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* Context.--An immunohistochemistry (IHC) assay developed to detect lymphocyte-activation gene 3 (LAG-3), a novel immune checkpoint inhibitor target, has demonstrated high analytic precision and interlaboratory reproducibility using a Leica staining platform, but it has not been investigated on other IHC staining platforms. Objective.--To evaluate the performance of LAG-3 IHC assays using the 17B4 antibody clone across widely used IHC staining platforms: Agilent/Dako Autostainer Link 48 and VENTANA BenchMark ULTRA compared to Leica BOND-RX (BOND-RX). Design.--Eighty formalin-fixed, paraffin-embedded melanoma tissue blocks were cut into consecutive sections and evaluated using staining platform-specific IHC assays with the 17B4 antibody clone. Duplicate testing was performed on the BOND-RX platform to assess intraplatform agreement. LAG-3 expression using a numeric score was evaluated by a pathologist and with a digital scoring algorithm. LAG-3 positivity was determined from manual scores using a 1% or greater cutoff. Results.--LAG-3 IHC staining patterns and intensities were visually similar across all 3 staining platforms. Spearman and Pearson correlations were 0.75 or greater for interplatform and BOND-RX intraplatform concordance when LAG-3 expression was evaluated with a numeric score determined by a pathologist. Correlation increased with a numeric score determined with a digital scoring algorithm (Spearman and Pearson correlations [greater than or equal to] 0.88 for all comparisons). Overall percentage agreement was 77.5% or greater for interplatform and BOND-RX intraplatform comparisons when LAG-3 positivity was determined using a 1 % or greater cutoff. Conclusions.--Data presented here demonstrate that LAG-3 expression can be robustly and reproducibly assessed across 3 major commercial IHC staining platforms using the 17B4 antibody clone. doi: 10.5858/arpa.2022-0082-OA, Lymphocyte-activation gene 3 (LAG-3) is a cell-surface immune checkpoint molecule expressed on immune cells (ICs) initiating an inhibitory signal that can impair T-cell activity and attenuate proinflammatory cytokine responses. (1-3) [...]

As a component of Earth's hydrologic cycle, and especially at higher latitudes, falling snow creates snowpack accumulation that in turn provides a large proportion of the freshwater resources required by [...]

The 'Masters Hypothesis' is the claim that unprecedented buying pressure in recent years from new index investment created a massive bubble in commodity futures prices. Due to data limitations, some [...]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.comnet.2010.01.013 Byline: P. Casas (a)(c), S. Vaton (a), L. Fillatre (b), I. Nikiforov (b) Keywords: Network Monitoring and Traffic Analysis; Traffic Matrix; Network Traffic Modeling; Optimal Volume Anomaly Detection and Isolation Abstract: Recent studies from major network technology vendors forecast the advent of the Exabyte era, a massive increase in network traffic driven by high-definition video and high-speed access technology penetration. One of the most formidable difficulties that this forthcoming scenario poses for the Internet is congestion problems due to traffic volume anomalies at the core network. In the light of this challenging near future, we develop in this work different network-wide anomaly detection and isolation algorithms to deal with volume anomalies in large-scale network traffic flows, using coarse-grained measurements as a practical constraint. These algorithms present well-established optimality properties in terms of false alarm and miss detection rate, or in terms of detection/isolation delay and false detection/isolation rate, a feature absent in previous works. This represents a paramount advantage with respect to current in-house methods, as it allows to generalize results independently of particular evaluations. The detection and isolation algorithms are based on a novel linear, parsimonious, and non-data-driven spatial model for a large-scale network traffic matrix. This model allows detecting and isolating anomalies in the Origin-Destination traffic flows from aggregated measurements, reducing the overhead and avoiding the challenges of direct flow measurement. Our proposals are analyzed and validated using real traffic and network topologies from three different large-scale IP backbone networks. Author Affiliation: (a) Telecom Bretagne, Brest, France (b) Universite de Technolgie de Troyes, Troyes, France (c) Universidad de la Republica, Montevideo, Uruguay Article History: Received 10 August 2009; Revised 13 January 2010; Accepted 23 January 2010 Article Note: (miscellaneous) Responsible Editor: A. Popescu

A novel and unique algorithm for the retrieval of multilayer cloud-top pressure is presented, relying on synergetic observations of the Medium Resolution Imaging Spectrometer (MERIS) and Advanced Along Track Scanning Radiometer (AATSR) on board the Environmental Satellite (Envisat). The retrieval is based on the exploitation of the differing signals observed in the thermal infrared spectral region (AATSR) and the oxygen A band at 0.76 [micro]m (MERIS). Past studies have shown that the cloud-top pressure retrieved from MERIS measurements is highly accurate in the case of low single-layered clouds. In contrast, in the presence of multilayered clouds like cirrus overlying water clouds, the derived cloud height is biased. In this framework, an optimal estimation algorithm for the correction of the measured 02 A transmission for the influence of the upper cloud layer was developed. The algorithm is best applicable in cases of optically thin cirrus (1 [less than or equal to] [tau] [less than or equal to] 5) above optically thick water clouds ([tau] > 5), as found frequently in the vicinity of convective or frontal cloud systems. The split-window brightness temperature difference technique is used for the identification of suitable cases. The sensitivities of the AATSR and MERIS measurements to multilayered clouds are presented and discussed, revealing that in the case of dual-layered clouds, the AATSR-derived cloud height is close to the upper cloud layer, even if it is optically thin. In contrast, the cloud height retrieved from MERIS measurements represents the optical center of the cloud system, which is close to the lower layer in cases where the upper layer is optically thin. Two case studies of convective, multilayered cloud systems above the northern Atlantic Ocean are shown, demonstrating the plausibility of the approach. The presented work is relevant especially in view of the upcoming Global Monitoring for Environment and Security Sentinel-3 satellite to be launched in 2012 that will carry the respective MERIS and AATSR follow-up instruments Ocean and Land Colour Instrument (OLCI) and Sea and Land Surface Temperature Radiometer (SLSTR). DOI: 10.1175/2010JAMC2331.1

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.comnet.2009.08.003 Byline: Jeongkeun Lee (a), Jiho Ryu (b), Sung-Ju Lee (a), Ted Taekyoung Kwon (b) Keywords: IEEE 802.11; Physical layer capture; Interference; Carrier sense; Simulation model Abstract: In wireless networks, modeling of the physical layer behavior is an important yet difficult task. Modeling and estimating wireless interference is receiving great attention, and is crucial in a wireless network performance study. The physical layer capture, preamble detection, and carrier sense threshold are three key components that play important roles in successful frame reception in the presence of interference. Using our IEEE 802.11a wireless network testbed, we carry out a measurement study that reveals the detailed operation of each component and in particular we show the terms and conditions (interference timing, signal power difference, bitrate) under which a frame survives interference according to the preamble detection and capture logic. Based on the measurement study, we show that the operations of the three components in real IEEE 802.11a systems differ from those of popular simulators and present our modifications of the IEEE 802.11a PHY models to the NS-2 and QualNet network simulators. The modifications can be summarized as follows. (i) The current simulators' frame reception is based only on the received signal strength. However, real 802.11 systems can start frame reception only when the Signal-to-Interference Ratio (SIR) is high enough to detect the preamble. (ii) Different chipset vendors implement the frame reception and capture algorithms differently, resulting in different operations for the same event. We provide different simulation models for several popular chipset vendors and show the performance differences between the models. (iii) Based on the 802.11a standard setting and our testbed observation, we revise the simulator to set the carrier sense threshold higher than the receiver sensitivity rather than equal to the receiver sensitivity. We implement our modifications to the QualNet simulator and evaluate the impact of PHY model implementations on the wireless network performance; these result in an up to six times increase of net throughput. Author Affiliation: (a) Hewlett-Packard Laboratories, 1501 Page Mill Road, Palo Alto, CA 94304, USA (b) Seoul National University, Building 301, Room 553-1, 599 Gwanak-ro, Gwanak-gu, Seoul 151-742, Republic of Korea Article Note: (footnote) [star] This work was supported in part by NAP of Korea Research Council of Fundamental Science and Technology (KRCF) and the Ministry of Knowledge Economy, Korea, under the Information Technology Research Center support program supervised by the Institute of Information Technology Advancement. (Grant No. IITA-2009-C1090-0902-0006) The ICT at Seoul National University provides research facilities for this study.

A dynamic regularization scheme for rain-rate retrievals from attenuated radar measurements is presented. Most regularization techniques, including the optimal estimation method, use the state-space parameters to regularize the problem, which will always lead to a bias in the solution. To avoid this problem the authors introduce an evolutionary regularization technique, which is based on the spatial derivative of the measured reflectivity profile and allows for a bias-free global solution. The regularization strength is determined by the quadratic eigenvalue solution using the regularized total least squares method. With the new method, the authors perform a retrieval of rain-rate profiles from simulated measurements of a nadir-pointing W-band (94 GHz) radar, in a configuration similar to the cloud radar employed on CloudSat. The simulations assume that multiple scattering is negligible and only liquid hydrometeors are taken into account. The authors compare the results of this method with the outcome of an optimal estimation method and demonstrate that their method is superior in terms of reliability, correlation coefficient, and dispersion to the optimal estimation method for layers experiencing high values of attenuation: therefore, the a priori bias typical for optimal estimation solutions is avoided. DOI: 10.1175/2009JAMC2279.1

In compressed sensing, we seek to gain information about a vector x [member of] [R.sup.N] from d [much less than] N nonadaptive linear measurements. Candes, Donoho, Tao et al. (see, e.g., Candes, Proc. Intl. Congress Math., Madrid, 2006; Candes et al., Commun. Pure Appl. Math. 59:1207-1223, 2006; Donoho, IEEE Trans. Inf. Theory 52:1289-1306, 2006) proposed to seek a good approximation to x via [l.sub.1] minimization. In this paper, we show that in the case of Gaussian measurements, [l.sub.1] minimization recovers the signal well from inaccurate measurements, thus improving the result from Candes et al. (Commun. Pure Appl. Math. 59:1207-1223, 2006). We also show that this numerically friendly algorithm (see Candes et al., Commun. Pure Appl. Math. 59:1207-1223, 2006) with overwhelming probability recovers the signal with accuracy, comparable to the accuracy of the best k-term approximation in the Euclidean norm when k ~ d/ln N. Keywords Signal recovery algorithms * Restricted isometry condition * Compressed sensing * [l.sub.1]-minimization * Gaussian measurement matrix * Signal recovery * Sparse approximation Mathematics Subject Classification (2000) 68P30 * 68W20 * 41A46, 1 Introduction Compressed sensing is a new scheme which shows that some signals can be reconstructed from fewer measurements than previously considered. The mathematical formulation is the following. Our signal [...]

Simulated radar signatures within the melting layer in stratiform rain--namely, the radar bright band--are checked by means of comparisons with simultaneous measurements of the bright band made by the ER-2 Doppler radar (EDOP; X band) and Cloud Radar System (CRS; W band) airborne Doppler radars during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida-Area Cirrus Experiment (CRYSTAL-FACE) campaign in 2002. A stratified-sphere model, allowing the fractional water content to vary along the radius of the particle, is used to compute the scattering properties of individual melting snowflakes. Using the effective dielectric constants computed by the conjugate gradient-fast Fourier transform numerical method for X and W bands and expressing the fractional water content of a melting particle as an exponential function in particle radius, it is found that at X band the simulated radar brightband profiles are in an excellent agreement with the measured profiles. It is also found that the simulated W-band profiles usually resemble the shapes of the measured brightband profiles even though persistent offsets between them are present. These offsets, however, can be explained by the attenuation caused by cloud water and water vapor at W band. This is confirmed by comparisons of the radar profiles made in the rain regions where the unattenuated W-band reflectivity profiles can be estimated through the X- and W-band Doppler velocity measurements. The brightband model described in this paper has the potential to be used effectively for both radar and radiometer algorithms relevant to the satellite-based Tropical Rainfall Measuring Mission and Global Precipitation Measuring Mission. DOI: 10.1175/2009JAMC2033.1

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.robot.2009.06.001 Byline: Josep M. Font-Llagunes, Joaquim A. Batlle Abstract: Localization is a fundamental operation for the navigation of mobile robots. The standard localization algorithms fuse external measurements of the environment with the odometric evolution of the robot pose to obtain its optimal estimation. In this work, we present a different approach to determine the pose using angular measurements discontinuously obtained in time. The presented method is based on an Extended Kalman Filter (EKF) with a state-vector composed of the external angular measurements. This algorithm keeps track of the angles between actual measurements from robot odometric information. This continuous angular estimation allows the consistent use of the triangulation methods to determine the robot pose at any time during its motion. The article reports experimental results that show the localization accuracy obtained by means of the presented approach. These results are compared to the ones obtained applying the EKF algorithm with the standard pose state-vector. For the experiments, an omnidirectional robotic platform with omnidirectional wheels is used. Author Affiliation: Department of Mechanical Engineering, Universitat Politecnica de Catalunya, Av. Diagonal 647, 08028 Barcelona, Catalunya, Spain Article History: Received 17 April 2008; Revised 3 June 2009; Accepted 12 June 2009

Regression quantiles can be substantially biased when the covariates are measured with error. In this paper we propose a new method that produces consistent linear quantile estimation in the presence of covariate measurement error. The method corrects the measurement error induced bias by constructing joint estimating equations that simultaneously hold for all the quantile levels. An iterative EM-type estimation algorithm to obtain the solutions to such joint estimation equations is provided. The finite sample performance of the proposed method is investigated in a simulation study, and compared to the standard regression calibration approach. Finally, we apply our methodology to part of the National Collaborative Perinatal Project growth data, a longitudinal study with an unusual measurement error structure. KEY WORDS: Correction for attenuation: Growth curves; Longitudinal data; Measurement error; Quantile regression; Regression calibration; Regression quantiles.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2009.05.015 Byline: Andres J. Picazo-Tadeo (a), Diego Prior (b) Abstract: Production of desirable outputs often produces by-products that have harmful effects on the environment. This paper investigates technologies where the biggest good output producer is not the greatest polluter, i.e. technologies located on the downward-sloping segment of the frontier depicted in . Directional distance functions and Data Envelopment Analysis techniques are used to define an algorithm that allows them to be identified empirically. Furthermore, we show that in such situations producers can contribute social goods, i.e. reducing polluting wastes, without limiting their capacity to maximise production of marketable output. Finally, we illustrate our methodology with an empirical application to a sample of Spanish ceramic tile producers. Author Affiliation: (a) Universitat de Valencia. Dpto. Economia Aplicada II, Avda. dels Tarongers, s/n. 46022. Valencia, Spain (b) Universitat AutA[sup.2]noma de Barcelona. Dpt. Economia de l'Empresa, 08193 Bellaterra, Barcelona, Spain Article History: Received 8 February 2008; Revised 7 April 2009; Accepted 7 May 2009

This paper studies spurious signals produced by the nonlinear interaction of the previous output symbols of a digital-to-analog converter (DAC) with its current symbol. This effect, called nonlinear intersymbol interference (ISI), significantly degrades the spurious-free dynamic range of most high-speed DACs. Many papers have been devoted to suppressing level inaccuracies in multibit DACs. However, even when all levels are accurate, nonlinear ISI causes significant spurious output. This paper presents a simple and very general model for nonlinear ISI and uses it to design binary signals that can both measure and suppress the spurious tones that arise in a single-bit DAC. While the analysis in this paper is based on a 1-bit DAC, extension to multibit DACs is possible, since a multibit DAC is merely a collection of 1-bit DACs and exhibits the same nonlinear effects. Experimental verification is presented for three different hardware setups. Measurements first establish the presence of the spurious tones in the hardware, as predicted by the model, and then show how the spur level can be reduced by as much as 22 dB. Index Terms--Filter-amplifier model, list-decoding algorithm, nonlinear intersymbol interference (ISI), tone-injection, [SIGMA][DELTA] modulation.

An effective subject recognition approach is designed in this paper, using ground reaction force (GRF) measurements of human gait. The method is a three-stage procedure: 1) The original GRF data are translated through wavelet packet (WP) transform in the time--frequency domain. Using a fuzzy-set-based criterion, we determine an optimal WP decomposition, involving feature subspaces with distinguishing gait characteristics. 2) A feature extraction scheme is employed next for wavelet feature ranking, according to discrimination power. 3) The classification task is accomplished by means of a kernel-based support vector machine. The design parameters of the classifier are tuned through a genetic algorithm to improve recognition rates. The method is evaluated on a database comprising GRF records obtained from 40 subjects. To account for the natural variability of human gait, the experimental setup is designed, allowing different walking speeds and loading conditions. Simulation results demonstrate that high recognition rates can be achieved with moderate number of features and for different training/testing settings. Finally, the performance of our approach is favorably compared with the one obtained using other traditional classification algorithms. Index Terms--Feature selection, ground reaction forces (GRFs) of gait, human gait analysis, kernel-based support vector machine (SVM) classification, subject recognition, wavelet packet (WP) decomposition.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.comnet.2008.06.006 Byline: M. Fraiwan, G. Manimaran Keywords: Measurement scheduling; Overlay networks; Measurement conflict; Network monitoring Abstract: Network monitoring is essential to the correct and efficient operation of ISP networks and the kind of applications they support, and active measurement is a key design problem in network monitoring. Unfortunately, almost all active probing algorithms ignore the measurement conflict problem: Active measurements conflict with each other - due to the nature of these measurements, the associated overhead, and the network topology - which leads to reporting incorrect results. In this paper, we consider the problem of scheduling periodic QoS measurement tasks in overlay networks. We first show that this problem is NP-hard, and then propose two conflict-aware scheduling algorithms for uniform and non-uniform tasks whose goal is to maximize the number of measurement tasks that can run concurrently, based on a well-known approximation algorithm. We incorporate topological information to devise a topology-aware scheduling algorithm that reduces the number of time slots required to produce a feasible measurement schedule. Also, we study the conflict-causing overlap among overlay paths using various real-life Internet topologies of the two major service carriers in the US. Experiments conducted using the PlanetLab testbed confirm that measurement conflict is a real issue that needs to be addressed. Simulation results show that our algorithms achieve at least 25% better schedulability over an existing algorithm. Finally, we discuss various practical considerations, and identify several interesting research problems in this context. Author Affiliation: Real-Time Computing and Networking Laboratory, Department of Electrical and Computer Engineering, Iowa State University, Ames, IA 50011, United States

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.icarus.2006.10.037 Byline: David S. Choi (a), Don Banfield (b), Peter Gierasch (b), Adam P. Showman (a) Keywords: Jupiter; atmosphere; Atmospheres; dynamics Abstract: We have produced mosaics of the Great Red Spot (GRS) using images taken by the Galileo spacecraft in May 2000, and have measured the winds of the GRS using an automated algorithm that does not require manual cloud tracking. Our technique yields a high-density, regular grid of wind velocity vectors that is advantageous over a limited number of scattered wind vectors that result from manual cloud tracking. The high-velocity collar of the GRS is clearly seen from our velocity vector map, and highest wind velocities are measured to be around 170 mas.sup.-1. The high resolution of the mosaics has also enabled us to map turbulent eddies inside the chaotic central region of the GRS, similar to those mapped by Sada et al. [Sada, P.V., Beebe, R.F., Conrath, B.J., 1996. Icarus 119, 311-335]. Using the wind velocity measurements, we computed particle trajectories around the GRS as well as maps of relative and absolute vorticities. We have discovered a narrow ring of cyclonic vorticity that surrounds the main anti-cyclonic high-velocity collar. This narrow ring appears to correspond to a ring surrounding the GRS that is bright in 5 [mu]m [Terrile, R.J., Beebe, R.F., 1979. Science 204, 948-951]. It appears that this cyclonic ring is not a transient feature of the GRS, as we have discovered it in a re-analysis of Galileo data taken in 1996 first analyzed by Vasavada et al. [Vasavada, A.R., and 13 colleagues, 1998. Icarus 135, 265-275]. We also calculate how absolute vorticity changes as a function of latitude along a trajectory around the GRS and compare these measurements to similar ones performed by Dowling and Ingersoll [Dowling, T.E., Ingersoll, A.P., 1988. J. Atmos. Sci. 45, 1380-1396] using Voyager data. We show no dramatic evolution in the structure of the GRS since the Voyager era except for additional evidence for a counter-rotating GRS core, an increase in velocity in the main velocity collar, and an overall decrease in the length of the GRS. Author Affiliation: (a) Department of Planetary Sciences, University of Arizona, Tucson, AZ 85721, USA (b) Department of Astronomy, Cornell University, Ithaca, NY 14853, USA Article History: Received 23 June 2006; Revised 24 October 2006

To purchase or authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1523-1739.2006.00531.x Byline: ABEL G. WOLMAN (*) Keywords: biodiversity value; estimated data; expert judgment; measurement scale; systematic conservation planning Abstract: Abstract: Incomplete databases often require conservation scientists to estimate data either through expert judgment or other scoring, rating, and ranking procedures. At the same time, ecosystem complexity has led to the use of increasingly sophisticated algorithms and mathematical models to aid in conservation theorizing, planning, and decision making. Understanding the limitations imposed by the scales of measurement of conservation data is important for the development of sound conservation theory and policy. In particular, biodiversity valuation methods, systematic conservation planning algorithms, geographic information systems (GIS), and other conservation metrics and decision-support tools, when improperly applied to estimated data, may lead to conclusions based on numerical artifact rather than empirical evidence. The representational theory of measurement is described here, and the description includes definitions of the key concepts of scale, scale type, and meaningfulness. Representational measurement is the view that measurement entails the faithful assignment of numbers to empirical entities. These assignments form scales that are organized into a hierarchy of scale types. A statement involving scales is meaningful if its truth value is invariant under changes of scale within scale type. I apply these concepts to three examples of measurement practice in the conservation literature. The results of my analysis suggest that conservation scientists do not always investigate the scale type of estimated data and hence may derive results that are not meaningful. Recognizing the complexity of observation and measurement in conservation biology, and the constraints that measurement theory imposes, the examples are accompanied by suggestions for informal estimation of the scale type of conservation data and for conducting meaningful analysis and synthesis of this information. Abstract (Spanish): Medicion y Significado en la Ciencia de la Conservacion Resumen: Las bases de datos incompletas a menudo hacen que los cientificos de la conservacion estimen datos por medio de opinion experta u otros procedimientos de puntuacion, calificacion y clasificacion. Al mismo tiempo, la complejidad de l ecosistema ha conducido al uso de algoritmos y modelos matematicos cada vez mas sofisticados para auxiliar a la teoria, planificacion y toma de decisiones en conservacion. El entendimiento de las limitaciones impuestas por las escalas de medicion de los datos de conservacion es importante para el desarrollo de teorias y politicas de conservacion solidas. En particular, cuando son aplicados inapropiadamente a datos estimados, los metodos de valoracion de la biodiversidad, los algoritmos de planificacion sistematica de la conservacion, los SIG y otras medidas de la conservacion pueden conducir a conclusiones basadas en numeros artificiales y no en evidencia empirica. En este trabajo se describe la teoria representativa de la medicion, y se incluyen definiciones de los conceptos claves de escala, tipo de escala y significado. La medicion representativa considera que la medicion implica la asignacion confiable de numeros a entidades empiricas. Estas asignaciones forman escalas que estan organizadas en una jerarquia de tipos de escala. Una afirmacion que involucre escalas es significativa si su valor de veracidad es invariable bajo cambios de escala dentro de un tipo de escala. Aplique estos conceptos a tres ejemplos de practicas de medicion en la literatura sobre conservacion. Los resultados de mis analisis sugieren que los cientificos de la conservacion no siempre investigan el tipo de escala de los datos estimados y por lo tanto pueden derivar resultados que no son significativos. Reconociendo la complejidad de la observacion y la medicion en biologia de la conservacion, asi como las restricciones que impone la teoria de la medicion, los ejemplos son acompanados por sugerencias para la estimacion informal del tipo de escala para datos de conservacion y para realizar analisis y sintesis significativos de esta informacion. Author Affiliation: (*)AGW Consulting, Inc., 855 NW Lincoln Street, White Salmon, WA 98672-4326, U.S.A., emailwolman@gorge.net Article History: Paper submitted November 30, 2005; revised manuscript accepted March 23, 2006.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jss.2005.11.568 Byline: Marjan HeriAko, Ivan Rozman, AleA A1/2ivkoviA Keywords: Function points; Software size; Formal model; Object-oriented projects Abstract: Estimating software size is a difficult task that requires a methodological approach. Many different methods that exist today use distinct abstractions to depict a software system. The gap between abstractions becomes even greater with object-oriented artifacts developed in unified modeling language (UML). In this paper, a formal foundation for the representation of functional size measurement (FSM) methods is presented. The generalized abstraction of the software system (GASS) is then used to formalize different functional measurement methods, namely the FPA, MK II FPA and COSMIC-FFP. The same model is also used for object-oriented projects where UML artifacts are mapped into the GASS form. The algorithms in symbolic code for those UML diagrams that are crucial for size estimation are also given. The mappings defined in this paper enable diverse FSM methods to be supported in estimation tools, the automation of counting steps and a higher-level of independence from the FSM method, since the software abstraction is written in a generalized form. Both improvements are crucial for the practical use of FSM methods. Author Affiliation: Faculty of Electrical Engineering and Computer Science, University of Maribor, Smetanova 17, SI-2000 Maribor, Slovenia Article History: Received 11 April 2005; Accepted 5 November 2005

The utilization of Clarke's transformation in the estimation of power system frequency provides the classical single-phase methods with more robustness because the estimated frequency is computed using the information provided by the three-phase voltage. This approach is particularly important when asymmetric sags generate zero voltage in one of the three phases. In addition, the proposed algorithm exhibits good behavior during dynamic conditions. The Clarke components of the voltage signals are then used to compute the frequency of the system following an iterative approach based on a proportional-integral-derivative controller. The inverse component of the voltage is also used in order to detect unbalanced conditions. The proposed algorithm has been put to the test with distorted three-phase voltage supplied by an arbitrary waveform programmable power supply and with different signals generated with an Alternative Transients Program-Electromagnetic Transients Program model. Index Terms--Frequency measurement, power quality (PQ).

A set of theoretic formulations enables the derivation of the adaptive regularized constrained displacement vector field (DVF) estimation algorithm. A group of recursive gradient displacement estimation algorithms are unified by this algorithm. The algorithm's performance is enhanced due to this adaptivity, without an increase in the size of the spatial mask. The enhanced performance is essential for the regions around the occlusion areas of the image sequence. The algorithm is experimentally compared with the other existing algorithms in the estimation of the DVF of the synthetic and standard video conference images.

We consider the problem of adjusting provisional time series using a bivariate structural model with correlated measurement errors. Maximum likelihood estimators and a minimum mean squared error adjustment procedure are derived for a provisional and final series containing common trend and seasonal components. The model also includes measurement errors common to both series and errors that are specific to the provisional series. We illustrate the technique by using provisional data to forecast ischemic heart disease mortality. KEY WORDS: EM algorithm; Forecasting; Mortality surveillance; State-space model; Structural models; Trends., 1. INTRODUCTION There are many situations that arise in time series analysis where additional outside information may be available for use in forecasting one or more of the given series. [...]

Different nations use different algorithms or other techniques to convert temperatures and relative humidities from radiosonde observations to dewpoint depressions. Thus, it is possible for identical measured values to result in different reported dewpoints. On the basis of a sample of conversion methods, we calculate the possible differences among the national practices. In general, the discrepancies are not large and would often be lost in the usual round-off procedures associated with transmission over the Global Telecommunications System, but in cold, dry conditions dewpoints different by more than 1 degree C could be reported for identical conditions. Some of the methods have been changed over time, so there is also the possibility of inhomogeneities in climate records.

An on-line version of a recently proposed frequency-estimation algorithm based on structured autoregressive (AR) modeling of data is derived for the special case of a single cisoid in noise. The adaptive notch filter utilizes a weighted sum-of-squares of the AR prediction error that is recursively minimized with respect to the frequency of the cisoid. The steady-state performance of the algorithm is characterized by aid of a linear filter-approximation technique, and design rules for the tuning variables are given. An excellent agreement is demonstrated between the results predicted by theory, and the measured performance based on numerical simulations. The tracking ability and noise rejection is compared both with the performance of alternative algorithms and with the appropriate Cramer-Rao bound. It is shown that the algorithm is close to being statistically efficient. Index Terms--Adaptive filters, digital signal processing, parameter estimation, recursive estimation.