Models of student performance can incorporate a skill decomposition that lists the skills that each activity requires. A good model must be sensitive to improvements in skill decomposition. We validate the Recent-Performance Factors Analysis model of student performance by checking its sensitivity to the skill decomposition. We use a dataset from a tutoring system where the skill model has been...

This paper presents an effective Polar Format Algorithm (PFA) for spotlight bistatic synthetic aperture radar (SAR) with arbitrary geometry configuration. Nonuniform interpolation and resampling are adopted when converting raw data from polar coordinates to Cartesian coordinates according to the characteristics of raw data samples in spatial frequency space. Thus, the proposed algorithm avoids ...

Mass customization, aiming at delivering an increasing product variety that best serves customer needs while keeping mass production eciency, has recently received numerous attention and popularity in industry and academia alike. This paper presents a methodology of developing product family architecture (PFA) to rationalize product development for mass customization. Systematic steps are deve...

In this paper we describe the performance of the well-known polar formatting algorithm (PFA) for formation of spotlight-mode synthetic aperture imagery from phase history data, under conditions of large-angle synthetic apertures. Such conditions typically occur when the SAR center frequency is low and/or the azimuthal resolution is is very high. Traditional wisdom states that PFA is not desirab...

Chaired by the academic adviser of each presenter P h y s i c a T h e r a p y l Introduction Passive patellar mobility was believed to be one of the important forms of assessment for patient with patellofemoral pain (PFP) and the decreased range of motion (ROM) at the knee joint. Moreover, it shows the laxity of the knee joint which could also contribute to sports knee injuries. However, there ...

Our aim is to construct a factor analysis method that can resist the effect of outliers. We start with a highly robust initial covariance estimator, after which the factors can be obtained from maximum likelihood or from principal factor analysis (PFA). We find that PFA based on the minimum covariance determinant scatter matrix works well. We also derive the influence function of the PFA method...

Todorcevic introduced the forcing axiom PFA(S) and established many consequences. We contribute to this project. In particular, we consider status under PFA(S) of two important consequences of PFA concerning spaces of countable tightness. In particular we prove that the existence of a Souslin tree does not imply the existence of a compact non-sequential space of countable tightness. We contrast...