Optimising continuous microstructures: a comparison of gradient-based and stochastic methods

This work compares the use of a deterministic gradient based search with a stochastic genetic algorithm to optimise the geometry of a space frame structure. The goal is not necessarily to find a global optimum, but instead to derive a confident approximation of fitness to be used in a second optimisation of topology. The results show that although the genetic algorithm searches the space more broadly, and this space has several global optima, gradient descent achieves similar fitnesses with equal confidence. The gradient descent algorithm is advantageous however, as it is deterministic and results in a lower computational cost

Coarse-to-Fine Lifted MAP Inference in Computer Vision

There is a vast body of theoretical research on lifted inference in probabilistic graphical models (PGMs). However, few demonstrations exist where lifting is applied in conjunction with top of the line applied algorithms. We pursue the applicability of lifted inference for computer vision (CV), with the insight that a globally optimal (MAP) labeling will likely have the same label for two symmetric pixels. The success of our approach lies in efficiently handling a distinct unary potential on every node (pixel), typical of CV applications. This allows us to lift the large class of algorithms that model a CV problem via PGM inference. We propose a generic template for coarse-to-fine (C2F) inference in CV, which progressively refines an initial coarsely lifted PGM for varying quality-time trade-offs. We demonstrate the performance of C2F inference by developing lifted versions of two near state-of-the-art CV algorithms for stereo vision and interactive image segmentation. We find that, against flat algorithms, the lifted versions have a much superior anytime performance, without any loss in final solution quality.Comment: Published in IJCAI 201

Diversité floristique d´un lac du Bas-Sahara Algérien

Nous avons examiné la composition et la dynamique de la végétation vasculaire spontanée dans le Lac Ayata (Vallée d’Oued Righ, Bas-Sahara algérien). Le site se situe entre 33°29’17’’N à 33°29’48’’N et 05°59’10’’E à 05°59’37’’E. L’échantillonnage systématique de la flore a révélé l’existence de 13 espèces appartenant à 8 familles et 13 genres. Le plan d’eau est dépourvu de plantes submergées. Les types biologiques, la structure et la physionomie de la végétation sont été déterminés. L’occupation du sol par la végétation est cartographiée afin d’illustrer les répartitions saisonnières des espèces végétales dominantes. Des géostatistiques sur les surfaces occupées par la végétation ainsi que sur sa dynamique saisonnière sont ensuite obtenues puis discutées. Les types biologiques les plus fréquents sont les chamaephytes (53,8%) et les thérophytes (23,1%), qui caractérisent la végétation désertique ayant un recouvrement faible et une hauteur basse. Par ailleurs, la cartographie de la végétation a révélé l’existence de 3 types de formations végétales: (i) une végétation halophytique représentée par des espèces Chénopodiacées qui sont réparties tout autour des abords du plan d’eau; (ii) une végétation hydrophytique représentée par Phragmites communis et Juncus maritimus ; et (iii) une végétation éparse représentée par Limoniastrum guyonianum et Triganum nudatum. Le lac Ayata abrite une flore peu diversifiée mais bien adaptée aux conditions écologiques défavorables qui règnent sur le sol (salinité) et le climat (sécheresse)

Impact of one-to-one computing on middle school teaching and learning

The State of Maine was the first state in the U.S.A (and in the world) to implement One-to-One Computing in schools in 2001. Former Governor of Maine, King Angus believed that students needed to acquire 21st Century Skills to have a sustainable future in the working force. Many schools in the U.S.A. started taking on the initiative of One-to-One Computing after Maine. Also in third world countries, the United Nations Development Program (UNDP) along with major computer corporations provided subsidized laptops for many students worldwide. In the wake of 21st Century Skills, attaining One-to-One Computing has been a goal for most educational institutions. A private American School in Egypt initiated a pilot program providing all students in 7th and 8th grade with a laptop. In a qualitative study, based on interviews with the following: teachers, students and parents, it determined the impact One-to-One Computing had on Language Arts teaching and learning. The research examined how the One-to-One Computing Program altered teachers\u27 pedagogical approach to teaching and how that impacted the way students learn. The research implied that teachers are more creative and has allowed for more student and peer collaboration amongst the students. Students also reported having acquired the skills needed for the 21St Century, which include: responsibility, creativity, technological literacy, and organization. One-to-One Computing has enabled students to access, review and summarize digital information quicker. 21st Century skills are required for success in the work force but should all countries and schools acquire One-to-One Computing programs? Is there a procedure that must be followed before the program is implemented in schools? The study concludes with suggestions and limitations to the study

Bovine Serum Albumin Antibodies as a Disease Marker for Hepatitis E Virus Infection

This report evaluates the significance of antibody/bovine serum albumin (BSA) interactions as a risk factor for the diagnosis of acute hepatitis E. Serum samples from 40 patients with acute hepatitis E and from 40 age/sex matched healthy adult subjects were tested for IgA, IgG, and IgM by ELISA and by turbidimetric assay. BSA was used as a target to characterize changes in levels of interacting immunoglobulins. Initial results obtained before removal of antibodies that interacted with BSA suggested that HEV patients had increased levels of IgM in their sera. It was found that normal individuals had mean IgA, IgG, and IgM levels of 2.55 mg/mL, 9.80 mg/mL, and 1.73 mg/mL, respectively while HEV patients had mean levels of 2.66 mg/mL, 10.04 mg/mL, and 2.01 mg/mL (P < .26, P < .32, and P < .0004). However, the mean level of IgM in HEV-infected sera after purification from antibodies that interacted with BSA was determined to be 1.72 mg/mL indicating that there was no significant difference in IgM level in HEV patients compared to normal individuals (P < .6). The presence of antibodies that interact with BSA might serve as a diagnostic tool for detection of high-risk patients

Asphalt Pavement Crack Classification : A Comparative Study of Three AI Approaches: Multilayer Perceptron, Genetic Algorithms and Self-Organizing Maps

Thesis ( M.S.) Indiana University South Bend, 2008.This study presents a comparison of three Artificial Intelligence (AI) approaches: multilayer perception (MLP), genetic algorithms (GA) and self-organizing maps (SOM) to improve automated asphalt pavement crack classification using computer visio