Planning autonomous vehicles in the absence of speed lanes using an elastic strip

Planning of autonomous vehicles in the absence of speed lanes is a less-researched problem. However, it is an important step toward extending the possibility of autonomous vehicles to countries where speed lanes are not followed. The advantages of having nonlane-oriented traffic include larger traffic bandwidth and more overtaking, which are features that are highlighted when vehicles vary in terms of speed and size. In the most general case, the road would be filled with a complex grid of static obstacles and vehicles of varying speeds. The optimal travel plan consists of a set of maneuvers that enables a vehicle to avoid obstacles and to overtake vehicles in an optimal manner and, in turn, enable other vehicles to overtake. The desired characteristics of this planning scenario include near completeness and near optimality in real time with an unstructured environment, with vehicles essentially displaying a high degree of cooperation and enabling every possible(safe) overtaking procedure to be completed as soon as possible. Challenges addressed in this paper include a (fast) method for initial path generation using an elastic strip, (re-)defining the notion of completeness specific to the problem, and inducing the notion of cooperation in the elastic strip. Using this approach, vehicular behaviors of overtaking, cooperation, vehicle following,obstacle avoidance, etc., are demonstrated.

The timing of island effects in nonnative sentence processing

Using the eye-movement monitoring technique in two reading comprehension experiments, we investigated the timing of constraints on wh-dependencies (so-called ‘island’ constraints) in native and nonnative sentence processing. Our results show that both native and nonnative speakers of English are sensitive to extraction islands during processing, suggesting that memory storage limitations affect native and nonnative comprehenders in essentially the same way. Furthermore, our results show that the timing of island effects in native compared to nonnative sentence comprehension is affected differently by the type of cue (semantic fit versus filled gaps) signalling whether dependency formation is possible at a potential gap site. Whereas English native speakers showed immediate sensitivity to filled gaps but not to lack of semantic fit, proficient German-speaking learners of L2 English showed the opposite sensitivity pattern. This indicates that initial wh-dependency formation in nonnative processing is based on semantic feature-matching rather than being structurally mediated as in native comprehension.

An overview of mixed-effects statistical models for second language researchers

As in any field of scientific inquiry, advancements in the field of second language acquisition (SLA) rely in part on the interpretation and generalizability of study findings using quantitative data analysis and inferential statistics. While statistical techniques such as ANOVA and t-tests are widely used in second language research, this review article provides a review of a class of newer statistical models that have not yet been widely adopted in the field, but have garnered interest in other fields of language research. The class of statistical models called mixed-effects models are introduced, and the potential benefits of these models for the second language researcher are discussed. A simple example of mixed-effects data analysis using the statistical software package R (R Development Core Team, 2011) is provided as an introduction to the use of these statistical techniques, and to exemplify how such analyses can be reported in research articles. It is concluded that mixed-effects models provide the second language researcher with a powerful tool for the analysis of a variety of types of second language acquisition data.

Absence of Association of Metabolic Syndrome with PPARGC1A, PPARG and UCP1 Gene Polymorphisms in Asian Indians

The objective of this study was to evaluate the association of PPARG coactivator1 alpha (PPARGC1A), peroxisome proliferator activated receptor gamma (PPARG), and uncoupling protein1 (UCP1) gene polymorphisms with the metabolic syndrome (MS) in an Asian Indian population. Nine common polymorphisms were genotyped via polymerase chain reaction restriction fragment length polymorphism and direct sequencing in 950 normal glucose-tolerant subjects and 550 type 2 diabetic subjects, chosen randomly from the Chennai Urban Rural Epidemiological Study, an ongoing population based study in Southern India. Among the 9 polymorphisms examined, only the Thr394Thr variant of the PPARGC1A gene was significantly associated with diabetes and obesity. The genotype frequency of GA of Thr394Thr variant was 16% (138/887) in the nonMS group and 22% (136/613) in the MS group, and this genotype frequency was significantly higher with MS both in males (p = 0.01) and females (p = 0.05), compared to the without-MS group. Logistic regression analysis revealed that the odds ratio for MS for the susceptible genotype GA of Thr394Thr was 1.411 [95% CI: 1.03-1.84, p = 0.012]. In the multiple logistic regression analysis, however, there was no association of this polymorphism as an independent factor with MS. Hence, the study shows that the polymorphisms in the PPARGC1A, PPARG and UCP1 genes are not associated with MS in Asian Indians.

The processing of number and gender agreement in Spanish: an event related potential investigation of the effects of structural distance

Previous research suggests that the processing of agreement is affected by the distance between the agreeing elements. However, the unique contribution of structural distance (number of intervening syntactic phrases) to the processing of agreement remains an open question, since previous investigations do not tease apart structural and linear distance (number of intervening words). We used event related potentials (ERPs) to examine the extent to which structural distance impacts the processing of Spanish number and gender agreement. Violations were realized both within the phrase and across the phrase. Across both levels of structural distance, linear distance was kept constant, as was the syntactic category of the agreeing elements. Number and gender agreement violations elicited a robust P600 between 400 and 900ms, a component associated with morphosyntactic processing. No amplitude differences were observed between number and gender violations, suggesting that the two features are processed similarly at the brain level. Within-phrase agreement yielded more positive waveforms than across-phrase agreement, both for agreement violations and for grammatical sentences (no agreement by distance interaction). These effects can be interpreted as evidence that structural distance impacts the establishment of agreement overall, consistent with sentence processing models which predict that hierarchical structure impacts the processing of syntactic dependencies. However, due to the lack of an agreement by distance interaction, the possibility cannot be ruled out that these effects are driven by differences in syntactic predictability between the within-phrase and across-phrase configurations, notably the fact that the syntactic category of the critical word was more predictable in the within-phrase conditions.

An empirical investigation of the effects of rounding on the SPF probabilities of decine and output growth histograms

I consider the possibility that respondents to the Survey of Professional Forecasters round their probability forecasts of the event that real output will decline in the future, as well as their reported output growth probability distributions. I make various plausible assumptions about respondents’ rounding practices, and show how these impinge upon the apparent mismatch between probability forecasts of a decline in output and the probabilities of this event implied by the annual output growth histograms. I find that rounding accounts for about a quarter of the inconsistent pairs of forecasts.

Morphosyntactic processing in advanced second language (L2) learners: An event-related potential investigation of the effects of L1-L2 similarity and structural distance

Different theoretical accounts of second language (L2) acquisition differ with respect to whether or not advanced learners are predicted to show native like processing for features not instantiated in the native language (L1). We examined how native speakers of English, a language with number but not gender agreement, process number and gender agreement in Spanish. We compare agreement within a determiner phrase (órgano muy complejo “[DP organ-MASC-SG very complex-MASC-SG]”) and across a verb phrase (cuadro es auténtico “painting-MASC-SG [VP is authentic-MASC-SG]”) in order to investigate whether native like processing is limited to local domains (e.g. within the phrase), in line with Clahsen and Felser (2006). We also examine whether morphological differences in how the L1 and L2 realize a shared feature impact processing by comparing number agreement between nouns and adjectives, where only Spanish instantiates agreement, and between demonstratives and nouns, where English also instantiates agreement. Similar to Spanish natives, advanced learners showed a P600 for both number and gender violations overall, in line with the Full Transfer/Full Access Hypothesis (Schwartz and Sprouse, 1996), which predicts that learners can show native-like processing for novel features. Results also show that learners can establish syntactic dependencies outside of local domains, as suggested by the presence of a P600 for both within and across phrase violations. Moreover, similar to native speakers, learners were impacted by the structural distance (number of intervening phrases) between the agreeing elements, as suggested by the more positive waveforms for within than across-phrase agreement overall. These results are consistent with the proposal that learners are sensitive to hierarchical structure.

Heuristic based evolution for the coordination of autonomous vehicles in the absence of speed lanes

The current state of the art in the planning and coordination of autonomous vehicles is based upon the presence of speed lanes. In a traffic scenario where there is a large diversity between vehicles the removal of speed lanes can generate a significantly higher traffic bandwidth. Vehicle navigation in such unorganized traffic is considered. An evolutionary based trajectory planning technique has the advantages of making driving efficient and safe, however it also has to surpass the hurdle of computational cost. In this paper, we propose a real time genetic algorithm with Bezier curves for trajectory planning. The main contribution is the integration of vehicle following and overtaking behaviour for general traffic as heuristics for the coordination between vehicles. The resultant coordination strategy is fast and near-optimal. As the vehicles move, uncertainties may arise which are constantly adapted to, and may even lead to either the cancellation of an overtaking procedure or the initiation of one. Higher level planning is performed by Dijkstra's algorithm which indicates the route to be followed by the vehicle in a road network. Re-planning is carried out when a road blockage or obstacle is detected. Experimental results confirm the success of the algorithm subject to optimal high and low-level planning, re-planning and overtaking.

Model predictions of the occurrence of non-Maxwellian plasmas, and analysis of their effects on EISCAT data

The recent identification of non-thermal plasmas using EISCAT data has been made possible by their occurrence during large, short-lived flow bursts. For steady, yet rapid, ion convection the only available signature is the shape of the spectrum, which is unreliable because it is open to distortion by noise and sampling uncertainty and can be mimicked by other phenomena. Nevertheless, spectral shape does give an indication of the presence of non-thermal plasma, and the characteristic shape has been observed for long periods (of the order of an hour or more) in some experiments. To evaluate this type of event properly one needs to compare it to what would be expected theoretically. Predictions have been made using the coupled thermosphere-ionosphere model developed at University College London and the University of Sheffield to show where and when non-Maxwellian plasmas would be expected in the auroral zone. Geometrical and other factors then govern whether these are detectable by radar. The results are applicable to any incoherent scatter radar in this area, but the work presented here concentrates on predictions with regard to experiments on the EISCAT facility.

Novel flavours paired with glutamate condition increased intake in older adults in the absence of changes in liking

Previous research on the repeat exposure to a novel flavour combined with monosodium glutamate (MSG) has shown an increase in liking and consumption for the particular flavour. The aim of the current work was to investigate whether this could also be observed in the case of older people, since they are most affected by undernutrition in the developed world and ways to increase consumption of food are of significant importance for this particular age group. For this study, 40 older adults (age 65-88) repeatedly consumed potato soup with two novel flavours (lemongrass and cumin) which were either with or without a high level of MSG (5%w/w). A randomized single blind within-subject design was implemented, where each participant was exposed to both soup flavours three times over 6 days, with one of the soup flavours containing MSG. After three repeat exposures, consumption increased significantly for the soups where the flavours had contained MSG during the repeated exposure (mean weight consumed increased from 123 to 164 g, p=0.017), implying that glutamate conditioned for increased wanting and consumption, despite the fact that the liking for the soup had not increased.

The utility and application of mixed-effects models in second language research

Second language acquisition researchers often face particular challenges when attempting to generalize study findings to the wider learner population. For example, language learners constitute a heterogeneous group, and it is not always clear how a study’s findings may generalize to other individuals who may differ in terms of language background and proficiency, among many other factors. In this paper, we provide an overview of how mixed-effects models can be used to help overcome these and other issues in the field of second language acquisition. We provide an overview of the benefits of mixed-effects models and a practical example of how mixed-effects analyses can be conducted. Mixed-effects models provide second language researchers with a powerful statistical tool in the analysis of a variety of different types of data.

Development of speech fluency over a short period of time: effects of pedagogic intervention

This study investigates the effects of a short-term pedagogic intervention on the development of L2 fluency among learners studying English for Academic purposes (EAP) at a university in the UK. It also examines the interaction between the development of fluency, and complexity and accuracy. Through a pre-test, post-test design, data were collected over a period of four weeks from learners performing monologic tasks. While the Control Group (CG) focused on developing general speaking and listening skills, the Experimental Group (EG) received awareness-raising activities and fluency strategy training in addition to general speaking and listening practice i.e following the syllabus. The data, coded in terms of a range of measures of fluency, accuracy and complexity, were subjected to repeated measures MANOVA, t-tests and correlations. The results indicate that after the intervention, while some fluency gains were achieved by the CG, the EG produced statistically more fluent language demonstrating a faster speech and articulation rate, longer runs and higher phonation time ratios. The significant correlations obtained between measures of accuracy and learners’ pauses in the CG suggest that pausing opportunities may have been linked to accuracy. The findings of the study have significant implications for L2 pedagogy, highlighting the effective impact of instruction on the development of fluency.

Neurolinguistic measures of typological effects in multilingual transfer: introducing an ERP methodology

This article has two main objectives. First, we offer an introduction to the subfield of generative third language (L3) acquisition. Concerned primarily with modeling initial stages transfer of morphosyntax, one goal of this program is to show how initial stages L3 data make significant contributions toward a better understanding of how the mind represents language and how (cognitive) economy constrains acquisition processes more generally. Our second objective is to argue for and demonstrate how this subfield will benefit from a neuro/psycholinguistic methodological approach, such as event-related potential experiments, to complement the claims currently made on the basis of exclusively behavioral experiments.

Becoming a written word: eye movements reveal order of acquisition effects following incidental exposure to new words during silent reading

We know that from mid-childhood onwards most new words are learned implicitly via reading; however, most word learning studies have taught novel items explicitly. We examined incidental word learning during reading by focusing on the well-documented finding that words which are acquired early in life are processed more quickly than those acquired later. Novel words were embedded in meaningful sentences and were presented to adult readers early (day 1) or later (day 2) during a five-day exposure phase. At test adults read the novel words in semantically neutral sentences. Participants’ eye movements were monitored throughout exposure and test. Adults also completed a surprise memory test in which they had to match each novel word with its definition. Results showed a decrease in reading times for all novel words over exposure, and significantly longer total reading times at test for early than late novel words. Early-presented novel words were also remembered better in the offline test. Our results show that order of presentation influences processing time early in the course of acquiring a new word, consistent with partial and incremental growth in knowledge occurring as a function of an individual’s experience with each word.

Valorisation of side streams from wheat milling and confectionery industries for consolidated production and extraction of microbial lipids

Crude enzymes produced via solid state fermentation (SSF) using wheat milling by-products have been employed for both fermentation media production using flour-rich waste (FRW) streams and lysis of Rhodosporidium toruloides yeast cells. Filter sterilization of crude hydrolysates was more beneficial than heat sterilization regarding yeast growth and microbial oil production. The initial carbon to free amino nitrogen ratio of crude hydrolysates was optimized (80.2 g/g) in fed-batch cultures of R. toruloides leading to a total dry weight of 61.2 g/L with microbial oil content of 61.8 % (w/w). Employing a feeding strategy where the glucose concentration was maintained in the range of 12.2 – 17.6 g/L led to the highest productivity (0.32 g/L∙h). The crude enzymes produced by SSF were utilised for yeast cell treatment leading to simultaneous release of around 80% of total lipids in the broth and production of a hydrolysate suitable as yeast extract replacement.