Introduction to the Special Issue on Software Architecture for Language Engineering

Every building, and every computer program, has an architecture: structural and organisational principles that underpin its design and construction. The garden shed once built by one of the authors had an ad hoc architecture, extracted (somewhat painfully) from the imagination during a slow and non-deterministic process that, luckily, resulted in a structure which keeps the rain on the outside and the mower on the inside (at least for the time being). As well as being ad hoc (i.e. not informed by analysis of similar practice or relevant science or engineering) this architecture is implicit: no explicit design was made, and no records or documentation kept of the construction process. The pyramid in the courtyard of the Louvre, by contrast, was constructed in a process involving explicit design performed by qualified engineers with a wealth of theoretical and practical knowledge of the properties of materials, the relative merits and strengths of different construction techniques, et cetera. So it is with software: sometimes it is thrown together by enthusiastic amateurs; sometimes it is architected, built to last, and intended to be 'not something you finish, but something you start' (to paraphrase Brand (1994). A number of researchers argued in the early and middle 1990s that the field of computational infrastructure or architecture for human language computation merited an increase in attention. The reasoning was that the increasingly large-scale and technologically significant nature of language processing science was placing increasing burdens of an engineering nature on research and development workers seeking robust and practical methods (as was the increasingly collaborative nature of research in this field, which puts a large premium on software integration and interoperation). Over the intervening period a number of significant systems and practices have been developed in what we may call Software Architecture for Language Engineering (SALE). This special issue represented an opportunity for practitioners in this area to report their work in a coordinated setting, and to present a snapshot of the state-ofthe-art in infrastructural work, which may indicate where further development and further take-up of these systems can be of benefit

Parental Substance Abuse and Foster Care: Evidence from Two Methamphetamine Supply Shocks

Foster care caseloads have almost doubled over the last two decades, but the cause of the growth is poorly understood. We study the role of parental methamphetamine (meth) use, which social workers have linked to recent growth in foster care admissions. To mitigate the impact of omitted variable bias, we take advantage of two significant, exogenous supply-side interventions in meth markets in 1995 and 1997, and find robust evidence that meth use has caused growth in foster care caseloads. Further, we identify the mechanisms by which increased meth use caused an increase in foster care caseloads. First, we find that treatment for meth abuse caused foster caseloads to fall in situations where a child was removed because of parental incarceration, suggesting that substance abuse treatment is a substitute for foster care services and more generally an effective demand-side intervention. Secondly, we find that parental meth use causes an increase in both child abuse and child neglect foster care cases. These results suggest that child welfare policies should be designed specifically for the children of meth-using parents.child welfare, illegal drugs, crime

Binaural Cues for Distance and Direction of Nearby Sound Sources

To a first-order approximation, binaural localization cues are ambiguous: a number of source locations give rise to nearly the same interaural differences. For sources more than a meter from the listener, binaural localization cues are approximately equal for any source on a cone centered on the interaural axis (i.e., the well-known "cones of confusion"). The current paper analyzes simple geometric approximations of a listener's head to gain insight into localization performance for sources near the listener. In particular, if the head is treated as a rigid, perfect sphere, interaural intensity differences (IIDs) can be broken down into two main components. One component is constant along the cone of confusion (and thus co varies with the interaural time difference, or ITD). The other component is roughly constant for a sphere centered on the interaural axis and depends only on the relative pathlengths from the source to the two ears. This second factor is only large enough to be perceptible when sources are within one or two meters of the listener. These results are not dramatically different if one assumes that the ears are separated by 160 degrees along the surface of the sphere (rather than diametrically opposite one another). Thus, for sources within a meter of the listener, binaural information should allow listeners to locate sources within a volume around a circle centered on the interaural axis, on a "doughnut of confusion." The volume of the doughnut of confusion increases dramatically with angle between source and the interaural axis, degenerating to the entire median plane in the limit.Air Force Office of Scientific Research (F49620-98-1-0108

Do lemurs know when they could be wrong? An investigation of information seeking in three species of lemur (<i>Lemur catta, Eulemur rubriventer, </i>and<i> Varecia variegata</i>)

Sixteen lemurs, including representatives from three species (Lemur catta, Eulemur rubriventer, Varecia variegata), were presented with a food seeking task where information about the rewards location, in one of two plastic tubes, was either known or not known. We evaluated whether lemurs would first look into the tube prior to making a choice. This information-seeking task aimed to assess whether subjects would display memory awareness, seeking additional information when they became aware they lacked knowledge of the rewards location. We predicted lemurs would be more likely to look into the tube when they had insufficient knowledge about the rewards position. Lemurs successfully gained the reward on most trials. However, they looked on the majority of trials regardless of whether they had all the necessary information to make a correct choice. The minimal cost to looking may have resulted in checking behaviour both to confirm what they already knew and to gain knowledge they did not have. When the cost of looking increased (elevating end of tube requiring additional energy expenditure to look inside - Experiment 2), lemurs still looked into tubes on both seen and unseen trials; however, the frequency of looking increased when opaque tubes were used (where they could not see the rewards location after baiting). This could suggest they checked more when they were less sure of their knowledge state

Understanding the effects of violent video games on violent crime

Psychological studies invariably find a positive relationship between violent video game play and aggression. However, these studies cannot account for either aggressive effects of alternative activities video game playing substitutes for or the possible selection of relatively violent people into playing violent video games. That is, they lack external validity. We investigate the relationship between the prevalence of violent video games and violent crimes. Our results are consistent with two opposing effects. First, they support the behavioral effects as in the psychological studies. Second, they suggest a larger voluntary incapacitation effect in which playing either violent or non-violent games decrease crimes. Overall, violent video games lead to decreases in violent crime. --Video Games,Violence,Crime

Automatic design of concrete structures using a strut & tie approach

The major part of the work presented in this thesis is an investigation of the strut and tie method for designing 2-D in-plane, reinforced concrete structures. Two important issues relating to this method are addressed. Firstly, the issue of visualising an appropriate strut and tie model is dealt with. In many situations it may be difficult to visualise an appropriate model for a given structural system. Here, a convenient method of visualising strut and tie models is presented. Using elastic finite element analysis, low stressed parts of a structure are removed in a step by step process until the main stress paths, which represent the ties and struts, are defined. The second important issue to be addressed is that of serviceability of the designed structure because the strut and tie model naturally represents a great departure from the elastic stress distribution. Since the strut-tie model is used to design for the ultimate load situation, it is necessary to assess the suitability of the same model in relation to serviceability characteristics of the resulting design. It is important that ductility of the structure should be maintained at ultimate loads while avoiding excessive deflections and cracking at service loads. A wide variety of structures were designed, and to assess the performance of each design, non-linear finite element analysis was used. Verification of some of the numerical results was carried out through physical testing in the laboratory which also allowed the serviceability behaviour of the structures to be assessed. The test program comprised of three corbel joints and two frame corner joints. It was concluded that design from the strut and tie method can produce adequate performance both at service and ultimate loads. In terms of ultimate load prediction, the strut-tie method can produce results of comparable accuracy to non-linear finite element analysis

Applying self-processing biases in education:improving learning through ownership

Accepting ownership of an item is an effective way of associating it with self, evoking self-processing biases that enhance memory. This memory advantage occurs even in ownership games, where items are arbitrarily divided between participants to temporarily ‘own’. The current study tested the educational applications of ownership games across two experiments. In Experiment 1, 7 to 9-year-old children were asked to choose three novel, labelled shapes from an array of nine. The experimenter chose three shapes and three remained ‘un-owned’. A subsequent free-recall test showed that children reliably learned more self-owned than other-owned or un-owned shapes. Experiment 2 replicated this finding for shapes that were assigned to owners rather than chosen, and showed that ownership enhanced memory more effectively than a control game with no ownership manipulation. Together, these experiments show that ownership games can evoke self-processing biases in children’s memory, enhancing learning. Implications for education strategies are discussed