New approach to standing phase angle reduction for power system restoration During power system restoration , it is necessary to check the phase angle between two buses before closing circuit breakers to connect a line between them . These angles may occur across a tie line between two systems or between two connected subsystems within a system . In case of large standing phase angle -LRB- SPA -RRB- difference the synchro-check relay does not allow closing of the breaker for this line . Therefore , this excessive SPA has to be reduced before attempting to connect the line . In this paper , a new and fast method for reducing SPA is presented . For this purpose , the standing phase angle difference between two specific buses is represented in terms of sensitivity factors associated with the change in active power generations and consumption at the buses . Then , the proposed method reschedule generation of selected units or shed load of selected buses to reduce excessive SPA difference between two buses based on sensitivity factors

O O O O O O O O B I I O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I

power system restoration
synchrocheck relay
sensitivity factors

standing phase angle reduction approach
circuit breaker closing
power line connection


Steinmetz system design under unbalanced conditions This paper studies and develops general analytical expressions to obtain three-phase current symmetrization under unbalanced voltage conditions . It proposes two procedures for this symmetrization : the application of the traditional expressions assuming symmetry conditions and the use of optimization methods based on the general analytical equations . Specifically , the paper applies and evaluates these methods to analyze the Steinmetz system design . Several graphics evaluating the error introduced by assumption of balanced voltage in the design are plotted and an example is studied to compare both procedures . In the example the necessity to apply the optimization techniques in highly unbalanced conditions is demonstrated

B I I O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O B I O O O B I I O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

unbalanced voltage conditions
steinmetz system design
optimization methods
general analytical equations

three-phase current symmetrization
power system control design
balanced voltage assumption


Universal approximation by hierarchical fuzzy system with constraints on the fuzzy rule This paper presents a special hierarchical fuzzy system where the outputs of the previous layer are not used in the IF-parts , but used only in the THEN-parts of the fuzzy rules of the current layer . The proposed scheme can be shown to be a universal approximator to any continuous function on a compact set if complete fuzzy sets are used in the IF-parts of the fuzzy rules with singleton fuzzifier and center average defuzzifier . From the simulation of ball and beam control system , it is demonstrated that the proposed scheme approximates with good accuracy the model nonlinear controller with fewer fuzzy rules than the centralized fuzzy system and its control performance is comparable to that of the nonlinear controller

O O O B I I O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O B I O O B I O O O O O O O O O O O O O O O B I O O O O O O O O O O O O B I I I I O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O

hierarchical fuzzy system
fuzzy rules
universal approximator
continuous function
ball and beam control system

hierarchical fuzzy logic
stone-weierstrass theorem


An accurate COG defuzzifier design using Lamarckian co-adaptation of learning and evolution This paper proposes a design technique of optimal center of gravity -LRB- COG -RRB- defuzzifier using the Lamarckian co-adaptation of learning and evolution . The proposed COG defuzzifier is specified by various design parameters such as the centers , widths , and modifiers of MFs . The design parameters are adjusted with the Lamarckian co-adaptation of learning and evolution , where the learning performs a local search of design parameters in an individual COG defuzzifier , but the evolution performs a global search of design parameters among a population of various COG defuzzifiers . This co-adaptation scheme allows to evolve much faster than the non-learning case and gives a higher possibility of finding an optimal solution due to its wider searching capability . An application to the truck backer-upper control problem of the proposed co-adaptive design method of COG defuzzifier is presented . The approximation ability and control performance are compared with those of the conventionally simplified COG defuzzifier in terms of the fuzzy logic controller 's approximation error and the average tracing distance , respectively

O O O O O O O O O B O B O O O O O O O O O O O O O O O O O O O O B O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O B O O O B O O B I O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O

learning
evolution
fuzzy logic controller
local search


ECG-gated / sup 18/F-FDG positron emission tomography . Single test evaluation of segmental metabolism , function and contractile reserve in patients with coronary artery disease and regional dysfunction / sup 18/F-fluorodeoxyglucose -LRB- / sup 18/F-FDG -RRB- - positron emission tomography -LRB- PET -RRB- provides information about myocardial glucose metabolism to diagnose myocardial viability . Additional information about the functional status is necessary . Comparison of tomographic metabolic PET with data from other imaging techniques is always hampered by some transfer uncertainty and scatter . We wanted to evaluate a new Fourier-based ECG-gated PET technique using a high resolution scanner providing both metabolic and functional data with respect to feasibility in patients with diseased left ventricles . Forty-five patients with coronary artery disease and at least one left ventricular segment with severe hypokinesis or akinesis at biplane cineventriculography were included . A new Fourier-based ECG-gated metabolic / sup 18/F-FDG-PET was performed in these patients . Function at rest and / sup 18/F-FDG uptake were examined in the PET study using a 36-segment model . Segmental comparison with ventriculography revealed a high reliability in identifying dysfunctional segments -LRB- > 96 % -RRB- . / sup 18/F-FDG uptake of normokinetic/hypokinetic/akinetic segments was 75.4 + or-7 .5 , 65.3 + or-10 .5 , and 35.9 + or-15 .2 % -LRB- p < 0.001 -RRB- . In segments > or = 70 % / sup 18/F-FDG uptake no akinesia was observed . No residual function was found below 40 % / sup 18/F-FDG uptake . An additional dobutamine test was performed and revealed inotropic reserve -LRB- viability -RRB- in 42 akinetic segments and 45 hypokinetic segments . ECG-gated metabolic PET with pixel-based Fourier smoothing provides reliable data on regional function . Assessment of metabolism and function makes complete judgement of segmental status feasible within a single study without any transfer artefacts or test-to-test variability . The results indicate the presence of considerable amounts of viable myocardium in regions with an uptake of 40-50 % / sup 18/F-FDG

O O O O O O O O O O O O O O O O O O O O B O B I I O B I O O O O O O O O O O O O O O O O O O B I I O O B I O O O O O B O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O B I I O O O O B O O O O O O B O B I I O O B O B I I O O O O B I I O B I O B O B I O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O B I O O O O B I O O O O O B I O O B I O O O O O O O O O O O O B I O O O O O O O O O O B I O O O O O O O B I O O O O O O O O O O O O O B I O O O O O O O O O O O

ventriculography
dysfunctional segments
residual function
dobutamine test
inotropic reserve
akinetic segments
hypokinetic segments
regional function
segmental status
transfer artefacts
viable myocardium
regional dysfunction
myocardial glucose metabolism
myocardial viability
functional
transfer uncertainty
high resolution scanner
patients
diseased left ventricles
coronary artery disease
left ventricular segment
severe hypokinesis
akinesis
biplane cineventriculography

fourier-based ecg-gated metabolic /sup 18/f-fluorodeoxyglucose-positron emission tomography


Efficient tracking of the cross-correlation coefficient In many -LRB- audio -RRB- processing algorithms , involving manipulation of discrete-time signals , the performance can vary strongly over the repertoire that is used . This may be the case when the signals from the various channels are allowed to be strongly positively or negatively correlated . We propose and analyze a general formula for tracking the -LRB- time-dependent -RRB- correlation between two signals . Some special cases of this formula lead to classical results known from the literature , others are new . This formula is recursive in nature , and uses only the instantaneous values of the two signals , in a low-cost and low-complexity manner ; in particular , there is no need to take square roots or to carry out divisions . Furthermore , this formula can be modified with respect to the occurrence of the two signals so as to further decrease the complexity , and increase ease of implementation . The latter modification comes at the expense that not the actual correlation is tracked , but , rather , a somewhat deformed version of it . To overcome this problem , we propose , for a number of instances of the tracking formula , a simple warping operation on the deformed correlation . Now we obtain , at least for sinusoidal signals , the correct value of the correlation coefficient . Special attention is paid to the convergence behavior of the algorithm for stationary signals and the dynamic behavior if there is a transition to another stationary state ; the latter is considered to be important to study the tracking abilities to nonstationary signals . We illustrate tracking algorithm by using it for stereo music fragments , obtained from a number of digital audio recordings

B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O B I O O O O O O O O B I O O O O O O O O O O O O O O O B I O O O O B I O O B I O O O O O O O B I O O O O O O O O O O O O O O B I O O O B I O O O O B I I O O O O O O O O O

efficient tracking
warping operation
deformed correlation
sinusoidal signals
convergence behavior
stationary signals
dynamic behavior
stationary state
nonstationary signals
tracking algorithm
stereo music fragments

cross-correlation coefficient
audio processing algorithms
discrete-time signals
time-dependent correlation
recursive formula
digital audio recording


Robust speech recognition using probabilistic union models This paper introduces a new statistical approach , namely the probabilistic union model , for speech recognition involving partial , unknown frequency-band corruption . Partial frequency-band corruption accounts for the effect of a family of real-world noises . Previous methods based on the missing feature theory usually require the identity of the noisy bands . This identification can be difficult for unexpected noise with unknown , time-varying band characteristics . The new model combines the local frequency-band information based on the union of random events , to reduce the dependence of the model on information about the noise . This model partially accomplishes the target : offering robustness to partial frequency-band corruption , while requiring no information about the noise . This paper introduces the theory and implementation of the union model , and is focused on several important advances . These new developments include a new algorithm for automatic order selection , a generalization of the modeling principle to accommodate partial feature stream corruption , and a combination of the union model with conventional noise reduction techniques to deal with a mixture of stationary noise and unknown , nonstationary noise . For the evaluation , we used the TIDIGITS database for speaker-independent connected digit recognition . The utterances were corrupted by various types of additive noise , stationary or time-varying , assuming no knowledge about the noise characteristics . The results indicate that the new model offers significantly improved robustness in comparison to other models

B I I O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O B O O O B I I I O O O O O O O O O O B I I O O O O O O B I O O O B I O O O O O O O O B I O O O O O O O O O O O O O O B I O O O O O O O O O O B I O O O O O O O O O O O O O O O O O

robust speech recognition
probabilistic union models
automatic order selection
modeling
partial feature stream corruption
noise reduction techniques
stationary noise
nonstationary noise
tidigits database
additive noise
noise characteristics
missing feature theory
noisy bands


Approximation theory of fuzzy systems based upon genuine many-valued implications - SISO cases It is proved that the single input and single output -LRB- SISO -RRB- fuzzy systems based upon genuine many-valued implications are universal approximators . It is shown theoretically that fuzzy control systems based upon genuine many-valued implications are equivalent to those based upon t-norm implications , the general approach to construct fuzzy systems is given . It is also shown that defuzzifier based upon center of areas is not appropriate to the fuzzy systems based upon genuine many-valued implications

O O O B I O O O O O O B O O O O O O O O O O O O B O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O B I O O O O O

single input and single output fuzzy systems


A robust H/sub infinity / control approach for induction motors This paper deals with the robustness and stability of an induction motor control structure against internal and external disturbances . In the proposed control scheme , we have used an H/sub infinity / controller with field orientation and input-output linearization to achieve the above-specified features . Simulation results are included to illustrate the control approach performances

O O O O O O O O O O O O O O O B O B O O O O O O O O O B I O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O

robustness
stability
external disturbances
field orientation

robust h/sub infinity / control
induction motors control
internal disturbances
input-output linearization


A new voltage-vector selection algorithm in direct torque control of induction motor drives AC drives based on direct torque control of induction machines allow high dynamic performance to be obtained with very simple control schemes . The drive behavior , in terms of current , flux and torque ripple , is dependent on the utilised voltage vector selection strategy and the operating conditions . In this paper a new voltage vector selection algorithm , which allows a sensible reduction of the RMS value of the stator current ripple without increasing the average value of the inverter switching frequency and without the need of a PWM pulse generator block is presented Numerical simulations have been carried out to validate the proposed method

O O O O O O B I I O B I I B I O O B I I O O O O B I I O O O O O O O O O O O O O O O O O O O O B I O O O O O O B I I I O O B I O O O O O O O O O O O O O O O O O O B I O O B I I O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O

direct torque control
induction motor drives
ac drives
high dynamic performance
torque ripple
voltage vector selection strategy
operating conditions
rms value
stator current ripple
inverter switching frequency

voltage-vector selection algorithm
torque variations
flux variations
4-poles induction motor
steady-state operation
dynamic behavior
torque step response
220 v
50 hz
4 kw


Development of railway VR safety simulation system Abnormal conditions occur in railway transportation due to trouble or accidents and it affects a number of passengers . It is very important , therefore , to quickly recover and return to normal train operation . For this purpose we developed a system , `` Computer VR Simulation System for the Safety of Railway Transportation . '' It is a new type simulation system to evaluate measures to be taken under abnormal conditions . Users of this simulation system cooperate with one another to correct the abnormal conditions that have occurred in virtual reality . This paper reports the newly developed simulation system

O O O O O O O O O O O B I O O O O B O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O B I I I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

railway transportation
accidents
normal train operation
computer vr simulation system

virtual reality simulation system
abnormal conditions correction


How closely can a personal computer clock track the UTC timescale via the Internet ? Nowadays many software packages allow you to keep the clock of your personal computer synchronized to time servers spread over the internet . We present how a didactic laboratory can evaluate , in a statistical sense , the minimum synch error of this process -LRB- the other extreme , the maximum , is guaranteed by the code itself -RRB- . The measurement set-up utilizes the global positioning system satellite constellation in ` common view ' between two similar timing stations : one acts as a time server for the other , so the final timing difference at the second station represents the total synch error through the internet . Data recorded over batches of 10000 samples show a typical RMS value of 35 ms. This measurement configuration allows students to obtain a much better understanding of the synch task and pushes them , at all times , to look for an experimental verification of data results , even when they come from the most sophisticated ` black boxes ' now readily available off the shelf

O O O O B I I O O B I O O B O O O B I O O O O O O O O O O O O B I O O O B O O O O O B I O O O O O B I O O O B I O O O O O O O O O O O O O O O O O O O O O O O O B I I I I O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O B I O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O


Quick media response averts PR disaster Sometimes it 's not what you do , but how you do it . After hackers broke the blocking code on the home version of its popular Cyber Patrol Internet filtering software and posted it on the Internet , marketers at Microsystems Software pulled out a playbook of standard crisis management and PR techniques . But the Cyber Patrol PR team including outside PR counsel and the company 's outside law firm , used those tools aggressively in order to turn the tide of public and media opinion away from the hackers , who initially were hailed as folk heroes , and in favor of the company 's interests , to save the product 's and the company 's reputations and inherent value . And the entire team managed to move at Internet speed : The crisis was essentially over in about three weeks

O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I I O O O O O O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

cyber patrol internet filtering software


HEW selects network management software For more than 100 years , Hamburgische Electricitats-Werke AG -LRB- HEW -RRB- has provided a reliable electricity service to the city of Hamburg , Germany . Today , the company supplies electricity to some 1.7 million inhabitants via 285000 connections . During 1999 , the year the energy market was started in Germany , HEW needed to operate and maintain a safe and reliable network cheaply . The development and implementation of a distribution management system -LRB- DMS -RRB- is key to the success of HEW . HEW 's strategy was to obtain efficient new software for network management that also offered a good platform for future applications . Following a pilot and prequalification phase , HEW invited several companies to process the requirements catalog and to submit a detailed tender . The network information management system , Xpower , developed by Tekla Oyj , successfully passed HEW 's test program and satisfied all the performance and system capacity requirements . The system met all HEW 's conditions by presenting the reality of a network with the attributes of the operating resources . Xpower platform provides the ability to integrate future applications

O O B I I O O O O O O O O O O O O O O O O O O O O O O B O B O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O

hamburg
germany
distribution management system
network management software
xpower
tekla oyj


Application of time-frequency principal component analysis to text-independent speaker identification We propose a formalism , called vector filtering of spectral trajectories , that allows the integration of a number of speech parameterization approaches -LRB- cepstral analysis , Delta and Delta Delta parameterizations , auto-regressive vector modeling , ... -RRB- under a common formalism . We then propose a new filtering , called contextual principal components -LRB- CPC -RRB- or time-frequency principal components -LRB- TFPC -RRB- . This filtering consists in extracting the principal components of the contextual covariance matrix , which is the covariance matrix of a sequence of vectors expanded by their context . We apply this new filtering in the framework of closed-set speaker identification , using a subset of the POLYCOST database . When using speaker-dependent TFPC filters , our results show a relative improvement of approximately 20 % compared to the use of the classical cepstral coefficients augmented by their Delta - coefficients , which is significantly better with a 90 % confidence level

O O O O O O O O O O O O O O O O B I O B I O O O O O O O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O B I

vector filtering
spectral trajectories
speech parameterization
cepstral analysis
contextual principal components
contextual covariance matrix
polycost database
cepstral coefficients
confidence level


FLID-DL : congestion control for layered multicast We describe fair layered increase/decrease with dynamic layering -LRB- FLID-DL -RRB- : a new multirate congestion control algorithm for layered multicast sessions . FLID-DL generalizes the receiver-driven layered congestion control protocol -LRB- RLC -RRB- introduced by Vicisano et al. -LRB- Proc . IEEE INFOCOM , San Francisco , CA , , p.996-1003 , Mar. 1998 -RRB- ameliorating the problems associated with large Internet group management protocol -LRB- IGMP -RRB- leave latencies and abrupt rate increases . Like RLC , FLID-DL , is a scalable , receiver-driven congestion control mechanism in which receivers add layers at sender-initiated synchronization points and leave layers when they experience congestion . FLID-DL congestion control coexists with transmission control protocol -LRB- TCP -RRB- flows as well as other FLID-DL sessions and supports general rates on the different multicast layers . We demonstrate via simulations that our congestion control scheme exhibits better fairness properties and provides better throughput than previous methods . A key contribution that enables FLID-DL and may be useful elsewhere is dynamic layering -LRB- DL -RRB- , which mitigates the negative impact of long IGMP leave latencies and eliminates the need for probe intervals present in RLC . We use DL to respond to congestion much faster than IGMP leave operations , which have proven to be a bottleneck in practice for prior work

O O B I O O O O O O O O O B I O O O O O O O B I O O B I I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O B O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O B I O O B I I O O O O O O O O O O O O O O O O O B I O O O O B O O B I O O O O O O O O B O O O O O O O O O O O O O O O O B I O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O

congestion control
layered multicast sessions
internet group management protocol
igmp
transmission control protocol
multicast layers
simulations
throughput
dynamic layering


A digital fountain approach to asynchronous reliable multicast The proliferation of applications that must reliably distribute large , rich content to a vast number of autonomous receivers motivates the design of new multicast and broadcast protocols . We describe an ideal , fully scalable protocol for these applications that we call a digital fountain . A digital fountain allows any number of heterogeneous receivers to acquire content with optimal efficiency at times of their choosing . Moreover , no feedback channels are needed to ensure reliable delivery , even in the face of high loss rates . We develop a protocol that closely approximates a digital fountain using two new classes of erasure codes that for large block sizes are orders of magnitude faster than standard erasure codes . We provide performance measurements that demonstrate the feasibility of our approach and discuss the design , implementation , and performance of an experimental system

O B I O O B I I O O O O O O O O O O O O O O O O O B I O O O O O O O B I O O O O O O O B I O O O O O O O B I O O B I O O O O B I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O B I O O O O O B I O O O O O O O O O O O O B I O O O B I O O O O O O O O O O O O O O O O O O O O

digital fountain
asynchronous reliable multicast
autonomous receivers
broadcast protocols
scalable protocol
heterogeneous receivers
optimal efficiency
high loss rates
erasure codes
performance measurements

multicast protocol
large block size
experimental system performance
internet
fec codes
forward error correction
rs codes
tornado codes
luby transform codes
bulk data distribution
ip multicast
simulation results
interoperability
content distribution methods
reed-solomon codes
decoder


Wavelet-based image segment representation An efficient representation method for arbitrarily shaped image segments is proposed . This method includes a smart way to select a wavelet basis to approximate the given image segment , with improved image quality and reduced computational load

O B I I O O O O O B I I I O O O O O O O O O O O O B I O O O O O O O O B I I O B I I

image segment representation
arbitrarily shaped image segments
wavelet basis
improved image quality
reduced computational load


Study of ambiguities inherent to the spectral analysis of Voigt profiles-a modified Simplex approach In pulsed spectrometries , temporal transients are often analyzed directly in the temporal domain , assuming they consist only of purely exponentially decaying sinusoids . When experimental spectra actually consist of Gaussian or Voigt profiles -LRB- Gauss-Lorentz profiles -RRB- , we show that the direct methods may erroneously interpret such lines as the sum of two or more Lorentzian profiles . Using a Nelder and Mead Simplex method , modified by introducing new means to avoid degeneracies and quenchings in secondary minima , we demonstrate that a large number of different solutions can be obtained with equivalent accuracy over the limited acquisition time interval , with final peak parameters devoid of physical or chemical meaning

O O O O O O B I O O O O O O O B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O B I I I O O B I I O O O O O O

pulsed spectrometries
temporal transients
spectral analysis
voigt profiles
nelder and mead simplex method
accuracy
limited acquisition time interval
final peak parameters

gaussian profiles
gauss-lorentz profiles


An on-line distributed intelligent fault section estimation system for large-scale power networks In this paper , a novel distributed intelligent system is suggested for on-line fault section estimation -LRB- FSE -RRB- of large-scale power networks . As the first step , a multi-way graph partitioning method based on weighted minimum degree reordering is proposed for effectively partitioning the original large-scale power network into the desired number of connected sub-networks with quasi-balanced FSE burdens and minimum frontier elements . After partitioning , a distributed intelligent system based on radial basis function neural network -LRB- RBF NN -RRB- and companion fuzzy system is suggested for FSE . The relevant theoretical analysis and procedure are presented in the paper . The proposed distributed intelligent FSE method has been implemented with sparse storage technique and tested on the IEEE 14 , 30 and 118-bus systems , respectively . Computer simulation results show that the proposed FSE method works successfully for large-scale power networks

O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O B I I O O B I I I I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O B I O O O O O O O O O O O O O

weighted minimum degree reordering
minimum frontier elements
distributed intelligent system
radial basis function neural network
fuzzy system
sparse storage technique
computer simulation


Experimental design methodology and data analysis technique applied to optimise an organic synthesis The study was aimed at maximising the yield of a Michaelis-Becker dibromoalkane monophosphorylation reaction . In order to save time and money , we first applied a full factorial experimental design to search for the optimum conditions while performing a small number of experiments . We then used the principal component analysis -LRB- PCA -RRB- technique to evidence two uncontrolled factors . Lastly , a special experimental design that took into account all the influential factors allowed us to determine the maximum-yield experimental conditions . This study also evidenced the complementary nature of experimental design methodology and data analysis techniques

O O O O B I I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O O B I O O O O O O O O O O O O B I I O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

full factorial experimental design
optimum conditions
data analysis technique
organic synthesis
principal component analysis
uncontrolled factors

michaelis-becker dibromoalkane monophosphorylation reaction


Three-dimensional spiral MR imaging : application to renal multiphase contrast-enhanced angiography A fast MR pulse sequence with spiral in-plane readout and conventional 3D partition encoding was developed for multiphase contrast-enhanced magnetic resonance angiography -LRB- CE-MRA -RRB- of the renal vasculature . Compared to a standard multiphase 3D CE-MRA with FLASH readout , an isotropic in-plane spatial resolution of 1.4 * 1.4 mm/sup 2 / over 2.0 * 1.4 mm/sup 2 / could be achieved with a temporal resolution of 6 sec . The theoretical gain of spatial resolution by using the spiral pulse sequence and the performance in the presence of turbulent flow was evaluated in phantom measurements . Multiphase 3D CE-MRA of the renal arteries was performed in five healthy volunteers using both techniques . A deblurring technique was used to correct the spiral raw data . Thereby , the off-resonance frequencies were determined by minimizing the imaginary part of the data in image space . The chosen correction algorithm was able to reduce image blurring substantially in all MRA phases . The image quality of the spiral CE-MRA pulse sequence was comparable to that of the FLASH CE-MRA with increased spatial resolution and a 25 % reduced contrast-to-noise ratio . Additionally , artifacts specific to spiral MRI could be observed which had no impact on the assessment of the renal arteries

O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

deblurring
3d partition encoding
renal vasculature
image quality
spatial resolution


Time-resolved contrast-enhanced imaging with isotropic resolution and broad coverage using an undersampled 3D projection trajectory Time-resolved contrast-enhanced 3D MR angiography -LRB- MRA -RRB- methods have gained in popularity but are still limited by the tradeoff between spatial and temporal resolution . A method is presented that greatly reduces this tradeoff by employing undersampled 3D projection reconstruction trajectories . The variable density k-space sampling intrinsic to this sequence is combined with temporal k-space interpolation to provide time frames as short as 4 s . This time resolution reduces the need for exact contrast timing while also providing dynamic information . Spatial resolution is determined primarily by the projection readout resolution and is thus isotropic across the FOV , which is also isotropic . Although undersampling the outer regions of k-space introduces aliased energy into the image , which may compromise resolution , this is not a limiting factor in high-contrast applications such as MRA . Results from phantom and volunteer studies are presented demonstrating isotropic resolution , broad coverage with an isotropic field of view -LRB- FOV -RRB- , minimal projection reconstruction artifacts , and temporal information . In one application , a single breath-hold exam covering the entire pulmonary vasculature generates high-resolution , isotropic imaging volumes depicting the bolus passage

O O O O B I O B I O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O B I O O B I I I O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O B I

isotropic resolution
broad coverage
undersampled 3d projection trajectory
isotropic field of view
pulmonary vasculature
bolus passage

time-resolved contrast-enhanced imaging
3d mri angiography
variable density k-space sampling
temporal k-space interpolation
abdomen
thorax
image artifacts
breath-hold imaging


Geometric source separation : merging convolutive source separation with geometric beamforming Convolutive blind source separation and adaptive beamforming have a similar goal-extracting a source of interest -LRB- or multiple sources -RRB- while reducing undesired interferences . A benefit of source separation is that it overcomes the conventional cross-talk or leakage problem of adaptive beamforming . Beamforming on the other hand exploits geometric information which is often readily available but not utilized in blind algorithms . We propose to join these benefits by combining cross-power minimization of second-order source separation with geometric linear constraints used in adaptive beamforming . We find that the geometric constraints resolve some of the ambiguities inherent in the independence criterion such as frequency permutations and degrees of freedom provided by additional sensors . We demonstrate the new method in performance comparisons for actual room recordings of two and three simultaneous acoustic sources

B I I O O O O O O B I B I I I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O B I O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O B I I O O B I O O O O O O O O O O O O O O O O O O O B I O B I I O O O B O O O O O O O O O O O B I O O O O O B I

geometric source separation
geometric beamforming
convolutive blind source separation
adaptive beamforming
leakage problem
blind algorithms
geometric linear constraints
frequency permutations
degrees of freedom
sensors
room recordings
acoustic sources

cross-talk
cross-power minimization
second-order source separation


An overview of modems This paper describes cursory glance of different types of modems classified for application , range , line type , operating mode , synchronizing mode , modulation , etc. , highly useful for all engineering students of communication , electrical , computer science and information technology students . This paper also describes the standards and protocols used and the future trend

O O O B O O O O O O O O O B O O O O O O B I O B I O B I O B O O O O O O O B I O O O O O O O O B I I O O O O O O B O B O O O O O

modems
line type
operating mode
synchronizing mode
modulation
engineering students
information technology students
standards
protocols

communication students
electrical students
computer science students


MPEG-4 video object-based rate allocation with variable temporal rates In object-based coding , bit allocation is performed at the object level and temporal rates of different objects may vary . The proposed algorithm deals with these two issues when coding multiple video objects -LRB- MVOs -RRB- . The proposed algorithm is able to successfully achieve the target bit rate , effectively code arbitrarily shaped MVOs with different temporal rates , and maintain a stable buffer level

O O O O O O B I I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

bit allocation
multiple video objects
variable temporal rates

mpeg-4 video coding
rate-distortion encoding
object-based rate allocation


Reconstruction of MR images from data acquired on an arbitrary k-space trajectory using the same-image weight A sampling density compensation function denoted `` same-image -LRB- SI -RRB- weight '' is proposed to reconstruct MR images from the data acquired on an arbitrary k-space trajectory . An equation for the SI weight is established on the SI criterion and an iterative scheme is developed to find the weight . The SI weight is then used to reconstruct images from the data calculated on a random trajectory in a numerical phantom case and from the data acquired on interleaved spirals in an in vivo experiment , respectively . In addition , Pipe and Menon 's weight -LRB- MRM 1999 ; 41:179 -186 -RRB- is also used in the reconstructions to make a comparison . The images obtained with the SI weight were found to be slightly more accurate than those obtained with Pipe 's weight

O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

sampling density compensation
random trajectory
numerical phantom

mri image reconstruction
arbitrary k-space trajectory
spiral trajectory
same-image weight
convolution function
nyquist sampling conditions
iterative algorithm
weighting function


Molecular descriptor selection combining genetic algorithms and fuzzy logic : application to database mining procedures A new algorithm , devoted to molecular descriptor selection in the context of data mining problems , has been developed . This algorithm is based on the concepts of genetic algorithms -LRB- GA -RRB- for descriptor hyperspace exploration and combined with a stepwise approach to get local convergence . Its selection power was evaluated by a fitness function derived from a fuzzy clustering method . Different training and test sets were randomly generated at each GA generation . The fitness score was derived by combining the scores of the training and test sets . The ability of the proposed algorithm to select relevant subsets of descriptors was tested on two data sets . The first one , an academic example , corresponded to the artificial problem of Bullseye , the second was a real data set including 114 olfactory compounds divided into three odor categories . In both cases , the proposed method allowed to improve the separation between the different data set classes

B I I O B I O B I O O O B I O O O O O O O B I I O O O O B I O O O O O O O O O O O O O O B I O O O O B I I O O O O B I O O B I O O O O O O O O B I O O O B I I O O O O B I O O O O O O O O O B I O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O B I O O O B I O O O O O O O O O O O O O O O O O O O

molecular descriptor selection
database mining
data mining
genetic algorithms
fuzzy clustering method
fuzzy logic
descriptor hyperspace exploration
local convergence
stepwise approach
fitness function
test sets
fitness score
bullseye
olfactory compounds
odor categories


Comparison of non-stationary time series in the frequency domain In this paper we compare two nonstationary time series using nonparametric procedures . Evolutionary spectra are estimated for the two series . Randomization tests are performed on groups of spectral estimates for both related and independent time series . Simulation studies show that in certain cases the tests perform reasonably well . The tests are applied to observed geological and financial time series

O O B I I O O O O O O O O O O B I I O B I O O O O O O O O O O B I O O O O O B I O O O O B I I O B O O O O O O O O O O O O O O O O O O O O B I I

nonstationary time series
nonparametric procedures
randomization tests
spectral estimates
independent time series
simulation
financial time series

evolutionary spectra estimation
related time series
lag window
time window
geological time series


Distributed servers approach for large-scale secure multicast In order to offer backward and forward secrecy for multicast applications -LRB- i.e. , a new member can not decrypt the multicast data sent before its joining and a former member can not decrypt the data sent after its leaving -RRB- , the data encryption key has to be changed whenever a user joins or leaves the system . Such a change has to be made known to all the current users . The bandwidth used for such re-key messaging can be high when the user pool is large . We propose a distributed servers approach to minimize the overall system bandwidth -LRB- and complexity -RRB- by splitting the user pool into multiple groups each served by a -LRB- logical -RRB- server . After presenting an analytic model for the system based on a hierarchical key tree , we show that there is an optimal number of servers to achieve minimum system bandwidth . As the underlying user traffic fluctuates , we propose a simple dynamic scheme with low overhead where a physical server adaptively splits and merges its traffic into multiple groups each served by a logical server so as to minimize its total bandwidth . Our results show that a distributed servers approach is able to substantially reduce the total bandwidth required as compared with the traditional single-server approach , especially for those applications with a large user pool , short holding time , and relatively low bandwidth of a data stream , as in the Internet stock quote applications

B I O O O O O O O O O O O B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O B I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O B I I I

distributed servers
forward secrecy
multicast applications
data encryption key
system bandwidth
hierarchical key tree
user traffic
short holding time
internet stock quote applications

large-scale secure multicast
backward secrecy
re-key messaging
system complexity
traffic merging
dynamic split-and-merge scheme
key management


The use of subtypes and stereotypes in the UML model Based on users ' experiences of Version 1.3 of the Unified Modeling Language -LRB- UML -RRB- of the Object Management Group -LRB- OMG -RRB- , a Request For Information in 1999 elicited several responses which were asked to identify `` problems '' but not to offer any solutions . One of these responses is examined for `` problems '' relating to the UML metamodel and here some solutions to the problems identified there are proposed . Specifically , we evaluate the metamodel relating to stereotypes versus subtypes ; the various kinds of Classifier -LRB- particularly Types , Interfaces and Classes -RRB- ; the introduction of a new subtype for the whole part relationship ; as well as identifying areas in the metamodel where the UML seems to have been used inappropriately in the very definition of the UML 's metamodel

O O O B O B O O B I O O O O O O O O O O B I I O O O O O B I I O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O B O O O O O B O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O

subtypes
stereotypes
uml model
unified modeling language
object management group
request for information
classifier
whole part relationship


Using k-nearest-neighbor classification in the leaves of a tree We construct a hybrid -LRB- composite -RRB- classifier by combining two classifiers in common use - classification trees and k-nearest-neighbor -LRB- k-NN -RRB- . In our scheme we divide the feature space up by a classification tree , and then classify test set items using the k-NN rule just among those training items in the same leaf as the test item . This reduces somewhat the computational load associated with k-NN , and it produces a classification rule that performs better than either trees or the usual k-NN in a number of well-known data sets

O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O B I

classification trees
computational load
data sets

k-nearest-neighbor classification
tree leaves
hybrid composite classifier
feature space division
k-nn rule


Methods for outlier detection in prediction If a prediction sample is different from the calibration samples , it can be considered as an outlier in prediction . In this work , two techniques , the use of uncertainty estimation and the convex hull method are studied to detect such prediction outliers . Classical techniques -LRB- Mahalanobis distance and X-residuals -RRB- , potential functions and robust techniques are used for comparison . It is concluded that the combination of the convex hull method and uncertainty estimation offers a practical way for detecting outliers in prediction . By adding the potential function method , inliers can also be detected

O O B I O O O O B I O O O O B I O O O O O O O O O O O O O O O O O O O O O B I O O B I I O O O O O O O O O O O B I O O O O B I O B I O O O O O O O O O O O O O B I I O B I O O O O O O O O O O O O O O O O O B O O O O

outlier detection
prediction sample
calibration samples
uncertainty estimation
convex hull method
mahalanobis distance
potential functions
robust techniques
inliers


Application-layer multicasting with Delaunay triangulation overlays Application-layer multicast supports group applications without the need for a network-layer multicast protocol . Here , applications arrange themselves in a logical overlay network and transfer data within the overlay . We present an application-layer multicast solution that uses a Delaunay triangulation as an overlay network topology . An advantage of using a Delaunay triangulation is that it allows each application to locally derive next-hop routing information without requiring a routing protocol in the overlay . A disadvantage of using a Delaunay triangulation is that the mapping of the overlay to the network topology at the network and data link layer may be suboptimal . We present a protocol , called Delaunay triangulation -LRB- DT protocol -RRB- , which constructs Delaunay triangulation overlay networks . We present measurement experiments of the DT protocol for overlay networks with up to 10 000 members , that are running on a local PC cluster with 100 Linux PCs . The results show that the protocol stabilizes quickly , e.g. , an overlay network with 10 000 nodes can be built in just over 30 s . The traffic measurements indicate that the average overhead of a node is only a few kilobits per second if the overlay network is in a steady state . Results of throughput experiments of multicast transmissions -LRB- using TCP unicast connections between neighbors in the overlay network -RRB- show an achievable throughput of approximately 15 Mb/s in an overlay with 100 nodes and 2 Mb/s in an overlay with 1000 nodes

O O O B I I O O O B I O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O B I O O O O O O B I O O O B I O O B I O B I O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O B I O O O O O O O O O O O O O O O O O O O O O O B I O B I O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

delaunay triangulation overlays
group applications
logical overlay network
measurement experiments
overlay networks
local pc cluster
overlay network topology
data link layer
dt protocol
traffic measurements
average overhead
throughput experiments
multicast transmissions
tcp unicast connections

application-layer multicasting
network-layer multicast protocol
data transfer
delaunay triangulation protocol
linux pc
next-hop routing information
network nodes
15 mbit/s
2 mbit/s


Speech enhancement using a mixture-maximum model We present a spectral domain , speech enhancement algorithm . The new algorithm is based on a mixture model for the short time spectrum of the clean speech signal , and on a maximum assumption in the production of the noisy speech spectrum . In the past this model was used in the context of noise robust speech recognition . In this paper we show that this model is also effective for improving the quality of speech signals corrupted by additive noise . The computational requirements of the algorithm can be significantly reduced , essentially without paying performance penalties , by incorporating a dual codebook scheme with tied variances . Experiments , using recorded speech signals and actual noise sources , show that in spite of its low computational requirements , the algorithm shows improved performance compared to alternative speech enhancement algorithms

O O O O O O O O O B I O B I I O O O O O O O O B I O O B I I O O B I I O O O O O O O O O O O B I I O O O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O B I O O O O B I O O B I O O O O B I I O O B I O O O O O O O B I I O O O O O O O O O O O O

spectral domain
speech enhancement algorithm
mixture model
short time spectrum
clean speech signal
noisy speech spectrum
noise robust speech recognition
additive noise
performance penalties
dual codebook
tied variances
recorded speech signals
noise sources
low computational requirements

mixture-maximum model
speech signal quality
gaussian mixture model
mixmax model
speech intelligibility


Scalable secure group communication over IP multicast We introduce and analyze a scalable rekeying scheme for implementing secure group communications Internet protocol multicast . We show that our scheme incurs constant processing , message , and storage overhead for a rekey operation when a single member joins or leaves the group , and logarithmic overhead for bulk simultaneous changes to the group membership . These bounds hold even when group dynamics are not known a priori . Our rekeying algorithm requires a particular clustering of the members of the secure multicast group . We describe a protocol to achieve such clustering and show that it is feasible to efficiently cluster members over realistic Internet-like topologies . We evaluate the overhead of our own rekeying scheme and also of previously published schemes via simulation over an Internet topology map containing over 280 000 routers . Through analysis and detailed simulations , we show that this rekeying scheme performs better than previous schemes for a single change to group membership . Further , for bulk group changes , our algorithm outperforms all previously known schemes by several orders of magnitude in terms of actual bandwidth usage , processing costs , and storage requirements

B I I I O B I O O O O O O O O O O O O O B I I O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O B I O O O O O O B I O O O O O O B I O O O O O O O B I O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O B O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O B I O B I O O B I

scalable secure group communication
ip multicast
internet protocol multicast
storage overhead
logarithmic overhead
group membership
group dynamics
rekeying algorithm
secure multicast group
overhead
simulation
internet topology map
bandwidth usage
processing costs
storage requirements

cryptography
access control server
authentication
internet-like topologies
network routers


Stochastic recurrences of Jackpot Keno We describe a mathematical model and simulation study for Jackpot Keno , as implemented by Jupiters Network Gaming -LRB- JNG -RRB- in the Australian state of Queensland , and as controlled by the Queensland Office of Gaming Regulation -LRB- QOGR -RRB- -LRB- http://www.qogr.qld.gov.au/keno.shtml -RRB- . The recurrences for the house net hold are derived and it is seen that these are piecewise linear with a ternary domain split , and further , the split points are stochastic in nature . Since this structure is intractable -LRB- Brockett and Levine , Statistics & Probability & their Applications , CBS College Publishing , 1984 -RRB- , estimation of house net hold obtained through an appropriately designed simulator using a random number generator with desirable properties is described . Since the model and simulation naturally derives hold given payscale , but JNG and QOGR require payscale given hold , an inverse problem was required to be solved . This required development of a special algorithm , which may be described as a stochastic binary search . Experimental results are presented , in which the simulator is used to determine jackpot pay-scales so as to satisfy legal requirements of approximately 75 % of net revenue returned to the players , i.e. , 25 % net hold for the house -LRB- JNG -RRB- . Details of the algorithm used to solve this problem are presented , and notwithstanding the stochastic nature of the simulation , convergence to a specified hold for the inverse problem has been achieved to within 0.1 % in all cases of interest to date

B I O B I O O O B I O B O O B I O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O B I O O B I I O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O B I I O O O O O O O O B I I O O O O O O O O O O B O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O B I I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O B I O O O O O O O O O O O O O O

stochastic recurrences
jackpot keno
mathematical model
simulation
jupiters network gaming
house net hold
piecewise linear
ternary domain split
random number generator
inverse problem
stochastic binary search
probability
experimental results


Text-independent speaker verification using utterance level scoring and covariance modeling This paper describes a computationally simple method to perform text independent speaker verification using second order statistics . The suggested method , called utterance level scoring -LRB- ULS -RRB- , allows one to obtain a normalized score using a single pass through the frames of the tested utterance . The utterance sample covariance is first calculated and then compared to the speaker covariance using a distortion measure . Subsequently , a distortion measure between the utterance covariance and the sample covariance of data taken from different speakers is used to normalize the score . Experimental results from the 2000 NIST speaker recognition evaluation are presented for ULS , used with different distortion measures , and for a Gaussian mixture model -LRB- GMM -RRB- system . The results indicate that ULS as a viable alternative to GMM whenever the computational complexity and verification accuracy needs to be traded

O O O O B I I O B I O O O O B I I O O O O O O O B I I O O O O O O B I I O O O O O O O O O B I O O O O O O O O O O O O O O B I O O O O O O O O B I O O B I O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O B I I I O O O O O O O O B I O O O O B I I O B O O O O O O O O O O O O O B O O B I O B I O O O O

utterance level scoring
covariance modeling
computationally simple method
second order statistics
normalized score
sample covariance
speaker covariance
distortion measure
nist speaker recognition evaluation
distortion measures
gaussian mixture model
gmm
computational complexity
verification accuracy


Oxygen-enhanced MRI of the brain Blood oxygenation level-dependent -LRB- BOLD -RRB- contrast MRI is a potential method for a physiological characterization of tissue beyond mere morphological representation . The purpose of this study was to develop evaluation techniques for such examinations using a hyperoxia challenge . Administration of pure oxygen was applied to test these techniques , as pure oxygen can be expected to induce relatively small signal intensity -LRB- SI -RRB- changes compared to CO/sub 2 / - containing gases and thus requires very sensitive evaluation methods . Fourteen volunteers were investigated by alternating between breathing 100 % O/sub 2 / and normal air , using two different paradigms of administration . Changes ranged from > 30 % in large veins to 1.71 % + or-0 .14 % in basal ganglia and 0.82 % + or-0 .08 % in white matter . To account for a slow physiological response function , a reference for correlation analysis was derived from the venous reaction . An objective method is presented that allows the adaptation of the significance threshold to the complexity of the paradigm used . Reference signal characteristics in representative brain tissue regions were established . As the presented evaluation scheme proved its applicability to small SI changes induced by pure oxygen , it can readily be used for similar experiments with other gases

O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O B I O O O O B I O O O O O O O O O O O O B I O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

hyperoxia
brain
physiological response function
correlation analysis
venous reaction
significance threshold

bold contrast mri
oxygen-enhanced mri
oxygen breathing
normal air breathing
paradigm complexity
mri contrast agent
functional imaging
fourier transform analysis


Estimation of trifocal tensor using GMM A novel estimation of a trifocal tensor based on the Gaussian mixture model -LRB- GMM -RRB- is presented . The mixture model is built assuming that the residuals of inliers and outliers belong to different Gaussian distributions . The Bayesian rule is then employed to detect the inliers for re-estimation . Experiments show that the presented method is more precise and relatively unaffected by outliers

O O O O O B O O O O O O O O O O B I I O B O O O O O O O O O O O O O O B O B O O O B I O O B I O O O O O O B O O O O O O O O O O O O O O O O B

gmm
gaussian mixture model
gaussian distributions
bayesian rule
inliers
outliers

trifocal tensor estimation
motion analysis
image data
image analysis


Rank tests of association for exchangeable paired data We describe two rank tests of association for paired exchangeable data motivated by the study of lifespans in twins . The pooled sample is ranked . The nonparametric test of association is based on R/sup + / , the sum of the smaller within-pair ranks . A second measure L/sup + / is the sum of within-pair rank products . Under the null hypothesis of within-pair independence , the two test statistics are approximately normally distributed . Expressions for the exact means and variances of R/sup + / and L/sup + / are given . We describe the power of these two statistics under a close alternative hypothesis to that of independence . Both the R/sup + / and L/sup + / tests indicate nonparametric statistical evidence of positive association of longevity in identical twins and a negligible relationship between the lifespans of fraternal twins listed in the Danish twin registry . The statistics are also applied to the analysis of a clinical trial studying the time to failure of ventilation tubes in children with bilateral otitis media

B I O B O O O O O O O B I O B O B I I O O O O O O O O O O B I O O O O B I O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O B I O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O B O B O B I O O O O O O O O B I O O O B I I O O O O O O O O O O O B I O O O O O O O O O O O B I I

rank tests
association
paired exchangeable data
pooled sample
nonparametric test
null hypothesis
test statistics
exact means
nonparametric statistical evidence
longevity
identical twins
fraternal twins
danish twin registry
clinical trial
bilateral otitis media

twin lifespans
within-pair ranks
within-pair rank products
within-pair independence
exact variances
ventilation tube failure time


Source/channel coding of still images using lapped transforms and block classification A novel scheme for joint source/channel coding of still images is proposed . By using efficient lapped transforms , channel-optimised robust quantisers and classification methods it is shown that significant improvements over traditional source/channel coding of images can be obtained while keeping the complexity low

O O O B I O B I O B I O O O O O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O

still images
lapped transforms
block classification

joint source-channel coding
image coding
channel-optimised robust quantisers
low complexity


Scribe : a large-scale and decentralized application-level multicast infrastructure This paper presents Scribe , a scalable application-level multicast infrastructure . Scribe supports large numbers of groups , with a potentially large number of members per group . Scribe is built on top of Pastry , a generic peer-to-peer object location and routing substrate overlayed on the Internet , and leverages Pastry 's reliability , self-organization , and locality properties . Pastry is used to create and manage groups and to build efficient multicast trees for the dissemination of messages to each group . Scribe provides best-effort reliability guarantees , and we outline how an application can extend Scribe to provide stronger reliability . Simulation results , based on a realistic network topology model , show that Scribe scales across a wide range of groups and group sizes . Also , it balances the load on the nodes while achieving acceptable delay and link stress when compared with Internet protocol multicast

B O O O O O O O O O O O B O O O O O O O B O O O O O O O O O O O O O O O O B O O O O O B O O O O O O O O O O O O B O O O B O O O O O O B I O B O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O B O O O O O B I O O O O O B I I O O O B O O O O O O O O O O O O O O O O O O O O O O O B O B I O O O B O O

scribe
pastry
internet
locality properties
simulation results
network topology model
delay
link stress


Adaptive image enhancement for retinal blood vessel segmentation Retinal blood vessel images are enhanced by removing the nonstationary background , which is adaptively estimated based on local neighbourhood information . The result is a much better segmentation of the blood vessels with a simple algorithm and without the need to obtain a priori illumination knowledge of the imaging system

B I I O O O O O B I I I O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

adaptive image enhancement
retinal blood vessel images
local neighbourhood information

nonstationary background removal
image segmentation
personal identification
security applications


Score tests for zero-inflated Poisson models In many situations count data have a large proportion of zeros and the zero-inflated Poisson regression -LRB- ZIP -RRB- model may be appropriate . A simple score test for zero-inflation , comparing the ZIP model with a constant proportion of excess zeros to a standard Poisson regression model , was given by van den Broek -LRB- 1995 -RRB- . We extend this test to the more general situation where the zero probability is allowed to depend on covariates . The performance of this test is evaluated using a simulation study . To identify potentially important covariates in the zero-inflation model a composite test is proposed . The use of the general score test and the composite procedure is illustrated on two examples from the literature . The composite score test is found to suggest appropriate models

B I O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O B O O O O O O O O O O B O O O O O O B O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

count data
score tests
zero probability
covariates
excess zeros
simulation
composite test


A hybrid ML-EM algorithm for calculation of maximum likelihood estimates in semiparametric shared frailty models This paper describes a generalised hybrid ML-EM algorithm for the calculation of maximum likelihood estimates in semiparametric shared frailty models , the Cox proportional hazard models with hazard functions multiplied by a -LRB- parametric -RRB- frailty random variable . This hybrid method is much faster than the standard EM method and faster than the standard direct maximum likelihood method -LRB- ML , Newton-Raphson -RRB- for large samples . We have previously applied this method to semiparametric shared gamma frailty models , and verified by simulations the asymptotic and small sample statistical properties of the frailty variance estimates . Let theta / sub 0 / be the true value of the frailty variance parameter . Then the asymptotic distribution is normal for theta / sub 0 / > 0 while it is a 50-50 mixture between a point mass at zero and a normal random variable on the positive axis for theta / sub 0 / = 0 . For small samples , simulations suggest that the frailty variance estimates are approximately distributed as an x - -LRB- 100-x -RRB- % mixture , 0 < or = x < or = 50 , between a point mass at zero and a normal random variable on the positive axis even for theta / sub 0 / > 0 . We apply this method and verify by simulations these statistical results for semiparametric shared log-normal frailty models . We also apply the semiparametric shared gamma and log-normal frailty models to Busselton Health Study coronary heart disease data

O O O O O O O B I I O O O O O O O O O O O O O O O O O B I I O O O O O O O B I I I O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O B O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O B I I B I I I

maximum likelihood estimates
cox proportional hazard models
busselton health study
coronary heart disease data
hazard functions
simulations
frailty variance estimates
asymptotic distribution
normal random variable


Comparison between discrete STFT and wavelets for the analysis of power quality events This paper deals with the comparison of signal processing tools for power quality analysis . Two signal processing techniques are considered : the wavelet filters and the discrete short-time Fourier transforms -LRB- STFT -RRB- . Then , examples of the two most frequent disturbances met in the power system are chosen . An adjustable speed drive with a six-pulse converter using EMTP/ATP is designed and normal energizing of utility capacitors is presented . The analysis is tested on a system consisting of 13 buses and is representative of a medium-sized industrial plant . Finally , each kind of electrical disturbance is analyzed with examples representing each tool . A qualitative comparison of results shows the advantages and drawbacks of each signal processing technique applied to power quality analysis

O O B I O B O O O O B I I O O O O O O O B I I O O O O O O B I I O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O

discrete stft
wavelets
power quality events
signal processing tools
signal processing techniques
wavelet filters
adjustable speed drive
utility capacitors
electrical disturbance

discrete short-time fourier transforms
six-pulse converter
emtp/atp
medium-sized industrial plant
short-time fourier transforms


Multiecho segmented EPI with z-shimmed background gradient compensation -LRB- MESBAC -RRB- pulse sequence for fMRI A MultiEcho Segmented EPI with z-shimmed BAckground gradient Compensation -LRB- MESBAC -RRB- pulse sequence is proposed and validated for functional MRI -LRB- fMRI -RRB- study in regions suffering from severe susceptibility artifacts . This sequence provides an effective tradeoff between spatial and temporal resolution and reduces image distortion and signal dropout . The blood oxygenation level-dependent -LRB- BOLD -RRB- - weighted fMRI signal can be reliably obtained in the region of the orbitofrontal cortex -LRB- OFC -RRB- . To overcome physiological motion artifacts during prolonged multisegment EPI acquisition , two sets of navigator echoes were acquired in both the readout and phase-encoding directions . Ghost artifacts generally produced by single-shot EPI acquisition were eliminated by separately placing the even and odd echoes in different k-space trajectories . Unlike most z-shim methods that focus on increasing temporal resolution for event-related functional brain mapping , the MESBAC sequence simultaneously addresses problems of image distortion and signal dropout while maintaining sufficient temporal resolution . The MESBAC sequence will be particularly useful for pharmacological and affective fMRI studies in brain regions such as the OFC , nucleus accumbens , amygdala , para-hippocampus , etc

B I I O O O O O O O O O O O B O B I I O O O O O O O O O O O O O O O O O O B O O O O O O B I I O O O O O O O O O O B I O O B I O B I O O O O O O O O O O B O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O B I O B I O O O B I O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O

fmri
multiecho segmented epi
severe susceptibility artifacts
orbitofrontal cortex
navigator echoes
ghost artifacts
signal dropout
temporal resolution
image distortion


A case for end system multicast The conventional wisdom has been that Internet protocol -LRB- IP -RRB- is the natural protocol layer for implementing multicast related functionality . However , more than a decade after its initial proposal , IP multicast is still plagued with concerns pertaining to scalability , network management , deployment , and support for higher layer functionality such as error , flow , and congestion control . We explore an alternative architecture that we term end system multicast , where end systems implement all multicast related functionality including membership management and packet replication . This shifting of multicast support from routers to end systems has the potential to address most problems associated with IP multicast . However , the key concern is the performance penalty associated with such a model . In particular , end system multicast introduces duplicate packets on physical links and incurs larger end-to-end delays than IP multicast . We study these performance concerns in the context of the Narada protocol . In Narada , end systems self-organize into an overlay structure using a fully distributed protocol . Further , end systems attempt to optimize the efficiency of the overlay by adapting to network dynamics and by considering application level performance . We present details of Narada and evaluate it using both simulation and Internet experiments . Our results indicate that the performance penalties are low both from the application and the network perspectives . We believe the potential benefits of transferring multicast functionality from end systems to routers significantly outweigh the performance penalty incurred

O O O B I I O O O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O B I O O O O O O O O O B I O O O O O O B I I O O O O O O O B I O O O O O O O O O B I I O O O O O O O O O O B I O B I O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O B I O O O O O O O O O O O B I O O O O O O O O O B I O O O B I O O O O O O O O O O O O O O O O B I O O O B I I O O O O O O O O O O O B O B I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

end system multicast
internet protocol
protocol layer
ip multicast
network management
higher layer functionality
congestion control
membership management
packet replication
narada protocol
overlay structure
distributed protocol
network dynamics
application level performance
simulation
internet experiments
performance penalties

network scalability
network routers
end-to-end delays
self-organizing protocol


Detection and estimation of abrupt changes in the variability of a process Detection of change-points in normal means is a well-studied problem . The parallel problem of detecting changes in variance has had less attention . The form of the generalized likelihood ratio test statistic has long been known , but its null distribution resisted exact analysis . In this paper , we formulate the change-point problem for a sequence of chi-square random variables . We describe a procedure that is exact for the distribution of the likelihood ratio statistic for all even degrees of freedom , and gives upper and lower bounds for odd -LRB- and also for non-integer -RRB- degrees of freedom . Both the liberal and conservative bounds for chi / sub 1 / / sup 2 / degrees of freedom are shown through simulation to be reasonably tight . The important problem of testing for change in the normal variance of individual observations corresponds to the chi / sub 1 / / sup 2 / case . The non-null case is also covered , and confidence intervals for the true change point are derived . The methodology is illustrated with an application to quality control in a deep level gold mine . Other applications include ambulatory monitoring of medical data and econometrics

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I I O O O O O O O O B O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O B O O O O O O O B I I I O O O O O B I O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O B I O O B I I I O O O O B I O B I O B

abrupt change detection
abrupt change estimation
process variability
chi-square random variables
upper bounds
odd degrees of freedom
noninteger degrees of freedom
liberal bounds
non null case


A modified Fieller interval for the interval estimation of effective doses for a logistic dose-response curve Interval estimation of the gamma % effective dose -LRB- mu / sub gamma / say -RRB- is often based on the asymptotic variance of the maximum likelihood estimator -LRB- delta interval -RRB- or Fieller 's theorem -LRB- Fieller interval -RRB- . Sitter and Wu -LRB- 1993 -RRB- compared the delta and Fieller intervals for the median effective dose -LRB- mu / sub 50 / -RRB- assuming a logistic dose-response curve . Their results indicated that although Fieller intervals are generally superior to delta intervals , they appear to be conservative . Here an adjusted form of the Fieller interval for mu / sub gamma / termed an adjusted Fieller -LRB- AF -RRB- interval is introduced . A comparison of the AF interval with the delta and Fieller intervals is provided and the properties of these three interval estimation methods are investigated

O B I I O O B I O B I O O O O O B I O O O O O O O O O O O O O O O O O O O B I O O B I I O B I O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O

modified fieller interval
interval estimation
effective doses
asymptotic variance
maximum likelihood estimator
delta interval
median effective dose

logistic dose-response curve
fieller's theorem


Identifying multivariate discordant observations : a computer-intensive approach The problem of identifying multiple outliers in a multivariate normal sample is approached via successive testing using P-values rather than tabled critical values . Caroni and Prescott -LRB- Appl . Statist . 41 , p. 355 , 1992 -RRB- proposed a generalization of the EDR-ESD procedure of Rosner -LRB- Technometrics , 25 , 1983 -RRB- -RRB- . Venter and Viljoen -LRB- Comput . Statist . Data Anal . 29 , p. 261 , 1999 -RRB- introduced a computer intensive method to identify outliers in a univariate outlier situation . We now generalize this method to the multivariate outlier situation and compare this new procedure with that of Caroni and Prescott -LRB- Appl . Statist . 4 , p. 355 , 1992 -RRB-

O B I I O O O O O O O O B I O O B I I O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O

multivariate discordant observations
multiple outliers
multivariate normal sample
tabled critical values
univariate outlier
multivariate outlier

computer-intensive approach
p-values
data analysis
edr-ehd procedure
stepwise testing approach


Analysis and operation of hybrid active filter for harmonic elimination This paper presents a hybrid active filter topology and its control to suppress the harmonic currents from entering the power source . The adopted hybrid active filter consists of one active filter and one passive filter connected in series . By controlling the equivalent output voltage of active filter , the harmonic currents generated by the nonlinear load are blocked and flowed into the passive filter . The power rating of the converter is reduced compared with the pure active filters to filter the harmonic currents . The harmonic current detecting approach and DC-link voltage regulation are proposed to obtain equivalent voltage of active filter . The effectiveness of the adopted topology and control scheme has been verified by the computer simulation and experimental results in a scaled-down laboratory prototype

O O O O B I I O B I O O O O B I I O O O O O O O B I O O O O O O O O B I I O O O B I O O B I O O O O O O O B I I O B I O O B I O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O B I O O O O O O O O

hybrid active filter
harmonic elimination
active filter
passive filter
equivalent output voltage
harmonic currents
nonlinear load
computer simulation

harmonic currents suppression
converter power rating reduction
dc-link voltage regulation
active filter equivalent voltage
scaled-down laboratory prototype
voltage source inverter


An approximation to the F distribution using the chi-square distribution For the cumulative distribution function -LRB- c.d.f. -RRB- of the F distribution , F -LRB- x ; k , n -RRB- , with associated degrees of freedom , k and n , a shrinking factor approximation -LRB- SFA -RRB- , G -LRB- lambda kx ; k -RRB- , is proposed for large n and any fixed k , where G -LRB- x ; k -RRB- is the chi-square c.d.f. with degrees of freedom , k , and lambda = lambda -LRB- kx ; n -RRB- is the shrinking factor . Numerical analysis indicates that for n/k > or = 3 , approximation accuracy of the SFA is to the fourth decimal place for most small values of k . This is a substantial improvement on the accuracy that is achievable using the normal , ordinary chi-square , and Scheffe-Tukey approximations . In addition , it is shown that the theoretical approximation error of the SFA , | F -LRB- x ; k , n -RRB- - G -LRB- lambda kx ; k -RRB- | , is O -LRB- 1/n/sup 2 / -RRB- uniformly over x

O O O O B I O O O O O O B I I O O O O O B I O O O O O O O O O O O O B I I O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

f distribution
cumulative distribution function
degrees of freedom
shrinking factor approximation
numerical analysis


An intelligent tutoring system for a power plant simulator In this paper , an intelligent tutoring system -LRB- ITS -RRB- is proposed for a power plant simulator . With a well designed ITS , the need for an instructor is minimized and the operator may readily and efficiently take , in real-time , the control of simulator with appropriate messages he -LRB- she -RRB- gets from the tutoring system . Using SIMULINK and based on object oriented programming -LRB- OOP -RRB- and C programming language , a fossil-fuelled power plant simulator with an ITS is proposed . Promising results are demonstrated for a typical power plant

O B I I O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O B I I O O O O B I I O O O O O O O O O O O O O O O O O O O O O

intelligent tutoring system
simulink
object oriented programming
c programming language

fossil-fuelled power plant simulator
control simulation
cai


Modelling dependencies in paired comparison data a log-linear approach In many Bradley-Terry models a more or less explicit assumption is that all decisions of the judges are independent . An assumption which might be questionable at least for the decisions of a given judge . In paired comparison studies , a judge chooses among objects several times , and in such cases , judgements made by the same judge are likely to be dependent . A log-linear representation for the Bradley-Terry model is developed , which takes into account dependencies between judgements . The modelling of the dependencies is embedded in the analysis of multiple binomial responses , which has the advantage of interpretability in terms of conditional odds ratios . Furthermore , the modelling is done in the framework of generalized linear models , thus parameter estimation and the assessment of goodness of fit can be obtained in the standard way by using e.g. GLIM or another standard software

O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O B I I O O O O O O O O O O O B I I O O B I O O O O B I I O O O O O O O O O O B O O O O

multiple binomial responses
conditional odds ratios
generalized linear models
parameter estimation
goodness of fit
glim

paired comparison data dependency modelling


Calibrated initials for an EM applied to recursive models of categorical variables The estimates from an EM , when it is applied to a large causal model of 10 or more categorical variables , are often subject to the initial values for the estimates . This phenomenon becomes more serious as the model structure becomes more complicated involving more variables . As a measure of compensation for this , it has been recommended in literature that EMs are implemented several times with different sets of initial values to obtain more appropriate estimates . We propose an improved approach for initial values . The main idea is that we use initials that are calibrated to data . A simulation result strongly indicates that the calibrated initials give rise to the estimates that are far closer to the true values than the initials that are not calibrated

B I O O B O O B I O B I O O O O B O O O O O O O B I I O O O O B I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O B O O O O O B I O O O O O O O O O O O O O O O O O O O O

em
recursive models
categorical variables
calibrated initials
large causal model
initial values
simulation


Blind source separation applied to image cryptosystems with dual encryption Blind source separation -LRB- BSS -RRB- is explored to add another encryption level besides the existing encryption methods for image cryptosystems . The transmitted images are covered with a noise image by specific mixing before encryption and then recovered through BSS after decryption . Simulation results illustrate the validity of the proposed method

B I I O O B I O B I B I I O O O O O O O O O O O O O O O O B I O O B I O O O O B I O O O O O O O O O O O O O O O O O O O O O O

blind source separation
transmitted images
noise image
image cryptosystems
dual encryption


Vibration control of structure by using tuned mass damper -LRB- development of system which suppress displacement of auxiliary mass -RRB- In vibration control of a structure by using an active tuned mass damper -LRB- ATMD -RRB- , stroke of the auxiliary mass is so limited that it is difficult to control the vibration in the case of large disturbance input . In this paper , two methods are proposed for the problem . One of the methods is a switching control system by two types of controllers . One of the controllers is a normal controller under small relative displacement of the auxiliary mass , and the other is not effective only for first mode of vibration under large relative displacement of the auxiliary mass . New variable gain control system is constructed by switching these two controllers . The other method is the brake system . In active vibration control , it is necessary to use actuator for active control . By using the actuator , the proposed system puts on the brake to suppress displacement increase of the auxiliary mass under large disturbance input . Finally , the systems are designed and the effectiveness of the systems is confirmed by the simulation

B I O O O O B I I O O O O O O O O O O O O B I O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I I I O O O O O O B O O O O O O B I O O O B I O O O O O O B O B I O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

tuned mass damper
vibration control
variable gain control system
brake system
actuator
active control
controllers


Approximate confidence intervals for one proportion and difference of two proportions Constructing a confidence interval for a binomial proportion or the difference of two proportions is a routine exercise in daily data analysis . The best-known method is the Wald interval based on the asymptotic normal approximation to the distribution of the observed sample proportion , though it is known to have bad performance for small to medium sample sizes . Agresti et al. -LRB- 1998 , 2000 -RRB- proposed an Adding-4 method : 4 pseudo-observations are added with 2 successes and 2 failures and then the resulting -LRB- pseudo - -RRB- sample proportion is used . The method is simple and performs extremely well . Here we propose an approximate method based on a t-approximation that takes account of the uncertainty in estimating the variance of the observed -LRB- pseudo - -RRB- sample proportion . It follows the same line of using a t-test , rather than z-test , in testing the mean of a normal distribution with an unknown variance . For some circumstances our proposed method has a higher coverage probability than the Adding-4 method

B I I O O O O B I I I O O O O O O B I O O B I I I O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O B I O O O O

approximate confidence intervals
binomial proportion
difference of two proportions
data analysis
uncertainty
normal distribution
coverage probability

t-approximation
variance estimation
t-test
pseudo-sample proportion


A comparison of high-power converter topologies for the implementation of FACTS controllers This paper compares four power converter topologies for the implementation of flexible AC transmission system -LRB- FACTS -RRB- controllers : three multilevel topologies -LRB- multipoint clamped -LRB- MPC -RRB- , chain , and nested cell -RRB- and the well-established multipulse topology . In keeping with the need to implement very-high-power inverters , switching frequency is restricted to line frequency . The study addresses device count , DC filter ratings , restrictions on voltage control , active power transfer through the DC link , and balancing of DC-link voltages . Emphasis is placed on capacitor sizing because of its impact on the cost and size of the FACTS controller . A method for the dimensioning the DC capacitor filter is presented . It is found that the chain converter is attractive for the implementation of a static compensator or a static synchronous series compensator . The MPC converter is attractive for the implementation of a unified power flow controller or an interline power flow controller , but a special arrangement is required to overcome the limitations on voltage control

O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O B I O O O O O O O O O B O B I O O O O O O O O O B I O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O B I I I O O O O O O O O O O O B I I I O O O O O O O O O O O O O O O O O O O O

facts controllers
multilevel topologies
multipulse topology
inverters
switching frequency
device count
dc filter ratings
unified power flow controller
static compensator
static synchronous series compensator

high-power converter topologies comparison


Information and information technology This paper reveals the concepts of information and information technology . It also describes the close relationship between information and information technology . It explains a basic mechanism of different devices of information technology and connotes how they are useful to store , process and retrieve the information . In addition of this , the paper shows the present status of information technology and Indian universities

B O B I O O O O O O B O B I O O O O O O O O B O B I O O O O O O O O O O B I O O O O O O O O O O O O O B O O O O O O O O O O O O O B I O B I

information technology
information
indian universities

information storage
information processing
information retrieval


Technology CAD of SiGe-heterojunction field effect transistors A 2D virtual wafer fabrication simulation suite has been employed for the technology CAD of SiGe channel heterojunction field effect transistors -LRB- HFETs -RRB- . Complete fabrication process of SiGe p-HFETs has been simulated . The SiGe material parameters and mobility model were incorporated to simulate Si/SiGe p-HFETs with a uniform germanium channel having an L/sub eff / of 0.5 mu m . A significant improvement in linear transconductance is observed when compared to control-silicon p-MOSFETs

B I O O O O O O O O O O O O O O O O O B I O B O B I I I O O O O O B I O B O O O O O O B B I O B I O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O

technology cad
heterojunction field effect transistors
sige
fabrication process
material parameters
mobility model
linear transconductance


A novel genetic algorithm for the design of a signed power-of-two coefficient quadrature mirror filter lattice filter bank A novel genetic algorithm -LRB- GA -RRB- for the design of a canonical signed power-of-two -LRB- SPT -RRB- coefficient lattice structure quadrature mirror filter bank is presented . Genetic operations may render the SPT representation of a value noncanonical . A new encoding scheme is introduced to encode the SPT values . In this new scheme , the canonical property of the SPT values is preserved under genetic operations . Additionally , two new features that drastically improve the performance of our GA are introduced . -LRB- 1 -RRB- An additional level of natural selection is introduced to simulate the effect of natural selection when sperm cells compete to fertilize an ovule ; this dramatically improves the offspring survival rate . A conventional GA is analogous to intracytoplasmic sperm injection and has an extremely low offspring survival rate , resulting in very slow convergence . -LRB- 2 -RRB- The probability of mutation for each codon of a chromosome is weighted by the reciprocal of its effect . Because of these new features , the performance of our new GA outperforms conventional GAs

O O B I O O O O O O O O B I I B I I O O B I O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O B I O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O B I I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

genetic algorithm
quadrature mirror filter
lattice filter bank
encoding scheme
natural selection
offspring survival rate

signed power-of-two coefficient lattice structure


Novel line conditioner with voltage up/down capability In this paper , a novel pulsewidth-modulated line conditioner with fast output voltage control is proposed . The line conditioner is made up of an AC chopper with reversible voltage control and a transformer for series voltage compensation . In the AC chopper , a proper switching operation is achieved without the commutation problem . To absorb energy stored in line stray inductance , a regenerative DC snubber can be utilized which has only one capacitor without discharging resistors or complicated regenerative circuit for snubber energy . Therefore , the proposed AC chopper gives high efficiency and reliability . The output voltage of the line conditioner is controlled using a fast sensing technique of the output voltage . It is also shown via some experimental results that the presented line conditioner gives good dynamic and steady-state performance for high quality of the output voltage

O O O O O O O O O O O O O O O O O O B I I O O O O O O O O O O O B I O B I I O O O O O O O O O O B I O O O B I O O O O B O O O O O O O B I I O O B I I O O O O O O O O O O O O O O O O O O O O O O O B I O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O

output voltage control
ac chopper
reversible voltage control
switching operation
commutation
line stray inductance
regenerative dc snubber

pulsewidth-modulated line conditioner
series voltage compensation transformer
dynamic performance
steady-state performance