20,733 research outputs found
Link stability estimation based on link connectivity changes in mobile ad-hoc networks
No full textDear Wang,
Re: Link Stability Estimation Based on Link Connectivity Changes in Mobile Ad-hoc Networks
I have not been able to assess if this is an author version peer-reviewed or is it an author version non peer reviewed. Could you please clarify this so I can proceed to add your paper to Spiral. Spiral digital repository only accept peer-reviewed papers.
30/11/12 author has confirmed peer reviewe
Unlocking the Power of Azure AD: Best Practices for Enterprise Identity Control
No full textIn today's rapidly evolving digital landscape, managing enterprise identity has become a critical challenge for organizations. Azure Active Directory (Azure AD) offers a robust solution for identity and access management, providing enterprises with advanced tools to safeguard user credentials, manage authentication, and ensure secure access to corporate resources. This paper delves into the best practices for leveraging Azure AD to enhance enterprise identity control. It covers key strategies for optimizing authentication protocols, implementing multi-factor authentication (MFA), and adopting zero-trust principles to minimize security risks. Furthermore, the paper addresses how seamless integration with cloud applications, role-based access control (RBAC), and conditional access policies can streamline access management, foster compliance, and enhance operational efficiency. By following these best practices, organizations can unlock the full potential of Azure AD, empowering them to protect sensitive data, mitigate cyber threats, and ensure a secure digital environment for their users
Chapter 14: Lessons in Administration as Ad-Interim Chair of Lymphoma/Myeloma
No full textDr. Rodriguez begins this chapter by explaining how her view of the institution changed as she stepped into the role of Ad-Interim Chair of Lymphoma/Myeloma when Dr. Cabanillas retired. She sketches her new areas of responsibility and how this changed her view of operations and the institution as a whole. Next, Dr. Rodriguez explains that traditionally, a Department Chair is seen as an “erudite expert,” but to be successful a chair must let go of her/his ego and bring forth future leaders in the field.https://openworks.mdanderson.org/mchv_interviewchapters/1342/thumbnail.jp
Cerebral atrophy in mild cognitive impairment and Alzheimer disease: rates and acceleration.
No full textOBJECTIVE: To quantify the regional and global cerebral atrophy rates and assess acceleration rates in healthy controls, subjects with mild cognitive impairment (MCI), and subjects with mild Alzheimer disease (AD). METHODS: Using 0-, 6-, 12-, 18-, 24-, and 36-month MRI scans of controls and subjects with MCI and AD from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database, we calculated volume change of whole brain, hippocampus, and ventricles between all pairs of scans using the boundary shift integral. RESULTS: We found no evidence of acceleration in whole-brain atrophy rates in any group. There was evidence that hippocampal atrophy rates in MCI subjects accelerate by 0.22%/year2 on average (p = 0.037). There was evidence of acceleration in rates of ventricular enlargement in subjects with MCI (p = 0.001) and AD (p < 0.001), with rates estimated to increase by 0.27 mL/year2 (95% confidence interval 0.12, 0.43) and 0.88 mL/year2 (95% confidence interval 0.47, 1.29), respectively. A post hoc analysis suggested that the acceleration of hippocampal loss in MCI subjects was mainly driven by the MCI subjects that were observed to progress to clinical AD within 3 years of baseline, with this group showing hippocampal atrophy rate acceleration of 0.50%/year2 (p = 0.003). CONCLUSIONS: The small acceleration rates suggest a long period of transition to the pathologic losses seen in clinical AD. The acceleration in hippocampal atrophy rates in MCI subjects in the ADNI seems to be driven by those MCI subjects who concurrently progressed to a clinical diagnosis of AD
A Fair and Secure Cluster Formation Process for Ad Hoc Networks
No full textAn efficient approach for organizing large ad hoc networks is to divide the nodes
into multiple clusters and designate, for each cluster, a clusterhead which is responsible for
holding intercluster control information. The role of a clusterhead entails rights and duties.
On the one hand, it has a dominant position in front of the others because it manages the
connectivity and has access to other node¿s sensitive information. But on the other hand, the
clusterhead role also has some associated costs. Hence, in order to prevent malicious nodes
from taking control of the group in a fraudulent way and avoid selfish attacks from suitable
nodes, the clusterhead needs to be elected in a secure way. In this paper we present a novel
solution that guarantees the clusterhead is elected in a cheat-proof manner
Energy efficiency in ad-hoc wireless networks
No full textIn ad-hoc wireless networks, nodes are typically battery-powered, therefore energy limitations are among the critical constraints in ad-hoc wireless networks' development. The approaches investigated in this thesis to achieve energy efficient performance in wireless networks
can be grouped into three main categories.
1. Each wireless network node has four energy consumption states: transmitting, receiving, listening and sleeping states. The power consumed in the listening state is less than the power consumed in the transmitting and receiving states, but significantly greater than that in the sleeping state. Energy efficiency is achieved if as many nodes as possible are put into the sleeping states.
2) Since energy is consumed for transmission nonlinearly in terms of the transmission range, transmission range adjustment is another energy saving approach. In this work, the optimal transmission range is derived and applied to achieve energy efficient performance in a number of scenerios.
3) Since energy can be saved properly arranging the communication algorithms, network topology management or network routing is the third approach which can be utilised in combination with the above two approaches. In this work, Geographical Adaptive Fidelity (GAF) algorithms, clustering algorithms and Geographic Routing (GR) algorithms are all utilised to reduce the energy consumption of wireless networks, such as Sensor Networks and Vehicular Networks.
These three approaches are used in this work to reduce the energy consumption of wireless networks. With the GAF algorithm. We derived the optimal transmission range and optimal grid size in both linear and rectangular networks and as a result we show how the network energy consumptions can be reduced and how the network lifetime can be prolonged. With Geographic Routing algorithms the author
proposed the Optimal Range Forward (ORF) algorithm and Optimal Forward with Energy Balance (OFEB) algorithm to reduce the energy consumption and to prolong the network lifetime. The results show that compared to the traditional GR algorithms (Most Forward within Radius, Nearest Forward Progress), the network lifetime is prolonged. Other approaches have also been considered to improve the networks's energy efficient operation utilising Genetic Algorithms to find the optimal size of the grid or cluster. Furthermore realistic physical layer models, Rayleigh fading and LogNormal fading, are considered in evaluating energy efficiency in a realistic network environment
The impact of mobility models on the performance of mobile Ad Hoc network routing protocol
No full textA mobility model represents nodes distribution and movement over the network. Several research works have shown that a selection of mobility model can affect the outcome of routing performance simulation in Mobile Ad Hoc Networks. Thus, a routing protocol may only be effective in a particular mobility model or scenario but performs inferiorly in another. As a result, analyses of routing protocol performance are often based on inadequate information leading to inaccurate argument and conclusion. In this paper, three different mobility models have been selected, where each of them is highly distinctive in terms of nodes movement behavior. In addition, a new measurement technique called probability of route connectivity is introduced. The technique is used to quantify the success rate of route established by a routing protocol. Extensive simulation runs are done and results are compared between each mobility model
The practice of access pricing : telecommunications in the United Kingdom
No full textTelecommunications was the first network utility to be privatized in the United Kingdom. Drawing on 15 years'experience and discussion in the field, the author shows the economic principles of regulation in general and access pricing in particular that have been implemented. British Telecommunications (BT), formed as a public enterprise in 1980-81, was privatized in 1984. Since then the approaches to regulation have changed in three broad periods: the duoply, the transition to competition, and the recently introduced normalization phase. Dealing with each period, the author focuses on how the actual implementation of access charges are determined, at the same time providing background needed on regulatory intervention generally. Rather than follow the model of competition for a common infrastructure, Oftel [the Office of Telecommunications, the regulatory agency]has encouraged competition between alternative networks, which benefits customers but involves duplication of fixed costs. As a result of Oftel's approach, customers have seen their bills reduced 50 percent in real terms since privatization. It is difficult to know how much to attribute this remarkable result to technological progress (BT halved its workforce in the same period), to regulatory intervention (Oftel set string caps until 1997), or to competition (there are hundreds of players in the market). The author contends more weight should probably be given to the first two. Entrants have not achieved big market shares, if one considers the asymmetric regulation that has been in place for more than a decade. Indirectly, at least, competition benefited consumers by applying discipline to BT's behavior. Oftel's approach was interventionist until 1997, when it began trying to normalize the industry, as authority overseeing competition. The odds on complete deregulation are slight, and some controls on industry will remain. In the longer term, Oftel should especially monitor anticompetitive practices and collusive behavior among the bigger players (BT, CWC, and cellulator operators), The United Kingdom's interconnection experience demonstrates the complexity of the problem and its relationship to other topics, such as tariff rebalancing, access deficit, and universal service. Although a bit ad hoc, the recent incentive regulation, with a network cap based on proper accounting procedures and engineering models, may represent the best practice available today in the telecommunications industry, says the author.Public Sector Economics&Finance,Decentralization,Knowledge Economy,Economic Theory&Research,Payment Systems&Infrastructure,Public Sector Economics&Finance,Education for the Knowledge Economy,Knowledge Economy,Economic Theory&Research,ICT Policy and Strategies
Internet connection method for mobile ad hoc wireless networks
No full textIn recent years, wireless networks with Internet services have become more and
more popular. Technologies which integrate Internet and wireless networks have
extended traditional Internet applications into a more flexible and dynamic
environment. This research work investigates the technology that supports the
connection between a Mobile Ad Hoc Wireless Network (MANET) and the
Internet, which enables the current wireless Internet technologies to provide a
ubiquitous wireless life style.
With detailed analysis of the existing wireless Internet technologies and
MANETs regarding their features and applications, the demand and lack of
research work for an application to provide Internet connection to MANET is
indicated. The primary difficulty for MANET and Internet connection is that the
dynamic features of MANET do not suit the traditional connection methods used
in infrastructure wireless networks. This thesis introduces new concept of the
'Gateway Awareness' (GAW) to the wireless devices in the MANET. GAW is a
new routing protocol designed by the author of this thesis, at the University of
Warwick. Based on GAW, an inclusive definition for the connection method,
which supports the Internet connection and keeps the independency of routing in
MANET, is addressed. Unlike other research work, this method supports the
MANET and Internet communication in both directions. Furthermore, it explores
possible ways of using the Internet as an extension for wireless communications.
The GAW routing method is developed from destination sequenced distance
vector (DSDV) routing protocol. However, it defines a layer of wireless nodes
(known as GAWNs) with exclusive functions for the Internet connection task.
The layer of GAWNs brings a new set of route update and route selection
method. Simulations show that the GAW routing method provides quality
Internet connection performance in different scenarios compared with other
methods. In particular, the connection is completed with minimum effect on the
independent MANET while the routing efficiency and accuracy is guaranteed
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