers and demonstrates how this approach is able to defeat a SYN and SMURF attack. Other approaches to network design, such as the introduction of a firewall and intrusion detection systems, can be used to protect networks, however, weaknesses remain. It is proposed that the adoption of an active router approach to protecting networks overcomes many of these weaknesses and therefore offers enhanced protection

A novel platform for context maintenance and discovery in a ubiquitous environment

Context maintenance and discovery, which aim to represent, manage and share context information, have been discussed since context-awareness was presented in the 1990s. These become more challenging when being applied to a ubiquitous environment where dynamic and distributed computing happens anytime, anywhere. In this paper, a platform for ubiquitous context representation and its distribution is introduced. Five semantic dimensions are used to recognize and organize potential context information. A context information base (CiB), a context repository, is integrated in each device of a ubiquitous network to maintain context parameters discovered from neighbor nodes. The CiComm protocol distributes context information and accordingly realizes the capabilities of context deployment and retrieval. The resulting architecture is fully extensible being infrastructure-less and based on an ontological model. Simulations carried out using NS-2 have also demonstrated the operations of the protocol and proven through experimental results that it works efficiently in a dynamic ubiquitous environment

Staan op twee benen

Rede, uitgesproken bij de aanvaarding van het ambt van gewoon hoogleraar in de Orthopaedie aan de Medische Faculteit Rotterdam op woensdag 26 april 1972 Inaugurele rede Medische Faculteit Rotterda

Ensuring the Full Freedom of Religion on Public Lands: Devils Tower and the Protection of Indian Sacred Sites

Federal land management agencies historically have disregarded American Indian cries for protection of sacred sites on public lands, and the federal judiciary consistently has supported such action according to a formalistic interpretation of the Religion Clauses of the First Amendment. This Note takes issue with the pattern of religious oppression in the context of public land management by positing a more inclusive, “full,” conception of religious freedom under the First Amendment. This Note then analyzes the recent controversy at Devils Tower National Monument as an important opportunity to break the trend and embrace Indian religious freedoms around sacred sites on public lands