Shortest Path versus Multi-Hub Routing in Networks with Uncertain Demand

We study a class of robust network design problems motivated by the need to scale core networks to meet increasingly dynamic capacity demands. Past work has focused on designing the network to support all hose matrices (all matrices not exceeding marginal bounds at the nodes). This model may be too conservative if additional information on traffic patterns is available. Another extreme is the fixed demand model, where one designs the network to support peak point-to-point demands. We introduce a capped hose model to explore a broader range of traffic matrices which includes the above two as special cases. It is known that optimal designs for the hose model are always determined by single-hub routing, and for the fixed- demand model are based on shortest-path routing. We shed light on the wider space of capped hose matrices in order to see which traffic models are more shortest path-like as opposed to hub-like. To address the space in between, we use hierarchical multi-hub routing templates, a generalization of hub and tree routing. In particular, we show that by adding peak capacities into the hose model, the single-hub tree-routing template is no longer cost-effective. This initiates the study of a class of robust network design (RND) problems restricted to these templates. Our empirical analysis is based on a heuristic for this new hierarchical RND problem. We also propose that it is possible to define a routing indicator that accounts for the strengths of the marginals and peak demands and use this information to choose the appropriate routing template. We benchmark our approach against other well-known routing templates, using representative carrier networks and a variety of different capped hose traffic demands, parameterized by the relative importance of their marginals as opposed to their point-to-point peak demands

Effect of Diabetes Mellitus of Patients on Sensorineural Hearing Loss in a Tertiary Health Care Center

INTRODUCTION: Diabetes Mellitus is the single most important metabolic disease which can affect nearly every organ system in the body. Almost all the macro and microvascular complications of diabetes have been studied extensively. Sensorineural hearing loss (SNHL) is a type of hearing loss, or deafness, in which the root cause lies in the inner ear (cochlea and associated structures), vestibulocochlear nerve (cranial nerve VIII), or central auditory processing centers of the brain. Hearing impairment is defined by the World Health Organization (WHO) as a hearing loss with thresholds higher than 25db in one or both ears. The degree of hearing loss is classified as mild, moderate, severe or profound. Early detection of hearing loss is possible with the help of high frequency pure tone audiometry which may be undetected by a conventional audiometry. RATIONALE: The link between diabetes and SNHL makes intuitive sense, given the documented neuropathic and microvascular complications of diabetes and the complex blood supply of the inner ear. AIMS OF STUDY: 1. Early detection of Hearing loss in high risk individuals, with predilection to Diabetes Mellitus. 2. To compare the efficacy of conventional hearing assessment (tuning fork test) against the high frequency audiometer in detection of hearing loss. 3. Early intervention and prevention of diabetes mellitus induced hearing loss. 4. Increase awareness among health care providers and laypersons. METHODOLOGY: The study was a hospital based cross sectional study conducted in the department of ENT, Sree Mookambika Institute of Medical Sciences Hospital, Kanyakumari from December 2016 to October 2018 (Approximately 18 months). A total of 30 Human subjects were examined above the age 30years with Type 2 Diabetes Mellitus requiring assessment of hearing loss and willingness to participate in the study. All the cases were subjected to tuning fork test and pure tone audiometry. Risks and Benefits of the Study: Benefits: Appropriate early diagnosis of causative factors for SNHL in diabetics to ensure prompt and effective management and to avoid or minimize the occurrence of complications. No risks so far have been detected following the study. CONCLUSION: In patients with diabetes mellitus, by the time hearing loss is detected using conventional tuning fork tests, damage has already affected the sensorineural component, which will affect the hearing component of the patient and hence affect the quality of life. Therefore by using audiometry early detection of hearing loss in people affected with Type 2 Diabetes mellitus can be done. It will help us to take early steps to make the patients affected by diabetes aware of the deafness and to take early measures for prevention and further progression of deafness

Use of remote sensing in the context of cage aquaculture

Remote sensing has much to offer to the cage aquaculture industry. First, it is helpful in the choice of sites for development of cage culture. Here, the opposing requirements of dispersion of waste products and shelter for the cages have to be balanced. The ability of remote sensing to deliver spatially-extensive data at high resolution is important, especially when complemented by numerical modelling. The most favourable period for cage deployments of less than one year can also be assessed from the seasonal wind field. Once the sites are selected, remote sensing continues to be beneficial in operational culture by providing early indications of the advent of water masses that are potentially antagonistic, either because of their physical properties or their microflora. Such warning gives producers the option to harvest their fish early and thereby minimize potential losses

A Unified Multi-Functional Dynamic Spectrum Access Framework: Tutorial, Theory and Multi-GHz Wideband Testbed

Dynamic spectrum access is a must-have ingredient for future sensors that are ideally cognitive. The goal of this paper is a tutorial treatment of wideband cognitive radio and radar—a convergence of (1) algorithms survey, (2) hardware platforms survey, (3) challenges for multi-function (radar/communications) multi-GHz front end, (4) compressed sensing for multi-GHz waveforms—revolutionary A/D, (5) machine learning for cognitive radio/radar, (6) quickest detection, and (7) overlay/underlay cognitive radio waveforms. One focus of this paper is to address the multi-GHz front end, which is the challenge for the next-generation cognitive sensors. The unifying theme of this paper is to spell out the convergence for cognitive radio, radar, and anti-jamming. Moore’s law drives the system functions into digital parts. From a system viewpoint, this paper gives the first comprehensive treatment for the functions and the challenges of this multi-function (wideband) system. This paper brings together the inter-disciplinary knowledge

Characterising anamolous events using change-point correlation on unsolicited network traffic

Monitoring unused or dark IP addresses offers opportunities to extract useful information about both on-going and new attack patterns. In recent years, different techniques have been used to analyze such traffic including sequential analysis where a change in traffic behavior, for example change in mean, is used as an indication of malicious activity. Change points themselves say little about detected change; further data processing is necessary for the extraction of useful information and to identify the exact cause of the detected change which is limited due to the size and nature of observed traffic. In this paper, we address the problem of analyzing a large volume of such traffic by correlating change points identified in different traffic parameters. The significance of the proposed technique is two-fold. Firstly, automatic extraction of information related to change points by correlating change points detected across multiple traffic parameters. Secondly, validation of the detected change point by the simultaneous presence of another change point in a different parameter. Using a real network trace collected from unused IP addresses, we demonstrate that the proposed technique enables us to not only validate the change point but also extract useful information about the causes of change points

Running Header: Statistical Problem Detection.

tel:(518)276-8424; fax:(518)276-2433. The detection of network fault scenarios was achieved using an appropriate subset of Man-agement Information Base (MIB) variables. Anomalous changes in the behavior of the MIB variables was detected using a sequential Generalized Likelihood Ratio (GLR) test. This in-formation was then temporally correlated using a duration filter to provide node level alarms which correlated with observed network faults and performance problems. The algorithm was implemented on data obtained from two different network nodes. The algorithm was optimized using five of the nine fault data sets and it proved general enough to detect three of the re-maining four faults. Consistent results were obtained from the second node as well. Detection of most faults occurred in advance (at least 5 mins) of the fault suggesting the possibility of ∗Supported by DARPA under contract number F30602-97-C-0274 1 prediction and recovery in the future

End-to-end service quality measurement using source-routed probes

Abstract — The need to monitor real time network services has prompted service providers to use new measurement technologies, such as service-specific probes. Service-specific probes are active probes that closely mimic the service traffic so that it receives the same treatment from the network as the actual service traffic. These probes are end-to-end and their deployment depends on solutions that address questions such as minimizing probe traffic, while still obtaining maximum coverage of all the links in the network. In this paper, we provide a polynomial-time probe-path computation algorithm, as well as a-approximate solution for merging probe paths when the number of probes exceed a required bound�. Our algorithms are evaluated using ISP topologies generated via Rocketfuel. We find that for most topologies, it is possible to cover more than��of the edges using just�of the nodes as terminals. Our work also suggests that the deployment strategy for active probes is dependent on cost issues, such as probe installation, probe set-up, and maintenance costs. I