Scalable Layer-2/Layer-3 Multistage Switching Architectures for Software Routers

Software routers are becoming an important alternative to proprietary and expensive network devices, because they exploit the economy of scale of the PC market and open-source software. When considering maximum performance in terms of throughput, PC-based routers suffer from limitations stemming from the single PC architecture, e.g., limited bus bandwidth, and high memory access latency. To overcome these limitations, in this paper we present a multistage architecture that combines a layer-2 load-balancer front-end and a layer-3 routing back-end, interconnected by standard Ethernet switches. Both the front-end and the back-end are implemented using standard PCs and open- source software. After describing the architecture, evaluation is performed on a lab test-bed, to show its scalability. While the proposed solution allows to increase performance of PC- based routers, it also allows to distribute packet manipulation functionalities, and to automatically recover from component failures

Predictive Analytics for Real-time Auction Bidding Support: a Case on Fantasy Football

This work reports about an end-to-end business analytics experiment, applying predictive and prescriptive analytics to real-time bidding support for fantasy football draft auctions. Forecast methods are used to quantify the expected return of each investment alternative, while subgradient optimization is used to provide adaptive online recommendations on the allocation of scarce budget resources. A distributed front-end implementation of the prescriptive modules and the rankings of simulated leagues testify the viability of this architecture for actual support

Improved Storage Security using IDS and Performance using Container De-Duplication

Due to enormous increase in use of web services in our day today life, web services have moved to multitier design where in web server runs the application front-end logic and data are outsourced to a database or file server. In our system, we will implement secure de-duplication which is a technique for eliminating duplicate copies of data, it has been largely used in cloud storage to reduce storage space and upload bandwidth with Container security, an IDS system that models the network acts as user sessions across both front-end web server and back-end database. By monitoring both the web and subsequent database requests, we are capable to search out attacks that an independent Intrusion Detection System (IDS) unable to identify. In this system, each user requesting for our application will be allocated separate container. The container based web architecture not only fasters profiling of causal mapping, but it also provides an isolation that obstruct future session hijacking attacks .Each user will hold de-key which is a new construction in which users do not require to manage any keys on their own but as an alternative securely distribute the convergent key shares across multiple servers. We implement De-key to demonstrate that De-key incurs limited overhead in realistic environments

ATLAS Tile Calorimeter Readout Electronics Upgrade Program for the High Luminosity LHC

The Tile Calorimeter (TileCal) is the hadronic calorimeter covering the most central region of the ATLAS experiment at LHC. The TileCal readout consists of about 10000 channels. The ATLAS upgrade program is divided in three phases: The Phase~0 occurs during 2013-2014, Phase~1 during 2018-1019 and finally Phase~2, which is foreseen for 2022-2023, whereafter the peak luminosity will reach 5-7 x 10$^{34}$ cm$^2$s$^{-1}$ (HL-LHC). The main TileCal upgrade is focused on the Phase~2 period. The upgrade aims at replacing the majority of the on- and off-detector electronics so that all calorimeter signals are directly digitized and sent to the off-detector electronics in the counting room. All new electronics must be able to cope with the increased radiation levels. An ambitious upgrade development program is pursued to study different electronics options. Three options are presently being investigated for the front-end electronic upgrade. The first option is an improved version of the present system built using commercial components, the second alternative is based on the development of a dedicated ASIC (Application Specific Integrated Circuit) and the third is the development of a new version of the QIE (Charge Integrator and Encoder) based on the one developed for Fermilab. All three options will use the same readout and control system using high speed (up to 40 Gb/s) links for communication and clock synchronization. For the off-detector electronics a new back-end architecture is being developed. A demonstrator prototype read-out for a slice of the calorimeter with most of the new electronics, but still compatible with the present system, is planned to be inserted in ATLAS already in mid 2014 (at the end of the Phase~0 upgrade).Comment: 6 pages, 6 figures, LISHEP 201

Linguistic Processing and Classification of Semi Structured Bibliographic Data on Complementary Medicine

Complementary and alternative therapies and medicines (CAM) such as acupuncture or mistletoe treatment are much asked for by cancer patients. With a growing interest in such therapies, physicians need a simple tool with which to get an overview of the scientific publications on CAM, particularly those that are not listed in common bibliographic databases like MEDLINE. CAMbase is an XML-based bibliographical database on CAM which serves to address this need. A custom front end search engine performs semantic analysis of textual input enabling users to quickly find information relevant to the search queries. This article describes the technical background and the architecture behind CAMbase, a free online database on CAM (www.cambase.de). We give examples on its use, describe the underlying algorithms and present recent statistics for search terms related to complementary therapies in oncology

A Goertzel Filter Based System for Fast Simultaneous Multi-Frequency EIS

Bioimpedance measurement is a non-invasive, radiation-free, and inexpensive method for measuring the electrical properties of biological tissues. In applications where transients occur, the commonly used swept sinewave is replaced with broadband signals such as multisine. This makes the signal generation and the extraction of the real and imaginary parts of the impedance challenging. In this brief, an alternative to traditional fast Fourier transform (FFT) or coherent demodulation is presented. Based on the Goertzel filter, this alternative is simpler and requires very few digital resources. Its robustness to the harmonic fold back phenomenon, enables simple ternary current pulses to be used for excitation. The developed digital architecture is capable of simultaneous demodulation of 16 frequencies with an accuracy of 97% and 96% on the magnitude and phase measurement respectively. Employing a ternary sequence allows the use of a low power H-bridge current driver. The analog front-end and demodulation algorithm were implemented in an ASIC using a 180-nm CMOS technology. The system was tested on an isolated pig heart distinguishing edema from non-edema tissue by impedance changes

Periodic Preamble-Based Frequency Recovery in OFDM Receivers Plagued by I/Q Imbalance

The direct conversion receiver (DCR) architecture has received much attention in the last few years as an effective means to obtain user terminals with reduced cost, size, and power consumption. A major drawback of a DCR device is the possible insertion of I/Q imbalances in the demodulated signal, which can seriously degrade the performance of conventional synchronization algorithms. In this paper, we investigate the problem of carrier frequency offset (CFO) recovery in an OFDM receiver equipped with a DCR front-end. Our approach is based on maximum likelihood (ML) arguments and aims at jointly estimating the CFO, the useful signal component, and its mirror image. In doing so, we exploit knowledge of the pilot symbols transmitted within a conventional repeated training preamble appended in front of each data packet. Since the exact ML solution turns out to be too complex for practical purposes, we propose two alternative schemes which can provide nearly optimal performance with substantial computational saving. One of them provides the CFO in closed-form, thereby avoiding any grid-search procedure. The accuracy of the proposed methods is assessed in a scenario compliant with the 802.11a WLAN standard. Compared with existing solutions, the novel schemes achieve improved performance at the price of a tolerable increase of the processing load

Multi-standard RF front-end for avionic systems

Aerodynamic issues such as drag, weight and aeroacoustic noise are important factors in evaluating the impact of a given antenna on an aircraft’s overall performance. These factors are directly related to aircraft fuel consumption, speed and range. This project’s focus is on RF front-end electronics. The main goal here is to bring aircraft radio equipment as close as possible to the antennas in order to minimize wiring weight and complexity. This calls for a drastic volume reduction of the radio equipment. To this end, the system level requirements for the RF front-ends in terms of frequency bandwidths, data rates, etc, are first investigated in order to identify applications where the proposed volume reductions are the most beneficial and feasible. Following this, the focus was on an architectural investigation of alternative topologies that can meet the specification. For each topology considered the front-end-level specification need to be translated to circuit/component level requirements. For each case, performance, cost and technical risk analyses are carried out. Then, the design and prototyping of key RF front-end circuits for the selected architecture are undertaken. The multilayered Low Temperature Co-fired Ceramic (LTCC) technology had to be considered as a high risk but more advantageous option in terms of volume/weight reduction. Finally, we aimed at integrating and testing the proposed RF front-end chain, first by characterizing each component individually, and then as a whole front-end subsystem

Analysis and Development of a Low Cost GSM Telephone System for a Rural Area

This work presents the analysis and development of a low cost GSM telephone system. A review of radio receiver and·transmitter architectures showed the superheterodyne as having a better performance over the direct conversion radio in terms of selectivity and complexitY.. A low power bidirectional transceiver was developed based on the superheterodyne architecture. The specifications of the bidirectional transceiver were computed using specifications of the component modules in the spreadsheet approach. The resulting design was optimized using Matlab programs and simulated using the Genesys simulation software. The results show the front end of the transceiver as the most critical part of the transceiver. Both the generic and proposed transceivers had frequency response from 1700MHz to 1900MHz, the same dynamic range and noise figure but the proposed transceiver achieved these results with a 50% reduction in power amplifier and low noise amplifier chi!JS and the 75% reduction in the number of voltage oscillator chips. This reduction in component count fed to a 40.59% reduction in power requirement and a reduction in the overall cost of the proposed transceiver. The reduced power consumption of the architecture enables the use of solar energy as an alternative source of power supply for the transceivers