Down-Sampling coupled to Elastic Kernel Machines for Efficient Recognition of Isolated Gestures

In the field of gestural action recognition, many studies have focused on dimensionality reduction along the spatial axis, to reduce both the variability of gestural sequences expressed in the reduced space, and the computational complexity of their processing. It is noticeable that very few of these methods have explicitly addressed the dimensionality reduction along the time axis. This is however a major issue with regard to the use of elastic distances characterized by a quadratic complexity. To partially fill this apparent gap, we present in this paper an approach based on temporal down-sampling associated to elastic kernel machine learning. We experimentally show, on two data sets that are widely referenced in the domain of human gesture recognition, and very different in terms of quality of motion capture, that it is possible to significantly reduce the number of skeleton frames while maintaining a good recognition rate. The method proves to give satisfactory results at a level currently reached by state-of-the-art methods on these data sets. The computational complexity reduction makes this approach eligible for real-time applications.Comment: ICPR 2014, International Conference on Pattern Recognition, Stockholm : Sweden (2014

THE ORIGINS OF HUMANKIND: A SURVEY OF SCHOOL TEXTBOOKS AND TEACHERS' CONCEPTIONS IN 14 COUNTRIES

International audienceTo investigate the difficulty teaching human origins, and particularly the possible link between values and taught scientific knowledge, research was carried out in 14 countries, in the context of the project BIOHEAD-Citizen. In eight countries (Cyprus, Estonia, Finland, France, Hungary, Italy, Romania, Senegal), this topic is included in the biology syllabus; in the six other countries (Algeria, Burkina Faso, Lebanon, Morocco, Portugal and Tunisia), it is not. Analysis of the images of timelines or trees depicting evolution revealed that Homo sapiens is never represented by a woman alone, only twice by a couple, and never with ethnic diversity. Homo sapiens is generally at the top or end of the evolutionary schemas, indicating a goal-ended conception of evolution. Thus scientific knowledge related to human origins can be mixed with implicit values. In the 14 countries, 5,706 teachers (primary and secondary school teachers of biology or national language) completed a questionnaire. Conceptions differed greatly among countries. Creationist conceptions were correlated with level of belief in God, as well as with shorter training at university. In the countries where evolution is included in the students' curriculum, the biology teachers' conceptions were less radically creationist than when it was not included in the curriculum

L'évolution humaine dans les programmes et les manuels scolaires de science français de 1994 à aujourd'hui : interactions entre connaissances, valeurs et contexte socioculturel

Seconde communication du symposiume 188 / 2 (site Actes AREF 2013)International audienceEn ce début de XXIe siècle, le concept d'évolution biologique fait consensus au sein de la communauté scientifique internationale, mais sa place dans les programmes reste discutée dans plusieurs pays. En France, l'enseignement de l'évolution est central dans le cursus scolaire, mais celui de l'évolution humaine a été limité aux seuls élèves de la classe de terminale scientifique. Nous analysons ici la transposition didactique de ces connaissances dans les programmes et manuels scolaires français (éditions Bordas et Nathan) de 1994 à aujourd'hui. Nous utilisons pour cette analyse la catégorisation des conceptions scientifiques ainsi que la grille de traitement de l'information scientifique de nos précédents travaux,. Nous évaluons le délai de transposition didactique (DTD) des connaissances. Les schémas représentant l'évolution humaine sont étudiés selon leur nature scientifique et selon les valeurs implicites associées. Les programmes de 1994 et 2001 intègrent des nouvelles données scientifiques avec un DTD très court. Ceux de 2011 présentent des connaissances moins détaillées et plus distanciées, ce qui les préserve d'une obsolescence rapide. Une tendance à une plus grande vigilance épistémologique apparaît avec une présentation non dogmatique des connaissances. Il existe toujours une forte adéquation entre les programmes et les manuels. Les éditions les plus récentes sont moins marquées par les valeurs implicites telles que le finalisme et l'anthropocentrisme et l'androcentrisme mais certaines faiblesses d'ordre épistémologique et didactique persistent notamment dans la schématisation. Les controverses socioscientifiques sur l'évolution humaine et son enseignement ne sont pas du tout prises en compte dans les manuels étudiés. L'absence de référence au créationnisme témoigne d'une volonté institutionnelle de séparation stricte des registres scientifiques et religieux en classe de sciences selon le NOMA de Gould (1997). Aborder les controverses socioscientifiques qui ont marqué l'histoire des sciences ou l'actualité pourrait permettre aux élèves de mieux identifier les registres scientifiques et idéologiques et de fonder leur jugement sur une approche critique interdisciplinaire

Review of soil conservation legislation : Carnarvon horticultural area

Lower Gascoyne Management Strategy The Carnarvon horticultural area has suffered considerable erosion damage following flooding of the Gascoyne River. Factors contributing to the erosion include a move to greater vegetable production, the carrying out of unauthorised earthworks and general confusion about the laws that apply to land management and erosion control. With this context, the purpose of this report is: • to clarify the laws applying to erosion control in the Carnarvon horticultural area; • to identify the public authorities with management responsibility for erosion control; and • to suggest a model by which erosion controls and management responsibilities can be conducted in a more coordinated and efficient manner

Doctor of Philosophy

dissertationStrontium isotope ratio (87Sr/86Sr) has a strong potential to complement atmospherically-derived traditional stable isotopes in geochemical provenance studies because strontium (Sr) in Earth surface reservoirs is sourced from local bedrock. As such, 87Sr/86Sr variations are discrete and differ drastically from the large scale smoothed variations of atmospherically-derived stable isotopes. Among the most successful recent applications, 87Sr/86Sr has been used to interpret provenance of individuals in archeology, to identify the origin of dust aerosols, to reconstruct cation source and mobility in rivers, and to reconstruct animal or material movement pathways. However, extending the applications of 87Sr/86Sr for provenance to larger spatial scales is currently hampered by the absence of methods to predict the 87Sr/86Sr of Sr sources at the regional scale. In this dissertation, a flexible geostatistical framework is established to predict 87Sr/86Sr distributions in bedrock, river water and soil water at regional scale. This approach leverages publically-available geospatial data on rock geochemistry, surficial and bedrock geology, climate, hydrology, and aerosols to model the input and propagation of Sr from multiple geological sources through hydrosystems and ecosystems. In a first step, we develop predictive models for 87Sr/86Sr in bedrock as a function of variations in rock age and rock type. In a second step, we model the Sr release from different rock units, its transport as dissolved Sr or in aerosols, and its accumulation and mixing in ecosystems. The model was tested for the contiguous USA and circum-Caribbean region and the model showed promising results but the predictive power remained too low for routine provenance interpretations. In a final step, we develop a flexible geochemical framework that explicitly accounts for prediction uncertainty and local variability of 87Sr/ 86Sr and includes a Sr-specific process-based chemical weathering model. This improved model version is applied to predict 87Sr/86Sr in bedrock and rivers over Alaska and explain 82% of 87Sr/ 86Sr variance in Alaska Rivers. Integrated into a multi-isotopes framework, 87Sr/86Sr could dramatically improve the spatial resolution of provenance assignments. Predictive 87Sr/86Sr models are also a powerful standalone tool to visualize, identify and model mechanistic processes influencing local to global 87Sr/86Sr in Earth surface reservoirs

Multi-Armed Bandits for Intelligent Tutoring Systems

We present an approach to Intelligent Tutoring Systems which adaptively personalizes sequences of learning activities to maximize skills acquired by students, taking into account the limited time and motivational resources. At a given point in time, the system proposes to the students the activity which makes them progress faster. We introduce two algorithms that rely on the empirical estimation of the learning progress, RiARiT that uses information about the difficulty of each exercise and ZPDES that uses much less knowledge about the problem. The system is based on the combination of three approaches. First, it leverages recent models of intrinsically motivated learning by transposing them to active teaching, relying on empirical estimation of learning progress provided by specific activities to particular students. Second, it uses state-of-the-art Multi-Arm Bandit (MAB) techniques to efficiently manage the exploration/exploitation challenge of this optimization process. Third, it leverages expert knowledge to constrain and bootstrap initial exploration of the MAB, while requiring only coarse guidance information of the expert and allowing the system to deal with didactic gaps in its knowledge. The system is evaluated in a scenario where 7-8 year old schoolchildren learn how to decompose numbers while manipulating money. Systematic experiments are presented with simulated students, followed by results of a user study across a population of 400 school children

A GENDER EFFECT RELATED TO TEACHERS' CONCEPTIONS ON BIOLOGICAL GENDER DIFFERENCES. A SURVEY IN 14 COUNTRIES

In the context of the European research project Biohead-Citizen, 5,706 in-service and pre-service teachers from 14 countries (most in Europe, but also in Africa and Middle East) filled in a questionnaire containing 16 questions mainly related to the existence and to the origins of differences between men and women. We analyse the teachers' answers on biological gender differences, as possible interactions between their scientific knowledge (K) and values (V). Nine questions were focused on possible KV interactions, dealing with biological and / or social differences between men and women. Five questions were related only to scientific knowledge and two questions only to values. In each country we applied the questionnaire to six different samples : pre-service and in-service primary schools teachers , and biology and national language upper schools teachers . The answers were submitted to multivariate analyses. The results confirm that biology teachers have more scientific knowledge on this issue than their colleagues. Nevertheless, the answers to questions related to sexist or hereditarianist values show very significant differences among countries, the less economically developed countries being more sexist than the other ones. There is a significant gender effect for the sexist variables. The ratio men / women being different from one country to another, and inside the six samples in each country, we suppressed these two effects to show that the gender effect is still significant independently to these variables. Female teachers are significantly less sexist than their male colleagues

The genetic determinism of human performances. A comparison between teachers' conceptions in Finland and France

International audienceFinland has the best mean sciences scores among the OECD countries while France is in the OECD average (PISA 2006). Nevertheless, when measuring interactions between knowledge and values in teachers' conceptions, the comparison between the two countries shows surprising results. In the context of the European research project Biohead-Citizen, in-service and pre-service teachers filled out a questionnaire including 31 questions related to the genetic determinism of human performances. The samples (732 in France, 306 in Finland) comprised Primary School teachers and Secondary School Biology and Language teachers. The answers to the questions dealing with only scientific knowledge, or with only social values, did not differ with the country. Nevertheless, there are very significant differences for the interactions between knowledge and values mainly related to innatism: for instance, Finnish teachers more agree with the proposition "there are genetic factors in parents that predispose their children to be good in school" (or "good violinists"); or with "It is for biological reasons that women more often than men take care of housekeeping". Our results are analysed with different statistical tests including multivariate analyses. They are then discussed, taking into account the respective content of school textbooks in the two countries

Primary schools teachers' conceptions of environment. A comparison between Australia and France.

International audienceBoth Australia and France are similarly developed countries with comparable egalitarian societies but differ in some issues such as energy generation, agricultural and mining history, GMO cultivation, immigration. Both countries have implemented Education for a Sustainable Development (ESD) in their respective education systems. This paper explores primary teachers' conceptions of the environment, and how these relate to the broader national socio-scientific differences. Using the questionnaire of the European research project Biohead-Citizen, we compared, by multivariate analyses, conceptions of 98 Australian and 272 French primary school teachers. The Australian teachers' conceptions significantly differ from those of French teachers, mainly being more pro-GMO, more anthropocentric and believing more that some animals can feel happiness. The most anthropocentric and pro-GMO conceptions are correlated with more belief in God, practising religion, and trusting more in private than in public institutions, for schools, for health services and pensions. They also agree more with the propositions: "It is for biological reasons that women more often than men take care of housekeeping", "Ethnic groups are genetically different and that is why some are superior to others" and "There are too many foreigners in my country: the government should limit immigration". Some hypotheses are proposed to interpret these differences, such as resistance to GMOs in France and Australia's immigration history. The greater endorsement in the Australian sample of values against equality between men and women, or among ethnic groups, is more difficult to explain, but may possibly relate to education or to characteristics of the local sociopolitical contexts