Harmonic balance surrogate-based immunity modeling of a nonlinear analog circuit

A novel harmonic balance surrogate-based technique to create fast and accurate behavioral models predicting, in the early design stage, the performance of nonlinear analog devices during immunity tests is presented. The obtained immunity model hides the real netlist, reduces the simulation time, and avoids expensive and time-consuming measurements after tape-out, while still providing high accuracy. The model can easily be integrated into a circuit simulator together with additional subcircuits, e.g., board and package models, as such allowing to efficiently reproduce complete immunity test setups during the early design stage and without disclosing any intellectual property. The novel method is validated by means of application to an industrial case study, being an automotive voltage regulator, clearly showing the technique's capabilities and practical advantages

Bias-corrected estimation of panel vector autoregressions

We derive a bias-corrected least-squares estimator for panel vector autoregressions with fixed effects. The estimator is straightforward to implement and is asymptotically unbiased under asymptotics where the number of time series observations and the number of cross-sectional observations grow at the same rate. This makes the estimator particularly well suited for most macroeconomic data sets

Split-panel jackknife estimation of fixed-effect models

© The Author 2015. Maximum-likelihood estimation of nonlinear models with fixed effects is subject to the incidentalparameter problem. This typically implies that point estimates suffer from large bias and confidence intervals have poor coverage. This article presents a jackknife method to reduce this bias and to obtain confidence intervals that are correctly centred under rectangular-array asymptotics.The method is explicitly designed to handle dynamics in the data, and yields estimators that are straightforward to implement and can be readily applied to a range of models and estimands. We provide distribution theory for estimators of model parameters and average effects, present validity tests for the jackknife, and consider extensions to higher-order bias correction and to two-step estimation problems. An empirical illustration relating to female labour-force participation is also provided

LIKELIHOOD INFERENCE IN AN AUTOREGRESSION WITH FIXED EFFECTS

We calculate the bias of the profile score for the regression coefficients in a multistratum autoregressive model with stratum-specific intercepts. The bias is free of incidental parameters. Centering the profile score delivers an unbiased estimating equation and, upon integration, an adjusted profile likelihood. A variety of other approaches to constructing modified profile likelihoods are shown to yield equivalent results. However, the global maximizer of the adjusted likelihood lies at infinity for any sample size, and the adjusted profile score has multiple zeros. Consistent parameter estimates are obtained as local maximizers inside or on an ellipsoid centered at the maximum likelihood estimator.</jats:p

Технология проведения гидравлических испытаний промысловых нефтепроводов в условиях Западной Сибири

Объектом исследования является методика и технология проведения гидравлических испытаний нефтепровода. Целью данной работы является исследование актуальной научно-технической проблемы обеспечения требуемых условий и средств для проведения гидравлических испытаний промысловых нефтепроводов. В соответствии с поставленной целью были выдвинуты следующие задачи: 1. Определить необходимую номенклатуру и объем подготовительных работ для проведения испытаний промыслового нефтепровода; 2. Исследовать основные факторы и их влияние на процесс гидравлических испытаний нефтепровода в промысловых условиях; 3. Выбор средств и методов, исключающих влияние внешних факторов на достоверность результатов испытаний.The object of study is the methodology and technology for conducting hydraulic tests of the oil pipeline. The aim of this work is to study the urgent scientific and technical problems of providing the required conditions and means for conducting hydraulic tests of field pipelines. In accordance with the goal, the following tasks were put forward: 1. To determine the necessary nomenclature and scope of preparatory work for testing the oil field pipeline; 2. Investigate the main factors and their influence on the process of hydraulic testing of the pipeline in the field; 3. The choice of tools and methods that exclude the influence of external factors on the reliability of the test results