In open distributed systems of mobile agents, where code from remote sites may run locally, protection of sensitive data and system resources is of paramount importance. We present a security-based typing system that provides such protection, using a mix of static and runtime typing; mobile agents are allowed access to local resources in accordance with security clearance. We formalize security...

Automated writing evaluation (AWE) software is an increasingly popular tool for English second language learners. However, research on the accuracy of such has been both scarce and largely limited in its scope. As such, this article broadens field AWE by using a mixed design to holistically evaluate corrective feedback leading program Grammarly. 1136 Grammarly-identified errors related style, l...

A challenge in SAR system development involves compensation for nonlinear motion errors of the sensor platform. The uncompensated along-track motions can cause a severe loss of geometry accuracy and degrade SAR image quality. Autofocus techniques improve image focus by removing a large part of phase errors present after conventional motion compensation. It refers to the computer-automated error...

Phase errors introduced in the object beam of a digital hologram degrade the image quality of the object. We present computer simulations showing the effect of multiple planes of phase errors in the propagation path. By using a nonlinear optimization technique to maximize sharpness metrics, we show results that account for aberrations in multiple planes and correct anisoplanatic blur. This pape...

This paper presents an investigation into the error probability performance for binary phase-shift keying modulation in distributed beamforming with phase errors. The effects of the number of nodes on the beamforming performance are examined as well as the influences of the cumulative phase errors and the total transmit power. Simulation results show a good match with the mathematical analysis ...

High-performance data processing algorithms for phase-shifting interferometry accommodate adjustment errors in the phase shift increment as well as harmonic distortions in the interference signal. However, a widely overlooked error source is the combination of these two imperfections. Phase shift tuning errors increase the sensitivity of phase estimation algorithms to second-order and higher ha...

A statistical analysis of a corrected electron trajectory through a planar FEL undulator is used to predict the optimal beam position monitor (BPM) spacing. The undulator is composed of modular sections, each containing many dipoles with random field and roll angle errors. Located between each section are inaccurate BPMs, steering correctors, and possibly quadrupole magnets. An analytical formu...

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We analyze several mechanisms leading to errors in a course of measurement of a superconducting fluxbiased phase qubit. Insufficiently long measurement pulse may lead to nonadiabatic transitions between qubit states 1 and 0 , before tunneling through a reduced barrier is supposed to distinguish the qubit states. Finite though large ratio of tunneling rates for these states leads to incomplete d...

We present a detailed description of an improved arrayed-waveguide-grating (AWG) layout for both, low and high diffraction orders. The novel layout presents identical bends across the entire array; in this way systematic phase errors arising from different bends that are inherent to conventional AWG designs are completely eliminated. In addition, for high-order AWGs our design results in more t...