An authentication protocol for mobile cellular network

Current cellular telephone system is vulnerable to various attacks. With more complicated equipments, it is possible to receive the ESN and PIN of legal user and use them to commit cellular telephone frauds. Generally, the frauds can be classified into three: subscription fraud, technical fraud, and internal fraud. This paper analyses the frauds in cellular mobile communication and provides an efficient authentication protocol that can be taken to protect the current system

Design of simulation system for performance predictions of WDM single-hop networks

Describes the design, development and use of a software architecture for a simulation environment to examine, validate and predict the performance of piggybacked token passing protocol for a wavelength division multiplexed (WDM) optical network. This simulation environment overcomes many of the limitations found with analytical models. A set of the principal components and their dynamics, which make up the simulation design has been identified. It is shown that this protocol optimises the usage of the bandwidth available in the optical fibre with more than 70% used for data transmission. It is also suggested that the number of channels required to accomplish a single-hop connection within a local environment is small with number of channels to nodes ratio of 1:4. This is comparatively small and requires only limited-tuneable transceivers

A fuzzy channel allocation scheme for the WDM hierarchical all-optical network

The fuzzy means of allocating WDM channels in a hierarchical all-optical network (AON) for the modified token medium access protocol is addressed. The goal is to minimise the average delay of local subnet and global bound traffic, and to maximise the number of nodes that can be supported by the network. This is achieved by allotting a minimum number of spatially-reuse channels to the subnets, which can accommodate a certain maximum number of nodes. Actually the minimum number of nodes that are sought for each subnet in terms of cost. By working out the maximum number of nodes for each subnet and the total subnets that can be supported, the optimum number of global channels and the overall total number of nodes for the entire network, can hence be determined. The packet generation rate and average delay in slot time are used to gauge the performance of the fuzzy channel allocation model

New call blocking probability (NCBP) in improved adaptive quality of service (AdQoS) for wireless multimedia communications using hierarchical cellular approach

The maintenance of quality of service (QoS) in a wireless environment is a difficult problem. Most researchers have already acknowledged adaptive techniques as the appropriate method to deal with the fluctuation of QoS in a wireless cellular network. This paper proposes an improved new call blocking probability (NCBP) from an adaptive QoS (AdQoS) to support the QoS guarantee. Besides using an adaptive technique, this method utilizes a hierarchical cellular approach with a bandwidth reallocation algorithm to determine the acceptance or rejection of a new call. The approach would improve the NCBP performance of the multimedia application over high-speed wireless cellular networks

Location Management Cost Reduction Using Adaptive Velocity-movement Based Scheme

Wireless personal communication networks (PCNs) consist of a fixed wireless network and a large number of mobile terminals. These terminals are free to travel within the PC coverage area without service interruption. Each terminal periodically reports its location to the network by a process called location update (or registration). When a call arrives for a particular mobile terminal, the network will determine the exact location of the destination terminal by a process called terminal paging. One major problem that arises in this scenario is the cost associated with paging and registration. Several papers in the literature attempt to reduce the cost by devising new schemes for paging and registration. One of the many interesting schemes was presented by Wan and Lin (1998) that considers a dynamic paging scheme based on the semi-real time velocity information of an individual mobile user, which allows a more accurate prediction of the user location when a call arrives. In this paper, we modified the scheme presented by Wan and Lin by creating an adaptive velocity timer that changes according to the speed of the mobile and applies the same analysis to the movement-based scheme. The investigation shows that the proposed approach of Wan and Lin has better results than what was reported therein and our new approach helps reduce the total cost drastically compared to the original scheme. Results also show that the movement threshold and the adaptive velocity time unit, when they are adaptive, provide significant savings of cost under different cell sizes and velocities in high and low mobility systems

A hand segmentation scheme using clustering technique in homogeneous background

Segmentation serves as the first step in any image analysis and it plays a very vital role as the success of the image analysis in the later stage depends very much on a suitable and robust segmentation scheme. Hand segmentation on the other hand is the first step for hand image analysis such as hand gesture recognition. An image subtraction method is implemented on a gray level image, RGB color image and image in normalized RGB color space under homogeneous background to investigate their appropriateness for segmentation. A skin color model based on the clustering property of skin color is then built to improve the segmentation result obtained from the image subtraction on the normalized RGB image. It is found that the proposed skin color modeling technique is able to improve the segmentation and provide a faster and reliable method for hand segmentation

A scheduling algorithm for WDM optical networks

This paper proposes a scheduling algorithm for time-slotted WDM broadcast-and-select optical networks. The algorithm is free from collision and supports a particular class of quality of service (QoS), namely constant bit rate (CBR). The running time complexity of the algorithm is O(Mlog2N)1, where M and N are the number of packets used for scheduling and the number of nodes, respectively. This running time can be improved to O(log3N) by parallel processing

The use of agent to incorporate network awareness into dynamic proxy framework: an overview

It has been observed that research in mobile agent focused on the development of platforms and on the application of the concept. Network awareness is one of the applications of mobile agent, concerning of how agent determine and make the most efficient use of network resources. This paper describes the role and functionality of mobile agent in the context of a dynamic proxy framework named the Chek Proxy Framework (CPF). Attention is paid on setting out a multi-agent-based framework to enrich CPF with a Network Awareness Module (NAM), which is implemented in an agent named ObjectBasket (OB). NAM is a single framework that integrates resource discovery, load monitoring and migration, and fault management, to operate in a network with dynamic proxy servers. The main objective of NAM is to deliver robustness and best-effort QoS guarantees into the existing CPF system adaptively, based on the availability of resources in the network. In this paper, we present the architecture of NAM, status generation algorithm, implementation rules, and the management of faults and overloading.Facultad de Informátic

MAT2A Mutations Predispose Individuals to Thoracic Aortic Aneurysms

Up to 20% of individuals who have thoracic aortic aneurysms or acute aortic dissections but who do not have syndromic features have a family history of thoracic aortic disease. Significant genetic heterogeneity is established for this familial condition. Whole-genome linkage analysis and exome sequencing of distant relatives from a large family with autosomal-dominant inheritance of thoracic aortic aneurysms variably associated with the bicuspid aortic valve was used for identification of additional genes predisposing individuals to this condition. A rare variant, c.1031A>C (p.Glu344Ala), was identified in MAT2A, which encodes methionine adenosyltransferase II alpha (MAT IIα). This variant segregated with disease in the family, and Sanger sequencing of DNA from affected probands from unrelated families with thoracic aortic disease identified another MAT2A rare variant, c.1067G>A (p.Arg356His). Evidence that these variants predispose individuals to thoracic aortic aneurysms and dissections includes the following: there is a paucity of rare variants in MAT2A in the population; amino acids Glu344 and Arg356 are conserved from humans to zebrafish; and substitutions of these amino acids in MAT Iα are found in individuals with hypermethioninemia. Structural analysis suggested that p.Glu344Ala and p.Arg356His disrupt MAT IIα enzyme function. Knockdown of mat2aa in zebrafish via morpholino oligomers disrupted cardiovascular development. Co-transfected wild-type human MAT2A mRNA rescued defects of zebrafish cardiovascular development at significantly higher levels than mRNA edited to express either the Glu344 or Arg356 mutants, providing further evidence that the p.Glu344Ala and p.Arg356His substitutions impair MAT IIα function. The data presented here support the conclusion that rare genetic variants in MAT2A predispose individuals to thoracic aortic disease

Meningococcal disease surveillance in the Asia-Pacific region (2020): The global meningococcal initiative.

The degree of surveillance data and control strategies for invasive meningococcal disease (IMD) varies across the Asia-Pacific region. IMD cases are often reported throughout the region, but the disease is not notifiable in some countries, including Myanmar, Bangladesh and Malaysia. Although there remains a paucity of data from many countries, specific nations have introduced additional surveillance measures. The incidence of IMD is low and similar across the represented countries (<0.2 cases per 100,000 persons per year), with the predominant serogroups of Neisseria meningitidis being B, W and Y, although serogroups A and X are present in some areas. Resistance to ciprofloxacin is also of concern, with the close monitoring of antibiotic-resistant clonal complexes (e.g., cc4821) being a priority. Meningococcal vaccination is only included in a few National Immunization Programs, but is recommended for high-risk groups, including travellers (such as pilgrims) and people with complement deficiencies or human immunodeficiency virus (HIV). Both polysaccharide and conjugate vaccines form part of recommendations. However, cost and misconceptions remain limiting factors in vaccine uptake, despite conjugate vaccines preventing the acquisition of carriage.S