The use of kriging models for approximation and metamodel-based design optimization has been steadily on the rise in past decade. widespread usage appears to be hampered by (1) lack guidance selecting appropriate form model, (2) computationally efficient algorithms estimating model’s parameters, (3) an effective method assess resulting quality. In this paper, we compare Maximum Likelihood Estimation (MLE) Cross-Validation (CV) parameter estimation methods a parameters given its R 2...

The authors have augmented the NASA DC-8 AIRSAR instrument with a pair of C-band antennas displaced across track to form an interferometer sensitive topographic variations Earth's surface. During 1991 flight campaign, data were acquired over several sites in US and Europe, maps produced from these lines. Analysis results indicate that statistical errors are 2-4-m range, while systematic effects due aircraft motion 10-20-m range. initial development second-generation processor show...

Abstract. NASADEM is a near-global elevation model that being produced primarily by completely reprocessing the Shuttle Radar Topography Mission (SRTM) radar data and then merging it with refined ASTER GDEM elevations. The new improved SRTM elevations in result from better vertical control of each swath via reference to ICESat void reductions using advanced interferometric unwrapping algorithms. Remnant voids will be filled GDEM3, but reduction glitches (mostly related clouds) therefore only...

Although necessary for complex problem solving, such as engineering design, team agility is often difficult to achieve in practice. The evolution of Artificial Intelligence (AI) affords unique opportunities supporting solving. While integrating assistive AI agents into human teams has at times improved performance, it still unclear if, how, and why affects agility. A large-scale experiment answers these questions, revealing that, with appropriately interfaced AIs, AI-assisted enjoy...

The use of kriging models for approximation and global optimization has been steadily on the rise in past decade. standard approach used Design Analysis Computer Experiments (DACE) is to an Ordinary model approximate a deterministic computer model. Universal Detrended are two alternative types models. In this paper, description basics given, highlighting similarities differences between these three different underlying assumptions behind each. A comparative study then presented using six...

The details of a method to reduce the computational burden experienced while estimating optimal model parameters for Kriging are presented. A is type surrogate that can be used create response surface based set observations computationally expensive system design analysis. This then as efficient original model, providing opportunity rapid exploration resulting tradespace. provide more complex than traditional linear regression through introduction few terms quantify spatial correlation...

Abstract Managing the design process of teams has been shown to considerably improve problem-solving behaviors and resulting final outcomes. Automating this activity presents significant opportunities in delivering interventions that dynamically adapt state a team order reap most impact. In work, an artificial intelligence (AI) agent is created manage engineering real time, tracking features teams’ actions communications during complex path-planning task multidisciplinary teams. Teams are...

In February 2000 the Shuttle Radar Topography Mission (SRTM) mapped topography of world's landmasses between /spl plusmn/60/spl deg/ using radar interferometry. The instrument, designed for global coverage, is a two-aperture C-band interferometer, comprising modified SIR-C system and an added receive antenna mounted at end 60 m deployable boom. Full coverage Earth was possible in 10 day mission by operating two two-beam ScanSAR modes, one with vertical polarization, other horizontal...

The use of kriging models for approximation and metamodel-based design optimization has been steadily on the rise in past decade. widespread usage appears to be hampered by (1) lack guidance selecting appropriate form model, (2) computationally efficient algorithms estimating model’s parameters, (3) an effective method assess resulting quality. In this paper, we compare Maximum Likelihood Estimation (MLE) Cross-Validation (CV) parameter estimation methods a parameters given its R2 prediction...

This paper describes a method to implement an adaptive metamodeling procedure during simulation- based design. Metamodels can be used for design space visualization and optimization applications when model evaluation performance is critical. The proposed uses sequential technique update kriging metamodel. will determine the point of metamodel's with maximum mean square error select this as next use At each iteration quality metamodel assessed using leave- k-out cross-validation three...

Current design decisions must be made while considering uncertainty in both models of the and inputs to design. In most cases, high fidelity are used with assumption that resulting model uncertainties insignificant decision making process. This paper presents a methodology for managing during system-level conceptual complex multidisciplinary systems. is based upon quantifying information available set observations computationally expensive subsystem more efficient kriging models. By using...

In Brief Today, there exist a variety of lower limb prosthetic devices. Each device differs in design and function. A relatively new particularly interesting category prosthetics are those that microprocessor controlled. These devices ultimately seek to mimic the human anatomical control system, surpassing abilities mechanical-based prosthetics, by incorporating sensor input, processing, output actuation, feedback input features. However, it is important understand not all...

In this paper, we investigate the resulting probability distribution of a kriging model when values parameters must be estimated from observations process being modeled. The output defines Gaussian are given. practice, these modeled (typically computationally expensive computer model). We found that treated as random variables instead known values, can well approximated by Student-t distribution, with fatter tails than or normal distribution. Markov chain Monte Carlo (MCMC) method was used...

The theoretical efficiencies of class-D amplifiers are compared with those conventional by means a power balance. As result certain similarities, it is suggested that class-AD and class-BD modes operation should be defined. amplifier converts the collector dissipation into load components at large number modulation frequencies. When these removed filtering, high overall efficiency results. analysis presented includes an idealised treatment inductive load, enables constructive comparisons to made.

Hybrid powered locomotives can provide significant savings on the energy consumed to move freight railways. The SCORE toolset is an open source, web-based application assess impact of new powering technologies railroad performance, specifically capable both putting power into rail (motive force) and taking from (regeneration). SCORE’s primary goal generate trade studies analyze different train make-up options minimize usage greenhouse gas generation. At core generating these spaces...

An experimental class-BD amplifier circuit is reported, which confirms the previously announced principle of circuit. Although slightly more complex than conventional class-AD circuit, filtering problems are simplified, and it may have applications as a high-power amplifier.

Abstract Adding battery locomotives to traditional diesel form a hybrid consist has the potential reduce fuel consumption and emissions in freight rail operations. This paper provides route-based estimates of (hpd/ton) (hpb/ton) power requirements (gal/ton) (hpbhr/ton) energy for consists. Given route-specific profile, split between pack engine is optimized minimize by running at maximum efficiency during entire route. Simulations 200-mile round trips Chicago Harrisburg show that...

Kriging models are frequently used as metamodels during system design optimization. In many applications, a kriging model is deterministic of computationally expensive analysis or simulation. this paper, employed probabilistic on one-dimensional and two two-dimensional test problems. A in which the parameters random variables resulting probability distribution output rather than value. can be to quantify knowledge designers have about subsystem lack uncertainty model. Using requires that...

Kriging models have proven useful in estimating complex and computationally expensive analyses. They are capable of interpolating a set observations by quantifying both longer range variations with parametric trends shorter spatial correlations. had some difficulty robustness situations when there larger number input dimensions few as well dimensions. This paper will detail how to add parameter the kriging model that account for random or measurement errors. The result is no interpolate all...

Current design decisions must be made while considering uncertainty in both models and inputs to the design. In most cases this is ignored hope that it not important decision making process. This paper presents a methodology for managing during system-level conceptual of complex multidisciplinary systems. The based upon quantifying information available computationally expensive subsystem with more efficient kriging models. By using models, computational expense Monte Carlo simulation assess...