The Ideal Collaborative Partner: A Tribute to Jana Singer

Collaboration has been defined as a “pervasive, long-term relationship in which participants recognize common goals and objectives, share more tasks, and participate in extensive planning and implementation.” I feel most fortunate to have had a collaborative partnership with Jana Singer for almost three decades. I am fortunate because such relationships are uncommon among legal scholars, given the “individualistic culture” of law schools and law professors. Even more unusual, I found in Jana a scholarly partner with all the qualities of the ideal collaborator: strong intellect, enthusiasm, curiosity, generosity, and humility. Since the early days of our academic careers, Jana and I have shared ideas about family law that have informed our teaching, scholarship, and service. This collaboration has led to co-authoring law review articles, blog posts and, most importantly, two books. In this Essay, I will focus on our scholarly collaboration and explore the connections between that scholarship and Jana’s significant public service that has improved family law practice on both a local and national level

An algorithm for maximum likelihood estimation using an efficient method for approximating sensitivities

An algorithm for maximum likelihood (ML) estimation is developed primarily for multivariable dynamic systems. The algorithm relies on a new optimization method referred to as a modified Newton-Raphson with estimated sensitivities (MNRES). The method determines sensitivities by using slope information from local surface approximations of each output variable in parameter space. The fitted surface allows sensitivity information to be updated at each iteration with a significant reduction in computational effort compared with integrating the analytically determined sensitivity equations or using a finite-difference method. Different surface-fitting methods are discussed and demonstrated. Aircraft estimation problems are solved by using both simulated and real-flight data to compare MNRES with commonly used methods; in these solutions MNRES is found to be equally accurate and substantially faster. MNRES eliminates the need to derive sensitivity equations, thus producing a more generally applicable algorithm

Gain selection method and model for coupled propulsion and airframe systems

A longitudinal model is formulated for an advanced fighter from three subsystem models: the inlet, the engine, and the airframe. Notable interaction is found in the coupled system. A procedure, based on eigenvalue sensitivities, is presented which indicates the importance of the feedback gains to the optimal solution. This allows ineffectual gains to be eliminated; thus, hardware and expense may be saved in the realization of the physical controller

A methodology for airplane parameter estimation and confidence interval determination in nonlinear estimation problems

An algorithm for maximum likelihood (ML) estimation is developed with an efficient method for approximating the sensitivities. The ML algorithm relies on a new optimization method referred to as a modified Newton-Raphson with estimated sensitivities (MNRES). MNRES determines sensitivities by using slope information from local surface approximations of each output variable in parameter space. With the fitted surface, sensitivity information can be updated at each iteration with less computational effort than that required by either a finite-difference method or integration of the analytically determined sensitivity equations. MNRES eliminates the need to derive sensitivity equations for each new model, and thus provides flexibility to use model equations in any convenient format. A random search technique for determining the confidence limits of ML parameter estimates is applied to nonlinear estimation problems for airplanes. The confidence intervals obtained by the search are compared with Cramer-Rao (CR) bounds at the same confidence level. The degree of nonlinearity in the estimation problem is an important factor in the relationship between CR bounds and the error bounds determined by the search technique. Beale's measure of nonlinearity is developed in this study for airplane identification problems; it is used to empirically correct confidence levels and to predict the degree of agreement between CR bounds and search estimates

A systematic review of people with autism spectrum disorder and the Criminal Justice System

This paper provides a systemic review of the available literature on people with autism spectrum disorder (ASD) in the criminal justice system (CJS). The review considers two main types of study: those that examined the prevalence of people with ASD in the CJS and those that examined the prevalence of offending in populations with ASD. In addition, types of offences in people with ASD, co-morbid psychiatric diagnoses, and characteristics of people with ASD who commit offences (including predisposing factors) are considered. A combination of search terms was used in a variety of databases in order to find all of the available literature on this topic, and research studies were included based on specified inclusion and exclusion criteria. It was found that whilst there is an emerging literature base on this topic, there are a wide variety of methodologies used, making direct comparison difficult. Nevertheless it can be concluded so far that people with ASD do not seem to be disproportionately over-represented in the CJS, though they commit a range of crimes and seem to have a number of predisposing features. There is poor evidence of the presence of comorbid psychiatric diagnoses (except in mental health settings) amongst offenders with ASD, and little evidence of the oft-asserted over-representation of certain kinds of crimes. It is recommended that further research of good quality is required in this area, rather than studies that examine populations that are not representative of all those with ASD

The relationship between visual memory and rider expertise in a show-jumping context

Individuals develop visual skills while participating in sport. The aim of this study was to assess the effect of reported riding expertise on the recall of visual information relating to show-jumps. We identified a relevant (F1) and irrelevant (F2) point of focus in 22 photographs of show-jumps. Participants were students (n = 40) with varying levels of horse riding ability. The task, having viewed each photograph for four seconds, was to identify F1s or F2s from four alternatives viewed for ten seconds. F1s were recalled significantly more than F2s (P<0.001). Riding expertise did not affect overall recall but only intermediate/advanced riders recalled F1s significantly better than F2s (P<0.05 and P<0.001 respectively). Recall of F1s but not of F2s was significantly correlated with riding expertise (P<0.05). Training riders in visual attention techniques might improve ridden performance and could reduce the number of accidents associated with lack of experience and/or rider error

Transonic flutter and gust-response tests and analyses of a wind-tunnel model of a torsion free wing airplane

An exploratory study of a 1/5.5 size, complete airplane version of a torsion free wing (TFW) fighter aircraft was conducted. The TFW consisted of a wing/boom/canard assembly on each fuselage side that was interconnected by a common pivot shaft so that the TFW could rotate freely in pitch. The effect of the TFW was evaluated by comparing data obtained with the TFW free and the TFW locked to the fuselage. With the model mounted on cables to simulate an airplane free flying condition, flutter boundaries were measured at Mach number (M) from 0.85 to 1.0 and gust responses at M = 0.65 and 0.90. The critical flutter mode for the TFW free configuration was found experimentally to occur at M = 0.95 and had the rigid TFW pitch mode as its apparent aerodynamic driver