178 research outputs found
Where museums, libraries, and archives intersect
Diaporama d\u27une intervention au 32e congrÚs LIBER qui s\u27est tenu à Rome du 17 au 20 juin 2003. Exemple de coopération entre bibliothÚques, musées et archives pour le développement des ressources en ligne à partir de l\u27activité du Research Libraries Group (RLG)
Engineered quasi-phase matching for nonlinear quantum optics in waveguides
Entanglement is the hallmark of quantum mechanics. Quantum entanglement -- putting two or more identical particles into a non-factorable state -- has been leveraged for applications ranging from quantum computation and encryption to high-precision metrology. Entanglement is a practical engineering resource and a tool for sidestepping certain limitations of classical measurement and communication. Engineered nonlinear optical waveguides are an enabling technology for generating entangled photon pairs and manipulating the state of single photons. This dissertation reports on: i) frequency conversion of single photons from the mid-infrared to 843nm as a tool for incorporating quantum memories in quantum networks, ii) the design, fabrication, and test of a prototype broadband source of polarization and frequency entangled photons; and iii) a roadmap for further investigations of this source, including applications in quantum interferometry and high-precision optical metrology.
The devices presented herein are quasi-phase-matched lithium niobate waveguides. Lithium niobate is a second-order nonlinear optical material and can mediate optical energy conversion to different wavelengths. This nonlinear effect is the basis of both quantum frequency conversion and entangled photon generation, and is enhanced by i) confining light in waveguides to increase conversion efficiency, and ii) quasi-phase matching, a technique for engineering the second-order nonlinear response by locally altering the direction of a material's polarization vector. Waveguides are formed by diffusing titanium into a lithium niobate wafer. Quasi-phase matching is achieved by electric field poling, with multiple stages of process development and optimization to fabricate the delicate structures necessary for broadband entangled photon generation.
The results presented herein update and optimize past fabrication techniques, demonstrate novel optical devices, and propose future avenues for device development. Quantum frequency conversion from 1848nm to 843nm is demonstrated for the first time, with >75% single-photon conversion efficiency. A new electric field poling methodology is presented, combining elements from multiple historical techniques with a new fast-feedback control system. This poling technique is used to fabricate the first chirped-and-apodized Type-II quasi-phase-matched structures in titanium-diffused lithium niobate waveguides, culminating in a measured phasematching spectrum that is predominantly Gaussian (R^2 = 0.80), nearly eight times broader than the unchirped spectrum, and agrees well with simulations
Searching for the effect of multiple uncontrolled interventions in BRMS
We search for the effects of 8 different (uncontrolled) interventions (1intervention per school) on the sub-concepts of learnerâs (4th to 8th grade)motivation, self-regulation, and ICT competency data over the past threeyears. Data marking for intervention (yes/no), ICT competence of teachersand the presence of specially trained teachers are added to the formulas.Assessment of ICT competency in 3rd grade can be used as prior. Smoothsillustrate if the (motivation or self-regulation) concepts grow over timegrouped by intervention, school or grade. Grades are nested within schoolsand data is grouped by student. Are we missing anything
Towards a high-precision atomic gyroscope
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Physics, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (pages 69-72).In this thesis, I report on the design and construction of the Rubidium Atomic Gyroscope Experiment (RAGE) at Draper Lab.by Mackenzie A. Van Camp.S.M
Ăvaluation du projet « ComplĂ©ment d'aide aux victimes d'actes criminels », dĂ©veloppĂ© par le Service de protection des citoyens de Laval en coopĂ©ration avec le Centre d'aide aux victimes d'actes criminels (CAVAC) de Laval
Ce rapport de recherche concerne les rĂ©sultats dâune recherche Ă©valuative du projet « ComplĂ©ment dâaide aux victimes » du Service de protection des citoyens de Laval en coopĂ©ration avec le CAVAC de Laval. Ce projet vise premiĂšrement Ă assurer que toutes les victimes sont systĂ©matiquement informĂ©es de leur rĂŽle et de leurs droits au sein du systĂšme pĂ©nal. DeuxiĂšmement, lâobjectif du complĂ©ment dâaide est dâaugmenter lâaccessibilitĂ© aux services dâaide aux victimes. TroisiĂšmement, lâinstallation du complĂ©ment dâaide devrait amĂ©liorer la collaboration entre les services policiers et le CAVAC afin dâoptimiser le soutien offert aux victimes dâactes criminels. LâĂ©valuation de ce projet a Ă©tĂ© effectuĂ©e en utilisant un devis quantitatif. Des questionnaires ont Ă©tĂ© remplis par des policiers de Laval, les intervenants du CAVAC de Laval et des victimes de crimes contre la personne. Nous pouvons conclure que suite Ă lâintroduction du complĂ©ment dâaide, il y a eu une augmentation importante du nombre de fois que la police rĂ©fĂšre les victimes au CAVAC ainsi que du nombre de contacts de la police avec le CAVAC. De plus, les intervenants du CAVAC sont tous trĂšs satisfaits avec la communication et la collaboration avec les policiers. Par ailleurs, les rĂ©sultats de lâĂ©valuation dĂ©montrent aussi que, bien que les services soient plus accessibles suite Ă la diffusion proactive de lâinformation, les victimes de notre Ă©chantillon ne se sentent pas plus impliquĂ©es. Finalement, les donnĂ©es suggĂšrent que le projet devrait Ă lâavenir se centrer sur la sensibilisation des policiers par rapport Ă lâimportance du traitement policier de la victime ainsi quâaux services offerts par le CAVAC
pour quâils puissent encore plus adĂ©quatement rĂ©fĂ©rer les victimes. De plus, une attention particuliĂšre doit ĂȘtre portĂ©e afin dâinformer les victimes sur leurs droits, sur leur rĂŽle et sur les services disponibles pour elles, car celles-ci ne semblent pas suffisamment renseignĂ©es.Fonds Victimes du MinistĂšre de la Justice du Canada;Chapitre 1. Le projet « complĂ©ment dâaide aux victimes » Ă Laval â consolider les droits des victimes dâactes criminels
1.1. Les attentes des victimes dâactes criminels
1.2. Les droits des victimes
1.3. Une opportunité structurelle : le policier comme informateur et comme référent
1.4. Projet complĂ©ment dâaide aux victimes Ă Laval
Chapitre 2. Mesurer lâimpact du projet complĂ©ment dâaide aux victimes
2.1. Objectifs du projet de recherche
2.2. HypothĂšses
2.3. Devis méthodologique et instrument de recherche
2.4. Collecte de données (Police, CAVAC, Victimes, Calendrier de la collecte de données)
Chapitre 3. Lâeffet du complĂ©ment dâaide sur la pratique des policiers de Laval
3.1. Description de lâĂ©chantillon
3.2. Nombre de références et de contacts avec le CAVAC
3.3. Reconnaissance de lâimpact de la victimisation
3.4. Reconnaissance de son propre rĂŽle dans le traitement de la victime
3.5. La connaissance du CAVAC
3.6. Conclusions par rapport Ă lâimpact du complĂ©ment dâaide sur les policiers
Chapitre 4. Lâimpact du complĂ©ment dâaide selon les intervenants du CAVAC de Laval
4.1. Description de lâĂ©chantillon
4.2. La fréquence et la pertinence des références de la police
4.3. Contact et communication avec la police
4.4. Connaissance du CAVAC par les policiers
4.5. Information donnée par les policiers aux victimes référées
4.6. Conclusion
Chapitre 5. La perspective des victimes
5.1. Description de lâĂ©chantillon
5.2. Le rÎle de la victime au sein du systÚme pénal
5.3. Les droits de la victime au sein du systĂšme judiciaire
5.4. Information reçue ou rĂ©fĂ©rence au service dâaide
5.5. Connaissance des ressources disponibles aux victimes
5.6. Satisfaction
5.7. Attentes non-répondues
5.8. Conclusion
Chapitre 6. Discussion et recommandations
Bibliographie
Annexes
1. Engagements des partenaires complĂ©ment dâaide aux victimes dâactes criminels CAVAC / SPCL d.d. dĂ©cembre 2004
2. Formulaire de référence du CAVAC
3. Questionnaire police
4. Questionnaire CAVAC
5. Questionnaire victime
Measuring the Development of ICT Skills for Personalized Learning:Developing an Instrument for Dutch Primary Education
Our study investigates the development and validation of a questionnaire for competencies learners need to learn in a personalized way using ICT. 9 Dutch schools for primary education collaborate to make personalized learning with ICT evidence-informed. At these 9 iXperium schools, multidisciplinary design teams (consisting of primary school teachers and principals, teachers and students of the teacher-training program of a Dutch university of applied science, researchers from a Dutch university, and external ICT experts) design and research integrated interventions for PL with ICT. We defined personalized learning conditions before filtering the twenty-four learning objectives needed to measure development in personalized learning using ICT. The final questionnaire consists of thirty-three questions to cover the learning objectives. The validity and reliability of our questionary are analyzed in six steps. Cognitive validity (1) and a response model (2) are reported based on literature and a pilot with three iterative rounds of interviews (n=19). Internal constancy (3), confirmatory factor analysis (4), coefficient H (5) are reported after the first run of the questionnaire (n=800), and a test-retest alpha is reported after the second run of the questionnaire (n=800)
Nutritional profile of foods offered and consumed in a Belgian university canteen
Objective: To evaluate the nutritional profile of a lunch offered and consumed in a university canteen in Belgium.
Design: The qualitative and quantitative content of 4365 meals theoretically available and 330 meals consumed was recorded during five weekdays spread over three weeks. Meal combinations were evaluated using a scoring system based on recommendations for Na content, energy from fat, and fruit and vegetable portions.
Setting: University canteen in Belgium.
Results: Only a 5 % of the meal combinations available and consumed complied with the three basic dietary recommendations for a hot lunch. The nutritional profile of the meals consumed was in line with that of the meals available.
Conclusions: Our results show how the nutritional profile of what is eaten is largely determined by what is offered. To ensure overall compliance with dietary recommendations, considerable changes on the supply side, i.e. an increase in fruit and vegetable portions and a reduction in salt and fat of the lunch, are needed first in our setting. Our assessment provides baseline data to pilot a nutrient profiling intervention and shows how a nutrient profiling system can be used for meal evaluation purposes
Emplacement of inflated PÄhoehoe flows in the Naudeâs Nek Pass, Lesotho remnant, Karoo continental flood basalt province: use of flow-lobe tumuli in understanding flood basalt emplacement
Physical volcanological features are presented for a 710-m-thick section, of the Naudeâs Nek Pass, within the lower part of the Lesotho remnant of the Karoo Large Igneous Province. The section consists of inflated pÄhoehoe lava with thin, impersistent sedimentary interbeds towards the base. There are seven discreet packages of compound and hummocky pÄhoehoe lobes containing flow-lobe tumuli, making up approximately 50% of the section. Approximately 45% of the sequence consists of 14 sheet lobes, between 10 and 52-m-thick. The majority of the sheet lobes are in two packages indicating prolonged periods of lava supply capable of producing thick sheet lobes. The other sheet lobes are as individual lobes or pairs, within compound flows, suggesting brief increases in lava supply rate. We suggest, contrary to current belief, that there is no evidence that compound flows are proximal to source and sheet lobes (simple flows) are distal to source and we propose that the presence of flow-lobe tumuli in compound flows could be an indicator that a flow is distal to source. We use detailed, previously published, studies of the Thakurvadi Formation (Deccan Traps) as an example. We show that the length of a lobe and therefore the sections that are âmedial or distal to sourceâ are specific to each individual lobe and are dependent on the lava supply of each eruptive event, and as such flow lobe tumuli can be used as an indicator of relative distance from source
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