Building blocks for IP telephony

Convergence between the existing telephone networks and data transfer over the Internet not only demands that new software be written to handle telephony applications which span both networks, but also makes new and innovative applications possible. Rather than writing these applications from the ground up, it would be helpful to have a relatively high-level API on which to prototype new applications. In this article we describe a set of Java packages developed at Cornell University to accomplish this purpose. The software's name is ITX; it is available for download at no charge, and includes sample applications and documentation     

An adaptive ensemble classifier for mining concept drifting data streams

It is challenging to use traditional data mining techniques to deal with real-time data stream classifications. Existing mining classifiers need to be updated frequently to adapt to the changes in data streams. To address this issue, in this paper we propose an adaptive ensemble approach for classification and novel class detection in concept drifting data streams. The proposed approach uses traditional mining classifiers and updates the ensemble model automatically so that it represents the most recent concepts in data streams. For novel class detection we consider the idea that data points belonging to the same class should be closer to each other and should be far apart from the data points belonging to other classes. If a data point is well separated from the existing data clusters, it is identified as a novel class instance. We tested the performance of this proposed stream classification model against that of existing mining algorithms using real benchmark datasets from UCI (University of California, Irvine) machine learning repository. The experimental results prove that our approach shows great flexibility and robustness in novel class detection in concept drifting and outperforms traditional classification models in challenging real-life data stream applications.     

Hybrid PSO feature selection-based association classification approach for breast cancer detection

Neural Computing and Applications - Breast cancer is one of the leading causes of death among women worldwide. Many methods have been proposed for automatic breast cancer diagnosis. One popular...     

A scheduling discipline and admission control policy for xunet 2

Xunet 2 is a collaborative research program with a goal of understanding the fundamental issues in the performance of ATM networks. These networks are expected to carry a mixture of constant bit-rate traffic, variable bit-rate traffic and computer traffic spanning a wide range of performance requirements. This paper describes these service requirements and matches them with performance guarantees that can be provided by the scheduling discipline supported by an experimental ATM switch. The scheduler supports per-virtual-circuit queueing and several priorities of round robin service in order to segregate real-time and non-real-time traffic and provide fair sharing for bursty computer traffic. Detailed simulations show that real-time traffic can be efficiently integrated with non-real-time traffic using appropriate call admission policies and enhancements to traditional round robin scheduling. While the present study focuses on providing quality of service guarantees in the Xunet 2 network, the design of the scheduler and the call admission policies are relevant to ATM networks in general. On leave of: Indian Institute of Technology, Delhi, India     

Blood flow through the embryonic heart outflow tract during cardiac looping in HH13–HH18 chicken embryos

Blood flow is inherently linked to embryonic cardiac development, as haemodynamic forces exerted by flow stimulate mechanotransduction mechanisms that modulate cardiac growth and remodelling. This study evaluated blood flow in the embryonic heart outflow tract (OFT) during normal development at each stage between HH13 and HH18 in chicken embryos, in order to characterize changes in haemodynamic conditions during critical cardiac looping transformations. Two-dimensional optical coherence tomography was used to simultaneously acquire both structural and Doppler flow images, in order to extract blood flow velocity and structural information and estimate haemodynamic measures. From HH13 to HH18, peak blood flow rate increased by 2.4-fold and stroke volume increased by 2.1-fold. Wall shear rate (WSR) and lumen diameter data suggest that changes in blood flow during HH13–HH18 may induce a shear-mediated vasodilation response in the OFT. Embryo-specific four-dimensional computational fluid dynamics modelling at HH13 and HH18 complemented experimental observations and indicated heterogeneous WSR distributions over the OFT. Characterizing changes in haemodynamics during cardiac looping will help us better understand the way normal blood flow impacts proper cardiac development.     

Self-focusing of Gaussian Laser Beam Through Collisionless Plasmas and Its Effect on Second Harmonic Generation

This paper presents an investigation of self-focusing of gaussian laser beam in a collisionless plasma and its effect on second harmonic generation. In the presence of gaussian beam, the carriers get redistributed from the high field region to low field region by ponderomotive force and transverse density gradient is established in plasma which in turn generates the plasma wave at pump frequency. This plasma wave interacts with incident laser beam and a second harmonic is generated. Furthermore, if the initial power of input beam is more than the critical power for self-focusing, the beam gets self-focused and hence the generated plasma wave and second harmonic which depend upon the background electron concentration and power of the main beam also get modified accordingly.     

Self-focusing of Gaussian Laser Beam Through Collisional Plasmas: Moment Theory Approach

In the present paper, self-focusing of Gaussian laser beam through collisional plasma is studied by moment theory approach. Nonlinear differential equation for beam width parameter of laser beam has been set up and solved numerically to study the variation of beam width parameter with normalized distance of propagation. Effect of absorption coefficient and plasma density on the beam width parameter has been studied. It is observed from the analysis that increasing the value of absorption coefficient brings about reduction in extent of self-focusing on account of decrease in energy of beam, which is equivalent to weakening of nonlinearity effect. On the other hand, increase in plasma density results in a sharp decrease in focusing length due to increase in nonlinear part of dielectric constant.     

A sequence in the N-terminal region of human uracil-DNA glycosylase with homology to XPA interacts with the C-terminal part of the 34-kDa subunit of replication protein A

Uracil-DNA glycosylase releases free uracil from DNA and initiates base excision repair for removal of this potentially mutagenic DNA lesion. Using the yeast two-hybrid system, human uracil-DNA glycosylase encoded by the UNG gene (UNG) was found to interact with the C-terminal part of the 34-kDa subunit of replication protein A (RPA2). No interaction with RPA4 (a homolog of RPA2), RPA1, or RPA3 was observed. A sandwich enzyme-linked immunosorbent assay with trimeric RPA and the two-hybrid system both demonstrated that the interaction depends on a region in UNG localized between amino acids 28 and 79 in the open reading frame. In this part of UNG a 23-amino acid sequence has a significant homology to the RPA2-binding region of XPA, a protein involved in damage recognition in nucleotide excision repair. Trimeric RPA did not enhance the activity of UNG in vitro on single- or double-stranded DNA. A part of the N-terminal region of UNG corresponding in size to the complete presequence was efficiently removed by proteinase K, leaving the proteinase K-resistant compact catalytic domain intact and fully active. These results indicate that the N-terminal part constitutes a separate structural domain required for RPA binding and suggest a possible function for RPA in base excision repair.     

Modal analysis of cold-formed pallet rack structures with semi-rigid connections

The three dimensional (3D) model of conventional pallet racking systems were prepared using the finite element program ANSYS and free vibration modal analysis carried out on conventional pallet racks with the 18 types of column sections developed along with semi-rigid connection. The stiffness of the connector was tested using the conventional cantilever method and also using a double cantilever method. Non-linear finite element analysis of both the tests was carried out. From the experimental study on connection and finite element modal analysis, a simple analytical model that captures the seismic behavior of storage racks in their down aisle direction is proposed. The model is aimed at developing simplified equation for the fundamental period of storage racks in their down aisle direction. A parametric study was carried out to find out fundamental mode shape and time period. Finite element method is used for the accuracy and appropriateness of cold-formed steel frame.     

Electrolytic surface hardening of steel, cast iron and aluminium-bronze

T he electrolytic hardening is quite a m odern heat treatm entprocess,which can be applied to ferrous and non-ferrous alloys like alum inum bronzes. The norm al surfacehardeningprocessesare: (1)Flam ehardening (2)Induction hardening. (3)Laserhardening (4)Electrolytichardening H owever,out of the above four last two m ethods are m ore m odern.In this paperm odern process electrolytic hardening hasbeen discussed.Theeffortshavebeen m adeto setvarious process param eters, which give new approach…