Simulating Problem Difficulty in Arithmetic Cognition Through Dynamic Connectionist Models

The present study aims to investigate similarities between how humans and connectionist models experience difficulty in arithmetic problems. Problem difficulty was operationalized by the number of carries involved in solving a given problem. Problem difficulty was measured in humans by response time, and in models by computational steps. The present study found that both humans and connectionist models experience difficulty similarly when solving binary addition and subtraction. Specifically, both agents found difficulty to be strictly increasing with respect to the number of carries. Another notable similarity is that problem difficulty increases more steeply in subtraction than in addition, for both humans and connectionist models. Further investigation on two model hyperparameters --- confidence threshold and hidden dimension --- shows higher confidence thresholds cause the model to take more computational steps to arrive at the correct answer. Likewise, larger hidden dimensions cause the model to take more computational steps to correctly answer arithmetic problems; however, this effect by hidden dimensions is negligible.Comment: 7 pages; 15 figures; 5 tables; Published in the proceedings of the 17th International Conference on Cognitive Modelling (ICCM 2019

Direct synthesis of timed asynchronous circuits

Journal ArticleThis paper presents a new method to synthesize timed asynchronous circuits directly from the specification without generating a state graph. Our synthesis procedure begins with a deterministic signal transition graph specification to which timing constraints can be added. First, a timing analysis extracts the timed concurrency relation and timed causality relation between any two signal transitions. Then, a hazard-free implementation under the timing constraints is synthesized by constructing a precedence graph and finding a shortest path in the graph. Our method does not have the state explosion problem while the synthesized circuits have nearly the same area with the previous timed circuits

A research design in technology-enhanced scaffolding in language teaching: What lessonLAMS can offer at the interface of educational and language learning research

This chapter aims to provide a language learning design principle using the Learning Activity Management System (LAMS) as a platform in authentic classroom situations. A LessonLAMS sequence has been developed for this research project and was designed using a ‘Dynamic Scaffolding Technique’ within the learner’s zone of proximal development (ZPD) (Vygotsky & Cole, 1978). Participants for this study were South East Queensland secondary students who are studying Korean as a foreign language as an elective subject. The learning design of the LessonLAMS sequence was incorporated in classroom instruction with the research focus on technology-enhanced learning tasks, which was designed and implemented in the foreign language classroom at the participating school.No Full Tex

Auxiliary relations and sandwich theorems

A well-known topological theorem due to Katv etov states: Suppose $(X,tau)$ is a normal topological space, and let $f:Xto[0,1]$ be upper semicontinuous, $g:Xto[0,1]$ be lower semicontinuous, and $fleq g$. Then there is a continuous $h:Xto[0,1]$ such that $fleq hleq g$. We show a version of this theorem for many posets with auxiliary relations. In particular, if $P$ is a Scott domain and $f,g:Pto[0,1]$ are such that $fleq g$, and $f$ is lower continuous and $g$ Scott continuous, then for some $h$, $fleq hleq g$ and $h$ is both Scott and lower continuous. As a result, each Scott continuous function from $P$ to $[0,1]$, is the sup of the functions below it which are both Scott and lower continuous

In vivo1H-MR spectroscopy of the human heart

4. Conclusions: Combined respiratory and cardiac triggering improves the localization accuracy and spectral quality in cardiac1H-MRS dramatically leading to substantially increased spectral reproducibility. The best practical realization of double triggering turned out to be the use of the ECG amplitude when making use of the fact that it is modulated by respiration. In spite of the spectral quality achieved in most subjects, we still fail to record satisfactory spectra in a minority of subjects. The reasons for this are not understood at present but must be some particulars of either a given subject or the experimental setup. The cardiac1H-MR spectra contain quantifiable contributions from creatine, TMA, lipids, and probably taurine. It is possible that the spectral contributions of creatine are subject to dipolar coupling similar to the observations for skeletal muscl

Information Content of Credit Rating Affirmations

We examine whether the reiteration of past credit ratings (i.e., credit rating affirmation) provides value-relevant information to equity analysts and stock investors. While a large body of accounting and finance research provides evidence on the informational role of credit rating downgrades and upgrades, the informational effects of credit rating affirmations remain unexplored, despite the fact that the frequency of issuing rating affirmations is 1.6 times greater than that of issuing both rating downgrades and upgrades. Using a sample of US corporate credit rating reports that reiterate the previous credit ratings over the period of April 1995-June 2018, we find that equity analysts’ earnings forecast dispersion and stock return volatility—proxies for information uncertainty—decrease within a 30-day window following the credit rating affirmation announcements. The reduction in information uncertainty after rating affirmation is mainly driven by firms with non-investment grade bonds, whereas such reduction is not statistically significant for firms with investment grade bonds. We next find that the stock market reaction to affirmations is significantly positive on average and the positive reaction is most pronounced for firms with non-investment grade bonds. Taken together, our findings suggest that credit rating affirmations reduce information uncertainty and stock market investors find it useful for their investment decisions, particularly for firms with non-investment grade bonds. This study enhances our under-standing of the non-trivial informational value of the credit rating affirmations for equity market participants

Enhanced saccadic control in young people with Tourette syndrome despite slowed pro-saccades

Tourette syndrome (TS) is a neurodevelopmental disorder characterised by motor and vocal tics. Tics are repetitive and uncontrolled behaviours that have been associated with basal ganglia dysfunction. We investigated saccadic eye movements in a group of young people with TS but without co-morbid ADHD. Participants performed two tasks. One required them to perform only pro-saccade responses (pure pro-saccade task). The other involved shifting, unpredictably, between executing pro- and anti-saccades (mixed saccade task). We show that in the mixing saccade task, the TS group make significantly fewer errors than an age-matched control group, while responding equally fast. By contrast, on the pure pro-saccade task the TS group were shown to be significantly slower to initiate and to complete the saccades (longer movement duration and decreased peak velocity) than controls, while movement amplitude and direction accuracy were not different. These findings demonstrate enhanced shifting ability despite slower reflexive responding in TS and are discussed with respect to a disorder-related adaptation for increased cognitive regulation of behaviour

Modulation of Locomotion and Reproduction by FLP Neuropeptides in the Nematode Caenorhabditis elegans

Neuropeptides function in animals to modulate most, if not all, complex behaviors. In invertebrates, neuropeptides can function as the primary neurotransmitter of a neuron, but more generally they co-localize with a small molecule neurotransmitter, as is commonly seen in vertebrates. Because a single neuron can express multiple neuropeptides and because neuropeptides can bind to multiple G protein-coupled receptors, neuropeptide actions increase the complexity by which the neural connectome can be activated or inhibited. Humans are estimated to have 90 plus neuropeptide genes; by contrast, nematodes, a relatively simple organism, have a slightly larger complement of neuropeptide genes. For instance, the nematode Caenorhabditis elegans has over 100 neuropeptide-encoding genes, of which at least 31 genes encode peptides of the FMRFamide family. To understand the function of this large FMRFamide peptide family, we isolated knockouts of different FMRFamide-encoding genes and generated transgenic animals in which the peptides are overexpressed. We assayed these animals on two basic behaviors: locomotion and reproduction. Modulating levels of different neuropeptides have strong as well as subtle effects on these behaviors. These data suggest that neuropeptides play critical roles in C. elegans to fine tune neural circuits controlling locomotion and reproduction