ABSTRACT Distributed software development is a globally accepted practice by large organizations ... more ABSTRACT Distributed software development is a globally accepted practice by large organizations for achieving significant cost savings in research and development. However when it comes to product quality, defect prevention and early detection has always been a challenge. Factors such as differences in language, coding standards and documentation styles across distributed teams can aggravate the situation. These issues, if not addressed, will manifest themselves as product defects leading to enormous costs in fixing at later phases of development. This in turn reduces the business partner or product owner's confidence. Thus, along with defining effective processes to address these issues, it becomes very important to ensure that the product quality expectations of various stakeholders are understood and mutually agreed upon. This paper summarizes our approach and practice in managing these issues while also delivering the expected product quality in our recent project.
Geometric volume has been used for correlating ten molecular and thermodynamic properties of a pa... more Geometric volume has been used for correlating ten molecular and thermodynamic properties of a particular category of halomethane refrigerants. The properties have been selected such that their conformity to certain specified norms qualify a compound as a good refrigerant. Based on the developed correlations, these properties have been predicted for the entire range of halomethanes belonging to the same category. A number of new halomethanes have emerged as potentially capable refrigerants. Existing refrigerants are mostly low geometric volume compounds. However, for some of the properties, namely, critical volume, critical density, density of saturated vapour pressure at boiling point and thermal conductivity, higher geometric volume compounds are as efficient as the lower volume members
Abstract 629 haloethanes are theoretically possible by different combinations of fluorine, chlori... more Abstract 629 haloethanes are theoretically possible by different combinations of fluorine, chlorine, bromine and iodine atoms. Geometric and common volumes of all these compounds have been computed. Rotation of the methyl group about the CC single bond effects changes in the geometric and common volumes. The most stable conformer of ethane corresponds to the highest geometric volume conformation. The experimental boiling points of haloethanes have been correlated with a multivariable nonlinear correlation equation and the boiling points of all 629 haloethanes have been predicted therefrom. The Atomic Contribution Method (ACM), developed for halomethanes, has been extended to haloethanes. The predicted boiling points of the haloethanes using the ACM agree well with the experimental boiling points.
Third IEEE International Vacuum Electronics Conference (IEEE Cat. No.02EX524)
Summary form only given. We have made measurements of and modelled cold and hot phase velocities ... more Summary form only given. We have made measurements of and modelled cold and hot phase velocities for the custom-made XWING broadband traveling wave tube. The TWT used in this investigation, termed the XWING TWT (for experimental Wisconsin Northrop Grumman TWT), is a research version of a product manufactured by Northrop Grumman. This two-stage, helical TWT provides a moderate gain of
We have reported the formation of magnetic and non magnetic regime in the same sample by oblique ... more We have reported the formation of magnetic and non magnetic regime in the same sample by oblique incidence 36 keV Fe3+ ion bombardment on Si(100) ripple structures prefabricated by 8 keV O1+ bombardment at oblique angle. The same phenomenon is also observed on ion induced rippled ZnO thin films deposited of on Si(100). Ex situ atomic force microscopy (AFM) and
Journal of Physics A: Mathematical and General, 1984
ABSTRACT Transformation of nonlinear plasma equations to a space-independent frame with the help ... more ABSTRACT Transformation of nonlinear plasma equations to a space-independent frame with the help of the Lorentz transformation gives in place of partial differential equations a set of ordinary differential equations in a single independent variable for solution of nonlinear field equations. In this paper, this transformation has been used to yield the nonlinear precessional rotation of electromagnetic waves in plasmas in addition to the nonlinear shift in a wave parameter. Moreover, the Lagrangian and Hamiltonian of motion for a circularly polarised wave have been transformed to the space-independent frame and the equations of Akhiezer and Polovin (1956) for nonlinear plasma oscillations have been rectified by making them relativistically correct.
Proceedings DARPA Active Networks Conference and Exposition
Active networks represent a change in network paradigm from a static, one-size-fits-all packet-tr... more Active networks represent a change in network paradigm from a static, one-size-fits-all packet-transport service to a flexible platform capable of being programmed to provide new services. Active networks will allow rapid deployment of new and complex network services. An important property of an active network API is the support it provides for composing complex services out of components. An efficient
Page 1. Fast Timescale Control for MPLS Traffic Engineering ∗ S. Phuvoravan⋆, KT Kuo T. Guven⋆, ... more Page 1. Fast Timescale Control for MPLS Traffic Engineering ∗ S. Phuvoravan⋆, KT Kuo T. Guven⋆, L. Sudarsan⋆, HS Chang⋆, S. Bhattacharjee and MA Shayman⋆. ... Sm = m ∑ k=1 Xt (1) Let vm = Var(Sm/m). So vm = σ2 [1+2 m ∑ k=1 (1 − k m )ρk] m−1 (2) ...
A large number of molecular and thermodynamic properties of the alkane molecules containing up to... more A large number of molecular and thermodynamic properties of the alkane molecules containing up to eight carbon atoms have been correlated with a newly developed theoretical index, geometric volume. The geometric volume gives an estimate of the molecular size and is characteristic of each alkane molecule. The n-alkanes generally show a smooth positive variation in their molecular properties with the geometric volume while the isomers correlate differently in many cases. In such cases, however, a single bilinear correlation equation may be derived for the entire set of alkane molecules. It is possible to obtain more realistic and meaningful correlation equations, if the regularities in the molecular properties of the alkane molecules are properly identified by graph theoretical ordering of the structure.
Microfabricated folded waveguide traveling wave tubes (FWG-TWT) are potential compact sources of ... more Microfabricated folded waveguide traveling wave tubes (FWG-TWT) are potential compact sources of wideband ( 20instantaneous bandwidth), high power (0.01 - 1 W) THz radiation (i.e., between 100 - 1000 GHz). We describe a scaled experiment at 50 GHz to investigate an oscillator concept using an amplifier with recirculated feedback. Oscillations are observed between 42 - 44 GHz with the total
Flame spread over thin cellulosic fuel in a quiescent, microgravity environment of a 50/50 volume... more Flame spread over thin cellulosic fuel in a quiescent, microgravity environment of a 50/50 volumetric mixture of oxygen (oxygen mass fraction 0.53) and nitrogen at 152 kPa (1.5 atm) has been analyzed theoretically, and the results are compared to a recently conducted experiment in the microgravity environment on board a Space Shuttle flight. Experimental results suggest that the fuel preheat zone upstream of the gas-phase flame is followed by a constant temperature pyrolysis zone, which is followed by a large zone of surface reaction. Because the theory does not treat surface reaction, results of the theory apply only to regions close to the flame leading edge. Although CO2 and H2O radiation is included in the theory, the absorption and emission of radiation by the fuel surface is modeled only approximately. The theory compares well with experiment near the flame leading edge. The flame spread rate, peak surface temperature, and gas-phase temperature at two different locations are predicted within 5%. The success of the theory leads to the conclusion that the flame structure near the flame leading edge determines the flame spread rate and that gas-phase radiation plays a significant role in quiescent, microgravity flame spread.
Results from recently conducted experiments on flame spread over a thin cellulosic fuel in a quie... more Results from recently conducted experiments on flame spread over a thin cellulosic fuel in a quiescent, microgravity environment of a 50/50 volumetric mixture of oxygen and nitrogen (oxygen mass fraction 0.53) at three different pressures—101, 152, and 203 kPa (1, 1.5, and 2.0 atm)—are analyzed. The results are compared with established theoretical results and two different computational flame spread models: one that includes gas-phase radiation, and one that does not. The spread rate behavior from experiment, i.e., an increase of spread rate with pressure, is consistent with the theoretical model that includes gas-phase radiation, and side-view photographs of the flames compare favorably with two-dimensional temperature contours produced computationally from the same model. In contrast, neither the dependence of spread rate on pressure nor the flame shape can be predicted with favorable comparison to experiment if radiation is neglected.
A computational model of flame spread over a thermally thick solid fuel in an opposing-flow envir... more A computational model of flame spread over a thermally thick solid fuel in an opposing-flow environment is presented. Unlike thermally thin fuels, for which the effect of fuel surface radiation is negligible for high levels of opposing flow, fuel surface radiation is important for thermally thick fuels for all flow levels. This result is shown to derive from the fact that the ratio of the rate of heat transfer by re-radiation from the surface to that by conduction from the gas to the solid is proportional to the length over which heat can be conducted forward of the flame to sustain spreading. For thin fuels, this length decreases with increasing flow velocity such that while radiation is important at low flow velocities it is not at the higher velocities. For thick fuels at low flow velocities, the conduction length is determined by gas-phase processes and decreases with increasing flow velocity. But at higher flow velocities, the conduction length is determined by solid-phase proc...
Workshop on image analysis for multimedia interactive services, May 31, 1999
A content-based image-retrieval system is described in this paper. The system is designed to admi... more A content-based image-retrieval system is described in this paper. The system is designed to administer a heterogeneous collection of images. The goal is to support querying in a rotationand translation-, and juxtaposition-invariant fashion. The conceptual similarity measure used to compare two images is the number of small image-patches the images have in common. The patches to be compared are chosen using a 2D continuous wavelet which acts as a low-level corner detector. The local maxima in the response of ...
ABSTRACT Distributed software development is a globally accepted practice by large organizations ... more ABSTRACT Distributed software development is a globally accepted practice by large organizations for achieving significant cost savings in research and development. However when it comes to product quality, defect prevention and early detection has always been a challenge. Factors such as differences in language, coding standards and documentation styles across distributed teams can aggravate the situation. These issues, if not addressed, will manifest themselves as product defects leading to enormous costs in fixing at later phases of development. This in turn reduces the business partner or product owner's confidence. Thus, along with defining effective processes to address these issues, it becomes very important to ensure that the product quality expectations of various stakeholders are understood and mutually agreed upon. This paper summarizes our approach and practice in managing these issues while also delivering the expected product quality in our recent project.
Geometric volume has been used for correlating ten molecular and thermodynamic properties of a pa... more Geometric volume has been used for correlating ten molecular and thermodynamic properties of a particular category of halomethane refrigerants. The properties have been selected such that their conformity to certain specified norms qualify a compound as a good refrigerant. Based on the developed correlations, these properties have been predicted for the entire range of halomethanes belonging to the same category. A number of new halomethanes have emerged as potentially capable refrigerants. Existing refrigerants are mostly low geometric volume compounds. However, for some of the properties, namely, critical volume, critical density, density of saturated vapour pressure at boiling point and thermal conductivity, higher geometric volume compounds are as efficient as the lower volume members
Abstract 629 haloethanes are theoretically possible by different combinations of fluorine, chlori... more Abstract 629 haloethanes are theoretically possible by different combinations of fluorine, chlorine, bromine and iodine atoms. Geometric and common volumes of all these compounds have been computed. Rotation of the methyl group about the CC single bond effects changes in the geometric and common volumes. The most stable conformer of ethane corresponds to the highest geometric volume conformation. The experimental boiling points of haloethanes have been correlated with a multivariable nonlinear correlation equation and the boiling points of all 629 haloethanes have been predicted therefrom. The Atomic Contribution Method (ACM), developed for halomethanes, has been extended to haloethanes. The predicted boiling points of the haloethanes using the ACM agree well with the experimental boiling points.
Third IEEE International Vacuum Electronics Conference (IEEE Cat. No.02EX524)
Summary form only given. We have made measurements of and modelled cold and hot phase velocities ... more Summary form only given. We have made measurements of and modelled cold and hot phase velocities for the custom-made XWING broadband traveling wave tube. The TWT used in this investigation, termed the XWING TWT (for experimental Wisconsin Northrop Grumman TWT), is a research version of a product manufactured by Northrop Grumman. This two-stage, helical TWT provides a moderate gain of
We have reported the formation of magnetic and non magnetic regime in the same sample by oblique ... more We have reported the formation of magnetic and non magnetic regime in the same sample by oblique incidence 36 keV Fe3+ ion bombardment on Si(100) ripple structures prefabricated by 8 keV O1+ bombardment at oblique angle. The same phenomenon is also observed on ion induced rippled ZnO thin films deposited of on Si(100). Ex situ atomic force microscopy (AFM) and
Journal of Physics A: Mathematical and General, 1984
ABSTRACT Transformation of nonlinear plasma equations to a space-independent frame with the help ... more ABSTRACT Transformation of nonlinear plasma equations to a space-independent frame with the help of the Lorentz transformation gives in place of partial differential equations a set of ordinary differential equations in a single independent variable for solution of nonlinear field equations. In this paper, this transformation has been used to yield the nonlinear precessional rotation of electromagnetic waves in plasmas in addition to the nonlinear shift in a wave parameter. Moreover, the Lagrangian and Hamiltonian of motion for a circularly polarised wave have been transformed to the space-independent frame and the equations of Akhiezer and Polovin (1956) for nonlinear plasma oscillations have been rectified by making them relativistically correct.
Proceedings DARPA Active Networks Conference and Exposition
Active networks represent a change in network paradigm from a static, one-size-fits-all packet-tr... more Active networks represent a change in network paradigm from a static, one-size-fits-all packet-transport service to a flexible platform capable of being programmed to provide new services. Active networks will allow rapid deployment of new and complex network services. An important property of an active network API is the support it provides for composing complex services out of components. An efficient
Page 1. Fast Timescale Control for MPLS Traffic Engineering ∗ S. Phuvoravan⋆, KT Kuo T. Guven⋆, ... more Page 1. Fast Timescale Control for MPLS Traffic Engineering ∗ S. Phuvoravan⋆, KT Kuo T. Guven⋆, L. Sudarsan⋆, HS Chang⋆, S. Bhattacharjee and MA Shayman⋆. ... Sm = m ∑ k=1 Xt (1) Let vm = Var(Sm/m). So vm = σ2 [1+2 m ∑ k=1 (1 − k m )ρk] m−1 (2) ...
A large number of molecular and thermodynamic properties of the alkane molecules containing up to... more A large number of molecular and thermodynamic properties of the alkane molecules containing up to eight carbon atoms have been correlated with a newly developed theoretical index, geometric volume. The geometric volume gives an estimate of the molecular size and is characteristic of each alkane molecule. The n-alkanes generally show a smooth positive variation in their molecular properties with the geometric volume while the isomers correlate differently in many cases. In such cases, however, a single bilinear correlation equation may be derived for the entire set of alkane molecules. It is possible to obtain more realistic and meaningful correlation equations, if the regularities in the molecular properties of the alkane molecules are properly identified by graph theoretical ordering of the structure.
Microfabricated folded waveguide traveling wave tubes (FWG-TWT) are potential compact sources of ... more Microfabricated folded waveguide traveling wave tubes (FWG-TWT) are potential compact sources of wideband ( 20instantaneous bandwidth), high power (0.01 - 1 W) THz radiation (i.e., between 100 - 1000 GHz). We describe a scaled experiment at 50 GHz to investigate an oscillator concept using an amplifier with recirculated feedback. Oscillations are observed between 42 - 44 GHz with the total
Flame spread over thin cellulosic fuel in a quiescent, microgravity environment of a 50/50 volume... more Flame spread over thin cellulosic fuel in a quiescent, microgravity environment of a 50/50 volumetric mixture of oxygen (oxygen mass fraction 0.53) and nitrogen at 152 kPa (1.5 atm) has been analyzed theoretically, and the results are compared to a recently conducted experiment in the microgravity environment on board a Space Shuttle flight. Experimental results suggest that the fuel preheat zone upstream of the gas-phase flame is followed by a constant temperature pyrolysis zone, which is followed by a large zone of surface reaction. Because the theory does not treat surface reaction, results of the theory apply only to regions close to the flame leading edge. Although CO2 and H2O radiation is included in the theory, the absorption and emission of radiation by the fuel surface is modeled only approximately. The theory compares well with experiment near the flame leading edge. The flame spread rate, peak surface temperature, and gas-phase temperature at two different locations are predicted within 5%. The success of the theory leads to the conclusion that the flame structure near the flame leading edge determines the flame spread rate and that gas-phase radiation plays a significant role in quiescent, microgravity flame spread.
Results from recently conducted experiments on flame spread over a thin cellulosic fuel in a quie... more Results from recently conducted experiments on flame spread over a thin cellulosic fuel in a quiescent, microgravity environment of a 50/50 volumetric mixture of oxygen and nitrogen (oxygen mass fraction 0.53) at three different pressures—101, 152, and 203 kPa (1, 1.5, and 2.0 atm)—are analyzed. The results are compared with established theoretical results and two different computational flame spread models: one that includes gas-phase radiation, and one that does not. The spread rate behavior from experiment, i.e., an increase of spread rate with pressure, is consistent with the theoretical model that includes gas-phase radiation, and side-view photographs of the flames compare favorably with two-dimensional temperature contours produced computationally from the same model. In contrast, neither the dependence of spread rate on pressure nor the flame shape can be predicted with favorable comparison to experiment if radiation is neglected.
A computational model of flame spread over a thermally thick solid fuel in an opposing-flow envir... more A computational model of flame spread over a thermally thick solid fuel in an opposing-flow environment is presented. Unlike thermally thin fuels, for which the effect of fuel surface radiation is negligible for high levels of opposing flow, fuel surface radiation is important for thermally thick fuels for all flow levels. This result is shown to derive from the fact that the ratio of the rate of heat transfer by re-radiation from the surface to that by conduction from the gas to the solid is proportional to the length over which heat can be conducted forward of the flame to sustain spreading. For thin fuels, this length decreases with increasing flow velocity such that while radiation is important at low flow velocities it is not at the higher velocities. For thick fuels at low flow velocities, the conduction length is determined by gas-phase processes and decreases with increasing flow velocity. But at higher flow velocities, the conduction length is determined by solid-phase proc...
Workshop on image analysis for multimedia interactive services, May 31, 1999
A content-based image-retrieval system is described in this paper. The system is designed to admi... more A content-based image-retrieval system is described in this paper. The system is designed to administer a heterogeneous collection of images. The goal is to support querying in a rotationand translation-, and juxtaposition-invariant fashion. The conceptual similarity measure used to compare two images is the number of small image-patches the images have in common. The patches to be compared are chosen using a 2D continuous wavelet which acts as a low-level corner detector. The local maxima in the response of ...
Uploads
Papers by Samrat Bhattacharjee