912 resultados para design space exploration
Resumo:
Tämän insinöörityön tarkoituksena on kehittää avaruusinstrumentti, joka on osa Euroopan avaruusjärjestön ESA:n ja Japanin avaruusjärjestön JAXA:n BepiColombo-yhteistyöhanketta. Satelliitti lähetetään Merkurius-planeetan kiertoradalle vuonna 2013. Avaruusaluksen matka Merkuriukseen kestää yhteensä kuusi vuotta ja on perillä vuonna 2019. Yksi BepiColombo-satelliitin tieteellisistä instrumenteista on Oxford Instruments Analytical Oy:n kehittämä SIXS-instrumentti (Solar Intensity X-ray and particle Spectrometer). Instrumentin tarkoituksena on mitata auringosta tulevaa röntgen- ja partikkelisäteilyä. Se toimii yhteistyössä Merkuriuksen pintaa mittaavan MIXS-instrumentin (Mercury Imaging X-ray Spectrometer) kanssa. Tuloksista pystytään analysoimaan ne alkuaineet, joista Merkuriuksen pinta koostuu. Työn alussa esitellään teoriataustaa alkuaineiden mittauksesta niiltä osin, kuin se tämän työn kannalta on tarpeellista. Työssä syvennytään tarkemmin auringosta tulevan säteilyn mittauksesta vastaavan instrumentin tekniikkaan ja mekaniikkasuunnitteluun. Instrumentin lämpöteknisestä suunnittelusta, värähtelymittauksista ja lujuusanalyysista on työhön sisällytetty pääasiat. Työn tuloksena on kehitetty instrumenttiin tulevan partikkelidetektorin prototyyppi sekä instrumenttikotelon malli. Lopullisen koon instrumenttikotelolle määrittää vaadittavan elektroniikan viemä tila. Mittalaitteen kehitystyö jatkuu Oxford Instruments Analytical Oy:ssä vuoteen 2011 saakka.
Resumo:
An easy-living home requires a full-sized bathroom on the main level. Family members will appreciate the extra space and guests of all ages and abilities will feel more welcome. At a minimum, you’ll need a five foot circle of open floor space for maneuvering a wheelchair between bathroom fixtures. A small powder room won’t work for guests who use walkers or wheelchairs. A shower stall—with no curb to step over—is more convenient than a tub for most guests. Make sure the doorway opening for the bathroom is at least 32 inches wide (preferably 36 inches). Universal design features, such as these, make homes better for everyone.
Resumo:
The paper proposes an approach aimed at detecting optimal model parameter combinations to achieve the most representative description of uncertainty in the model performance. A classification problem is posed to find the regions of good fitting models according to the values of a cost function. Support Vector Machine (SVM) classification in the parameter space is applied to decide if a forward model simulation is to be computed for a particular generated model. SVM is particularly designed to tackle classification problems in high-dimensional space in a non-parametric and non-linear way. SVM decision boundaries determine the regions that are subject to the largest uncertainty in the cost function classification, and, therefore, provide guidelines for further iterative exploration of the model space. The proposed approach is illustrated by a synthetic example of fluid flow through porous media, which features highly variable response due to the parameter values' combination.
Resumo:
Optimizing collective behavior in multiagent systems requires algorithms to find not only appropriate individual behaviors but also a suitable composition of agents within a team. Over the last two decades, evolutionary methods have emerged as a promising approach for the design of agents and their compositions into teams. The choice of a crossover operator that facilitates the evolution of optimal team composition is recognized to be crucial, but so far, it has never been thoroughly quantified. Here, we highlight the limitations of two different crossover operators that exchange entire agents between teams: restricted agent swapping (RAS) that exchanges only corresponding agents between teams and free agent swapping (FAS) that allows an arbitrary exchange of agents. Our results show that RAS suffers from premature convergence, whereas FAS entails insufficient convergence. Consequently, in both cases, the exploration and exploitation aspects of the evolutionary algorithm are not well balanced resulting in the evolution of suboptimal team compositions. To overcome this problem, we propose combining the two methods. Our approach first applies FAS to explore the search space and then RAS to exploit it. This mixed approach is a much more efficient strategy for the evolution of team compositions compared to either strategy on its own. Our results suggest that such a mixed agent-swapping algorithm should always be preferred whenever the optimal composition of individuals in a multiagent system is unknown.
Resumo:
We present a heuristic method for learning error correcting output codes matrices based on a hierarchical partition of the class space that maximizes a discriminative criterion. To achieve this goal, the optimal codeword separation is sacrificed in favor of a maximum class discrimination in the partitions. The creation of the hierarchical partition set is performed using a binary tree. As a result, a compact matrix with high discrimination power is obtained. Our method is validated using the UCI database and applied to a real problem, the classification of traffic sign images.
Resumo:
Since the year 2000, the concept of "bientraitance" (for which no equivalent term has yet emerged in either the English or German language) has gained widespread credence among educators, sociologists and health professionals in France and Belgium. This concept emphasizes a constructive approach to care and education rather than merely one of prevention of disasters. Applied in public health, and in particular to mental health promotion, the use of the concept of "bientraitance" can help promote both effectiveness and meaning in the design and planning of community interventions. The article presents an example of an intervention for children and adolescents in Fribourg, Switzerland. The underpinning hypothesis is that the children and youth groups (such as sports clubs, artistic and cultural associations, scouts and guides) represent largely untapped, or under-tapped, informal health resources with a favourable cost-effectiveness profile. "Bientraitance" criteria are used in selecting certain associations offering structured extracurricular group educational activities and collective out-of-school (or after school) programmes. Support is provided to the organisations selected for recruiting new members, in particular those with potentially lower levels of access, for example disabled children or new migrants. The results will be evaluated for the impact of participation in various out-of-school activities on health and health determinants from a prospective and comparative perspective. This paper shows how the concept of "bientraitance" can be useful in the development of a public health intervention.
Resumo:
This paper presents a customizable system used to develop a collaborative multi-user problem solving game. It addresses the increasing demand for appealing informal learning experiences in museum-like settings. The system facilitates remote collaboration by allowing groups of learners tocommunicate through a videoconferencing system and by allowing them to simultaneously interact through a shared multi-touch interactive surface. A user study with 20 user groups indicates that the game facilitates collaboration between local and remote groups of learners. The videoconference and multitouch surface acted as communication channels, attracted students’ interest, facilitated engagement, and promoted inter- and intra-group collaboration—favoring intra-group collaboration. Our findings suggest that augmentingvideoconferencing systems with a shared multitouch space offers newpossibilities and scenarios for remote collaborative environments and collaborative learning.
Resumo:
En este artículo planteamos una aproximación a la idea de espacio público como articulador del conjunto de acontecimientos que intervienen en la vida de las ciudades. Entendemos este fenómeno como una red poliédrica y multidimensional, cuyo estudio pasa por el análisis de diversas problemáticas: la identificación de los límites entre espacio público y esfera pública; la conformación del espacio público construido; la aproximación teórica al fenómeno desde la contemporaneidad; la dimensión social del espacio público; y finalmente la perspectiva de la gestión de las ciudades. Todas estas dimensiones expresan una mirada crítica del objeto i ponen en valor niveles de trabajo interdisciplinar y multiescala, fundamentales para entender e intervenir en el espacio público de la ciudad contemporánea.
Resumo:
En este artículo planteamos una aproximación a la idea de espacio público como articulador del conjunto de acontecimientos que intervienen en la vida de las ciudades. Entendemos este fenómeno como una red poliédrica y multidimensional, cuyo estudio pasa por el análisis de diversas problemáticas: la identificación de los límites entre espacio público y esfera pública; la conformación del espacio público construido; la aproximación teórica al fenómeno desde la contemporaneidad; la dimensión social del espacio público; y finalmente la perspectiva de la gestión de las ciudades. Todas estas dimensiones expresan una mirada crítica del objeto i ponen en valor niveles de trabajo interdisciplinar y multiescala, fundamentales para entender e intervenir en el espacio público de la ciudad contemporánea.
Resumo:
3 Summary 3. 1 English The pharmaceutical industry has been facing several challenges during the last years, and the optimization of their drug discovery pipeline is believed to be the only viable solution. High-throughput techniques do participate actively to this optimization, especially when complemented by computational approaches aiming at rationalizing the enormous amount of information that they can produce. In siiico techniques, such as virtual screening or rational drug design, are now routinely used to guide drug discovery. Both heavily rely on the prediction of the molecular interaction (docking) occurring between drug-like molecules and a therapeutically relevant target. Several softwares are available to this end, but despite the very promising picture drawn in most benchmarks, they still hold several hidden weaknesses. As pointed out in several recent reviews, the docking problem is far from being solved, and there is now a need for methods able to identify binding modes with a high accuracy, which is essential to reliably compute the binding free energy of the ligand. This quantity is directly linked to its affinity and can be related to its biological activity. Accurate docking algorithms are thus critical for both the discovery and the rational optimization of new drugs. In this thesis, a new docking software aiming at this goal is presented, EADock. It uses a hybrid evolutionary algorithm with two fitness functions, in combination with a sophisticated management of the diversity. EADock is interfaced with .the CHARMM package for energy calculations and coordinate handling. A validation was carried out on 37 crystallized protein-ligand complexes featuring 11 different proteins. The search space was defined as a sphere of 15 R around the center of mass of the ligand position in the crystal structure, and conversely to other benchmarks, our algorithms was fed with optimized ligand positions up to 10 A root mean square deviation 2MSD) from the crystal structure. This validation illustrates the efficiency of our sampling heuristic, as correct binding modes, defined by a RMSD to the crystal structure lower than 2 A, were identified and ranked first for 68% of the complexes. The success rate increases to 78% when considering the five best-ranked clusters, and 92% when all clusters present in the last generation are taken into account. Most failures in this benchmark could be explained by the presence of crystal contacts in the experimental structure. EADock has been used to understand molecular interactions involved in the regulation of the Na,K ATPase, and in the activation of the nuclear hormone peroxisome proliferatoractivated receptors a (PPARa). It also helped to understand the action of common pollutants (phthalates) on PPARy, and the impact of biotransformations of the anticancer drug Imatinib (Gleevec®) on its binding mode to the Bcr-Abl tyrosine kinase. Finally, a fragment-based rational drug design approach using EADock was developed, and led to the successful design of new peptidic ligands for the a5ß1 integrin, and for the human PPARa. In both cases, the designed peptides presented activities comparable to that of well-established ligands such as the anticancer drug Cilengitide and Wy14,643, respectively. 3.2 French Les récentes difficultés de l'industrie pharmaceutique ne semblent pouvoir se résoudre que par l'optimisation de leur processus de développement de médicaments. Cette dernière implique de plus en plus. de techniques dites "haut-débit", particulièrement efficaces lorsqu'elles sont couplées aux outils informatiques permettant de gérer la masse de données produite. Désormais, les approches in silico telles que le criblage virtuel ou la conception rationnelle de nouvelles molécules sont utilisées couramment. Toutes deux reposent sur la capacité à prédire les détails de l'interaction moléculaire entre une molécule ressemblant à un principe actif (PA) et une protéine cible ayant un intérêt thérapeutique. Les comparatifs de logiciels s'attaquant à cette prédiction sont flatteurs, mais plusieurs problèmes subsistent. La littérature récente tend à remettre en cause leur fiabilité, affirmant l'émergence .d'un besoin pour des approches plus précises du mode d'interaction. Cette précision est essentielle au calcul de l'énergie libre de liaison, qui est directement liée à l'affinité du PA potentiel pour la protéine cible, et indirectement liée à son activité biologique. Une prédiction précise est d'une importance toute particulière pour la découverte et l'optimisation de nouvelles molécules actives. Cette thèse présente un nouveau logiciel, EADock, mettant en avant une telle précision. Cet algorithme évolutionnaire hybride utilise deux pressions de sélections, combinées à une gestion de la diversité sophistiquée. EADock repose sur CHARMM pour les calculs d'énergie et la gestion des coordonnées atomiques. Sa validation a été effectuée sur 37 complexes protéine-ligand cristallisés, incluant 11 protéines différentes. L'espace de recherche a été étendu à une sphère de 151 de rayon autour du centre de masse du ligand cristallisé, et contrairement aux comparatifs habituels, l'algorithme est parti de solutions optimisées présentant un RMSD jusqu'à 10 R par rapport à la structure cristalline. Cette validation a permis de mettre en évidence l'efficacité de notre heuristique de recherche car des modes d'interactions présentant un RMSD inférieur à 2 R par rapport à la structure cristalline ont été classés premier pour 68% des complexes. Lorsque les cinq meilleures solutions sont prises en compte, le taux de succès grimpe à 78%, et 92% lorsque la totalité de la dernière génération est prise en compte. La plupart des erreurs de prédiction sont imputables à la présence de contacts cristallins. Depuis, EADock a été utilisé pour comprendre les mécanismes moléculaires impliqués dans la régulation de la Na,K ATPase et dans l'activation du peroxisome proliferatoractivated receptor a (PPARa). Il a également permis de décrire l'interaction de polluants couramment rencontrés sur PPARy, ainsi que l'influence de la métabolisation de l'Imatinib (PA anticancéreux) sur la fixation à la kinase Bcr-Abl. Une approche basée sur la prédiction des interactions de fragments moléculaires avec protéine cible est également proposée. Elle a permis la découverte de nouveaux ligands peptidiques de PPARa et de l'intégrine a5ß1. Dans les deux cas, l'activité de ces nouveaux peptides est comparable à celles de ligands bien établis, comme le Wy14,643 pour le premier, et le Cilengitide (PA anticancéreux) pour la seconde.
Resumo:
The term Space Manifold Dynamics (SMD) has been proposed for encompassing the various applications of Dynamical Systems methods to spacecraft mission analysis and design, ranging from the exploitation of libration orbits around the collinear Lagrangian points to the design of optimal station-keeping and eclipse avoidance manoeuvres or the determination of low energy lunar and interplanetary transfers
Resumo:
Digital art interfaces presents cognitiveparadigms that deals with the recognition of the symbols and representations through interaction.What is presented in this paper is anapproximation of the bodily experience in that particular scenario and a new proposal which has the aim to contribute more ideas and criteria in the analysis of the learning process of aparticipant discovering an interactive space or interface. For that I propose a first new approach where metaphorically I tried to extrapolate the stages of the psychology of development stated byJean Piaget in the interface design domain.
Resumo:
The term Space Manifold Dynamics (SMD) has been proposed for encompassing the various applications of Dynamical Systems methods to spacecraft mission analysis and design, ranging from the exploitation of libration orbits around the collinear Lagrangian points to the design of optimal station-keeping and eclipse avoidance manoeuvres or the determination of low energy lunar and interplanetary transfers
Resumo:
The study reports a set of forty proteinogenic histidine-containing dipeptides as potential carbonyl quenchers. The peptides were chosen to cover as exhaustively as possible the accessible chemical space, and their quenching activities toward 4-hydroxy-2-nonenal (HNE) and pyridoxal were evaluated by HPLC analyses. The peptides were capped at the C-terminus as methyl esters or amides to favor their resistance to proteolysis and diastereoisomeric pairs were considered to reveal the influence of configuration on quenching. On average, the examined dipeptides are less active than the parent compound carnosine (βAla + His) thus emphasizing the unfavorable effect of the shortening of the βAla residue as confirmed by the control dipeptide Gly-His. Nevertheless, some peptides show promising activities toward HNE combined with a remarkable selectivity. The results emphasize the beneficial role of aromatic and positively charged residues, while negatively charged and H-bonding side chains show a detrimental effect on quenching. As a trend, ester derivatives are slightly more active than amides while heterochiral peptides are more active than their homochiral diastereoisomer. Overall, the results reveal that quenching activity strongly depends on conformational effects and vicinal residues (as evidenced by the reported QSAR analysis), offering insightful clues for the design of improved carbonyl quenchers and to rationalize the specific reactivity of histidine residues within proteins.
Resumo:
Cooperative transmission can be seen as a "virtual" MIMO system, where themultiple transmit antennas are in fact implemented distributed by the antennas both at the source and the relay terminal. Depending on the system design, diversity/multiplexing gainsare achievable. This design involves the definition of the type of retransmission (incrementalredundancy, repetition coding), the design of the distributed space-time codes, the errorcorrecting scheme, the operation of the relay (decode&forward or amplify&forward) and thenumber of antennas at each terminal. Proposed schemes are evaluated in different conditionsin combination with forward error correcting codes (FEC), both for linear and near-optimum(sphere decoder) receivers, for its possible implementation in downlink high speed packetservices of cellular networks. Results show the benefits of coded cooperation over directtransmission in terms of increased throughput. It is shown that multiplexing gains areobserved even if the mobile station features a single antenna, provided that cell wide reuse of the relay radio resource is possible.