Conceptual modelling: framework, principles, and future research

The conceptual modelling task in a simulation project is very important and yet is still generally regarded as more of an art than a science. The meaning and nature of conceptual modelling are discussed and a framework set out. The overall aim should be to choose the best model for the project and conceptual modelling can be viewed as a difficult optimisation problem that can be tackled effectively using a creative search process that develops alternative models and predicts their performance throughout the project. An experiment relating model characteristics to some aspects of performance is described and this type of experiment may inform the process of predicting model performance. Based on advice from the literature and my own previous work on conceptual modelling 17 principles of conceptual modelling are suggested. Conceptual modelling research is still at an early stage and ideas for future research are proposed

Efficacy of property marking: police identification of stolen property

Property marking, as a situational crime prevention technique, has found to be largely ineffectual in the reduction of property theft, although past studies have not considered the role property marking as an aid to the return of stolen or lost property. However, automotive identification and some studies have found that in some cases property marking is effective. Furthermore, many crime prevention groups focus on property marking as a means to reduce crime and the fear of crime. Therefore, the study investigated the processes of lost, stolen and seized goods by law enforcement personnel. The study undertook a qualitative analysis of law enforcement property identification process, including a documentary analysis of procedures and practitioner interviews for content-thematic analysis. The study found that the use of manufacturer serial numbers was the initial line of investigative enquiry. Limiting factors were technical capability to find and use covert property markings. The successful implementation of a code of best practice or standardisation in the recording of serial numbers, and the availability of the community to quickly and easily record their property may have a significant effect in the reduction of property crimes; due to the perceived increase of risk and potential reduction of reward to the offender

Experimental prediction of performance by superconducting cables

Broken superconductor method of short sample testing makes possible the prediction of the performance of well cooled, stabilized, superconducting cable coils. It yields a field-versus-current curve for a short sample of cable. Plots are given for the superconductor and copper currents at various magnetic field strengths

Linking adult second language learning and diachronic change:a cautionary note

It has been suggested that the morphological complexity of a language is negatively correlated with the size of its population of speakers. This relationship may be driven by the proportion of non-native speakers, among other things, and reflects adaptations to learning constraints imposed by adult language learners. Here we sound a note of caution with respect to these claims by arguing that (a) morphological complexity is defined in somewhat contradictory ways and hence not straightforward to measure, and (b) there is insufficient evidence to suggest that children’s cognitive limitations support mechanisms beneficial for learning of complex morphology relative to adults. We suggest that considering the informational value of morphological cues may be a better way to capture learnability of morphology. To settle the issue of how age related constraints on learning might impact language change, more cross-linguistic studies comparing learning trajectories of different second languages and laboratory experiments examining language transmission in children and adults are needed

How are exemplar representations transformed by encoding, retrieval, and explicit knowledge? A commentary on Ambridge (2020)

The radical exemplar model resonates with work on perceptual classification and categorization highlighting the role of exemplars in memory representations. Further development of the model requires acknowledgment of both the fleeting and fragile nature of perceptual representations and the gist-based, good-enough quality of long-term memory representations. Retrieval operations potentially serve as a mechanism for abstraction as representations of exemplars are distorted through reconstructive processes. As a framework applicable to both first and second language acquisition, the model needs to account for how explicit knowledge arises and its role in filtering input via selective attention

More is more in language learning:reconsidering the less-is-more hypothesis

The Less-is-More hypothesis was proposed to explain age-of-acquisition effects in first language (L1) acquisition and second language (L2) attainment. We scrutinize different renditions of the hypothesis by examining how learning outcomes are affected by (1) limited cognitive capacity, (2) reduced interference resulting from less prior knowledge, and (3) simplified language input. While there is little-to-no evidence of benefits of limited cognitive capacity, there is ample support for a More-is-More account linking enhanced capacity with better L1- and L2-learning outcomes, and reduced capacity with childhood language disorders. Instead, reduced prior knowledge (relative to adults) may afford children with greater flexibility in inductive inference; this contradicts the idea that children benefit from a more constrained hypothesis space. Finally, studies of childdirected speech (CDS) confirm benefits from less complex input at early stages, but also emphasize how greater lexical and syntactic complexity of the input confers benefits in L1-attainment

Standard arc welders provide high amperage direct current source

Standard arc welders or power supplies are hooked up in parallel or series connections to obtain an adequate supply of current or voltage for various purposes. This method provides maximum flexibility in a wide range of voltages and currents

Analysis of thermal test errors resulting from imperfectly collimated solar simulation beams Final technical report

Two effects of noncollimation of solar light beams in spacecraft thermal testing simulation chambe